Promax 2D Seismic Processing & Analysis

March 26, 2018 | Author: amrymoko | Category: Reflection Seismology, Spreadsheet, Databases, Computing, Technology
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ProMAX 2D Seismic Processing and Analysiscopyright © 1998 by Landmark Graphics Corporation 626075 Rev. B June 1998 Copyright © 1998 Landmark Graphics Corporation All Rights Reserved Worldwide This publication has been provided pursuant to an agreement containing restrictions on its use. The publication is also protected by Federal copyright law. No part of this publication may be copied or distributed, transmitted, transcribed, stored in a retrieval system, or translated into any human or computer language, in any form or by any means, electronic, magnetic, manual, or otherwise, or disclosed to third parties without the express written permission of: Landmark Graphics Corporation 15150 Memorial Drive, Houston, TX 77079, U.S.A. Phone: 713-560-1000 FAX: 713-560-1410 Trademark Notices Landmark, OpenWorks, SeisWorks, ZAP!, PetroWorks, and StratWorks are registered trademarks of Landmark Graphics Corporation. Pointing Dispatcher, Log Edit, Fast Track, SynTool, Contouring Assistant, TDQ, RAVE, 3DVI, SurfCube, SeisCube, VoxCube, Z-MAP Plus, ProMAX, ProMAX Prospector, ProMAX VSP, MicroMAX, DepthTeam and Landmark Geo-dataWorks are trademarks of Landmark Graphics Corporation. Technology for Teams is a service mark of Landmark Graphics Corporation. ORACLE is a registered trademark of Oracle Corporation. IBM is a registered trademark of International Business Machines, Inc. AIMS is a trademark of GX Technology. Motif, OSF, and OSF/Motif are trademarks of Open Software Corporation. UNIX is a registered trademark of UNIX System Laboratories, Inc. SPARC, SPARCstation, Sun, SunOs and NFS are trademarks of SUN Microsystems. X Window System is a trademark of the Massachusetts Institute of Technology. SGI is a trademark of Silicon Graphics Incorporated. All other brand or product names are trademarks or registered trademarks of their respective companies or organizations. Note The information contained in this document is subject to change without notice and should not be construed as a commitment by Landmark Graphics Corporation. Landmark Graphics Corporation assumes no responsibility for any error that may appear in this manual. Some states or jurisdictions do not allow disclaimer of expressed or implied warranties in certain transactions; therefore, this statement may not apply to you. ProMAX 2D Seismic Processing and Analysis Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Mouse Button Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Exercise Organization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Manual Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Agenda . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Day 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introductions, Course Outline, and Miscellaneous Topics . . . . . . . . . . . . . . . . . . . . . . 1 ProMAX 2D Geometry - Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ProMAX 2D Geometry - Full Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ProMAX 2D Geometry - Extraction with Editing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Trace Editing using Trace Statistics and DBTools . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Day 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Parameter Selection and Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Elevation Static Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Brute Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Neural Network First Break Picking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Refraction Static Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Stack Comparisons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Velocity Analysis and the Volume Viewer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Day 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Residual Statics Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Dip Moveout (DMO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 PostStack Signal Enhancement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Velocity: QC, Editing, Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 PostStack Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Additional Topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Landmark ProMAX 2D Seismic Processing and Analysis i Contents Manual Geometry Assignment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Chapter Objectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 ProMAX Geometry Assignment Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 Geometry assignment path for this exercise. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 Land Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5 View Shot Gathers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 First look at the data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 Load Geometry into the Spreadsheet and Database . . . . . . . . . . . . . . . . . . . . . 1-7 Description of Geometry for this line. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7 Load Survey information to the spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9 Receivers spreadsheet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11 Sources spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17 Patterns spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19 TraceQC spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-24 Binning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25 View Database Attributes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29 Load Geometry to the Trace Headers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-33 Graphical Geometry QC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-35 QC your Geometry Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-36 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-38 ii ProMAX 2D Seismic Processing and Analysis Landmark Contents Full Extraction Geometry Assignment . . . . . . . . . . . . . . . . . . . . . . . . 2-1 Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 ProMAX Geometry Assignment Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 Geometry assignment path for this exercise . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 Extract Database Files Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4 Database file extraction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7 Full Extraction Geometry Assignment with Editing . . . . . . 3-1 Chapter Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 ProMAX Geometry Assignment Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 Geometry assignment path for this exercise . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 Extract Database Files Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 Database file extraction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 Spreadsheet completion and binning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6 Load Geometry to the trace headers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12 Landmark ProMAX 2D Seisic Processing and Analysis iii Contents Trace Editing using Trace Statistics and DBTools . . . . . . . . . 4-1 Chapter Objectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 Picking a Time Window for Statistical Analysis . . . . . . . . . . . . . . . . . . . . . . . . 4-3 Running the Trace Statistics Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 Displaying the Statistics using DBTools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5 Selecting the Data of Interest Graphically. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9 Focusing on a Range of data on the Histogram . . . . . . . . . . . . . . . . . . . . . . . . 4-12 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14 iv ProMAX 2D Seismic Processing and Analysis Landmark Contents System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 Directory Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3 /ProMAX (or $PROMAX_HOME) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . /ProMAX/sys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . /ProMAX/port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . /ProMAX/etc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . /ProMAX/scratch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . /ProMAX/data (or $PROMAX_DATA_HOME). . . . . . . . . . . . . . . . . . . . . . . . 5-3 5-5 5-5 5-6 5-6 5-6 ProMAX Data Directories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7 Program Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8 User Interface ($PROMAX_HOME/sys/bin/promax) . . . . . . . . . . . . . . . . . . . . 5-8 Super Executive Program (super_exec.exe) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9 Executive Program (exec.exe) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10 Processing Pipeline Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11 Types of Executive Processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14 Stand-Alone Processes and Socket Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14 Ordered Parameter Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15 Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OPF Matrices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Database Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . File Naming Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15 5-16 5-18 5-19 Parameter Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20 Creating a Parameter Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20 ASCII Import to a Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21 ASCII File Export from the Parameter Table Editor . . . . . . . . . . . . . . . . . . . . 5-22 Disk Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23 Secondary Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24 Tape Datasets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26 Tape Trace Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26 Tape Catalog System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28 Tape Catalog Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28 Landmark ProMAX 2D Seisic Processing and Analysis v . . . . . . . . . . . . . . . . . . . . . . . 7-6 Apply Elevation Statics . . . . 6-5 Test True Amplitude Recovery with Parameter Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11 Apply External Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 Chapter Objectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20 Interactive Spectral Analysis. . . . . . . . . . . . . . . . . . . . . . . . . 6-5 IF/ENDIF Conditional Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 Pick Parameter Tables . . . . . . . . . . . . . . . . . . . . . . 6-11 Compare Data With and Without Deconvolution . . . . . . . . . . . 5-28 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . 6-22 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16 vi ProMAX 2D Seismic Processing and Analysis Landmark . . . . . . . . . . . . . . 6-12 F-K Analysis and Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-30 Elevation Static Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3 Calculate Elevation Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-22 Spectral Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 Chapter Objectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . 6-2 Parameter Table Picking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 Parameter Test. . . . 6-16 Compare F-K filtered shots using an IF loop . . . . . . . . . . . . . . . . 6-16 F-K Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Contents Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8 Apply User Statics . . . 5-30 Parameter Selection and Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2 Elevation Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3 Coordinate Based Refraction Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3 Batch Neural Network First Break Picking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-16 Landmark ProMAX 2D Seisic Processing and Analysis vii . . . . . . . . . . 9-12 Refraction Static Corrections . . . . . . . . . . . . . . 8-10 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-8 Apply Refraction Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-10 Pick First Breaks for entire survey . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3 CDP/Ensemble Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1 Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1 Chapter Objectives . . 9-10 Chapter Summary . . . . . . . . . . . . . . . . . . . . . 8-8 Display Stack . . . . . . . . . . . . . . . . 8-2 RMS Velocity Field ASCII Import . . . . . . . . . . . . . . . . . . . . . . . . 9-2 Interactive NN First Break Training/Picking . . . . . . . . . . . . . . . . . . . 10-3 Refraction Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . .2D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-14 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3 Interactive Training. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12 Neural Network First Break Picking . . . . . . . . . . . . . . . . 10-2 Refraction Statics . . . . . . . . . 8-1 Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . 10-13 Apply Refraction Statics to your data. .Contents Brute Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-12 Compare Static Solutions in the Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-9 Autostatics calculation . . . . . . . . . . . . . . . . . . . . . . . 12-16 Chapter Summary . . . . . . . . . . 13-15 viii ProMAX 2D Seismic Processing and Analysis Landmark . . . . . . . . . . . . . 11-2 Compare Stacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1 Chapter Objectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-10 QC and Application of Residual Statics. . . . 11-1 Chapter Objectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-4 Data preparation and horizon picking for residual statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-18 Residual Statics Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2 Velocity Analysis Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-4 Precompute Velocity Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-13 Compare Autostatics Stacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Contents Stack Comparisons . . . . . . . . . . . . . . . . . . . . . . . 12-13 Velocity Analysis PD Tool. . . . . . . . . . . . . 12-12 Using the Volume Viewer . . . . . . . . . . . . . . . . . . . . . . . . . . 13-3 Data Preparation for Input to Residual Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3 Velocity Analysis Precompute . . . . . . . . . . . . . . . . . . . . . . . . . 12-5 Velocity Analysis . . . . . . . . . . . . . 11-4 Velocity Analysis and the Volume Viewer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-4 Calculation of Residual Statics. . . . . . . . . . . . . . 12-1 Chapter Objectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-2 Autostatics Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-9 Velocity Analysis Icons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-3 Trace Math . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-18 Final Stack . 14-20 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-18 Create Eigen Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-9 Landmark ProMAX 2D Seisic Processing and Analysis ix . . . . . . . . . . . . . . . . . . . . . 15-7 Use Trace Math to view differences between stacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-2 F-X Decon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-21 Poststack Signal Enhancement . . . . . . . . . . . . . . . . . . . 14-3 Determine trace binning parameters . . . 15-3 Signal Enhancement . . . . . . . . . 14-17 Apply DMO to the data. . . . . . 15-7 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-12 DMO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-4 Assign DMO offset bins to the data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-2 Common Offset Binning . . . 15-1 Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-17 External Model Autostatics Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Contents Compare two or more Autostatics Stacks. . . . . and BLEND . . . . . . . . . . . . . . . . . . . . . . 14-1 Chapter Objectives . . . . . . . . . . . . . 13-16 External Model Autostatics Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-19 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-30 Dip Moveout (DMO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dynamic S/N Filtering. . . . . . . . . 17-4 Poststack Migration . . . . . . . . . . . . 16-1 Chapter Objectives. . . . . . . . . . . . . . . . . . . . . . . . . . . 16-12 PostStack Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-5 Apply Phase Shift Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-8 Shift interval velocities to final datum . . . . . . . . . . . . . . . 1-2 Transferring the Database to Trace Headers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-3 Velocity Manipulation .Contents Velocity: QC. . 16-3 Smooth RMS velocities. 17-3 Tapering . . . . . . . . . 17-12 Appendices Appendix 1: Additional Geometry Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-11 Chapter Summary . . . . . . . . 16-2 Velocity Viewer/Point Editor . . . . . . . 17-5 Apply FK migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 How to Decide on the Primary Geometry Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-10 Compare Migrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-8 Shift smoothed RMS velocities to final datum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-11 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Geometry Core Path Overview. . . . . . . . . . . . . . . . . . . 17-1 Chapter Objectives. . . . . . . . . and convert to interval velocity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-10 Output a single interval velocity function . . . . . . . . . . . . . 17-8 Apply FD Migration . . . . . . 1-3 x ProMAX 2D Seismic Processing and Analysis Landmark . . . . . . . . . Editing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-2 PostStack Migration Processes . . . . . . . . . . . . . . . . . Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 Create Supergather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12 Inline Geometry Header Load after Pre-Initialization . . . . . . . . . . . . . . . . 3-7 Appendix 4: Database/Header Manipulation . 1-11 Complete the Spreadsheet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13 Load Geometry to Trace Headers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9 Pre Geometry Initialization flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13 Appendix 2: Supergathers . . . . . . . . . . . . . . Between Extraction and Geom Load . . . . . 3-1 CVS Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Valid Trace Number Origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Steps Performed By Extraction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7 Appendix 3: Alternate Velocity Analysis Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 Create Supergather and Horizontally Stack. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 Landmark ProMAX 2D Seisic Processing and Analysis xi . Valid Trace Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 Header Manipulation Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 1-5 1-6 1-6 1-7 1-8 Pre-Geometry Database Initialization . . . . . . . . . . . . . . . . . . 1-4 Steps Performed by Inline Geom Header Load . . . . . . . . . . . . . . . . . . . . . Geometry Load Procedures. . . . . . 3-2 Interactive Velocity Analysis (IVA). . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 Apply a Linear Moveout Correction. . . .Contents Details of the Geometry Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5 5-6 5-7 5-8 Flows and Data Summaries . . . . . . . . . 5-12 Datasets: OPF-SIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13 Datasets: OPF-CDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4 Reference Graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Promax Data Directories . . . . 5-9 Datasets: Seismic . . . . . .Contents Appendix 5: Training Summary . . . . . . . . . . . . 5-2 PostStack Migration Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3 Apply Statics. . . . . . . . . . . . . . . 5-15 Datasets: OPF-OFB . . . . . . . . . . . . . . . . . . . Promax Directory Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Geometry Assignment Map . . . . . . . . . . . . . . . . . . . . . . . . 5-9 Flows . . . . . . . . 5-14 Datasets: OPF-CHN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 Reference Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5 Datum Statics Terminology . . 5-2 Organization of Ordered Parameter Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15 Datasets: OPF-PAT . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11 Datasets: OPF-SRF. . . . . . . . . . . . . . . . . . . . . . . 5-10 Datasets: OPF-TRC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16 xii ProMAX 2D Seismic Processing and Analysis Landmark . . . . . . . . . . . . . . . . . . or simply as a means of refreshing your memory on a previously covered topic. along with diagrams and explanations. we try to provide key examples and descriptions. Landmark ProMAX 2D Seismic Processing and Analysis 1 .Preface Preface About The Manual This manual is intended to accompany the instruction given during the standard ProMAX 2D course. You will find it easy to use the manual as a reference document for identifying a topic of interest and moving directly into the associated exercise or reference. chapters conform to the following outline: • Introduction: A brief discussion of the important points of the topic and exercise(s) contained within the topic. The manual is designed to be flexible for both you and the trainer. Topic Description: More detail about the individual skills or processes covered in the chapter. in the order that they are covered in the exercise. Because of the power and flexibility of ProMAX. Instead. it is unreasonable to attempt to cover all possible features and applications in this manual. and in what order to present material to best meet your needs. Examples and diagrams will assist you during the course by minimizing note taking requirements. If you need more information. Topics Covered and Chapter Objectives: Brief list of skills or processes. How To Use The Manual This manual is divided into chapters that discuss the key aspects of the ProMAX system. For more progressive training please take Advanced 2D. see the Exercise sections of each topic. using exercises which are directed toward common uses of the system. Chapter Summary: A brief list of skills the chapter was designed to train. In general. and providing guidance through specific exercises. You are encouraged to copy the exercise workflows and optimize them to your personal situation. Trainers can choose which topics. Exercise: Details pertaining to each skill in an exercise. • • • • This format allows you to glance at the topic description to either quickly reference an implementation. execute the flow. help with parameter selection. Mouse buttons will not work properly if either Caps Lock or Nums Lock are on. As you progress through the exercises. familiar parameters will not always be listed in the flow example. Shift-Click: Hold the shift key while depressing the mouse button. Drag: Hold down the mouse button while moving the mouse. Many of the steps give a detailed explanation of how to correctly pick parameters or use the functionality of interactive processes. and analyze the results. Actions that can be applied to any mouse button include: • • • • Click: Briefly depress the mouse button. The exercises are organized so that your dataset is used throughout the training session. Double Click: Quickly depress the mouse button twice. MB2 is the middle mouse button.Preface Conventions Mouse Button Help This manual does not refer to using mouse buttons unless they are specific to an operation. MB1 is used for most selections. MB3 is the right mouse button. Exercise Organization Each exercise consists of a series of steps that will build a flow. Carefully follow the instructor’s direction when assigning geometry and checking the results of your flow. The flow examples list key parameters for each process of the exercise. An improperly generated dataset or database may cause a subsequent exercise to fail. 2 ProMAX 2D Seismic Processing and Analysis Landmark . The mouse buttons are numbered from left to right so: MB1 refers to an operation using the left mouse button. Residual Statics 8. Processing WorkFlow 1. PostStack Migration Velocity Modeling Pick First Breaks Field Data Landmark ProMAX 2D Seismic Processing and Analysis 3 . PostStack Signal Enhancement 10. Dip Moveout (DMO) 9. Brute Stack 6. Parameter Selection 4a. Trace Editing 3. Geometry Assignment 2. Refraction Statics 5. Velocity Analysis 7.Preface Manual Organization The manual will take you through a typical workflow of a geoscientist processing a land 2D seismic dataset. Elevation Statics 4b. The processing functions of ProMAX will be introduced and discussed as they appear in the workflow. Preface 4 ProMAX 2D Seismic Processing and Analysis Landmark . Full Extraction • Database File Extraction ProMAX 2D Geometry . Course Outline.Manual • • • • Input Data into the Spreadsheet CDP Binning Loading Geometry to Trace Headers QC Database Attributes ProMAX 2D Geometry .Agenda Agenda Day 1 Introductions. and Miscellaneous Topics ProMAX 2D Geometry .Extraction with Editing • • • Database File Extraction Spreadsheet Completion and CDP Binning Loading Geometry to Trace Headers Trace Editing using Trace Statistics and DBTools • • • Running Trace Statistics Display Trace Statistics using DBTools Selecting Bad Traces with DBTools System Overview • • • • • • Directory Structure Program Execution Ordered Parameter Files Parameter Tables Disk Datasets Tape Datasets Landmark ProMAX 2D Seismic Processing and Analysis 1 . Agenda Day 2 Parameter Selection and Analysis • • • • • • Parameter Table Picking Parameter Test IF/ENDIF Conditional Processing F-K Analysis and Filtering F-K Filtering Comparisons Interactive Spectral Analysis (ISA) Elevation Static Corrections • • • Elevation Statics Discussion Apply Elevation Statics Apply User Statics Brute Stack • • RMS Velocity Field ASCII Import Brute Stack with Elevation Statics Neural Network First Break Picking • • Interactive NN First Break Training/Picking Batch Neural Network First Break Picking Refraction Static Corrections • • • • Refraction Statics Refraction Statics Calculation .coordinate based Apply Refraction Statics Stack with Refraction Statics Stack Comparisons • Compare Stacks Velocity Analysis and the Volume Viewer • • • Velocity Analysis Precompute Velocity Analysis Volume Viewer/Editor 2 ProMAX 2D Seismic Processing and Analysis Landmark . Dynamic S/N Filtering.Agenda Day 3 Residual Statics Corrections • • • • Data Preparation for Input to Residual Statics Calculation of Residual Statics QC and Application of Residual Statics External Model Autostatics Dip Moveout (DMO) • • • Common Offset Binning DMO Final Stack PostStack Signal Enhancement • • F-X Decon. Editing. and BLEND Trace Math Velocity: QC. Modeling • • Velocity Viewer/Point Editor Velocity Manipulation PostStack Migration • • • Poststack Migration Processes Tapering Poststack Migration Additional Topics Landmark ProMAX 2D Seismic Processing and Analysis 3 . Agenda 4 ProMAX 2D Seismic Processing and Analysis Landmark . The sequence of steps. These next three chapters are examples of a difficult. and a most common approach to geometry assignment. or flows. Geometry is clearly one of the most important aspects of processing.Chapter 1 Manual Geometry Assignment Geometry Assignment is designed to create the ProMAX Database Files and load header information into the trace headers of ProMAX data. The Geometry Overview section in the Reference Manual and online helpfile provides further details of the geometry assignment process. Topics covered in this chapter: t Chapter Goals t Geometry Assignment Map t Land Geometry t View Shot Gathers t Load Geometry in Spreadsheet and Database t View Database Attributes t Load Geometry to the Trace Headers t Graphical Geometry QC t Chapter Summary Landmark ProMAX 2D Seismic Processing and Analysis 1-1 . depends upon available information. an easy. This chapter serves as an introduction to different approaches of geometry assignment. Upon completion of this chapter you should: • • • • • • • • • Understand what the Ordered Parameter Files (OPF’s) represent Edit the OPF’s via the Geometry Spreadsheet View Trace Header values for Geometry Attributes Import Observer Data into the Geometry Spreadsheet QC and Edit Geometry via DBTools and XDB Understand ProMAX Sign Conventions Understand what a Pattern Represents Understand the steps of Binning Graphically QC Geometry with Farr Displays 1-2 ProMAX 2D Seismic Processing and Analysis Landmark . as it is in a normal processing sequence. Geometry Assignment Field Data We are at step one.Chapter 1: Manual Geometry Assignment Chapter Objectives 1. Geometry Assignment. of our processing workflow. If we can get the geometry correct we are well on our way to having the best possible seismic data for the interpreter. Geometry is probably the longest and most difficult subject in the manual. B.Chapter 1: Manual Geometry Assignment ProMAX Geometry Assignment Map All Possible Geometry Assignment Paths UKOOA O. Notes ASCII Field Data Manual Input UKOOA Import Spreadsheet Import Database Import SEG-? Input Seismic Data (ProMAX) Extract Database Files Inline Geom Header Load Geometry Spreadsheet Ordered Parameter Files Disk Data Output Inline Geom Header Load Valid Trace Numbers Overwrite Trace Headers Seismic Data (ProMAX) Disk Data Output Seismic Data (ProMAX) Geometry assignment map for output to disk Landmark ProMAX 2D Seismic Processing and Analysis 1-3 . Notes and Survey Information ASCII Spreadsheet Import Manual Input Field Data SEG-Y Input Geometry Spreadsheet Ordered Parameter Files Inline Geom Header Load Disk Data Output Seismic Data (ProMAX) 1-4 ProMAX 2D Seismic Processing and Analysis Landmark . The following map shows a simplified path that we will use for geometry assignment in this exercise. The previous map. however.Chapter 1: Manual Geometry Assignment Geometry assignment path for this exercise ProMAX geometry assignment is designed to be both flexible and robust. Manual Geometry Assignment Path O. displays the complicated price we pay for that flexibility.B. If the input seismic data has pertinent geometry information in the trace headers. Landmark ProMAX 2D Seismic Processing and Analysis 1-5 . residing in the ProMAX database.Chapter 1: Manual Geometry Assignment Land Geometry The 2D Land Geometry Spreadsheet is used to assign the geometry. you can extract this information using the process Extract Database Files prior to working with the spreadsheet. The spreadsheet is an editor used to input/modify geometry information. the spreadsheet has options to import geometry information. such as source and receiver coordinates from ASCII files. While you can manually key in data. 3. From the Area menu add a new area.Chapter 1: Manual Geometry Assignment View Shot Gathers First look at the data Before we get into the geometry assignment steps. then we will build a flow to display the raw shots. Add the following flow. 2. Notice how the shot rolls onto the spread and that there is a discontinuity between channels 60 and 61. Use the Next Ensemble icon to move through all 20 shots for this line. Give your area a descriptive name that has meaning to you.1-View Shots Add Delete Execute View Exit SEG-Y Input Type of storage to use: ------------------------------Disk Image Enter DISK file path name: ---------------------------------------------------/misc_files/2d/segy_0_value_headers ----Default the remaining parameters---- Automatic Gain Control ----Default all parameters for this process---- Trace Display Number of ENSEMBLES (line segments)/screen: -------2 ----Default the remaining parameters---4. let us look at the data that we will be using. When the Line menu appears add a new line named “Watson Rise”. You might want to use your name in this case. First we will create a workspace by adding an Area and Line. 1-6 ProMAX 2D Seismic Processing and Analysis Landmark . Editing Flow: 1. 1. Execute the flow. 505 506 507 508 392. Source Interval 2 Second Record Length 4 ms Sample Rate Dynamite Source Landmark ProMAX 2D Seismic Processing and Analysis 1-7 . . .5 Pattern for Source 2 60 61 120 Channel 1 Station 387 388 389 390 391 392 393 394 . 505 506 507 508 Pattern for Source 16 448. 506 507 508 509 20 Sources 120 Channels 55 ft. . . Pattern for Source 1 388. . . 447 450 451 452 453 454 .Chapter 1: Manual Geometry Assignment Load Geometry into the Spreadsheet and Database Description of Geometry for this line The following figure and table describe the acquisition geometry for the Watson Rise line.5 Channel 1 Station 60 61 120 387 388 389 390 391 392 393 394 . Receiver Interval 220 ft.5 Channel 1 Station 60 61 120 388 389 390 391 392 393 394 395 . 446 449 450 451 452 453 . . 446 449 450 451 452 453 . . . . . . 5 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 22 23 93 93 93 93 93 93 93 93 93 93 93 93 93 93 93 93 93 93 93 93 0 0 50 0 15 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 First Live Station=387 22 20 20 23 18 24 20 19 17 20 22 19 19 20 21 23 22 20 20 20 387 387 387 387 387 387 387 387 387 387 387 387 387 387 387 388 392 396 398 404 446 446 446 446 446 446 446 446 446 446 446 446 446 446 446 447 451 455 457 463 449 449 449 449 449 449 449 449 449 449 449 449 449 449 449 450 454 458 460 466 508 508 508 508 508 508 508 508 508 508 508 508 508 508 508 509 513 517 519 525 Source.5 416.Chapter 1: Manual Geometry Assignment Observer’s Report Group Int.5 412.=55 Shot Loc.5 428.5 440.5 404.5 396.5 452.5 444.5 400.5 392. File no.5 464.=220 Depth Offset Sample Int.5 456.5 424.5 408. and Receiver Azimuth=90 degrees Last Live Station=525 Source Type = Shot.=4 ms Uphole Time Chan 1 Chan 60 # of Chan=120 Chan.5 431. Shot Int. 61 Chan 120 388.5 448.5 458. Units=ft 1-8 ProMAX 2D Seismic Processing and Analysis Landmark .5 420.5 436. Watson Rise. The following 2D Land Geometry Assignment window appears: Landmark ProMAX 2D Seismic Processing and Analysis 1-9 . you will assign geometry to the 2DTutorial dataset. Build the following flow : Editing Flow: 1. Execute the flow.Chapter 1: Manual Geometry Assignment Load Survey information to the spreadsheet In this exercise. • One flow will use the spreadsheet as an editor to automatically enter data to the database. • The following spreadsheet guide is designed to help you assign geometry to the line you are processing in the class. 1. Please consult the Reference Manual for additional documentation. using the geometry spreadsheet. Two flows are required to accomplish this task. The second flow will load the geometry from the database to the trace headers.2-Geometry Spreadsheet Add Delete Execute View Exit 2D Land Geometry Spreadsheet* 2. It is by no means a complete description of all the capabilities. and leave the survey azimuth blank as it will be calculated later. Select Setup. 5. 6. 4. Select to assign midpoints by Matching pattern numbers using first live chan and station. Enter the first and last live station numbers. Set source type to shot holes. select Yes to base source station numbers on receiver station numbers. Enter source and receiver station interval. and fill out the menu with information from the observer’s log. You may also enlarge the font. and units are feet. Select OK when you have entered all the information.Chapter 1: Manual Geometry Assignment 3. 7. 1-10 ProMAX 2D Seismic Processing and Analysis Landmark . so you will need to insert rows into the default spreadsheet so that there are 139 rows. 3. There are 139 receiver stations in this survey. If you created more than 139 blocks. Scroll to the bottom of the spreadsheet. 2. Select Edit ¦ Delete. mark the excess blocks by selecting block 140 with shift-MB2. This will select all blocks numbered 140 and greater. mark all rows active with MB3 again. Insert enough rows to accommodate all receiver stations.Chapter 1: Manual Geometry Assignment Receivers spreadsheet 1. X. and OK. Marked blocks will turn a different color. Mark all rows active by clicking MB3 on any of the numbered blocks under the Mark Block column. Station. • Notice how many rows are present in your default spreadsheet (this number will vary depending on your font). Select Receivers from the main spreadsheet window. and Y are required in 2D geometry. and insert the proper number of rows after the last marked block. Select Edit ¦ Insert. • • Landmark ProMAX 2D Seismic Processing and Analysis 1-11 . so that you can easily work with the entire spreadsheet. After you are certain that you have exactly 139 rows in the spreadsheet. and has a nominal receiver spacing of 55ft. Fill in the appropriate values for the Station column. Follow the same procedure to fill the X coordinate. (An easier way to fill. We will make up some fake XYs assuming that the line is straight.Chapter 1: Manual Geometry Assignment 4. Enter 387 as a starting value and an increment of 1. Mark the Station column by clicking MB1 on the Station column heading. 1-12 ProMAX 2D Seismic Processing and Analysis Landmark . for which there were no XY values recorded. starting with 0 and incrementing by 55 and the Y coordinate with all 0s. From the menu bar select Edit ¦ Fill.) 5. Import the Elevation values from an ASCII file. runs from West to East. is to click MB2 on the column header. This will bring up a popup menu. 6. This is an old land line. then select OK. When working with ASCII file import there are three required steps: • • • Open the ASCII file. Define which “cards” or rows to exclude from the import. Define which numbers are in which columns. This immediately causes the fill window to display. then select Filter.Chapter 1: Manual Geometry Assignment 7. 1 3 4 2 In the Filter box of the File Import Selection window. Select the ASCII filename and OK.. enter the directory path (./misc_files/2d/*) to your ASCII file. Select File ¦ Import to import ASCII elevation values. Landmark ProMAX 2D Seismic Processing and Analysis 1-13 . followed by /*. Two windows will pop up allowing you to open an ASCII file.. NOTE: Look at the Mouse Button help descriptions at the bottom of the ASCII text window. such as station. In the “Column Import Definition” menu. 11.Chapter 1: Manual Geometry Assignment 8. Highlight the columns that contain the numbers for the attribute you selected by holding down MB1 and dragging from left to right. click on a “parameter” attribute name. to define that column’s information Note that the selection turns white. You will see a new window at this point. Repeat the previous two steps for elevations. Note that they reflect the MB1 “press and drag” operation for column definition 10. 1-14 ProMAX 2D Seismic Processing and Analysis Landmark . Click Format and enter a name “recs” for a format description containing ASCII import column definition information. Example ASCII Import Column Definition 9. From the main import menu. and allows you to interactively delete them. Now freeze the column definitions by clicking MB3 over the Parameter Column. select Filter. You will want to exclude title rows. NOTE: Look at the Mouse Button help descriptions at the bottom of the ASCII text window. 12. 13. This writes a “Ignore Record for Import” message on all the defined rows. Landmark ProMAX 2D Seismic Processing and Analysis 1-15 . and MB2 to select the last row to exclude. 15. This will check for any “cards” with inappropriate information. There are also rows at the bottom of this file containing source information that need to be ignored. Note that they now reflect block selection and deletion options. blank rows.Chapter 1: Manual Geometry Assignment Switch to “card” or row exclusion mode. and press Ctrl-d. 16. and rows with information that you do not want to import. Use MB1 to select the first row to exclude. Click MB3 with the cursor positioned over the word “Station” or one of the other columnar attributes. 14. 20. select Apply. 22. 18. Use the display capabilities in the spreadsheet to QC the imported elevations. 1-16 ProMAX 2D Seismic Processing and Analysis Landmark . and the information looks correct.Chapter 1: Manual Geometry Assignment 17. • • Select View ¦ View All ¦ XYGraph from the menu bar. Click MB1 in the X column heading. From the main import menu. 19. Leave the Static column filled with zeros. Make sure you have 139 stations defined in your receiver spreadsheet. The import windows will disappear. and MB2 in the Elev column heading. This will add the elevations to your spreadsheet by matching the station numbers in the ASCII file with those already in the spreadsheet. Select Merge existing station values with matching station data and click OK. Select File ¦ Save. 21. select Color ¦ Bar from the menu. • Landmark ProMAX 2D Seismic Processing and Analysis 1-17 . • Exit the XYGraph by selecting File ¦ Exit ¦ Confirm. When this icon is activated. 23. and then edit the value in the spreadsheet. and automatically jump to that line in the spreadsheet. You can easily locate bad values in the XYGraph. Notice that the X Coordinate is displayed on the horizontal axis. • Activate the Notebook icon. and the Station numbers are represented by color. • This is a powerful QC tool. you can select a point in the XYGraph. • Select a point in the XYGraph with MB1.Chapter 1: Manual Geometry Assignment • After the XYGraph displays. the Elevations are on the vertical axis. Use the File ¦ Exit pulldown menu to save the information and exit the receiver spreadsheet. In our case. You must go through the same procedure as in the Receiver spreadsheet to make 20 rows in the spreadsheet to accommodate the 20 shots in this survey. 3. y.5 as the observers report states. y. Select Sources from the main spreadsheet window. • • 1-18 ProMAX 2D Seismic Processing and Analysis Landmark . Start at 388. you can see from the Observer’s Report that a few of the shot station numbers do not increment by four. Therefore. Fill the Station column. Also notice that the x. The Sources (SIN) spreadsheet appears. and z values updated. You will specify this half station difference using the skid column later. the source elevations are the elevations of the previous receiver location. We will do this later from the Database tool. This is because the spreadsheet will only accept integer numbers. Fix the station numbers for those shots in the spreadsheet now. Because you told the spreadsheets that the source and receiver station numbers were linked. 2. Finally. you need to interpolate elevations between receiver locations. the Sources spreadsheet uses the x. y. • Notice that you did not input 388. and z values entered in the Receivers spreadsheet. and z values change as you change the Station number. and increment by 4. Notice that the x.Chapter 1: Manual Geometry Assignment Sources spreadsheet 1. Source numbers are user defined and could be set to any value. 5. Fill the Source column to match the Station column. This is where you specify the inline offsets that move the shots from integer station numbers to half station numbers. East. and incrementing by 1. Landmark ProMAX 2D Seismic Processing and Analysis 1-19 . Instead of North. South.Chapter 1: Manual Geometry Assignment 4.y) Direction of Increasing Station Numbers (Source Azimuth) (+) Positive Offset 7. ProMAX uses the following sign convention: Skid Sign Convention Shot (x. and West. Import the Uphole time and Hole Depth information from the ASCII file using the same procedure as described in the Receivers spreadsheet. Scroll the spreadsheet to the right. Notice from the Observer’s Report that there is a gap in the FFID numbers between 19. ProMAX uses the following sign convention: Offset Sign Convention (-) Negative Offset Shot (x. and 22. Fill the FFID column starting at 2.y) (-) Negative Skid Toward lower stations Source Azimuth (Direction of Increasing Station Numbers) (+) Positive Skid Toward higher stations 8. Enter the offsets of 50 and 15 for the appropriate stations in the Offset column of the spreadsheet.5. and will fill the column starting with 1. 6. Some people prefer to use this number as a counter. and fill the Skid column with 27. and incrementing by 1. Enter this gap in the spreadsheet. each shot or receiver used one row of the spreadsheet. one pattern can use as many rows of the spreadsheet as necessary. 1-20 ProMAX 2D Seismic Processing and Analysis Landmark . This method is available if you chose either to assign midpoints by matching pattern numbers using first live chan and station. leave the Sources spreadsheet. In the Pattern spreadsheets. or matching pattern number using pattern station shift. There are two methods of defining patterns. and fill in the patterns spreadsheet. use the Static Gap Method. In the Sources and Receivers spreadsheets. After filling out the pattern. use the Dynamic Gap Method. Static Gap Method: Static Gap Size and Gap Chan Definition Stn 387 Ch 1 Stn 446 Ch 60 Shot Sources Spreadsheet Gap Chan=0 and Gap Size=0 Patterns Spreadsheet Pat 1 1 Min Max/Gap Chan Rcvr Chan Chan Inc MinChan 1 61 60 120 1 1 387 449 Rcvr Rcvr MaxChan Inc 446 508 1 1 Stn 449 Ch 61 Stn 508 Chn 120 In this method gap size and location is specified in the Patterns spreadsheet. you will finish the remainder of the Sources spreadsheet. If your shot gap changes locations.Chapter 1: Manual Geometry Assignment Patterns spreadsheet At this point. This method is only available if you chose to assign midpoints by matching pattern numbers using first live chan and station in the setup menu. If the shot gap stays in a constant location. Landmark ProMAX 2D Seismic Processing and Analysis 1-21 . that is the relationship of channels to receiver locations. The shot gap size and location is specified in the Sources spreadsheet. 1. Select Patterns from the main spreadsheet window. you specify the first and last channels and stations in the Pattern spreadsheet. When you enter the Pattern spreadsheet for the first time.Chapter 1: Manual Geometry Assignment Dynamic Gap Method: Dynamic Gap Size and Gap Chan Definition Stn 387 Ch 1 Stn 446 Ch 60 Shot Sources Spreadsheet Gap Chan=60 and Gap Size=2 Stn 449 Ch 61 Stn 508 Chn 120 Patterns Spreadsheet Pat 1 Min Max/Gap Chan Rcvr Rcvr Chan Chan Inc MinChan MaxChan 1 120 1 387 506 Rcvr Inc 1 In this method. You will now define your cable configuration. a window will appear that asks you to enter some information about the number of channels. 1st Live Sta. Enter 120 for the maximum number of channels. If you need to edit the number of channels later select Edit ¦ NChans. and reorder the columns so that the pattern description columns will be displayed next to the Station column. These values will be used for error checking when you exit the patterns spreadsheet. Pattern. and exit the Patterns spreadsheet. select Constant number of channels/record. Gap Chan Dlt. If you define your pattern for more or less than 120 channels. Follow the mouse button help. Gap Size Dlt. Num Chn. 5. and Static. Since our shot gap is in a constant location. the error column in the spreadsheet fills with ***** and will force you to correct your error before exiting the Patterns spreadsheet. Return to the Sources spreadsheet. fill in the Pattern spreadsheet using the Static Gap Method. 1st Live Chn. 1-22 ProMAX 2D Seismic Processing and Analysis Landmark . then OK. Shot Fold. you cannot see the Station column after scrolling the spreadsheet to the right. To change the displayed order of the columns select Setup ¦ Order the menu bar. Select File ¦ Exit to save the information. 3. and click MB1 in the column heading for Station. 4. • • • With the default column order.Chapter 1: Manual Geometry Assignment 2. Recall that you only defined one pattern for this survey. 6. 7. Fill the 1st Live Chn column with ones. This tells the Sources spreadsheet to use pattern number 1 from the Patterns spreadsheet. Fill the Num Chn column with 120. This specifies that the first live channel for each shot is 1.Chapter 1: Manual Geometry Assignment • Finish the selection by clicking MB2 in the column heading for Static. Fill in the Pattern column with ones. 9. 10. This column will be calculated and filled when you assign midpoints later in the exercise. Notice that the first live station for this survey is 387 for all but the last five shots. You cannot edit the Shot Fold* column. 8. The columns you selected will now move to the left of the spreadsheet as pictured below. Fill the 1st Live Sta column with information from the Observer’s Report. Landmark ProMAX 2D Seismic Processing and Analysis 1-23 . This specifies that there are 120 channels for each shot on this survey. Select File ¦ Save. you could enter any previously calculated datum static values in this column. and leave the Gap Size Dlt column filled with zeros. 1-24 ProMAX 2D Seismic Processing and Analysis Landmark . you would enter the shot gap’s location in Gap Chan Dlt. Leave the Static column filled with zeros. 12. and the shot gap’s size in Gap Size Dlt. The information entered in these two columns depends on which method you chose for entering the pattern in the Patterns spreadsheet. you have already specified the shot gap’s size and location in the pattern spreadsheet. Since you chose the Static Gap method. If you had chosen the Dynamic Gap method. and do not need to specify it here. If the information were available. Leave the Gap Chan Dlt column blank.Chapter 1: Manual Geometry Assignment 11. 13. The information in the traces spreadsheet will be calculated by the binning process. Press MB3 (notice the mouse button help) near the first shot on the line. To get a better view of the shots select Display ¦ Sources Control Points ¦ White. From the main Land Geometry window. 15. 16. make note of the azimuth (Azi) readout in the mouse button help. TraceQC spreadsheet 1. and enter 90 for the Nominal Survey Azimuth. Exit the Sources spreadsheet by selecting File ¦ Exit. Select OK to save the information an close the window.Chapter 1: Manual Geometry Assignment 14. Now select the Cross Domain icon to allow you to measure the station azimuth. Also notice the two offset shots. and measure the station azimuth. and drag the mouse to the end of the line. and the shots are displayed as an asterisk ‘*’. Landmark ProMAX 2D Seismic Processing and Analysis 1-25 . Display a basemap of both the shots and receivers. the azimuth should be 90 degrees. Select File ¦ Exit ¦ Confirm in the XYGraph display. For this line. select Setup. • Select View ¦ View All ¦ Basemap 2 1 • • • Notice that the receivers are displayed as a plus ‘+’ sign. You can not edit this information. While still holding down MB3. 17. Make sure that you only have 20 rows in the Sources spreadsheet. Select Assign midpoints by: Matching pattern numbers using first live chan and station. • • • 1-26 ProMAX 2D Seismic Processing and Analysis Landmark .) Computes the Midpoint coordinate between the shot and receiver. Computes the Shot to Receiver Azimuth. and then select OK.Chapter 1: Manual Geometry Assignment Binning 1. In this case the Assignment step is performing the following calculations: • Computes the SIN and SRF for each trace and populates the TRC OPF. Computes the Shot to Receiver Offset (Distance. Select Bin from the main window. There are three steps to be completed in order: • • • Assign Midpoints One of the several Binning options Finalize database 2. Choose Binning with a method of “Add source and receiver stations. This step also creates the OFB ordered parameter file.Chapter 1: Manual Geometry Assignment An Assignment Warning window will pop up warning that some or all of the data in the Trace spreadsheet will be overwritten. 4. Not much help is given to you. Click Proceed. the problems are usually related to the spread and/or pattern definitions. 3. A final Status window appears notifying that you “Successfully completed geometry assignment. the last CDP will be 989 (464 + 525). you have an error in your spreadsheets somewhere.” Click Ok. Fill in the parameters in the bottom of the window. If this step fails. but. A number of progress windows will flash on the screen as this step runs. Select OK in the final status window when successfully completed. user defined OFB parameters”. and select OK. The first CDP will be 775 (387 + 388). This step calculates CDP numbers for each trace by adding source and receiver numbers. Landmark ProMAX 2D Seismic Processing and Analysis 1-27 . From the Receivers spreadsheet. Highlight the Cross Domain icon. Click and hold MB2 near a receiver location to see which shots contributed to that receiver.Chapter 1: Manual Geometry Assignment • Select Finalize Database. 7. 1-28 ProMAX 2D Seismic Processing and Analysis Landmark . The binning step filled in the data in the Traces spreadsheet. 6. then click OK. Drag your mouse to the end of the line to see the receiver range change. 5. Click and hold MB1 near a source location to see which receivers contributed to that shot. You can QC this information from a basemap. select View ¦ View All ¦ Basemap. Open the Receivers spreadsheet. Click Cancel in the Land 2D Binning window to exit the binning window. • • Clcik OK in the final status window when successfully completed. 10. Select File ¦ Exit from the Receivers spreadsheet. 9. Select File ¦ Exit ¦ Confirm to exit the basemap display. Landmark ProMAX 2D Seismic Processing and Analysis 1-29 . Select File ¦ Exit from the main spreadsheet window.Chapter 1: Manual Geometry Assignment 8. SRF. source-receiver offsets. such as CDP x. OFB is created when certain processes are run. such as channel gain constants and channel statics. Contains information varying by offset bin number. such as surface consistent amplitude analysis. CDP elevation. such as surface consistent amplitude analysis. SIN. TRC. Contains information varying by surface receiver location. The DBTools window allows basic viewing and editing of the 8 orders (spreadsheets) of the database: LIN. source elevations. PAT. such as surface location x. Contains information varying by channel number. nearest surface location. such as FB Picks. surface location statics. type of units.y coordinates. TRC (Trace) SRF (Surface location) SIN (Source Index #) CDP (Common Depth Point) CHN (Channel) OFB (Offset Bin) PAT (Pattern) 1-30 ProMAX 2D Seismic Processing and Analysis Landmark . nearest surface location to source. surface location elevations. Contains information varying by source point.Chapter 1: Manual Geometry Assignment View Database Attributes 1. such as final datum. such as source x. number of traces received at each surface location. source statics. CDP fold. trim statics. CDP. source uphole times. The contents of the OPF files are summarized in Table 1: Table 1: Organization of Ordered Parameter Files LIN (Line) Contains constant line information. source type. Contains information describing the recording patterns. Contains information varying by CDP location. total number of shots. CHN.y coordinates. In the Flows menu select Database. OFB. Select Exit from the Flow Editing menu of the User Interface.y coordinates. and receiver fold. Contains information varying by trace. compare the land geometry database for receiver and shot elevations at station number 428. then GEOMETRY ELEV. and click on the SIN order. For example.6. You see that they both read an elevation of 842 feet. you see an elevation of 845.Chapter 1: Manual Geometry Assignment To graphically QC and edit the database select Database ¦ XDB Database Display. After this is displayed. then GEOMETRY ELEV. From the XDB window select Database ¦ Get. however.5. and therefore at an elevation around 843.3. Looking at the elevation for station number 429. From the observer notes and geometry assignment you remember that the shot is actually at station location 428. By projecting the SRF elevations into the SIN elevations you will correct for the “skid” of the elevation being on the half station. To fix the source elevations go to the attribute selection window. 2. click on the SRF order. Landmark ProMAX 2D Seismic Processing and Analysis 1-31 . Project SRF elevations into SIN. 3. 4. select New ¦ Project ¦ Sin.Chapter 1: Manual Geometry Assignment While SRF Geometry Elev is highlighted. then click on OK. To save this new attribute. 1-32 ProMAX 2D Seismic Processing and Analysis Landmark . Notice how station 428 has been corrected. In the popup list. then Exit the Database tool. select Database ¦ Save. SIN:GEOMETRY:ELEV. Your new attribute will be plotted. You can verify the source elevation was corrected by going back into the source spreadsheet. In the popup window. 5. Select OK from the overwrite warning and from the acknowledgment window. type in “ELEV” for the new attribute name. click on the name of the new attribute. XDB SIN: GEOMETRY: NCHANS (DBTools: double click on NCHANS from SIN tab) • Used to check for variations in number of channels per source. Landmark ProMAX 2D Seismic Processing and Analysis 1-33 . OFFSET (DBTools: View ¦ Predefined ¦ SIN-SRF-offset) • Used to check the live receivers for each shot. CDP. There are several useful QC plots that can be made from the DBTools or from the XDB Database Display. SIN (DBTools: View ¦ Predefined ¦ offset-CDP-SIN) • Used to check offset distribution in CDPs for velocity analysis placement and DMO binning. Some examples are listed below. XDB 3D XYGraph: TRC: OFFSET. SIN. XDB CDP: GEOMETRY: FOLD (DBTools: double click on FOLD from CDP tab) • Used to check CDP fold for variations.Chapter 1: Manual Geometry Assignment 6. XDB 3D XYGraph: TRC:SRF. File?: ----------------------------------------New Record length to output: ------------------------------------------0.3-Inline Header Load Add Delete Execute View Exit SEG-Y Input Type of storage to use: ------------------------------Disk Image Enter DISK file path name: ---------------------------------------------------/misc_files/2d/segy_0_value_headers ----Default the rest of the parameters---- Inline Geom Header Load Primary header to match database: ---------------------FFID Secondary header to match database: ----------------None Match by valid trace number?: -------------------------------No Drop traces with NULL CDP headers?: --------------------No Drop traces with NULL receiver headers: ----------------No Verbose diagnostics?: --------------------------------------------No Disk Data Output Output Dataset Filename: -----------Shots-with geometry New.Chapter 1: Manual Geometry Assignment Load Geometry to the Trace Headers 1. 1-34 ProMAX 2D Seismic Processing and Analysis Landmark . 3. or Existing. select FFID as the Primary and None as the Secondary headers to match the database. A trace is excluded from further processing if it is not described in the geometry. Build the following flow: Editing Flow: 1. 4. Trace sample format: ----------------------------------------16 bit Skip primary disk storage?: -----------------------------------No 2. enter a name for a new output dataset. In Disk Data Output. In SEG-Y Input. 5. Execute the flow. In Inline Geom Header Load. select Disk Image and enter the path given to you by your instructor for the raw shot dataset. Landmark ProMAX 2D Seismic Processing and Analysis 1-35 .1-View Shots” to check the trace headers of your dataset. 8. Edit your flow “1.1-View Shots Add Delete Execute View Exit <SEG-Y Input> Disk Data Input Select dataset: ----------------------------Shots-with geometry Trace read option: -----------------------------------------------Sort Select Primary trace header entry:--------------SIN Select secondary trace header entry:---OFFSET Select order list for dataset----------------------------------*:* Automatic Gain Control ----Default all parameters for this process---- Trace Display Number of ENSEMBLES (line segments)/screen: -------2 Do you want to use variable trace spacing?------------Yes ----Default the remaining parameters---7. Change the sort order as shown in the flow. 9. Editing Flow: 1. In the trace display use variable trace spacing to highlight the source gap in the shots. Write down this value as it will be used later in the Graphical Geometry QC section. While viewing the data in Trace Display.Chapter 1: Manual Geometry Assignment 6. use the dx/dt icon to measure the first break velocity of a few shots. you may find that your first break data is far from being flat. such as the last panel in the Farr display. but for one shot they line up at 200 ms. The process applies linear moveout to shots and splices multiple shots together in a vertical fashion based on receiver surface station. Check the geometry in these areas. In other cases. 1-36 ProMAX 2D Seismic Processing and Analysis Landmark . This display is often referred to as a Farr display. Shot t LMO Shot Farr Display Mistakes in geometry assignment show up as obvious anomalies.Chapter 1: Manual Geometry Assignment Graphical Geometry QC Graphical Geometry QC* is a macro designed to quickly find mistakes in your geometry assignment. Another indicator is when all first breaks tend to line up at 100 ms. with your onset of energy coming in much later with longer offsets. 4. For a quick check of all the data. 3. Specify the LMO velocity function.4-Graphical Geometry QC Add Delete Execute View Exit Graphical Geometry QC* Select input trace data file: ----------Shots-with geometry SIN and SOU_SLOC range of dataset: ---------------------*:* dB/sec gain value to apply: ------------------------------------6.Chapter 1: Manual Geometry Assignment QC your Geometry Assignment 1. you could input all 20 shots instead of 4. An editor appears for specifying a velocity function. Set the maximum number of traces per screen to 139. In this example. one absolute offset value (0 ft). This will cover the full spread 120 channels plus 5 extra shots 4 channels apart. Select Individual for Trace scaling option. 5. Select your input dataset name. if you have any spikes in your data. we only need to specify one primary value (1) for the first shot. Enter 4 for the Maximum number of shots to vertically splice. we will enter one LMO velocity for the entire dataset. Landmark ProMAX 2D Seismic Processing and Analysis 1-37 . 1:0:8000 should work fine. Build the following flow: Editing Flow: 1. Trace scaling option: -----------------------------------Individual 2. Therefore. 6. and one velocity (8000 ft/sec). Specify LMO velocity function(s): -------------------1:0:8000 Additional bulk shift: -------------------------------------------100 Maximum time for each spliced trace: -------------------400 Maximum number of shots (traces) to vertically splice: --------------------------------------------------------------------4 Resulting maximum number of traces per screen: --139 Select display device: -------------------------------This Screen Scalar for sample value multiplication: ---------------------1. Execute the flow using MB2. any reversed traces should remain at a constant surface location. instead of Trace Display. such as a back spread shifted 50-100 ms higher than a front spread. the data is automatically displayed. 7. When you execute with MB2. to get the proper trace headers loaded you need to rerun the inline header load flow. NOTE: If you find any mistakes you must go back to the spreadsheets and correct them. This process uses Screen Display for displaying your data. Use the Header tool icon to check vertically constant SRF_SLOC trace header values.Chapter 1: Manual Geometry Assignment The spikes will bias the entire screen scaling scalar and cause many of the traces to appear having zero amplitude. or severely undercorrected or overcorrected shots. Look for anomalies. Also. Then you will need to rebin. 1-38 ProMAX 2D Seismic Processing and Analysis Landmark . Finally. Note what shot you are on. Chapter 1: Manual Geometry Assignment Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • • • • • • • • Do you understand what the Ordered Parameter Files represent Can you edit the OPF’s via the Geometry Spreadsheet Can you view Trace Header values for Geometry Attributes Can you import Observer Data into the Geometry Spreadsheet Can you QC and edit Geometry via DBTools and XDB Do you understand ProMAX Sign Conventions Do you understand what a Pattern Represents Do you understand the steps of Binning Can you graphically QC Geometry with Farr Displays Landmark ProMAX 2D Seismic Processing and Analysis 1-39 . Chapter 1: Manual Geometry Assignment 1-40 ProMAX 2D Seismic Processing and Analysis Landmark . Topics covered in this chapter: t Database file extraction Landmark ProMAX 2D Seismic Processing and Analysis 2-1 . The Geometry Overview section in the Reference Manual and online helpfile provides further details of the geometry assignment process.Chapter 2 Full Extraction Geometry Assignment Geometry Assignment is designed to create the ProMAX Database Files and load header information into the trace headers of ProMAX data. The sequence of steps. or flows. This approach can be very quick and effective for reprocessing data. This chapter serves as a simplistic alternative approach to Chapter 1 for geometry assignment. In this chapter we will cover the steps necessary to assign geometry to a line if all of the required information is present in the trace headers of the input dataset. depends upon available information. For reprocessing data this method can be very fast and efficient.Chapter 2: Full Extraction Geometry Assignment Chapter Objectives 1. Upon completion of this chapter you should: • • Understand how to Remap SEG-Y headers Create Database Files from Extraction 2-2 ProMAX 2D Seismic Processing and Analysis Landmark . Geometry Assignment. Geometry Assignment Field Data This is an alternative method of completing step one. of our processing workflow. Full Extraction Field Data SEG-Y Input Seismic Data (ProMAX) Extract Database Files Disk Data Output Ordered Parameter Parameter Ordered Files Files Seismic Data (ProMAX) Landmark ProMAX 2D Seismic Processing and Analysis 2-3 .Chapter 2: Full Extraction Geometry Assignment ProMAX Geometry Assignment Map Geometry assignment path for this exercise The following map shows the path that we will use for geometry assignment in this exercise. 2-4 ProMAX 2D Seismic Processing and Analysis Landmark . Watson Rise. “Database Full Extraction”. Make sure you are in your Area. and then press Enter. Type in the line name.Chapter 2: Full Extraction Geometry Assignment Extract Database Files Method Database file extraction In this exercise you will assign geometry to the 2D user tutorial dataset. Go to the Line level of the ProMAX User Interface and click on Add. If the input SEG-Y headers are fully populated then you are done and the data should be ready to be processed without touching the spreadsheet or having to run an Inline Geometry Header Load. This only involves extracting geometry information from the input SEG-Y trace headers and outputting the trace data in ProMAX format. A fully populated trace header must have the following valid values: • • • Shot X Y and Station Receiver X Y and Station CDP X Y and CDP number 1. Create a new Line. 201/ Extract Database Files Is this a 3D survey: ------------------------------------------------No Data Type: --------------------------------------------------------LAND Source index method: -----------------------------------------FFID Receiver index method: ------------------------------STATIONS Mode of operation: ----------------------------------OVERWRITE Pre-geometry extraction?: ---------------------------------------No Extract CDP binning?: -------------------------------------------Yes Minimum cdp bin in survey: ----------------------775 Calculate trace midpoints coordinates?: -----------------Yes Extract OFB binning?: --------------------------------------------No Disk Data Output Output Dataset Filename: --------”raw shots w/ extract” New.. This input SEG-Y file already has most geometry information in its trace headers. SRF_SLOC. Build the following flow: Editing Flow: 1. CDP_SLOC.4I. In SEG-Y Input..Disk Image Enter DISK file path name: ---------------------------------------------------------------------------/misc_files/2d/segy2d_remap Remap SEGY header values?: -------------------------------Yes Input/override trace header entries: --------------------------sou_sloc.4I.. File?: ----------------------------------------New Record length to output: ------------------------------------------0. and Landmark ProMAX 2D Seismic Processing and Analysis 2-5 . Trace sample format: ----------------------------------------16 bit Skip primary disk Storage?: -----------------------------------No 3.193/ cdp_y. The remap option allows information in non-standard or extended header locations to be accessed and assigned to a ProMAX header word.181/srf_sloc..4I...4I.. CDP_Y. select Yes for Remap SEGY header values.Chapter 2: Full Extraction Geometry Assignment 2.185/ cdp_sloc.1-Extract Database Files Add Delete Execute View Exit SEG-Y Input Type of storage to use: ----------------------------.... The ProMAX spreadsheets use the values for SOU_SLOC.189/cdp_x..197/cdp_elev. or Existing.. CDP_X.4I.4I. 5. 6. the SRF OPF will be built anyway. and CDP OPF files look proper. You must then enter the missing information into the Receivers spreadsheet. If no receiver information exists in the input trace headers and you answer Yes to Pre-Geometry Initialization. NOTE: If no receiver information exists in the input trace headers and you answer no to PreGeometry Initialization. These are not standard SEG-Y headers. receiver. Output a new ProMAX disk dataset. shot. Select Stations for Receiver Index Method. 7. Now confirm that the SEG-Y headers were complete by doing some QC plotting from the Database to check that the trace. Select No for Pre-Geometry initialization because you have receiver information in the input SEG-Y headers and thus the SRF OPF directory will be properly built. the job will fail. Execute the flow. In Extract Database Files. as well as define pattern information in the Sources and Patterns spreadsheets. select No for Pre-Geometry database initialization.y values. 4. 8. and therefore must be stored in the extended header section of the SEG-Y data. Choose the remap option to read in these values. Do you believe the extracted geometry? 2-6 ProMAX 2D Seismic Processing and Analysis Landmark . Did you notice how the receivers (SRF GEOMETRY X_COORD) were out of order? 9. However. Enter FFID to Source index method. coordinates can be selected since the SEGY file contains both station numbers and x.Chapter 2: Full Extraction Geometry Assignment CDP_ELEV. Chapter 2: Full Extraction Geometry Assignment Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • Can you Remap SEG-Y headers Can you Create Database Files from Extraction Landmark ProMAX 2D Seismic Processing and Analysis 2-7 . Chapter 2: Full Extraction Geometry Assignment 2-8 ProMAX 2D Seismic Processing and Analysis Landmark . This chapter serves as the most likely alternative approach to Chapters 1 and 2 for geometry assignment.Chapter 3 Full Extraction Geometry Assignment with Editing Geometry Assignment is designed to create the ProMAX Database Files and load header information into the trace headers of ProMAX data. depends upon available information. The Geometry Overview section in the Reference Manual and online helpfile provides further details of the geometry assignment process. Topics covered in this chapter: t ProMAX Geometry Assignment Map t Database file extraction t Spreadsheet completion and binning t Inline Geometry Header Load Landmark ProMAX 2D Seismic Processing and Analysis 3-1 . In this chapter we will cover the steps necessary to assign geometry to a line if some of the required information is present in the trace headers of the input dataset. The sequence of steps. or flows. Chapter 3: Full Extraction Geometry Assignment with Editing Chapter Goals 1. For reprocessing data this method can be fast and efficient. Geometry Assignment Field Data This is another alternative method of completing step one. of our processing workflow. Geometry Assignment. Upon completion of this chapter you should: • • • Better Understand OPF/SpreadSheet operations Learn How to Finalize the Database Load Geometry to Trace Headers 3-2 ProMAX 2D Seismic Processing and Analysis Landmark . Extraction + Editing Field Data SEG-Y Input Seismic Data (ProMAX) Extract Database Files Geometry Geometry Spreadsheet Spreadsheet Ordered Parameter Parameter Ordered Files Files Disk Data Output Inline Geom Header Load Valid Trace Numbers Overwrite Trace Headers Seismic Data (ProMAX) Landmark ProMAX 2D Seismic Processing and Analysis 3-3 .Chapter 3: Full Extraction Geometry Assignment with Editing ProMAX Geometry Assignment Map Geometry assignment path for this exercise The following map shows the path that we will use for geometry assignment in this exercise. Flow 3 loads the geometry information to the trace headers of the ProMAX dataset. 1. Watson Rise. Go to the Line level of the ProMAX User Interface and click on Add. “Database Partial Extraction”. Type in the line name. extracts information from the headers. Please consult the Reference Manual for additional documentation. It is by no means a complete description of all the capabilities. 3-4 ProMAX 2D Seismic Processing and Analysis Landmark . and then press Enter. You will also have to do the CDP binning.Chapter 3: Full Extraction Geometry Assignment with Editing Extract Database Files Method Database file extraction In this exercise you will assign geometry to the 2D user tutorial dataset. Flow 2 uses the spreadsheet as an editor to update/add values. Create a new Line. and to automatically enter the information into the database. Three flows are required to accomplish this task: • Flow 1 reads a SEG-Y file. and outputs a ProMAX disk dataset. You will first extract geometry information from the input SEG-Y trace headers. • • The following spreadsheet guide is designed to help you assign geometry to the line you are processing in the class. writes it to the database/spreadsheets. You will then need to update and add information using the geometry spreadsheet. Make sure you are in your Area. 4I.Disk Image Enter DISK file path name: ---------------------------------------------------------------------------/misc_files/2d/segy2d_remap Remap SEGY header values?: -------------------------------Yes Input/override trace header entries: -------------------------------------------sou_sloc.181/srf_sloc.. or Existing. The ProMAX spreadsheets use the values for SOU_SLOC and SRF_SLOC These are not standard SEG-Y headers. The remap option allows information in non-standard or extended header locations to be accessed and assigned to a ProMAX header word..4I.Chapter 3: Full Extraction Geometry Assignment with Editing 2. Build the following flow: Editing Flow: 1. select Yes for Remap SEGY header values. Choose the remap option to read in these values. In SEG-Y Input. and therefore must be stored in the extended header section of the SEG-Y data... Landmark ProMAX 2D Seismic Processing and Analysis 3-5 . File?: ----------------------------------------New Record length to output: ------------------------------------------0.185/ Extract Database Files Is this a 3D survey: ------------------------------------------------No Data Type: --------------------------------------------------------LAND Source index method: -----------------------------------------FFID Receiver index method: ------------------------------STATIONS Mode of operation: ----------------------------------OVERWRITE Pre-geometry extraction?: ---------------------------------------No Extract CDP binning?: -------------------------------------------Yes Minimum cdp bin in survey: ----------------------775 Calculate trace midpoints coordinates?: -----------------Yes Extract OFB binning?: --------------------------------------------No Disk Data Output Output Dataset Filename: --------”raw shots w/ extract” New. Trace sample format: ----------------------------------------16 bit Skip primary disk Storage?: -----------------------------------No 3. This input SEG-Y file already has most geometry information in its trace headers.1-Extract Database Files Add Delete Execute View Exit SEG-Y Input Type of storage to use: ----------------------------. This disk dataset is used in Flow 03 as input to the Inline Geom Header Load. select No for Pre-Geometry database initialization. If no receiver information exists in the input trace headers and you answer Yes to Pre-Geometry Initialization. Spreadsheet completion and binning 1. Output a new ProMAX disk dataset. the SRF OPF will be built anyway. you will need to build the following flow: Editing Flow: 1. Execute the flow. You must then enter the missing information into the Receivers spreadsheet. 3-6 ProMAX 2D Seismic Processing and Analysis Landmark . 5. as well as define pattern information in the Sources and Patterns spreadsheets. Enter FFID to Source index method. Select Stations for Receiver Index Method.2-Geometry Spreadsheet Add Delete Execute View Exit 2D Land Geometry Spreadsheet* 2.y values. the job will fail.Chapter 3: Full Extraction Geometry Assignment with Editing 4. Select No for Pre-Geometry initialization because you have receiver information in the input SEG-Y headers and thus the SRF OPF directory will be properly built. However. coordinates can be selected since the SEGY file contains both station numbers and x. 6. Since some of the OPF files were not complete in the Database. NOTE: If no receiver information exists in the input trace headers and you answer no to PreGeometry Initialization. In Extract Database Files. Execute the flow. 4. Select Setup from the main window. Choose OK in the warning window that appears. Since you used Extract Database Files. You may notice that some of the receivers are not in sequential order. and then select the Station column with MB2. leave the rest of the Setup window blank and select OK. You can sort these by selecting Setup ¦ Sort ¦ Ascending. Choose Proceed and then OK to the following messages. and select File ¦ Exit. Select Receivers from the main window. Check for incorrect information. This will sort the spreadsheet by ascending station number. the default option in setup is to Assign midpoints by existing index number mappings in the TRC.Chapter 3: Full Extraction Geometry Assignment with Editing 3. Landmark ProMAX 2D Seismic Processing and Analysis 3-7 . Reset the units to feet. All of this information should be correct. If Assign midpoints by pattern number in the source and pattern spreadsheets is selected. 6. 3-8 ProMAX 2D Seismic Processing and Analysis Landmark . so they are separated out in this menu. Select Assign midpoints by existing index number mappings in the TRC. All of this information should be correct. the pattern columns in the Sources spreadsheet and the Patterns spreadsheet would have to be completed. NOTE: You must execute all three options available in this window.Chapter 3: Full Extraction Geometry Assignment with Editing 5. Each of these options may be time consuming in the case of 3D data. then select Proceed in the warning window. and select File ¦ Exit. Select Sources. The Patterns spreadsheet and the pattern related columns in the Sources spreadsheet are deactivated when you select Assign midpoints by existing index number mappings in the setup menu. Select Bin. The Patterns spreadsheet option should be grayed out and not functional. Click OK. 7. Check for incorrect information. Click OK in the Status window when successfully completed. then OK. Click Cancel in the Land 2D Binning window to exit Bin. select Using previously assigned CDP numbers.Chapter 3: Full Extraction Geometry Assignment with Editing Select only one of the three Bin midpoints options. Use a Binning bias of 0 and an offset bin center increment of 55. Click OK. In this case. This step fills in the LIN order of the database with the final survey information. Select OK when successfully completed. user defined OFB parameters. Landmark ProMAX 2D Seismic Processing and Analysis 3-9 . since our input SEGY trace headers included CDP numbers. 8. Select Finalize Database. 10.Chapter 3: Full Extraction Geometry Assignment with Editing 9. and check various attributes for correctness. Exit the current flow. (If the TRC flag is not set to valid. Build the following flow: Editing Flow: 1. In Disk Data Input. the TRC (trace flag) is valid.3-Header Load Add Delete Execute View Exit Disk Data Input Read data from other lines/surveys: ----------------------No Select Dataset: -------------------------”raw shots w/extract” Trace read option: --------------------------------------------Get All Read the data multiple times?: -------------------------------No Process trace headers only?: ---------------------------------Yes Override input data’s sample interval: --------------------No Inline Geom Header Load Match by valid trace number?: ------------------------------Yes Drop traces with NULL CDP headers?: --------------------No Drop traces with NULL receiver headers?: ---------------No Verbose Diagnostics?: --------------------------------------------No Disk Data Output Output Dataset Filename: ---------”raw shots w/extract” New. Load Geometry to the trace headers 1. you cannot process trace headers only). This dataset was written by ProMAX after using Extract Database Files. Skip primary disk Storage?: -----------------------------------No 2. access the database with the Database global command option. or Existing. 3-10 ProMAX 2D Seismic Processing and Analysis Landmark . Select File ¦ Exit from the main Geometry window. We will write the geometry information to the trace headers without reading the input traces. select Yes to Process trace headers only. File?: --------------------------------Overwrite Record length to output: ------------------------------------------0. From the Flows window. 3. Name a new ProMAX disk dataset name in Disk Data Output. you must: • • • Change Process trace headers only in Disk Data Input to No. the job will fail. select Yes to Match by valid trace number.Chapter 3: Full Extraction Geometry Assignment with Editing All traces in the dataset are described in the geometry. In Disk Data Output. 4. 6. Change Overwrite to New in Disk Data Output. Landmark ProMAX 2D Seismic Processing and Analysis 3-11 . Overwrite allows us to process and overwrite only the trace header files (HDRs. In Inline Geom Header Load.) If the existing HDR files are not large enough to accept the data to write out. Execute the flow. (There will be no Primary or Secondary headers listed. select Overwrite the input dataset.) The Inline Geom Header Load uses the valid trace number found on each trace of each ensemble to assign geometry. Create a simple display flow to check the trace headers of your dataset. If there are any missing traces in the input file. 5. Chapter 3: Full Extraction Geometry Assignment with Editing Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • • Are you confident in OPF/SpreadSheet operations What does it mean to “Finalize the Database” Can you Load Geometry to Trace Headers 3-12 ProMAX 2D Seismic Processing and Analysis Landmark . You will then only send the shots that contain these “bad” traces to Trace Display to visually edit these “bad” traces. Topics covered in this chapter: t Picking a time window to use for Statistical Analysis t Running the Trace Statistics Process t Displaying the Statistics using DBTools t Selecting the data to be viewed in Trace Display graphically using the DBTools displays. This chapter will serve as your introduction to the real power the DBTools program.Chapter 4 Trace Editing using Trace Statistics and DBTools In this chapter you will see how DBTools can be used to select which traces are sent to Trace Display for visual trace editing. You will run the Trace Statistics process to generate some values computed from the trace data that can be used to isolate “bad” traces. t Focusing on a range of data on the Histogram Landmark ProMAX 2D Seismic Processing and Analysis 4-1 . Chapter 4: Trace Editing using Trace Statistics and DBTools Chapter Objectives 2. Upon completion of this chapter you should: • • • Understand how to run Trace Statistics Be functional at using DBTools Understand how the Pointing Dispatcher communicates between processes 4-2 ProMAX 2D Seismic Processing and Analysis Landmark . Trace Editing In this chapter you learn some of the power of DBTools using it to isolate bad traces via Trace Statistics. Landmark ProMAX 2D Seismic Processing and Analysis 4-3 . Build the following flow to display a shot record: Editing Flow: 2.Chapter 4: Trace Editing using Trace Statistics and DBTools Picking a Time Window for Statistical Analysis 1. Execute the flow. We first need to pick a time gate that will be used by the Trace Statistics process.. “Trace Stats Gate” by AOFFSET..1-Edit by Trace Stats Add Delete Execute View Exit Disk Data Input Select dataset: --------------------------Shots . On the first shot select Picking ¦ Pick Miscellaneous Time Gate. 3.with geometry ----Default all other parameters---- Trace Display ----Default all parameters---2. Select Yes to save edits before exiting.Chapter 4: Trace Editing using Trace Statistics and DBTools Pick the top of the gate following the first break times. near 2 seconds: Time Gate Top Time Gate Bottom When you are done picking choose File Exit/Stop Flow. 4-4 ProMAX 2D Seismic Processing and Analysis Landmark . Use MB3 to add “NEW LAYER” for the bottom gate. Track the end of the reflection data in this case. Trace statistics is run to write the statistical attribute values to the database.select all Use first breaks or time gates?-------------------TIME GATE Time gate reference----------------------------------------.Database & Headers >Trace Display< 2.Time 0 Get analysis gates from the DB?--------------------------. Editing Flow: 2.Yes Select time gate parameter file----------. Edit the existing flow.Trace Stats Gate Form of statistical output-----------. Execute the flow.1-edit by trace stats Add Delete Execute View Exit Disk Data Input Select dataset: -----------------------------shots .w/ geometry ----Default all other parameters---- Trace Statistics Types of trace statistics to compute --------------. Landmark ProMAX 2D Seismic Processing and Analysis 4-5 .Chapter 4: Trace Editing using Trace Statistics and DBTools Running the Trace Statistics Process 1. You will need to “User Define” the trace header words. Execute this flow and wait for the display.TRC_AMPL Third DB parameter ----------.Chapter 4: Trace Editing using Trace Statistics and DBTools Displaying the Statistics using DBTools 1.TRC TRCSTATS PRE_FB_A First Header ----------------------------------------------PRE_FB_A Second DB parameter ------. Use Database/Header Transfer to selectively move the values of interest to the headers.TRC TRCSTATS AMPDECAY Fourth Header ---------------------------------------.1-edit by trace stats Add Delete Execute View Exit >Disk Data Input< >Trace Statistics< Disk Data Input Select dataset: -----------------------------shots .4 First DB parameter ----------.Source index number Secondary sort key ---------------------------------------------none Sort order ---------------------------------------------------------------*/ ----Default all other parameters---- Database/Header Transfer Direction of Transfer: Load TO header FROM database Number of parameters -------------------------------------------. 4-6 ProMAX 2D Seismic Processing and Analysis Landmark .w/ geometry Trace Read Option -----------------------------------------------Sort Interactive Data Access ----------------------------------------Yes Primary sort key ----------------------.TRC TRCSTATS T_SPIKES Third Header --------------------------------------------.T_SPIKES Fourth DB parameter -----. Edit the existing flow.AMPDECAY Trace Display ----Default all parameters---2.TRC TRCSTATS TRC_AMPL Second Header ---------------------------------------. Editing Flow: 2. 3. 6. Leave the Trace Display running. 5. exit from the flow menus and press Database on the User Interface. Use the View ¦ Predefined ¦ Source fold map pull down menu.Chapter 4: Trace Editing using Trace Statistics and DBTools You should get the IDA window and the trace display window. 4. For this example you may elect to change the background to white and then change to a monochrome color using the Options ¦ White Landmark ProMAX 2D Seismic Processing and Analysis 4-7 . Add a header plot of the TRC_AMPL in the Trace Display: View ¦ Header Plot ¦ Configure ¦ TRC_AMPL. The main DBTools window will appear. Make sure IDA is working by using the forward and reverse arrows. but. Generate a pre-defined Source Fold map. Lets call the new attribute “LOG_AMP” with an infotype of “TRCSTATS”. Select OK when done. Lets attack this problem by taking the log of the trace amplitude Edit ¦ Attribute ¦ Apply a Function. Because of the dynamic range of the data large amplitude spikes obscure the rest of the data.Chapter 4: Trace Editing using Trace Statistics and DBTools Background and Color ¦ Monochrome and Color ¦ Edit pull downs respectively. 8. 4-8 ProMAX 2D Seismic Processing and Analysis Landmark . 7. SIN. T_SPIKES. and AMP_DECAY from the TRC database. LOG_AMP. It should look like this: Landmark ProMAX 2D Seismic Processing and Analysis 4-9 . and the trace statistics: TRC_AMPL. SRF. (Click MB1 on OFFSET and then CNTL MB1 on the others and then click on OK to generate the histogram display. pull down menu to generate a “Summary Statistics” plot of OFFSET.Chapter 4: Trace Editing using Trace Statistics and DBTools 9... Use the View ¦ Summary Statistics. Chapter 4: Trace Editing using Trace Statistics and DBTools 10. Arrange the displays as shown below: 4-10 ProMAX 2D Seismic Processing and Analysis Landmark . (i. Notice that a few points will also turn red on the other displays. 3. This demonstrates that the high amplitude traces are distributed amongst the shots and receivers. drag the cursor across the anomalous range of the plot. there does not appear to be any single high amplitude shot or receiver.Chapter 4: Trace Editing using Trace Statistics and DBTools Selecting the Data of Interest Graphically 1. these are randomly placed traces) 2. This is the power of the summary statistics plot. “PROJECT” these points to the shot domain using the Project ¦ SIN pull down so that we know which shots contain these high amplitude traces.e. Highlight a range of points on the TRC_AMPL or the LOG_AMP histogram that covers the range of anomalously high amplitudes. Landmark ProMAX 2D Seismic Processing and Analysis 4-11 . drag the mouse (holding MB1) across this region Using MB1. “SELECT” these points using the Select ¦ All Highlighted pull down. The points will turn red and all the others will turn black. The points that were highlighted red will turn pink indicating that they are now “selected” Notice the difference between HIGHLIGHTING points and actually SELECTING them. 4. pull down. You should only have three shots available to page through in the display.. Open a Trace Kill table using the Picking ¦ Kill Traces. This way you are only presented with a few shots to examine instead of the entire data volume of shots.. 4-12 ProMAX 2D Seismic Processing and Analysis Landmark .Chapter 4: Trace Editing using Trace Statistics and DBTools Notice that some of the shots on the shot location map turned black: These are the shots that have the high amplitude traces. PD these shots to the trace display using the “bow and arrow” PD icon so that the display will only show you the shots that contain the high amplitude traces. 5. Assign this table a name such as “Kill list from DBTools interactive” and choose CHAN as the secondary sort key for the list. As you change the attribute of interest add a header plot of that attribute to the Trace Display to help identify the anomalous traces. To check that you killed the proper traces select the Paintbrush icon which toggles on and off the kills. Add the bad traces to the kill list. 7. 8. Repeat the sequence choosing different ranges of different attributes until you are happy that you have found all of the bad traces and have added them to the list.Chapter 4: Trace Editing using Trace Statistics and DBTools 6. Landmark ProMAX 2D Seismic Processing and Analysis 4-13 . 9. “SELECT” these traces. thus excluding the extremely high amplitude traces using the Select ¦ All Highlighted pull down. 2. Notice that almost the entire plot remains red except for a few traces that are marked in black. Highlight the one line of the histogram that represents all of the traces except for the highest amplitude on the TRC-AMPL plot. 1.Chapter 4: Trace Editing using Trace Statistics and DBTools Focusing on a Range of data on the Histogram A logical extension to this exercise would be to re-display the histogram excluding the anomalously high traces so that a more “focused” range of information can be analyzed. 4-14 ProMAX 2D Seismic Processing and Analysis Landmark . PD these shots to the Trace Display using the “bow and arrow” PD icon. After all traces of interest have been selected to the edit list. 5. Select these new points using the Select ¦ All highlighted pull down. 8. Project these points to the shot map using the Project ¦ SIN pull down. You can always reset the range of points displayed on the histogram by using the Focus ¦ On All pull down. You can now highlight a new range of points of interest. 7. saving the results. 6. Exit from the Trace Display. select Commit to save the LOG_AMP attribute you created to the database. Exit from the main DBTools window with the Database ¦ Exit pull down. new range of interest? 4. Landmark ProMAX 2D Seismic Processing and Analysis 4-15 .Chapter 4: Trace Editing using Trace Statistics and DBTools 3. Now we need to re-focus the display on only the selected data points using the Focus ¦ On Selection pull down. Chapter 4: Trace Editing using Trace Statistics and DBTools Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • • Can you run Trace Statistics Are you functional at using DBTools Are you comfortable with how PD is communicating between processes 4-16 ProMAX 2D Seismic Processing and Analysis Landmark . Topics covered in this chapter: t Directory Structure t Program Execution t Ordered Parameter Files t Parameter Tables t Disk Datasets t Tape Datasets Landmark ProMAX 2D Seismic Processing and Analysis 5-1 .Chapter 5 System Overview In this chapter we discuss some of the behind-the-scenes program operation. as well as the basic ProMAX framework. such as ordered parameter files. Understanding the ProMAX framework and its relationship to the UNIX directory structure can be useful. from the User Interface is critical to smooth operation of the software. The ability to manipulate the various components of the line database. Upon completion of this chapter you should: • • • Understand where and how data files are stored Know where menus and program executables are stored Know how data passes through a ProMAX flow 5-2 ProMAX 2D Seismic Processing and Analysis Landmark .Chapter 5: System Overview Chapter Objectives This chapter gives the processor a basic understanding of how ProMAX interacts with the operating system. /ProMAX/port/bin. and is used in all the following examples. All ProMAX development tools are included within the following subdirectories: /ProMAX/sys/lib. Landmark ProMAX 2D Seismic Processing and Analysis 5-3 . /ProMAX/sys/obj. /ProMAX/port/ src. This variable defaults to /ProMAX. /ProMAX/port/include and /ProMAX/port/ man. Set the $PROMAX_HOME environment variable to /my_disk/my_world/ProMAX to have your ProMAX directory tree begin below the /my_disk/my_world subdirectory.Chapter 5: System Overview Directory Structure /ProMAX (or $PROMAX_HOME) The directory structure begins at a subdirectory set by the $PROMAX_HOME environmental variable. .exe from command line /frame /sdi /3rd party software /lib lib*.dat /scratch /queues /data /area /line (or $PROMAX_DATA_HOME) 5-4 ProMAX 2D Seismic Processing and Analysis Landmark .a /plot /help /port /promax /etc *..rgb-colormaps ProMax_defaults /bin start-up executable config_file product install.exe from program /bin *.help -ASCII help Application window /promax3d managers /promaxvsp /menu /promax *.exe *.exe super_exec.lok .Chapter 5: System Overview ProMAX Directory Structure $PROMAX_HOME (default=.doc pvmhosts qconfig license.Frame help /lib/X11/app-defaults *./ProMAX) /sys /exe exec.menu Processes /promax3d /promaxvsp /misc *_stat_math *. Chapter 5: System Overview /ProMAX/sys Software that is Operating System Specific resides in /ProMAX/sys which is actually a symbolic link to subdirectories unique to a given hardware platform. /ProMAX/sparc for Sun Microsystems Sparcstations running SunOS. Third party software distributed by ProMAX will now be distributed in a subdirectory of /ProMAX/sys/exe using the company’s name. /ProMAX/sgimips for Silicon Graphics Indigo workstations using the 32 bit operating system and /ProMAX/sgimips4 for Silicon Graphics Indigo and Power Challenge workstations using the 64 bit operating system. These machinedependent directories are named after machine type. Machine specific executables are invoked from the UNIX command line. /ProMAX/solaris for Sun Microsystems Sparcstations and Cray 6400 workstations running Sun Solaris OS. are located under /ProMAX/sys/exe. a single set of executables is capable of running all ProMAX products. This link facilitates a single file server containing executable programs and libraries for all machine types owned by a client. miscellaneous Landmark ProMAX 2D Seismic Processing and Analysis 5-5 . help and miscellaneous files. located in /ProMAX/sys/bin. /ProMAX/port Software that is Portable across all Platforms is grouped under a single subdirectory /ProMAX/port. Operating System specific executables and libraries. Accommodating future hardware architectures will simply involve addition of new subdirectories. Unlike menus. not manufacturer. called from ProMAX. helpfiles(/ProMAX/port/help). This includes menus and Processes (/ProMAX/port/menu). to permit accommodation of different architectures from the same vendor. thus avoiding conflicts where two vendors use identical file names. SDI’s CGM Viewer software would be in /ProMAX/sys/exe/sdi and Frame Technology’s FrameViewer would be in /ProMAX/sys/exe/frame. provided the proper product specific license identification number is in place. such as: /ProMAX/rs6000 for IBM RS6000 workstations. For example. and Spreadsheets are heavy users of this file system.) Menus for additional products are added as new subdirectories under /ProMAX/port/menu. The . For instance. /ProMAX/data (or $PROMAX_DATA_HOME) The primary data partition defaults to /ProMAX/data. and ProMAX VSP (ProMAXVSP. under /ProMAX/port/menu. This location can be overridden with the environmental variable. /ProMAX/etc Files unique to a particular machine are located in the /ProMAX/etc subdirectory. /ProMAX/scratch The scratch area defaults to /ProMAX/scratch./ProMAX/port/bin contains a very special file “Promax” which is the ProMAX start-up script. This location can also be set with the environmental variable $PROMAX_DATA_HOME. You may want to edit this file and personalize it to your environment. The DMO.) Under the menu and help subdirectories are additional subdirectories for each ProMAX software product. 5-6 ProMAX 2D Seismic Processing and Analysis Landmark . The . which assigns unique pathnames for various products located on the machine.. with new areas being added as subdirectories beneath this subdirectory. If your system administrator is not afraid of the LISP programming language you can have them customize the ProMAX menus and defaults.. and the product file. We recommend you point this to the biggest file system you have write permission./ProMAX/port/lib/X11/app-defaults contains the color attributes and window configurations for the individual applications. We also recommend that you point this to a large files system you can write to. you will find subdirectories for ProMAX 2D (promax).Chapter 5: System Overview files (/ProMAX/port/misc. PROMAX_SCRATCH_HOME. Migrations. This default location is specified using the entry: — primary disk storage partition: /ProMAX/data 200 in the /ProMAX/etc/config_file. which contains peripheral setup information for all products running on a particular machine. We also recommend that you periodically clean this file system.. Examples of such files are the config_file. ProMAX 3D (ProMAX3D).. ELEV Each region identifies a collection of files and directories which can be summarized as the Area and Line separated into four main file types: 1) Parameter Tables. 2) Trace/Trace Headers.job /OPF.output packet.SRF #s0_OPF60_SRF.GEOMETRY. Landmark ProMAX 2D Seismic Processing and Analysis 5-7 .SIN Database subdirectory and a non-spanned file /OPF. 3) Flows.GEOMETRY.SRF Database subdirectory and a span file /OPF.SIN 1) Parameter Table files Index and Map Dataset files 2) Dataset subdirectory and Header and Trace Dataset files 3) A Flow subdirectory and its files OPF60_SIN. and 4) Ordered Parameter Files database.Chapter 5: System Overview ProMAX Data Directories PROMAX_DATA_HOME or /Data /Area DescName Project Area subdirectory and its files /Line DescName 17968042TVEL 31790267TGAT 36247238TMUT 12345678CIND 12345678CMAP /12345678 HDR1 HDR2 TRC1 TRC2 /Flow1 DescName TypeName job.ELEV 4) /OPF. one or more data manipulation processes. Flows are built by selecting processes from a list. the User Interface provides utility functions for: • copying. Lines. This Packet File provides the primary means of communication between the User Interface and the Super Executive program.Chapter 5: System Overview Program Execution User Interface ($PROMAX_HOME/sys/bin/promax) Interaction with ProMAX is handled through the User Interface. deleting and archiving Areas. See next section. In addition. A flow is a sequence of processes that you perform on seismic data. and execute processing flows.job) within each Flow subdirectory. Flows. However. modify. All information. and seismic datasets accessing and manipulating ordered database files and parameter tables displaying processing histories for your flows providing information about currently running jobs • • • The User Interface is primarily mouse-driven and provides point-andclick access to the functions 5-8 ProMAX 2D Seismic Processing and Analysis Landmark . Super Executive Program. A typical flow contains an input process. As you categorize your data into Areas and Lines. and then selecting parameters for each process. and a display and/or output process. is held within a Packet File (packet. needed to execute a flow. the primary function of the User Interface is to create. the User Interface automatically creates the necessary UNIX subdirectories and provides an easy means of traversing this data structure. Chapter 5: System Overview * Program Execution Super Executive Program (super_exec. Since this is the processing kernel for ProMAX. many of your processing flows.exe) Execution of a flow is handled by the Super Executive. Several of the processes are stand-alone programs. although they contain several processes. These processes cannot operate under the Landmark ProMAX 2D Seismic Processing and Analysis 5-9 . which is launched as a separate task by the User Interface. The majority of the processes are subroutines linked together to form the Executive.job and determines which executables to use. are handled by a single execution of the Executive. The Super Executive is a high level driver program that examines processes in your flow by reading packet. Chapter 5: System Overview control of the Executive. known as input and output tools.exe) for processing. The Packet File. This results in processes that are easier to develop and maintain. or another stand-alone process. At that point. defines the processes and their type for execution. meaning they accept input data and write output data at the driver level. The basic flow of data through the Executive pipeline is shown below: 5-10 ProMAX 2D Seismic Processing and Analysis Landmark . The Super Executive concerns itself with only two types of processes: • • Executive processes Stand-alone processes Executive processes are actually subroutines operating in a pipeline. Once this is completed. Special processes. multiple calls to the Executive in the proper sequence. The Super Executive sequentially gathers all Executive-type processes until a stand-alone is encountered. This continues until all processes in the flow have been completed. but rather must obtain input and/or produce output by directly accessing external datasets. packet. stand-alone processes cannot be executed within a pipeline.exe) The Executive program is the primary processing executable for ProMAX.job. if necessary. handle the tasks of reading and writing the seismic data. the Super Executive is responsible for invoking the stand-alone programs and. the Packet File information for the Executive processes is passed to the Executive routine (exec. The majority of the processes available under ProMAX are contained in this one executable program. However. The Executive features a pipeline architecture that allows multiple seismic processes to operate on the data before it is displayed or written to a dataset. and handle their own data input and output by directly accessing external datasets. and then another group of Executive processes. removing this burdensome task from the individual processes. the Super Executive invokes the stand-alone program for processing. Executive Program (exec. In these instances. Multi channel processes will wait until an entire ensemble is available.Chapter 5: System Overview Processing Pipeline Diagram Disk Data Input AGC Trace Display F-K Filter InterProcess Communication Tool Disk Data Output Processing Pipeline Each individual process will not operate until it has accumulated the necessary traces. in the example flow the FK Landmark ProMAX 2D Seismic Processing and Analysis 5-11 . For example. Single trace processes will run on each trace as the traces come down the pipe. 5-12 ProMAX 2D Seismic Processing and Analysis Landmark . An intermediate dataset and an additional input tool process is needed if a stand-alone process were included in this flow.Chapter 5: System Overview filter will not run until one ensemble of traces has passed through the DDI and AGC. it will not make a display until two shots have been processed through the DDI. A pipeline process must accept seismic traces from the Executive. If we specify for the Trace Display to display 2 ensembles. No additional traces will be processed until Trace Display is instructed to release the traces that it has displayed and is holding in memory by clicking on the traffic light icon or terminating its execution (but continuing the flow). process them. and return the processed data to the Executive. Note: All the processes shown are Executive processes and thus operate in the pipeline. AGC and FK filter. Chapter 5: System Overview Disk Data Input. Tape Data Input and standalone tools always start new pipes within a single flow Disk Data Input AGC F-K Filter Decon Disk Data Input NMO Disk Data Output CDP Stack Bandpass Filter Disk Data Output One pipe must complete successfully before a new pipe will start processing Multiple Pipes in One Flow Landmark ProMAX 2D Seismic Processing and Analysis 5-13 . These tools can be run inline in a ProMAX job flow and appear as ordinary tools. Typically. The current version of ProMAX does not provide the ability to output datasets from a stand-alone process. but in reality are launched as separate processes. these are tools making multiple passes through the data or requiring self-directed input. This type of process actually controls the flow of seismic data. Accepts and returns a variable number of seismic traces such as. Accepts and returns overlapping panels of traces to accommodate a group of traces too large to fit into memory.Chapter 5: System Overview Types of Executive Processes The table below describes the four types of processes defined for use in the Executive. Table 2: ProMAX Executive Process Types Process Type simple tools ensemble tools complex tools Description Accepts and returns a single seismic trace. Overlapping panels are processed and then merged along their seams. InterProcess Communication tools have the singular advantage of being able to accept and output traces in an asynchronous manner. panel tools Stand-Alone Processes and InterProcess Communication Tools Some seismic processing tools are not well suited to a pipeline architecture. InterProcess Communication tools start a new process and then communicates with the Executive via UNIX interprocess communications. Accepts and returns a gather of seismic traces. 5-14 ProMAX 2D Seismic Processing and Analysis Landmark . stack. statics and other surface consistent information. representing unique sets of information. For this reason. Ordered Parameter Files. Organization The Ordered Parameter Files contain information applying to a line and its datasets. The Ordered Parameter Files database is primarily used to obtain a list of traces to process. where N is the number of elements in the order. and provides a compact format without duplication of information. and pointers between the source. the index is used to extract the trace and trace header data from their files. Each slot contains various attributes in various formats for one Landmark ProMAX 2D Seismic Processing and Analysis 5-15 . known as Orders. such as traces for a shot or CDP.Chapter 5: System Overview Ordered Parameter Files Click to jump to the section This section discusses the following issues relating to the Ordered Parameter Files database: • • • Organization Database Structure File Naming Conventions The Ordered Parameter Files database serves as a central repository of information that you or the various tools can rapidly access. In each Order. Once determined. receiver and CDP domains. The design of the Orders is tailored for seismic data. the ordered database files store large classes of data. The Ordered Parameter Files database stores information in structured categories. such as the number of sources. This list of traces is then used to locate the index to actual trace data and headers in the MAP file of the dataset. there can be many datasets for a single set of Ordered Database Files. reside in the Area/Line subdirectory. number of surface locations. there are N slots available for storage of information. Collectively. unique to a line. geometry. including acquisition parameters. or number of CDPs. Note the relative size of the TRC OPF to the other OPF files.Chapter 5: System Overview particular element of the Order. such as channel gain constants and channel statics. such as surface consistent amplitude analysis. 5-16 ProMAX 2D Seismic Processing and Analysis Landmark .y coordinates. nearest surface location to source. such as CDP x. type of units. surface location elevations. TRC (Trace) SRF (Surface location) SIN (Source Index #) CDP (Common Depth Point) CHN (Channel) OFB (Offset Bin) PAT (Pattern) OPF Matrices The OPF database files can be considered to be matrices or flat files. source elevations. Contains information varying by offset bin number. The TRC is by far the largest contributor to the size of the database on disk. such as surface location x. Table 3: Organization of Ordered Parameter Files LIN (Line) Contains constant line information. source uphole times. Contains information describing the recording patterns. Contains information varying by channel number. total number of shots. CDP elevation. nearest surface location. number of traces received at each surface location. The OPF database files are not a relational database. Contains information varying by CDP location. Contains information varying by trace. trim statics. CDP fold.y coordinates. OFB is created when certain processes are run. Contains information varying by source point. such as source x. The Orders are organized as shown in the table below.y coordinates. Each OPF is indexed against the OPF counter and there are various single numbers per index. such as surface consistent amplitude analysis. such as final datum. source statics. surface location statics. and receiver fold. Contains information varying by surface receiver location. such as FB Picks. source type. source-receiver offsets. Chapter 5: System Overview SIN (Sources) Database SRF (Receivers) Database OPF Matrices Landmark ProMAX 2D Seismic Processing and Analysis 5-17 . The TRC. Then. SIN. subsequent spans are created in primary storage. All subsequent spans are written to the secondary storage partitions denoted by the OPF keyword in a round robin fashion until the secondary storage is full. There are two types of files contained in the OPF subdirectories: • Parameter: Contain attribute values. Non-span: All other OPFs are non-span. Span files may be moved to any disk partition within the secondary storage list for read purposes.5 million 4 byte values per span file. SUN. Index: Holds the list of parameters and their formats. the following command increases the file limit to 255 files open. From the csh. Newly created spans are written in the OPF denoted secondary storage partitions. There is no longer an import or 5-18 ProMAX 2D Seismic Processing and Analysis Landmark . named LIN. Non-span files lack this prefix.0 release to handle large 3D land and marine surveys.REC. The exception to this is the LIN OPF. • Given the fact that each parameter is managed by a file.TRC. the TRC is in the subdirectory OPF.NDX and LIN. specifically. The features of the new database structure are listed below: Each order is contained within a subdirectory under Area and Line. The geometry spreadsheet is a ProMAX database editor. The first span of 10MB for each parameter file is always written to primary storage. or approximately 2. one index and one parameter. Span files are created in the secondary storage partitions listed in the config_file as denoted with the OPF keyword. “limit de 255”. For example. There may be any number of attribute files associated with an OPF. Solaris and SGI. CDP. • OPF files are of two types: • Span: These files are denoted by the prefix. There is only one index file in each OPF subdirectory. The LIN information is managed by just two files.Chapter 5: System Overview Database Structure The ProMAX database was restructured for the 6. Span file size is currently fixed at 10 megabytes. Modifying information within a spreadsheet editor and saving the changes will automatically update the database. and SRF OPF parameters are span files. it may be necessary to increase the “maximum number of files open” limit on some systems. #s. All database reads and writes are in 4K pages.0 (and later) database format. there are often multiple attributes.Chapter 5: System Overview export from the geometry database to the ProMAX database files as was required prior to the 6. Where #s0_OPF60 indicates a first span file for the parameter.0 release. For example. Data can be added to the database via the OPF Extract tool or the geometry spreadsheet. the index file for the TRC is called OPF60_TRC. Span parameter files may be moved and distributed anywhere within primary and secondary storage. Database I/O across the network is optimized to an NFS default packet size of 4K. Landmark ProMAX 2D Seismic Processing and Analysis 5-19 .X databases are automatically converted to the 6. preceded by a prefix denoting the Order of the parameter. with each attribute being given a unique name.GEOMETRY. There is improved network access to the database. GEOMETRY describes the information type of the parameter. NOTE: The index file for each Order must remain in the primary storage partition. and X_COORD is the parameter name. Database append is allowed. Index file names contain the three letter Order name. the x coordinate for a shot in the SIN has the following name: #s0_OPF60_SIN. Existing and restored 5. Within each Order. For example. This allows for the database to be constructed incrementally as the data arrives.X_COORD. File Naming Conventions Parameter file names consist of information type and parameter name. _SIN denotes the Order. used 5-20 ProMAX 2D Seismic Processing and Analysis Landmark . For example a velocity function contains multiple velocity-time pairs at one CDP. the Ordered Parameter Files database files (those not in separate directories). These picks are stored in tabular format. and Flow subdirectories. Parameter tables contain more than one number per something. you would generate a table ending in THOR. They are stored in the Area/Line subdirectory along with seismic datasets. To increase access speed and reduce storage requirements. where they can be edited. The end result of your work is a parameter table. Parameter tables can be imported from ASCII files that were created by other software packages or hand-edited by you. you would generate a parameter table ending in TMUT. you pull down the Picking Menu and choose the type of table to create. If you were picking a time horizon. Parameter tables can be created by hand using the Parameter Table Editor which is opened by the Create option on the parameter table list screen. Creating a Parameter Table Parameter tables are typically created in three ways: • Processes store parameters to a table for later use by other processes. If you were to pick a top mute. • • An example is the interactive picking of time gates within the Trace Display process. After seismic data is displayed on the screen. Parameter tables differ from the OPF database in OPF files contain many attributes that are one number per something. Parameter Tables are often referred to as part of the database. Some examples may be mute functions or decon design time gates. parameter tables are stored in binary format.Chapter 5: System Overview Parameter Tables Parameter Tables are files used to store lists of information in a very generalized structure. Review the highlighted regions in the file display for accuracy. you name and store the parameter tables in their specific Area/Line subdirectory. Perform the Import: Select the Apply button. The application windows will close and the focus will return to the calling spreadsheet. Note: Filter and Apply appear grayed out and are insensitive to mouse button actions. Select Format: Select a previous format or create a new format. Therefore. it is displayed. Filter and Apply appear normally and are available for use. Text may be excluded or replaced within this interactive operation. you can inadvertently overwrite an existing parameter table by editing a parameter table in a different processing flow. or exported to ASCII files for use by other software packages WARNING: Remember. Filter the File for Invalid Text: Search the marked columns and rows for any invalid text. and End Col. ASCII Import to a Parameter Table File Import reads either ASCII or EBCDIC formatted files with fixed columnar data into the spreadsheet editor. 6. The steps involved in performing a file import are as follows: 1. Landmark ProMAX 2D Seismic Processing and Analysis 5-21 . 2. or by performing click and drag column definition. values. Columns can either be edited by hand entering Start Col. 4. 3.Chapter 5: System Overview by other processes in later processing. Select File: Select a file to import. use Width to set the line width and then reread the file. Save the Column Definition: Save any changes to the current column definition to disk for later retrieval. When the application is initialized. After Format has been pressed and a columnar format selected. After a file has been selected. Review or Edit Column Definitions: Review the previously defined columns in an existing format by selecting all the columns. two windows appear: the main ASCII/EBCDIC File Import window and the File Import Selection dialog. If the text file does not contain valid line terminators. and you can select rows. 5. values. 4. Select File: Select a file for export within the File Export Selection dialog. The steps involved in performing a file export are as follows: 1. then the ASCII text is displayed and the Apply button is activated. the main ASCII File Export window will appear. After a file and format has been selected. 5-22 ProMAX 2D Seismic Processing and Analysis Landmark . 5. Columns can either be edited by hand entering Start Col. Review or Edit Column Definitions: Review the previously defined columns in an existing format by selecting all the columns. Perform the Export: Select the Apply button. When the application is initialized. and End Col. Review the highlighted regions in the file display for accuracy. Save the Column Definition: Save any changes to the current column definition to disk for later retrieval.Chapter 5: System Overview ASCII File Export from the Parameter Table Editor Export writes either ASCII or EBCDIC formatted files with fixed columnar data from a spreadsheet editor. 3. 6. 2. Select Format: Select a previous format or create a new format. or by performing click and drag column definition. Cancel the Export Operation: Press the Cancel button to close the export windows and return to the calling spreadsheet. Chapter 5: System Overview Disk Datasets ProMAX uses a proprietary disk dataset format that is tailored for interactive processing and random disk access. Disk dataset files can span multiple filesystems, allowing for unlimited filesize datasets. A typical set of files might look like this: — /ProMAX/data/usertutorials/landexample/12345678CIND /ProMAX/data/usertutorials/landexample/12345678CMAP /ProMAX/data/usertutorials/landexample/12345678/TRC1 /ProMAX/data/usertutorials/landexample/12345678/HDR1 These files are described in more detail in the table below. Table 4: Composition of a Seismic Dataset File Name Trace (...TRCx) Trace Header (....HDRx) Contents File containing actual sample values for data trace. File containing trace header entries corresponding to data samples for traces in the trace file. This file may vary in length, growing as new header entries are added. Keep trace headers in a separate file so trace headers can be sorted without needing to skip past the seismic data samples. File keeps track of trace locations, even if data flows over many disks. Given a particular trace number, it will find the sequential trace number within the dataset. This rapidly accesses traces during processing. The map file is a separate file, as it may grow during processing, it is always held in the line directory. File has free-form format information relating to the entire dataset, including sample interval, number of samples per trace, processing history, and names of trace header entries. This file may grow during processing, and it is also always held in the line directory. Map (....CMAP) Index (....CIND) Landmark ProMAX 2D Seismic Processing and Analysis 5-23 Chapter 5: System Overview CIND HDRx CMAP TRCx Disk Dataset Components - Relative Sizes Secondary Storage In a default ProMAX configuration, all seismic dataset files reside on a single disk partition. The location of this disk partition is set in the $PROMAX_HOME/etc/config_file with the entry: — primary disk storage partition: /ProMAX/promax/data 200 In addition to the actual trace data files, the primary storage partition will always contain your flow subdirectories, parameter tables, ordered parameter files, and various miscellaneous files. The ...CIND and ...CMAP files which comprise an integral part of any seismic dataset are always written to primary storage. Since the primary storage file system is of finite size, ProMAX provides the capability to have some of the disk datasets, such as the ...TRCx and ...HDRx files, and some of the ordered parameter files span multiple disk partitions. Disk partitions other than the primary disk storage partition are referred to as secondary storage. All secondary storage disk partitions must be declared in the appropriate $PROMAX_HOME/etc/config_file. Samples entries are: 5-24 ProMAX 2D Seismic Processing and Analysis Landmark Chapter 5: System Overview secondary disk storage partition: /ProMAX/promax/data2 20 TRC OPF secondary disk storage partition: /ProMAX/promax/data3 20 TRC secondary disk storage partition: /ProMAX/promax/data4 20 OPF secondary disk storage partition: /ProMAX/promax/data5 20 Primary Data Secondary Data2 Secondary Data3 Secondary Data4 Secondary Data5 Refer to the ProMAX System Administration guide for a complete description of the config_file entries for primary and secondary disk storage. 20 is the default disk file size in Megabytes. This default is probably too small for modern surveys as it was based on the old Unix 2Gig file system limitation. A better value would be 4000, or as large as your dataset, or as large as a file as your system will allow. WARNING: If the Primary file system fills up ProMAX will crash and will not be able to launch until space on Primary has been cleaned up. Under the default configuration, the initial TRC1 and HDR1 files are written to the primary storage partition. It is possible to override this behavior by setting the appropriate parameter in Disk Data Output. If the parameter Skip primary disk partition? is set to Yes, then no TRC or HDR files will be written to the primary disk partition. This can be useful as a means of maintaining space on the primary storage partition. (To make this the default situation for all users, have your ProMAX system administrator edit the diskwrite.menu file, setting the value for Alstore to ‘t’ instead of ‘nil’). Secondary storage is used in a “as listed and available” fashion. As an attempt to minimize data loss due to disk hardware failure, ProMAX tries to write a dataset to as few physical disks as possible. If the primary storage partition is skipped by setting the appropriate parameter in Disk Data Output, the CIND and CMAP files are still written to the primary storage partition, but the TRCx or HDRx files will not be found there. Landmark ProMAX 2D Seismic Processing and Analysis 5-25 Chapter 5: System Overview Tape Datasets Tape datasets are stored in a proprietary format, similar to the disk dataset format, but incorporating required structures for tape input and output. Tape input/output operates either in conjunction with a tape catalog system, or without reference to the tape catalog. The tape devices used for the Tape Data Input, Tape Data Insert, and Tape Data Output processes are declared in the ProMAX device configuration window. This allows access to tape drives anywhere on a network. The machines that the tape drives are attached to do not need to be licensed for ProMAX, but the fclient.exe program must be installed. Tape Trace Datasets A ProMAX tape dataset is similar to a disk dataset in that the index file (...CIND) and map file (...CMAP) still reside on disk in the Line/survey database. Refer to the documentation in the Disk Datasets portion of this helpfile for a discussion of these files. Having the index and map files available on disk provides you with immediate access to information about the dataset, without needing to access any tapes. It also provides all the information necessary to access traces in a non-sequential manner. Although the index and map files still reside on disk, copies of them are also placed on tape(s), so that the tape(s) can serve as a self-contained unit(s). If the index and map files are removed from disk, or never existed, as in the case where a dataset is shipped to another site, the tapes can be read without them. However, access to datasets through the index and map files residing solely on tape must be purely sequential. Tape datasets are written by the Tape Data Output process, and can be read using the Tape Data Input or Tape Data Insert processes. These input processes include the capability to input tapes by reel, ensemble number, or trace number. Refer to the relevant helpfile for a complete description of the parameters used in these processes. The use or non-use of the tape catalog in conjunction with the tape I/O processes is determined by the tape catalog type entry in the appropriate $PROMAX_HOME/etc/config_file. Setting this variable to full activates catalog access, while an entry of none deactivates catalog access. An entry of external is used to indicate that an external tape catalog, such as the Cray Reel Librarian, will be used. You can override the setting provided in the config_file by setting the environment 5-26 ProMAX 2D Seismic Processing and Analysis Landmark Chapter 5: System Overview variable for BYPASS_CATALOG to ‘t’, in which case the catalog will not be used. The actual tape devices to use for tape I/O must also appear as entries in the config_file, under the tape device: stanza. Landmark ProMAX 2D Seismic Processing and Analysis 5-27 Chapter 5: System Overview Tape Catalog System Tape Catalog Overview The fundamental strategy of the tape catalog is that a group of tapes are introduced or logged into the tape catalog, which then works in conjunction with the Tape Input, Tape Insert, and Tape Output processes to provide access to those tapes from within the ProMAX system. Before being introduced to the catalog, an ANSI label is written to each tape using the catalog utilities outlined below. The catalog system knows the label and status (initially SCRATCH) of every tape, and can monitor and validate the tape catalog resources accordingly. For example, when a request for an output dataset is made, the catalog can decide which tape to use, and can verify that the correct tape is mounted. When a dataset overflows a tape, the catalog can decide which tape to use next, and can again verify that the correct tape is mounted. When a request for an input dataset is made, the catalog knows which tapes belong to the dataset, and can verify that the correct tapes are mounted in the correct order. Getting Started The first step in using the ProMAX tape catalog is to create some labeled tapes. The program $PROMAX_HOME/sys/bin/tcat is used for tape labelling, catalog creation and maintenance, and for listing current catalog information. The program is run from the UNIX command line. The following steps are required to successfully access the tape catalog: 1. Label tapes. 2. Read and Display tape labels. 3. Add labeled tapes to a totally new catalog. Before adding the tapes to a new catalog, it is a good idea to visually inspect the contents of the label information file for duplicate or missing entries. The contents typically look like: 0 AAAAAA 0 1 4 1 AAAAAB 0 1 4 5-28 ProMAX 2D Seismic Processing and Analysis Landmark Chapter 5: System Overview 2 AAAAAC 0 1 4 3 AAAAAD 0 1 4 4 AAAAAE 0 1 4 The fields are: volume serial number (digital form), volume serial number (character form), tape rack slot number, site number, and media type, respectively. You can manually edit these fields. 4. Write a label information file from the existing catalog. 5. Add labeled tapes (and datasets) to the existing catalog. 6. Merge an additional catalog into the existing catalog. 7. Delete a dataset from the catalog. Landmark ProMAX 2D Seismic Processing and Analysis 5-29 Chapter 5: System Overview Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • • • • • • Where is the Seismic Data stored Are the Trace Headers stored separate from the Data Where are the Ordered Parameter Files stored Where are the Parameter Tables stored Can you build a ProMAX start-up Script Can you personalize/change a default Menu Can you explain how data passes through: single trace tools. ensemble tools. interprocess communication and stand-alone tools 5-30 ProMAX 2D Seismic Processing and Analysis Landmark . such as F-K analysis and filtering. In this chapter. Data analysis tools and the resulting filtering processes. Topics covered in this chapter: t Parameter Table Picking t Parameter Test t IF/ENDIF Conditional Processing t F-K Analysis and Filtering t F-K Filtering Comparisons t Interactive Spectral Analysis (ISA) Landmark ProMAX 2D Seismic Processing and Analysis 6-1 . yet flexible parameter testing and data analysis capabilities. providing you with convenient. Using this method you can test multiple parameters in multiple processes. Parameter testing is broken down by type: manual and automatic. Manual parameter testing refers to the use of IF-ELSEIF-ENDIF conditional processing sequences to define a particular test scenario. With the automatic parameter testing. are good examples for parameter testing. one of the exercises is to design filters in the F-K domain and compare the F-K filtered data to your input seismic data. you can easily test one parameter in a single process. The processes are found in the process list category called Flow Control.Chapter 6 Parameter Selection and Analysis ProMAX 2D contains a suite of processes. Parameter Selection This chapter gives the processor a framework of how to define and test parameters. gates.Chapter 6: Parameter Selection and Analysis Chapter Objectives 3. windows and processing flows. Upon completion of this chapter you should: • • • • • Be proficient at Picking Gates and Windows in Trace Display Know how to Pick Bad Traces Understand Automatic Parameter Testing Be able to design IF/ENDIF conditional processing Be able to interactively test FK Filters and Spectral Analysis 6-2 ProMAX 2D Seismic Processing and Analysis Landmark . and a trace reversal list. Landmark ProMAX 2D Seismic Processing and Analysis 6-3 . In Disk Data Input.1-Pick Parameter Tables Add Delete Execute View Exit Disk Data Input Read data from other lines/surveys?: ---------------------No Select dataset: ----------------------------Shots-with geometry Trace read option: -----------------------------------------------Sort Interactive Data Access?: --------------------------------------Yes Select primary trace header entry: -----------------------FFID Select secondary trace header entry: --------------OFFSET Select tertiary trace header entry: ----------------------NONE Sort order for dataset: ------------------------------------------*:*/ Automatic Gain Control AGC operator length: -----------------------------------------1000 Trace Display Number of ENSEMBLES (line segments)/screen: -------2 Do you want to use variable trace spacing?: ----------Yes 2. 3. Build the following flow in your “Watson Rise” Line. Replace the AGC operator length default value with 1000. Sort the data by FFID and OFFSET. deconvolution design gate. These files are stored in binary format and are intended for use in subsequent flows. The interactivity of Trace Display allows you to generate these tables. 1. select “Shots-with geometry”. Editing Flow: 3.Chapter 6: Parameter Selection and Analysis Parameter Table Picking Parameter tables are generated when you interactively define lists or tables of information within various display tools. Pick Parameter Tables In this exercise you will pick a top mute. trace kill list. . “FB Mute” by AOFFSET. go ahead and pick the bad traces here: Picking ¦ Kill traces. In Trace Display.. 7.. Trace to be killed Mute Traces to be reversed Decon Gate Parameter tables 6. Also. set the number of ensembles per screen to 2. 6-4 ProMAX 2D Seismic Processing and Analysis Landmark . 5. “Kill list from Trace Display”. Pick a top mute to get rid of first break and refracted energy: Picking Pick Top Mute. use variable trace spacing. In this case you should see only hyperbolas after Paintbrush applies the top mute. Use the Paintbrush icon to see the effects of your current picks.. This will use the secondary sort key of OFFSET to variably space the traces.Chapter 6: Parameter Selection and Analysis 4. If you did not save your trace kill table from chapter 4. Execute the flow. Remember to use MB3 New Layer to pick the bottom of the decon gate. Pick a deconvolution gate on the first shot: Picking ¦ Pick Miscellaneous Time Gates. “reverse traces” by AOFFSET. 9.. If you desire you can pick the reverse traces: Picking ¦ Reverse traces. Select File ¦ Save Picks.Chapter 6: Parameter Selection and Analysis 8.. In general the reverse traces will be flagged in the field by the observers log. After projecting your windows use Interactive Data Access to move through all the shots and QC the windows. “decon gate” by AOFFSET.. Landmark ProMAX 2D Seismic Processing and Analysis 6-5 .. then select File ¦ Exit/Stop Flow. The statics routines will also detect the reverse traces for you. 10. 11. The second is called PARMTEST and is an ASCII string. Parameter Test creates two header words. uniquely interpreted by the Screen Display processes as a label for the traces. you will use Parameter Test to compare True Amplitude Recovery on shot gathers with different values for dB/sec. The first is called REPEAT data copy number and is used to distinguish each of the identical copies of input data. Test True Amplitude Recovery with Parameter Test In this exercise. The output consists of copies of the input data with a different test value applied to each copy.Chapter 6: Parameter Selection and Analysis Parameter Test The Parameter Test process provides a mechanism for automatically testing simple numeric parameters by creating multiple copies of input traces and replacing a key parameter in the process to be tested with specified test values. 6-6 ProMAX 2D Seismic Processing and Analysis Landmark . Build the following flow: Editing Flow: 3.with geometry Trace read option: ---------------------------------------------SORT Interactive Data Access?: ---------------------------------------No Select primary trace header entry: -------------------------SIN Sort order list for dataset: -------------------------------------16/ Trace Kill/Reverse Trace editing MODE: ---------------------------------------------Kill Get edits from the DATABASE?: ----------------------------Yes SELECT trace Kill parameter file: -----------------------------------------------------Kill list from DBTools interactive Trace Kill/Reverse Trace editing MODE: --------------------------------------Reverse Get edits from the DATABASE?: -----------------------------No Trace selection MODE: --------------------------------EXCLUDE PRIMARY edit list header word: ----------------------------SIN SECONDARY edit list header word: ------------SRF_SLOC TERTIARY edit list header word: -----------------------NONE SPECIFY trace to be edited: ------------------------1-17:469/ Trace Muting Re-apply previous mutes: ---------------------------------------No Mute time reference: ----------------------------------------Time 0 TYPE of mute: ------------------------------------------------------Top Starting ramp: ------------------------------------------------------30.2-Parameter Test Add Delete Execute View Exit Disk Data Input Select dataset: ---------------------------Shots.Chapter 6: Parameter Selection and Analysis 1. EXTRAPOLATE mute times?: ---------------------------------Yes Get mute file from the DATABASE?: -----------------------Yes SELECT mute parameter file: -------------------------FB Mute Parameter Test True Amplitude Recovery Trace Display Landmark ProMAX 2D Seismic Processing and Analysis 6-7 . 0-7000. and read the shot number 16. In the second Trace Kill/Reverse. select your top mute file. In Disk Data Input. In the first Trace Kill/Reverse. so set this to No. 6-8 ProMAX 2D Seismic Processing and Analysis Landmark .” Choose to sort data by SIN. select “Shots-with geometry.1300-12000.Chapter 6: Parameter Selection and Analysis Editing Flow: 3. choose to reverse SRF_SLOC 469 for SIN’s 1-17.12|9|6 Trace grouping to reproduce: ----------------------Ensembles True Amplitude Recovery Apply spherical divergence corrections?: ----------------Yes Basis for spherical spreading: ---------------1/dist Apply inelastic attenuation corrections?: -----------------No Get TAR velocity function from database?: ---No Should the velocity be treated as space variable: -----No Specify TAR velocity function: --------------------------. Parameter Test will not work with Interactive Data Access. 3.2-Parameter Test Add Delete Execute View Exit Disk Data Input Trace Kill/Reverse Trace Kill/Reverse Trace Muting Parameter Test Enter Parameter VALUES: -----------------------------. 5. select you trace kill file. 4. In Trace Muting.850-9000. 2000-15000 Apply dB/sec corrections?: ----------------------------------Yes dB/sec correction constant: ------------------99999 Apply time raised to a power corrections?: --------------No APPLY function to data or REMOVE effect of amplitude corrections?: -------------------------------------Apply Maximum application TIME: -------------------------------5000 Trace Display Number of ENSEMBLES(line segments)/screen: --------2 Trace scaling option: ------------------------------Entire Screen Number of display panels: ---------------------------------------2 2. ) 7. Select Yes to apply spherical divergence. To determine the format (real. 850-9000. each separated by a vertical bar (|). 8. Enter a list of parameter values for dB/sec correction constant. (Use values of 12. 1300-12000. and 6 dB/sec for this exercise. choose to display 2 ensembles/screen. Specify values for Parameter Test. Landmark ProMAX 2D Seismic Processing and Analysis 6-9 . look at the default value in the True Amplitude Recovery process. sequence) and a realistic range of test values. 9. This will display the original shot plus the three parameter tests on a single screen. integer. and enter five nines (99999) for the dB/sec correction constant. 2 display panels. 9. NOTE: Entering five nines (99999) is a flag that tells the process to use the values found in Parameter Test for this parameter. Execute the flow to compare displays. and enter the following velocity time pairs (0-7000. In Trace Display. Specify True Amplitude Recovery parameters. 2000-15000). Select Yes for Apply dB/sec Correction. and change the trace scaling from individual to entire screen.Chapter 6: Parameter Selection and Analysis 6. 6-10 ProMAX 2D Seismic Processing and Analysis Landmark . select File ¦ Exit/Stop Flow.Chapter 6: Parameter Selection and Analysis Viewing Parameter Tests After viewing the tests and deciding on the most appropriate value for the dB/sec correction. If you have problems with a ProMAX flow that you cannot solve simply email the “job. 14. that were not in your original flow. This occurs because Parameter Test is a macro.com” and they will help out in anyway they can. Use the Next ensemble icon to display the four tests. Select View from the flow builder menu and look at the processes that were actually executed in your flow. then use the Animation tool to review the tests. 11. Select File ¦ Exit/Stop Flow when finished. 13. Execute the flow. Landmark ProMAX 2D Seismic Processing and Analysis 6-11 .Chapter 6: Parameter Selection and Analysis 10. and change the following Trace Display parameters: Editing Flow: 3. Also notice that Parameter Test is absent.output” file to “support@advance. built from other processes. Edit you flow again.2-Parameter Test Add Delete Execute View Exit Disk Data Input Trace Kill/Reverse Trace Kill/Reverse Trace Muting Parameter Test True Amplitude Recovery Trace Display Number of ENSEMBLES(line segments)/screen: --------1 Automatically SAVE screens: --------------------------------yes Trace scaling option: ------------------------------Entire Screen Number of display panels: ---------------------------------------1 12.output” file is a listing of the executed processes. There are some additional processes listed here. Check to see if you would still use the same value for dB/sec as you chose before. Near the bottom of the “job. ELSEIF. such as a fan filter option instead of a polygon filter option in FK Filter. then pass that copy of the data to the next process. This is actually the same process. In order to manually test parameters you must: • • Generate multiple copies of the data. Branching the flow is a conceptual term for controlling the processes your dataset utilizes. When your testing requires evaluating multi-level tests. but prior to the processes you wish to compare. or comparing nonnumeric parameters. and so on until all copies of the data have been passed to unique processes. You should place Reproduce Traces after any processing which is common to all copies of the data. It is a numeric value from 1-N. allowing you to distinguish between the multiple versions of data. The series of conditions is ended with ENDIF. as in the case of corner frequencies used to define a bandpass filter. This is handled automatically by the Parameter Test process. then manual testing must be used. One method of generating multiple data copies is to use the Reproduce Traces process. It can only be used when the testing parameter is a simple numeric value. For example. designed into Parameter Test macro. each copy of the data is passed to a different process. 6-12 ProMAX 2D Seismic Processing and Analysis Landmark . In other words. such as the automatic gain control operator length. as you saw if you looked at the View information when you executed the previous flow. Branch your processing stream so that each copy of the data may be processed with different parameters. and ENDIF processes to select and direct traces for processing. More specifically. or a sequence of numerics.Chapter 6: Parameter Selection and Analysis IF/ENDIF Conditional Processing Automatic parameter testing is not always an option. pass that copy to a different process. Reproduce Traces generates a specified total number of copies and appends a header word to each trace. If the data copy number is 2. rather utilize the capability of the IF. This header word is known as Repeated Data Copy Number or REPEAT for short. or the same process with different parameter selection using a series of IF. where N is the total number of generated copies. if the data copy number (REPEAT) is 1. you do not actually break up any single flow into separate flows. ELSEIF and ELSE processes in the flow. This flow illustrates how to compare these three copies. and filtered shot gathers with deconvolution. It is always a good idea to have a control copy. you may use a process called Trace Display Label to generate a header word for posting a label on the display.Chapter 6: Parameter Selection and Analysis Finally. Compare Data With and Without Deconvolution Incorporate Reproduce Traces with IF and ENDIF to compare processed and unprocessed data. In this exercise you will compare unfiltered shot gathers with deconvolution. Landmark ProMAX 2D Seismic Processing and Analysis 6-13 . for further comparison. the original input. 9 Reproduce Traces Trace grouping to reproduce: ----------------------Ensembles Total Number of datasets: ----------------------------------------3 IF Trace selection MODE: ------------------------------------Include SELECT Primary trace header word: --------------REPEAT SELECT secondary trace header word: --------------NONE SPECIFY trace list: ---------------------------------------------------1 Trace Display Label Trace label: ------------------------------------------Original Input ELSEIF Trace selection MODE: ------------------------------------Include SELECT Primary trace header word: --------------REPEAT SELECT secondary trace header word: --------------NONE SPECIFY trace list: ---------------------------------------------------2 Spiking/Predictive Decon Trace Display Label ELSE Spiking/Predictive Decon Trace Display Label ENDIF Trace Display 6-14 ProMAX 2D Seismic Processing and Analysis Landmark .Chapter 6: Parameter Selection and Analysis 1.3-IF/ELSEIF Loop Add Delete Execute View Exit Disk Data Input Trace Kill/Reverse Trace Kill/Reverse Trace Muting True Amplitude Recovery dB/sec correction constant: ------------------------------------. Copy your previous flow and edit it to look like the following: Editing Flow: 3. 1 Window rejection factor: ------------------------------------------2.3-IF/ELSEIF Loop Add Delete Execute View Exit Disk Data Input Trace Kill/Reverse Trace Kill/Reverse Trace Muting True Amplitude Recovery Reproduce Traces IF Trace Display Label ELSEIF Spiking/Predictive Decon TYPE of deconvolution: -----------Minimum phase spiking Decon operator length(s): --------------------------------------160 Operator ‘white noise’ level(s): -------------------------------0. use those listed above---- Trace Display Label Trace label: ---------------------------------------Decon with filter ENDIF Trace Display Number of ENSEMBLES (line segments)/screen: -------3 Number of display panels: ---------------------------------------1 Trace Scaling Option: ----------------------------------Individual Landmark ProMAX 2D Seismic Processing and Analysis 6-15 . Time gate reference: ----------------------------------------Time 0 Get decon gates from the DATABASE?: ------------------Yes SELECT decon gate parameter file: -------------decon gate Output traces or filters: ---------------Normal decon output Apply a bandpass filter after decon? ----------------------No Re-apply trace mute after decon?: -------------------------Yes Trace Display Label Trace label: ------------------------------------------------------Decon ELSE Spiking/Predictive Decon Apply a bandpass filter after decon?:---------------------Yes Bandpass filter frequency values: --------------6-12-60-70 ----For remaining parameters.Chapter 6: Parameter Selection and Analysis Editing Flow: 3. Use Trace Display Label to create labels for each copy. After viewing the data in this mode. 3. In Reproduce Traces. 6. Execute the flow. The ELSE process selects all traces. 6-16 ProMAX 2D Seismic Processing and Analysis Landmark . Label the copies according to their unique processing. Select Repeat for Select Primary trace header word in IF and ELSEIF. In this example. 4. 8. You will generate two additional copies (3 total). one ensemble at a time. set the db/sec to the value you chose in the previous flow. In our case.” the second with “Decon. providing the mechanism for selecting or restricting traces which will be passed into a particular branch of the flow.” 7. The ELSEIF condition passes the second data copy number (REPEAT=2) to Spiking /Predictive Decon. enter 3 for the total number of datasets. Data copy 1 is passed to Trace Display Label in this example. IF acts as the gate keeper. you will apply deconvolution and filter. Use the same parameters as the previous flow for the first four processes. leaves only the third data copy (REPEAT=3) for the ELSE branch. In Trace Display.Chapter 6: Parameter Selection and Analysis 2. you may choose to display each copy on a different screen. and use the screen swap mode. In the first IF conditional. 5. select REPEAT as the primary trace header and 1 (copy number) as the trace list entry. label the first copy with “Original Input. not previously selected with IF or ELSEIF. Header words are used (just as in Disk Data Input) to uniquely identify the traces to include or exclude in a particular branch. For example.This will be the control copy. having selected two of the three copies of data for filtering. In True Amplitude Recovery.” and the final copy with “Decon with filter. choose to display all 3 copies on one screen. you would normally do the FK filter before the deconvolution. For class purposes we are using the deconvolution to enhance the ground roll so that we can demonstrate how powerful FK filters are at attenuating ground roll. F-K Analysis In this exercise you will bring in one shot with some slow linear noise. design a filter to reject the noise. There are ProMAX tools to view data in F-K space. After inspection in both the time domain and F-K space. since. design filters and subsequently apply filters to enhance your data. This separation can be exploited by defining a filter to reject the noise or accept the good data.Chapter 6: Parameter Selection and Analysis F-K Analysis and Filtering Separating trace data into signal and noise is often possible in F-K space. You will want to try a polygon filter as well as a fan filter to attenuate the noise. NOTE: This is not a real processing flow. Landmark ProMAX 2D Seismic Processing and Analysis 6-17 . TX panels in DB or Linear: ----------DBSCALE Initial TX gain setting (percentile): --------------------------98. Ending time for analysis: ----------------------------------------0. Select mute polygon table: ------------------------------fk mute Mode of F-K filter operation: ---------------------------REJECT Percent flat for F-K filter windowing: ----------------------90. Time length of F-K filter (ms): -------------------------------500.TK. Starting display configuration: ----------------TX-TK-FX-FK Position of zero wavenumber in display: --------CENTER Position of zero frequency in display: --------------------TOP Plot FK. Percent flat for trace ramping: ------------------------------100.optional Trace Kill/Reverse . use the same parameters as the previous flow.4-FK Analysis/Filter Add Delete Execute View Exit Disk Data Input Trace Kill/Reverse . Initial FK maximum gain setting (db): -----------------------0. Distance between input traces: ------------------------------55.optional Spiking/Predictive Decon Automatic Gain Control >F-K Filter< F-K Analysis Panel width in traces: ------------------------------------------120 Starting time for analysis: ---------------------------------------0. and add/delete processes so that it looks like the following: Editing Flow: 3.Chapter 6: Parameter Selection and Analysis 1. For all processes prior to F-K Analysis. Percent flat for time ramping: -------------------------------100. 6-18 ProMAX 2D Seismic Processing and Analysis Landmark . Initial FK minimum gain setting (db): ------------------------0.optional Trace Muting True Amplitude Recovery . Spatial extent of F-K filter (traces): --------------------------50 2. Copy your previous flow. You should identify the ground roll energy in the F-K domain by the velocity you measure in T-X space. for the distance between traces (do not let this default to 0). Landmark ProMAX 2D Seismic Processing and Analysis 6-19 . 6. View only the TX. 7. enter 122 for the panel width to account for the shot gap in the transform. In F-K Analysis. You may find it helpful to rotate the color scale using Controls ¦ Edit Colormap. 9. 8. and FK panels by selecting Configuration ¦ TX-and-FK. Use the dx/dt icon. 4. Add an output mute polygon table “fk mute”.Chapter 6: Parameter Selection and Analysis 3. With the default display you will see four panels. Execute the flow. Set 55 ft. 5. 3) Desired Polygon 2) Move points 1) Rectangle control points Picking Mute for FK Filter 11.Chapter 6: Parameter Selection and Analysis 10. Pick a polygon to include all the noise to filter. select the Picking tool icon to build a table for interactively picking a reject zone. 6-20 ProMAX 2D Seismic Processing and Analysis Landmark . It is best to start with a square or rectangle and then use MB1 to add new control points and MB3 to move the control points to customize the shape of the polygon as illustrated on the previous page. With the F-K data displayed. . Landmark ProMAX 2D Seismic Processing and Analysis 6-21 . To better view the operator now select Controls ¦ TX Display. You may also want to view the impulse response of the filter by selecting FilterResponse ¦ ImpulseResponse. ¦ Clip by amplitude ¦ .008 and then select OK. examine the response of the data to the filter by selecting FilterResponse ¦ FilteredOutput. After using Interactive Data Access option to view other shots.. 14. FK Filtered Output 13. select File ¦ Exit/Stop Flow. and then select Yes to save your polygon.Chapter 6: Parameter Selection and Analysis 12. After building the desired polygon. Percent flat for offset ramping: -----------------------------100.Chapter 6: Parameter Selection and Analysis Compare F-K filtered shots using an IF loop 1.4-FK Analysis/Filter Add Delete Execute View Exit Disk Data Input Interactive Data Access?: ---------------------------------------No Trace Kill/Reverse .optional Trace Muting True Amplitude Recovery . Trace Display Label Trace label: --------------------------------------------------FK Filter ELSE Trace Display Label ENDIF Trace Display Number of ENSEMBLES (line segments)/screen: -------2 6-22 ProMAX 2D Seismic Processing and Analysis Landmark . Spatial extent of F-K filter (traces): --------------------------50 Re-apply T-X trace mute after filter?: ---------------------Yes Percentage of K-space to keep around K=0: --------------0. Edit your flow to include an IF loop: Editing Flow: 3.optional Trace Kill/Reverse .optional Spiking/Predictive Decon Automatic Gain Control Reproduce Traces IF F-K Filter Type of F-K filter: -----------------------------Arbitrary Polygon Distance between input traces: -------------------------------55 Panel width in traces: ------------------------------------------122 Test the filter impulse response?: ---------------------------No Percent flat for time ramping: -------------------------------100. Time length of F-K filter (ms): -------------------------------500. Get polygon mute file from the database: ---------------Yes Select mute parameter file: ------------------fk mute Mode of F-K filter operation: ---------------------------REJECT Percent flat for F-K filter windowing: ----------------------90. You may try changing the mode of operation from REJECT to ACCEPT and re-running. except turn off the Interactive Data Access. and review the results. 4. and review the results. 8. Execute the flow. If you see any signal/hyperbolas you have removed some signal. 5. Create two copies of the shot with Reproduce Traces. Use the same parameters as before for the first seven processes. Landmark ProMAX 2D Seismic Processing and Analysis 6-23 . 6. 7.Chapter 6: Parameter Selection and Analysis 2. Execute the flow. 3. Modify the FK filter to use a fan filter instead of the arbitrary polygon. Use the Repeat option in IF to send one copy of the shot to the F-K Filter process. Deconvolution testing may become very involved in certain situations. or “whitening” of the spectrum after decon relative to before. the Spectral Analysis window updates itself for each new selection. In this exercise we will look at such a comparison on a single shot record. This allows spectra from different subsets to be compared. Subsets for Spectral Analysis are chosen from the Data Selection Window. and then compare the results of running deconvolution on the data. A Spectral Analysis window for the current selection is made by selecting Spectral Analysis from the Data Analysis menu. Multiple Subset Selection: Displays at least two windows: a Data Selection Window and one or more Spectral Analysis windows.Chapter 6: Parameter Selection and Analysis Interactive Spectral Analysis Interactive Spectral Analysis computes and displays power. By default. One criterion that you may use to help decide on decon parameters is to look at amplitude (or power) spectra of the trace data before and after decon. If the decon has worked properly. you should see some “flattening”. There are three modes of data selection: • Simple Selection: Analyzes only the displayed traces. During the interactive session you may analyze new traces by choosing Next Data from the Data menu. using the selection tool from the toolbox. These displays can be configured both interactively and from the ProMAX menu. Single Subset Selection: Enables you to interactively select a rectangular subset of the data for spectral displays. 6-24 ProMAX 2D Seismic Processing and Analysis Landmark . You can freeze the subset in the Spectral Analysis window so that it does not update with new selections. • • Spectral Analysis In this exercise you will run Interactive Spectral Analysis in all three modes. The spectral displays are automatically updated for each new rectangle selection. phase and F-X spectra estimates for interactively selected subsets of traces. NONE Sort order for dataset: ------------------------------------------16/ Automatic Gain Control Interactive Spectral Analysis Data select method: ---------------------------------------. Execute the flow. Build the following flow to run the ISA in its simplest configuration: Editing Flow: 3.Ensembles ----Default the remaining parameters---2.Chapter 6: Parameter Selection and Analysis 1. Landmark ProMAX 2D Seismic Processing and Analysis 6-25 .5-Decon Test and ISA Add Delete Execute View Exit Disk Data Input Select dataset: -------------------------”Shots-with geometry” Trace Read Option: ----------------------------------------------Sort Interactive Data Access?: ---------------------------------------No Select primary trace header entry: -------------------------SIN Select secondary trace header entry: ---------------.Simple Display data by traces or ensembles: -------. Chapter 6: Parameter Selection and Analysis Interactive Spectral Analysis . Change the contents of the display by using the View ¦ Visibility pull down menu. 6-26 ProMAX 2D Seismic Processing and Analysis Landmark .Simple Mode 3. Edit the parameters of the Interactive Spectral Analysis to execute the Single Subset mode instead of the Simple mode. Exit from the display using the File ¦ Exit and Stop Flow pull down menu. 4. 5. and selecting the individual tiles of interest. Landmark ProMAX 2D Seismic Processing and Analysis 6-27 .Chapter 6: Parameter Selection and Analysis 6. Interactive Spectral Analysis . Execute the flow again.Single Subset Mode In this mode you can select a Single Subset of the available data for the purposes of computing the average power and phase specta. 6-28 ProMAX 2D Seismic Processing and Analysis Landmark . Also choose to Freeze the selected subsets. Edit the parameters of the Interactive Spectral Analysis to execute the Multiple Subset mode instead of the Single Subset mode. 8. You can move or redraw this window as many times as you wish. The data window and spectral windows will change configuration to match your data selection. Click on the Select Rectangular Region icon and then draw a box around an area of interest.Chapter 6: Parameter Selection and Analysis 7. 9. Exit from the display using the File ¦ Exit and Stop Flow pull down menu. Landmark ProMAX 2D Seismic Processing and Analysis 6-29 . Click on the Select Rectangular Region icon and draw a box around an area of interest and then select the Options ¦ Spectral Analysis pull down menu. Execute the flow again.Chapter 6: Parameter Selection and Analysis 10. 11. 6-Decon QC with ISA Add Delete Execute View Exit Disk Data Input Automatic Gain Control Reproduce Traces Trace grouping to reproduce: --------------------.Ensembles Total number of datasets: ----------------------------------------2 IF SELECT Primary trace header word: ------------. After the display comes up you can select the Options ¦ Spectral Analysis pull down menu to show the spectral estimate for the data before decon. In this way you can compare the spectral results for different areas.REPEAT SPECIFY trace list: ---------------------------------------------------2 Trace Muting Select mute parameter file: --------------------------”FB Mute” Spiking/Predictive Decon Decon operator length(s):---------------------------------------160 Select decon gate parameter file: -------------”decon gate” ENDIF Interactive Spectral Analysis Data select method: --------------------------Multiple Subsets Freeze the selected subset?: ---------------------------------Yes Display data by traces or ensembles: -------. a new window will appear. 6-30 ProMAX 2D Seismic Processing and Analysis Landmark . Copy your flow to compare a shot before and after deconvolution with an IF-ELSEIF loop. If you select a new area and repeat the Options ¦ Spectral Analysis pull down selection.REPEAT SPECIFY trace list: ---------------------------------------------------1 ELSEIF SELECT Primary trace header word: ------------. 14.Ensembles 15. 13. Select File ¦ Exit and Stop Flow.Chapter 6: Parameter Selection and Analysis 12. Editing Flow: 3. Chapter 6: Parameter Selection and Analysis 16. When done File ¦ Exit and Stop Flow from each of the display windows. Click on the Next ensemble icon to display the data after decon. Observe the flattened amplitude spectrum and the change in the dB scale. You can use the Slope icon to calculate the dB roll on/off of the amplitude spectrum. 17. Select the Options ¦ Spectral Analysis pull down menu again to show the spectral estimate for the data after decon. 18. Landmark ProMAX 2D Seismic Processing and Analysis 6-31 . Do you believe the amplitudes above 80 Hz? 19. Chapter 6: Parameter Selection and Analysis Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • • • • Can you Pick Gates and Windows in Trace Display How do you Pick Bad Traces Do you understand Automatic Parameter Testing Can you design an IF/ENDIF conditional processing tree Can you interactively test FK Filters and Spectral Analysis 6-32 ProMAX 2D Seismic Processing and Analysis Landmark . This process utilizes a database_math file to create and manipulate related database entries. ProMAX offers three methods of applying datum-static corrections. All of these options are within the Datum Statics Calculation and the Datum Statics Apply processes. which actually calculate and apply the static corrections.Chapter 7 Elevation Static Corrections Datum static corrections are generally required for land data to compensate for adverse traveltime effects of topography and variations in weathering thickness and velocity. You can also use refraction statics to calculate and apply datum statics. Topics covered in this chapter: t Elevation Statics Discussion t Calculate Elevation Statics t Apply Elevation Statics t Apply User Statics Landmark ProMAX 2D Seismic Processing and Analysis 7-1 . (This file can be found in the $PROMAX_HOME/port/misc directory. depending on whether or not the sources are on the surface.) These database values are then used to create trace header entries and apply appropriate static shifts to traces. Refraction statics will be covered in a later chapter. Elevation Statics This chapter explains how to calculate and apply elevation statics. Upon completion of this chapter you should: • • • • Understand the concept of Elevation Statics Know how to choose a proper Processing Datum Be able to Calculate and Apply Elevation Statics Be able to Import and Apply User Statics 7-2 ProMAX 2D Seismic Processing and Analysis Landmark .Chapter 7: Elevation Static Corrections Chapter Objectives 4a. which will interpolate the data to the fractional static properly. In Datum Statics Calculation* you have the option to shift prestack data to a floating datum or a final datum. Details of this process can best be understood by examining the contents of the elev_stat_math file. Normally the NA_STAT is applied during NMO. the Pre (before) NMO term and Post (after) NMO terms relative to N_DATUM. C_STATIC is set to zero. S_STATIC.0*FNL_STAT. NMO_STAT is the static that shifts Landmark ProMAX 2D Seismic Processing and Analysis 7-3 . If you select to process to a final datum. N_DATUM. The elev_stat_math file then establishes values in the database for F_DATUM. • • Datum Statics Apply performs the following function: • Apply the Pre (before) NMO portion of the statics and write the remainder to the trace header. FNL_STAT. Datum Statics Apply applies the static corrections to input data.Chapter 7: Elevation Static Corrections Elevation Statics All statics computations are performed in the database. The integer multiple of the sample period (usually a multiple of 2 or 4 ms) portion of NMO_STAT is automatically applied by Datum Statics Apply. and C_STATIC. Compute N_DATUM (a smooth surface used as the processing datum). shifting traces to the floating datum. Recall that NMO_STAT = S_STATIC + R_STATIC + C_STATIC and that C_STATIC = -1. Partition the total statics into two parts. to a time reference as if the data were recorded on a final datum F_DATUM (usually flat) using a replacement velocity (usually constant). R_STATIC. Datum Statics Calculation* calculates the elevation (datum) static corrections. The fractional sample period portion is written to the NA_STAT header entry and applied later. Datum Statics Calculation* performs the following functions: • Compute static time shifts to take the seismic data from their original recorded times. Datum Statics Calculation* then creates four new header entries for statics: NMO_STAT. TOT_STAT and NA_STAT. You supply a final datum elevation and a replacement velocity. This file typically resides in $PROMAX_HOME/port/misc. CDP Receiver N_DATUM Surface Elevation Vweathering NMO_STAT NMO_STAT Shot Base Weathering Vreplacement S_STATIC F_DATUM FNL_STAT C_STATIC R_STATIC Database Attributes: N_DATUM = floating datum F_DATUM = final datum S_STATIC = (F_DATUM .Chapter 7: Elevation Static Corrections traces to the final processing datum.C_STATIC TOT_STAT = cumulative applied statics NA_STAT = statics less than one sample period which are not-yet-applied (If TOT_STAT = 21.UPHOLE C_STATIC = 2 * [(N_DATUM .2 ms. and FNL_STAT is zero because your data are at the final datum.2 ms) 7-4 ProMAX 2D Seismic Processing and Analysis Landmark .P. NA_STAT = 1.F_DATUM) / DATUMVEL] Trace Header Values: N_DATUM = floating datum NMO_STAT = S_STATIC + R_STATIC + C_STATIC FNL_STAT = . and the sample period is 4 ms. Datum Statics Terminology S.ELEV + DEPTH) / DATUMVEL] .ELEV + DEPTH) / DATUMVEL R_STATIC = [(F_DATUM . Chapter 7: Elevation Static Corrections Calculate Elevation Statics 1. Shot Holes Ignoring Uphole Times: If you do not trust the uphole information. and a replacement velocity of 8000 ft/sec. Surface Source: If you have a surface source. use the elev_stat_math file.Elevations. Use a smoother of 51. This option will use the noup_stat_math file. replacement velocity. and length of smoother. Enter the final datum. Editing Flow: 4a. then you can override the weathering velocities calculated with uphole times and shot depths and supply your own weathering velocity. use a final datum elevation of 800 ft. Select the NMO static method . Other: If you have built a new *_stat_math file by modifying one of the existing *_stat_math files. 3.1-Calculate Datum Statics Add Delete Execute View Exit Datum Statics Calculation* Elevation or Refraction: --------------------------------Elevation Final datum elevation: -----------------------------------------800 Replacement velocity: -----------------------------------------8000 Database math method:--Shot Holes Using Uphole Info NMO static method: ------------------------------------Elevations Length of smoother: -----------------------------------------------51 Processing DATUM: --------------------------------NMO DATUM Run ID:------------------------------------------------------------------01 2. Landmark ProMAX 2D Seismic Processing and Analysis 7-5 . There are 4 choices: • Shot Hole Using Uphole Info: If you want to honor the shot depth and uphole information. For this dataset.Shot Hole Using Uphole Info. The Database Math Method determines which *_stat_math file to utilize. • • • 4. Create the following flow to calculate elevation statics for your data. you can input the path name to the modified *_stat_math file. Select the Database Math Method . R_STAT01. 6. From the DBTools window select the SRF tab (order). Select NMO Datum (floating) for Processing datum. DATUMVEL. 7. R_STATIC. F_DATUM. This parameter may require some testing to generate the desired N_DATUM. and C_STAT01.Chapter 7: Elevation Static Corrections The smoother is defined as number of CDPs to smooth over. 8. 5. This will generate S_STATIC. Why are the source and receiver statics opposite signs? Perhaps the shots are buried beneath the final datum? 7-6 ProMAX 2D Seismic Processing and Analysis Landmark . and C_STATIC and copy them to S_STAT01. When the job completes exit the flow. Select the SIN tab. and ELEV (receiver elevation). and view the following attributes: S_STAT01. From the CDP order. and then by double clicking view the following attributes: R_STAT01. Choose a Run ID of 01. 9. and select the Database menu. 10. view the C_STAT01 attribute. Execute the flow. and ELEV (elevation of surface at the shot locations). Notice the inverted relationship between the static and the elevation. From the XDB display select Database ¦ Get. and N_DATUM (floating datum). Notice the effect of the 51 point CDP smoother you applied. Now from the DBTools window select Database ¦ XDB Database Display. From the CDP order. view ELEV.Chapter 7: Elevation Static Corrections 11. 12. Landmark ProMAX 2D Seismic Processing and Analysis 7-7 . Copy the flow “3. 2. and elevation statics to your data.2-Apply Datum Statics Add Delete Execute View Exit Disk Data Input Select dataset: ----------------------------Shots-with geometry Trace read option: --------------------------------------------Get All ----Default all other parameters---- Trace Kill/Reverse Trace Kill/Reverse Trace Muting True Amplitude Recovery F-K Filter Spiking/Predictive Decon Datum Statics Apply Source datum statics database parameter: ----------------------------------------------SIN GEOMETRY S_STAT01 Receiver datum statics database parameter: ------------------------------------------SRF GEOMETRY R_STAT01 CDP datum statics database parameter: ------------------------------------------------CDP GEOMETRY C_STAT01 Disk Data Output Output Dataset Filename: ------Shots-decon/elev statics ----Default all other parameters---Data output from this flow will later be input to velocity analysis. Once the job finishes view the shots with flow “1. 7-8 ProMAX 2D Seismic Processing and Analysis Landmark . and NA_STAT using the Header icon. Editing Flow: 4a. Execute the flow.Chapter 7: Elevation Static Corrections Apply Elevation Statics 1. FNL_STAT. 3. Examine the trace headers for NMO_STAT. TOT_STAT.4-FK Analysis/Filter” to apply pre-processing.1-View Shots”. they must both be of type Geometry and the Attribute names must be USERSTAT. Therefore Datum Statics Apply will recalculate NMO_STAT using the N_DATUM and C_STATIC previously calculated by Datum Statics Calculation* When these statics are imported to the SIN and SRF Ordered Database Files. Datum Statics Apply creates the necessary database entries. Recall: NMO_STAT = S_STATIC + R_STATIC + C_STATIC. For this class. Use the ASCII file import option in XDB Database Display to create entries which may be accessed by Datum Statics Apply. Refer to the helpfiles for additional statics related information. Landmark ProMAX 2D Seismic Processing and Analysis 7-9 . Use either Datum Statics Apply.Chapter 7: Elevation Static Corrections Apply User Statics If shot and receiver statics to a final datum have been calculated outside of ProMAX. Caution: Apply User Statics is an alternate method for applying datuming type statics. you will import static data calculated elsewhere. therefore. This will allow you to see both the ASCII import and export portions of the database. or Apply Refraction Statics. the statics can be incorporated into a processing flow. you will use the XDB Database ASCII Save functionality to output an ASCII file of shot and receiver statics created in the previous exercise. Apply User Statics. but only one. Only one of the datuming processes should be run on a dataset. and partitions these imported statics into NMO_STAT and FNL_STAT. Apply External Statics In this exercise. The sample period multiple portion of NMO_STAT is applied to the traces by Datum Statics Apply. and then apply it to your trace data. and the remainder is stored in NA_STAT to be applied later. no ASCII format statics file is available. You will then import these statics back to the database. Select User-defined File in the popup window and enter a full directory path and filename without an extension. • 7-10 ProMAX 2D Seismic Processing and Analysis Landmark . Step 2 . Select ASCII ¦ Save from the global commands to get the following window. bring up DBTools with the Database global command in the flows window. (The extension. and attribute name appear. You now have ASCII files that are ready to import in the next part of the exercise. Repeat this entire procedure to save S_STATIC to an ASCII file. and then select Database ¦ XDB Database Display. Bring up the attribute selection by Database ¦ Get. select Cancel from the ASCII save window. When finished. To initiate the save procedure. Enter your own description or accept the default description and click on OK to create the ASCII file.) Select OK. • 1 2 • Step 1 . in this case R_STATIC.a_db is created by the program. filename.Chapter 7: Elevation Static Corrections 1. Place a copy of the statics file in a directory.Click on the attribute name. create one with the database ASCII save function. This attribute can now be saved to an ASCII file.The defined path. • Since no ASCII statics file is available. accessible by ProMAX. . Display SRF: R_STATIC. Chapter 7: Elevation Static Corrections 2. Columns for Location Index numbers (station numbers) are painted using MB2 and highlight in red. The included rows will highlighted black. 3. Click OK and the contents of the ASCII file are displayed. select the Order (SRF or SIN). The rows and columns containing the values to be imported are identified one of two ways: • Rows can be painted by holding down MB1 and moving the mouse over all rows. • 6. Columns for Attributes (statics values in this example) are painted using MB3 and highlight in blue). Select ASCII ¦ Client from the menu bar. The ASCII/CLIENT path is a generic ASCII file import functionality. Infotype (GEOMETRY). Click on File and enter the full path and filename (including extension) of the ASCII file. 4. Click on Location Index and then define the rows and columns to import. 5. Click on Display. Once the ASCII file is displayed. Landmark ProMAX 2D Seismic Processing and Analysis 7-11 . and Attribute (USERSTAT). Click on any of the Rows or Columns buttons and you will be prompted to manually enter starting and ending values. This displays the data you defined on import. Click Cancel in the Client ASCII Import window.2-Apply Datum Statics. Wait a moment and click OK in the acknowledgment window.” Replace the static values in Datum Statics Apply with the user statics. Enter your description of the USERSTAT attribute “R_STATIC USER” and select OK. 8. Your USERSTAT values are now saved in the Database. Copy flow “4a. Save the new attribute in the database. Editing Flow: 4a. Click on USERSTAT in the On-Screen Attributes to save window.Chapter 7: Elevation Static Corrections You will be prompted for an attribute description. Be sure you complete the ASCII Import steps for both shot and receiver ASCII files. then select Database ¦ Save from the main menu bar. 7.3-Apply User Statics Add Delete Execute View Exit Disk Data Input Trace Kill/Reverse Trace Kill/Reverse Trace Muting True Amplitude Recovery F-K Filter Spiking/Predictive Decon Datum Statics Apply Source datum statics database parameter: --------------------------------------------SIN GEOMETRY USERSTAT Receiver datum statics database parameter: ------------------------------------------SRF GEOMETRY USERSTAT CDP datum statics database parameter: -------------------------------------------------CDP GEOMETRY C_STATIC Disk Data Output Output Dataset Filename: -----Shots-decon/user statics 7-12 ProMAX 2D Seismic Processing and Analysis Landmark . The trace headers are updated and the are traces shifted to the floating datum. and NA_STAT using the Header icon. These are partitioned into the database parameter C_STATIC and into the trace header value FNL_STAT. Datum Statics Apply will know to use the user_stat_math file for the Database Math Method. TOT_STAT. FNL_STAT. Landmark ProMAX 2D Seismic Processing and Analysis 7-13 . Examine the trace headers for NMO_STAT. 11. 10.1-View Shots”. The user_stat_math file generates S_STATIC and R_STATIC by copying the SRF and SIN USERSTAT values that were imported to the database. Once the job finishes view the shots with flow “1.Chapter 7: Elevation Static Corrections 9. Execute the flow. Chapter 7: Elevation Static Corrections Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • • • What are Elevation Statics What is a good smoother for the Processing Datum How do you Calculate and Apply Elevation Statics Can you Import and Apply User Statics 7-14 ProMAX 2D Seismic Processing and Analysis Landmark . You will then use this field to apply NMO and create a stack.Chapter 8 Brute Stack In this chapter you will import a velocity field. Topics covered in this chapter: t RMS Velocity Field ASCII Import t Brute Stack with Elevation Statics t Display Stack Landmark ProMAX 2D Seismic Processing and Analysis 8-1 . Chapter 8: Brute Stack Chapter Objectives 5. Brute Stack This chapter creates you first QC stack of the data. Upon completion of this chapter you should: • • Understand how to Import Velocities Understand the NMO and Stack Parameters 8-2 ProMAX 2D Seismic Processing and Analysis Landmark . You may want to build a stacking (RMS) velocity parameter table from a pre-existing field. This opens a parameter table editing window in the form of a spreadsheet. 5. The following exercise allows you to import an ASCII RMS velocity field to build the parameter table. 1. 4. Click on Create. From the Flows menu select Tables. Do not click on Add. Select the VEL (RMS (stacking) Velocity) table This will take you to the RMS velocity table menu. Use a name similar to “imported from ascii file”. 3. Enter the description name for your imported velocity. A list of possible parameter tables will appear. 2. Use the scrollbar located on the right-hand side of the window to scroll to the bottom of the list. Landmark ProMAX 2D Seismic Processing and Analysis 8-3 .Chapter 8: Brute Stack RMS Velocity Field ASCII Import One critical part of the pre-stack sequence is to apply normal moveout. ) 8. and the contents displayed in the Import viewing window. Click on the File ¦ Import pull down menu. 7.Chapter 8: Brute Stack 6. (/misc_files/2d/*. Click on Filter. Input the absolute path name to the directory where the velocity file is stored and append a /* to the end of the pathname. This opens two new windows. Select the file as indicated by your instructor and click on OK. The ASCII file is opened. an empty viewing window and a File selection window. 8-4 ProMAX 2D Seismic Processing and Analysis Landmark . 10.Chapter 8: Brute Stack 9. A format window will open. Click on OK. Enter a new format definition name “Vels Import Format” or select a previously defined format (you probably do not have any yet). 11. Landmark ProMAX 2D Seismic Processing and Analysis 8-5 . 12. Click on Format. Click on CDP and then drag the mouse over the appropriate columns on the import file window to define the correct columns for the CDP value. 15. 8-6 ProMAX 2D Seismic Processing and Analysis Landmark . Continue to define column numbers for Time and Vel_rms. This will open an ‘Apply Import’ window.Chapter 8: Brute Stack 13. 14. Click on Apply. NOTE: You do not have to select the rows to import since the database will search for valid CDP numbers with associated velocities. Select “Overwrite ALL existing values with new import values” and OK. 19.Chapter 8: Brute Stack This will load the values into the table: 16. 21. 20. Check the table for correctness by going back to the list of tables from the User Interface and select to Edit the table. Verify that the file has been saved properly. Landmark ProMAX 2D Seismic Processing and Analysis 8-7 . The XCOOR and YCOOR columns are ignored for 2D. 17. 18. Click on File ¦ Exit to save the parameter table and exit from the editor. Click on File ¦ Abort to exit from the editor. Click on Edit and then select the table name. 5 Apply final datum statics after stack? -------------------Yes Has NMO been applied?: --------------------------------------Yes Disk Data Output Output Dataset Filename: -------------------STK-elev statics 8-8 ProMAX 2D Seismic Processing and Analysis Landmark . 1. Editing Flow: 5. Apply any remaining static during NMO?: --Yes Long offset correction?:--------------------------------------NONE Anisotropy correction parameter eta:------------------------0.1-Stack Add Delete Execute View Exit Disk Data Input Select dataset: ----------------------Shots-decon/elev statics Trace read option: -----------------------------------------------Sort Interactive Data Access: -----------------------------------------No Select primary trace header entry: -----------------------CDP Sort order for dataset: ---------------------------------------------*/ Trace Display Label Trace label: ---------------------------------------elevation statics Normal Moveout Correction Direction for NMO application: --------------------FORWARD Stretch mute percentage: --------------------------30.Chapter 8: Brute Stack CDP/Ensemble Stack You will now use the CDP/Ensemble Stack process to create a stacked section of the data with elevation statics. Apply partial NMO?: ----------------------------------------------No Get velocities from the database?: -------------------------Yes SELECT Velocity parameter file: --------------------------------------------------------------------imported from ascii file CDP/Ensemble Stack Sort order of input ensembles: ------------------------------CDP METHOD for trace summing: ------------------------------Mean Root power scalar for stack normalization: -------------0. Build the following flow. Apply Normal Moveout Correction. Execute the flow. Stack the data with CDP/Ensemble Stack. Select the imported velocity file. select your shots with elevation statics applied. 7. Add a trace display label. In Disk Data Input. 5. 4. Landmark ProMAX 2D Seismic Processing and Analysis 8-9 . Write a new stacked dataset to disk. and sort by CDP. 6. 3.Chapter 8: Brute Stack 2. Chapter 8: Brute Stack Display Stack 1. Execute the flow.2-Display Stack Add Delete Execute View Exit Disk Data Input Select dataset: -----------------------------------STK-elev statics Automatic Gain Control ----Default all parameters---- Bandpass Filter Ormsby filter frequency values: -----------------. Build the following flow to display your stack.3-6-50-60 ----Default all other parameters---- Trace Display Primary trace LABELING header entry: --------------NONE Secondary trace LABELING header entry: ------------CDP 2. Editing Flow: 5. 8-10 ProMAX 2D Seismic Processing and Analysis Landmark . You may also stack and display the user statics dataset “STK-user statics” as a QC. 4. Exit the flow.Chapter 8: Brute Stack 3. View the stacked dataset. 5. Landmark ProMAX 2D Seismic Processing and Analysis 8-11 . Chapter 8: Brute Stack Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • Can you import Velocities Do you understand the NMO and Stack Parameters 8-12 ProMAX 2D Seismic Processing and Analysis Landmark . The neural network compares various attributes of the correct pick to other possible picks within a window. are all pattern recognition problems and lend themselves to the application of neural networks. typically tedious processing steps. Topics covered in this chapter: t Interactive Neural Network (NN) First Break Training/Picking t Batch Neural Network (NN) First Break Picking Landmark ProMAX 2D Seismic Processing and Analysis 9-1 . trace editing. For First-break picking and trace editing. and reversed trace selection. Advantages of this algorithm include decreased network learning time and the ability to incrementally add to an existing network.Chapter 9 Neural Network First Break Picking Artificial neural networks have had excellent results solving pattern recognition problems. ProMAX uses a Cascade-Correlation Learning Architecture. First break picking. The network recognizes the ability of an attribute to predict the correct pick and accordingly weights the network connection to that attribute. Upon completion of this chapter you should: • • Understand how to Pick First Breaks Be able to Train the Neural Network 9-2 ProMAX 2D Seismic Processing and Analysis Landmark . First break picks are a required input to the refraction statics algorithms. Refraction Statics Pick First Breaks This chapter serves as set-up for Chapter 10 “Refraction Static Corrections.Chapter 9: Neural Network First Break Picking Chapter Objectives 4b.” Refraction statics are necessary in areas of severe topography or areas of complex weathering zones. 20/ Trace Kill/Reverse ----Use the same parameters as before---- Trace Kill/Reverse ----Use the same parameters as before---- True Amplitude Recovery ----Use the same parameters as before---- Trace Display ----Default all parameters for this process---2. and you can QC these picks using Trace Display. and your dataset matches the database. Kill and reverse appropriate traces and apply true amplitude recovery before picking first breaks. Do not apply Trace Muting.Chapter 9: Neural Network First Break Picking Interactive NN First Break Training/Picking The first break picker in Trace Display gives you the opportunity to interactively create and train a neural network to pick first breaks.2-Apply Datum Statics” and add/delete/edit processes so that it looks like the following: Editing Flow: 4b. You will manually pick some first breaks and use these picks to train a neural network. NOTE: The NN First Break Picker menu in Trace Display only appears if geometry is defined. Landmark ProMAX 2D Seismic Processing and Analysis 9-3 . Interactive Training 1. The neural network will then try to pick first breaks on selected shots.1-NN First Break Picking Add Delete Execute View Exit Disk Data Input Select dataset: ----------------------------Shots-with geometry Trace read option:------------------------------------------------Sort Interactive Data Access?: --------------------------------------Yes Select primary trace header entry: -------------------------SIN Sort order for dataset: ----------------------------------1. Copy your flow “4a. You can check if geometry matches the database vie MB2 under the Dataset listing from the Flows menu.10. Chapter 9: Neural Network First Break Picking 3.. “fb_weight”) or. “test nn picks”) Trace Display -> FirstBreakPicker -> NO Purge Neural Net Delete (MB2) “test nn picks” Are the NN picks good? YES Do you want to continue to “Train” the Neural Network? NO YES Go to next gather Use Neural Network to pick every shot Interactive NN FB picking Trace Display -> FirstBreakPicker -> Neural Net Recall -> Continuous Recall Batch NN FB picking Exit Trace Display Run NN First Break Picker Run Trace Display QC and Edit the NN FB picks on every shot 9-4 ProMAX 2D Seismic Processing and Analysis Landmark . if continuing “Training”. Run Trace Display “Train” the Neural Network Trace Display -> FirstBreakPicker -> Set Neural Network Parameters Create Training Dataset Create a new time gate parameter file Pick or edit a set of good picks to store in “FB Training Data” Pick or edit the time gate centered on the “FB Training Data” Neural Net Training Create a new NN weight table (e.g.. Execute the flow to begin the NN sequence. Use the existing NN weight table Use Neural Network to make FB picks Trace Display -> FirstBreakPicker -> Neural Net Recall -> One time Recall Create a new OPF parameter file (e.g. Select the pick polarity and the signal/noise gate length. A second window will appear for selecting a secondary key. It is not necessary to make a pick on every trace. Select the “nn first break gate” table from the Pick Layers window. and select OK. Type in a name “nn first break gate” for your first break time gate. may key off of instantaneous phase/frequency. select FirstBreakPicker ¦ Create Training Data set. From the main menu bar.” 6. and pick the top of the gate. The neural network works well with peaks and a gate length of 100 ms. Landmark ProMAX 2D Seismic Processing and Analysis 9-5 . The Picking tool icon appears on the left side of the display. however. To pick the bottom of the gate click MB3 in the data window and select New Layer. or any other pattern it can recognize. as the gate is interpolated between picks. and then OK. 5. amplitude before or after the first break. From the main Trace Display menu bar. Usually picking about 25ms above the first break. Choose AOFFSET. The neural network itself. A First Break NN Dataset window appears.Chapter 9: Neural Network First Break Picking 4. but not be so large as to lengthen execution time. at timing line intersection works quite well. The following menu will appear. It will be helpful to Zoom in on the first breaks before picking. The network tries to follow the slope of the top gate when picking first breaks. The gate should contain at least three peaks. Select OK to accept these parameters. so it is necessary that the top gate closely follows the trend of the first breaks. There will be two entries in the Pick Layers box: “FB Training Data” and the “nn first break gate. select FirstBreakPicker ¦ Set Neural Network Parameters. This means you do not need many picks to begin training. Click on “FB Training Data” in the Pick Layer window and manually pick the first breaks. as more picks can be added in future training runs. Pick first breaks on 20-30 traces. Use MB3 to select the Snap to peak option. Because training is interactive you can incrementally train the network. 9-6 ProMAX 2D Seismic Processing and Analysis Landmark .Chapter 9: Neural Network First Break Picking 7. More picks means longer training time. First Break Picks Top of time gate Bottom of time gate Manually pick first breaks using MB1. A First Break NN Training window appears. When the cursor changes back to an arrow. training is complete. Landmark ProMAX 2D Seismic Processing and Analysis 9-7 . From the menu bar. Create a new table “weight1” and select OK.. including a list of First Break Weight Tables. The network will be trained using your picks. 9. After picking. select FirstBreakPicker ¦ Neural Net Training. While the network is training. the cursor will change from an arrow to a wristwatch. select FirstBreakPicker ¦ Neural Net Recall ¦ One Time Recall.Chapter 9: Neural Network First Break Picking 8.. To modify training picks. click on the Picking tool icon. 7. Set Neural Net Recall to Continuous and click the Next ensemble icon to go to the next shot. enter 1000 for the offset to start picking. and use the same weight table. Create a new OPF called “NN training test picks” for the name. select First Break NN Training. If the picks are bad. If you still cannot get satisfactory results. Select OK.Chapter 9: Neural Network First Break Picking The One time Recall option applies the neural network to the currently displayed gather. Remove the table from the list and activate the FB Training Data. The Neural Network is applied to the current gather display. and 8 until you are satisfied with the results. modify your FB Training Data and retrain the network. Iterate through steps 6. You will be prompted to either choose an Ordered Parameter File(OPF) from the list. or create a new OPF for storing picks. try purging the Neural Network (FirstBreakPicker ¦ Purge Neural Net) and starting over. 10. and default all other parameters. Your new table of picks appears in the Pick Layers window. 11. The results of the picking are displayed. A First Break NN Recall window appears. 9-8 ProMAX 2D Seismic Processing and Analysis Landmark . Modify or add to these training picks. and choose to save edits before exiting.Chapter 9: Neural Network First Break Picking You can retrain if necessary. Landmark ProMAX 2D Seismic Processing and Analysis 9-9 . and time gates are saved and can be used in the batch NN First Break Picker process to pick the entire dataset. or if you think the picks are close enough. select File ¦ Exit/Stop Flow. The weight table. Chapter 9: Neural Network First Break Picking Batch Neural Network First Break Picking This step uses the neural network weight matrix to pick first breaks on all shots.0001 9-10 ProMAX 2D Seismic Processing and Analysis Landmark . 1. neural network picks are stored in the ordered database and can be accessed for various uses including refraction static analysis. In the case of first-break picking. Alter the existing flow as follows: Editing Flow: 4b. Now we will use these as input to the NN First Break Picker to pick all shots in batch mode.1-NN First Break Picking Add Delete Execute View Exit Disk Data Input Select dataset: ----------------------------Shots-with geometry Trace read option: --------------------------------------------Get All ----Default all other parameters---- Trace Kill/Reverse Trace Kill/Reverse True Amplitude Recovery >Trace Display< NN First Break Picker Select weight matrix parameter file: ----------------weight1 Number or traces in median line fit: --------------------------5 Maximum trace to trace static:---------------------------------20 Starting offset to determine first break pick slope: 1000 Select time gate parameter file: -------nn first break gate First break storage: ------------------Header and Database 4 digit ID to store pick time in TRC database: -----. and a time gate. we interactively created and saved a fb_weight matrix file. Pick First Breaks for entire survey In the previous exercise. Input the fb_weight matrix “weight1” file. and PICK0001 (the 12345678 picks are from the interactive picker) from the OPF File Selector. and “Trace Display” active. Select NN_PICK as the Infotype. Execute the flow. The easiest way to view and edit your picks is to use the first break editing capabilities of the Refraction Statics process in the next chapter. In Disk Data Input. Specify an offset with good S/N and no shingling of refractors. Data dependent parameter selections are based on testing or experience. Some preprocessing may be necessary. select Picking ¦ Edit Database Values (first breaks). QC your picks. and execute the flow. Also do not worry about zero picks on the dead traces. Don’t spend too much time editing picks here. filtering. input your entire dataset. Preprocessing is the same as input to the interactive NN First Break Pick Training. From the menu bar in the Trace Display window. Landmark ProMAX 2D Seismic Processing and Analysis 9-11 . 4. For this data.Chapter 9: Neural Network First Break Picking 2. such as trace edits. You must specify a starting offset for the picker. 3. Once the picker is completed. 5. scaling. an offset value of about 1000 ft. and toggle “NN First Break Picker” inactive... Parameters are consistent with those for the interactive NN FB Pick Training. is adequate. Select NN First Break Picker parameters. Edit the same flow. and use the same name to save edits. Chapter 9: Neural Network First Break Picking Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • Can you Pick First Breaks Do you know how to train the Neural Network 9-12 ProMAX 2D Seismic Processing and Analysis Landmark . Topics covered in this chapter: t Refraction Statics t Refraction Statics Calculation .Chapter 10 Refraction Static Corrections This section covers the steps for calculating and applying refraction statics. Once these attributes are in the database the refraction statics processes can fill them in with more accurate static values than simple elevation static calculations. First break picks are required as input into this process.coordinate based t Apply Refraction Statics t Stack with Refraction Statics Landmark ProMAX 2D Seismic Processing and Analysis 10-1 . The refraction statics processes expects R_STATIC and S_STATIC to be present in the database. The recommended method to create R_STATIC and S_STATIC database entries is to run the process Datum Statics Calculation*. before running the refraction statics processes. ” Refraction statics are necessary in areas of severe topography or areas of complex weathering zones. Upon completion of this chapter you should: • • • Understand the difference between Refraction and Elevation Statics Be able to Calculate Refraction Statics Be able to Apply Refraction Statics 10-2 ProMAX 2D Seismic Processing and Analysis Landmark . Refraction Statics Pick First Breaks This chapter serves as an alternative to Chapter 7 “Elevation Statics Corrections.Chapter 10: Refraction Static Corrections Chapter Objectives 4b. Solutions are calculated by three methods: Generalized Reciprocal Method (GRM). and Diminishing Residual Matrices (DRM). velocity and delay time editing. therefore it is not applicable to crooked lines. The final results of this process are a near-surface depth/velocity model and travel-time corrections to the final datum written to the database. NOTE: First breaks must be picked and written to the database prior to this exercise. Results of this exercise will be used by Datum Statics Apply in a later exercise. Crooked may be defined as any line with a greater than 15 degree bend.Chapter 10: Refraction Static Corrections Refraction Statics ProMAX provides an interactive interface for final editing of first-break picks. Each solution is written to the database. NOTE: This process does not use XY values. This process calculates shot and receiver refraction statics to shift to the final datum and updates the database. refer to the Refraction Statics Calculation* process described later in this chapter. giving you the option of selecting the most appropriate solution. If you are calculating refraction statics on a crooked line. Landmark ProMAX 2D Seismic Processing and Analysis 10-3 . Standard Delay Time (DLT). Refraction Statics .2D In this exercise you will use the Refraction Statics* process and firstbreak pick times to calculate a near-surface model and travel-time corrections. Please refer to the Neural Network First Break Picking exercise earlier in this manual. layer assignment. Chapter 10: Refraction Static Corrections 1. Build the following flow: Editing Flow: 4b.2-Refraction Statics Add Delete Execute View Exit Refraction Statics* Select display DEVICE: -----------------------------This Screen Select First Break Times file: -TRC:NN_PICK:PICK0001 Get LAYER Picks from DATABASE: -------------------------No Get Refractor Velocities from DATABASE: ----------------No Select TRACE data file: ---------------Shots-with geometry Compute V0 from UPHOLE data?: -------------------------Yes Number of layers: ----------------------------------------------------1 Use Delay Times in velocity/depth model?: ------------Yes Use Deep Hole delay time algorithm?: ---------No Use GRM in velocity/depth model?: -----------------------Yes Specify GRM minimum XY distance: -------------0. and a replacement velocity of 8000 ft/sec. Specify GRM XY distance increment: ----------55. Input trace data will be the raw shots. Enter a final datum of 800 ft. Final datum Elevation: -----------------------------------------800 Replacement Velocity: ----------------------------------------8000 Use Uphole Time in source statics algorithm?: ---------No 2. 10-4 ProMAX 2D Seismic Processing and Analysis Landmark . Specify GRM maximum XY distance: ------------0. Picks are typically in the database in the TRC order and NN_PICK Infotype. Select the batch PICK0001 file for this exercise. Select your first break pick file. Select Refraction Statics parameters. Follow the normal sequence from top to bottom using mouse button helps. Landmark ProMAX 2D Seismic Processing and Analysis 10-5 . Execute the flow.Chapter 10: Refraction Static Corrections 3. A menu appears with a list of options. however. or MB3 to move backwards. Use the mouse button helps to guide your editing. This could lead to up to a 4ms pick error. and provide a name “RefrEdit” for the pick file. Residual statics. Warning: The editing in this function currently snaps to a sample and not necessarily the true peak. Select Yes to Output Updated Picks to the Database. should correct for these slight errors.Chapter 10: Refraction Static Corrections 4. Click MB2 below the data to move to the next set of shots. To guide your editing you may want to turn on the seismic by toggling on Add Traces. 10-6 ProMAX 2D Seismic Processing and Analysis Landmark . Click on Edit Picks. Use the Edit Picks option for final editing of first-break picks prior to inversion. Select Done to go back to the main menu. use the options on the right side of the screen to edit your data. Landmark ProMAX 2D Seismic Processing and Analysis 10-7 . Click on Define Layers. Note: The displayed velocity is only a guide. Define the offset range for each layer by holding down and dragging MB1 over the corresponding range. as in the case of split spread shooting. Select Done and then Yes to Output Refractor Picks to Database. you are not assigning a velocity for the layer. The velocity you get should be on the order of 7500 f/s. This is an interpretive process.Chapter 10: Refraction Static Corrections 5. Also avoid low S/N areas. then releasing MB1. This option displays pick times for both sides of the spread. Avoid inflection points where refractors are shingling. Editing or smoothing of the velocity values is done only in the bottom display which is a zoomed version of the top display. This option provides for interactive editing of the weathering velocity and the calculated velocity model for each refractor. Select a velocity to edit by selecting the appropriate box in the upper right. and Yes to Output Refractor Velocities and V0 to Database. Perhaps there is a problem in V0 resulting from questionable uphole times? You may want to smooth through V0 or replace it with a constant 5000 f/s.Chapter 10: Refraction Static Corrections 6. The plotted points represent the layer number and are color coded by the calculation method used. such as Edit V1. station. Select Done when editing is complete. The top display is a graph of velocity vs. Refer to mouse button helps for editing functionality. Click on Refractor Velocity. 10-8 ProMAX 2D Seismic Processing and Analysis Landmark . Refer to mouse button helps for editing functionality. Editing of the intercept values is done in the bottom display. You will first view/edit Receiver Delay Time Solutions. Select Yes to view either Receiver Delay Time corrected Shot Records or Source Delay Time corrected Receiver Records. Select Done when editing is complete. This option allows interactive editing of the calculated intercept times for each layer.Chapter 10: Refraction Static Corrections 7. then Source Delay Time Solutions. station. Landmark ProMAX 2D Seismic Processing and Analysis 10-9 . Click on View Static Solutions. depending on what you edited. Select Done when finished viewing. The top display is a graph of intercept time vs. Select Done and Yes to Output Refractor DEPTHS to Database. Click on Refractor Depth Model. This option allows viewing the calculated near-surface depth model. Although there is editing functionality in this option.Chapter 10: Refraction Static Corrections 8. if the depth model is not geologically possible you may want to re-edit first break picks. velocities or intercept times. 10-10 ProMAX 2D Seismic Processing and Analysis Landmark . calculated from the velocity and intercept data. Notice how the GRM method falls short where there are no sources for the reciprocal method to calculate the receiver static. and then rerun this step. If you choose to re-edit. Landmark ProMAX 2D Seismic Processing and Analysis 10-11 . Receiver statics from the elevation of the receiver through the model to final datum are displayed with the character “r”.Chapter 10: Refraction Static Corrections 9. This option allows viewing the shot and receiver statics calculated from the model data. Source statics from the elevation of the shot through the model to final datum are displayed with the character “s”. Select Exit. be sure to step through all subsequent options to correctly recalculate your final statics. click MB2 on any previous box to view its current values or MB1 to re-edit those values. 10. NOTE: In the main menu. Click on Output Statics. Select Yes to Output STATICS to the DATABASE. In the Statics Infotype. there are incremental statics that represent the difference between the total refraction statics. The Order is SRF or SIN. access the database with the Database global command option. and the original elevation statics. You can also go the XDB Database Display to overlay the static values. and the Infotype for the total static is Geometry. This is the value that will be used by the process Datum Statics Apply. To view the calculated refractor depths and statics solutions simply double click on the appropriate attribute. Exit the current flow. From the Flows window. To the right of the attributes are detailed descriptions of each.Chapter 10: Refraction Static Corrections 11. 10-12 ProMAX 2D Seismic Processing and Analysis Landmark . NOTE: First break times must be picked and written to the database prior to this exercise. First break picks are not required for every shot. and refractor velocities and depths and velocities will be computed for each layer. This process calculates shot and receiver refraction statics to shift to the final datum and updates the database. The source and receiver static solutions are applied to the data in a future step. Results of this exercise will be used by Apply Refraction Statics in the next exercise. By picking a Pick Top Mute in Trace Display. Apply Refraction Statics. There are many advantages to using this technique: • • • Very robust for noisy first break picks. There is also an option to edit first break pick files automatically. a near-surface depth/ velocity model and travel-time corrections to the final datum from offset and first break information. Please refer to the Neural Network First Break Picking exercise earlier in this manual. Works independent of shooting geometry. As a part of this exercise you will see that there are two ways to enter the refractor offset ranges. In this exercise you will use first-break pick times to calculate a nearsurface model and travel-time corrections. These are: • • Manually. Landmark ProMAX 2D Seismic Processing and Analysis 10-13 . All of the preceding attributes are written to the database. The main disadvantages are that there is not a graphical interface for editing. Multiple layer models can be created.Chapter 10: Refraction Static Corrections Coordinate Based Refraction Statics ProMAX provides a coordinate based refraction statics algorithm that computes refractor velocities and delay times. MEAN Iterate refractor velocity?: -------------------------.2-Refraction Statics Add Delete Execute View Exit >Refraction Statics*< Refraction Statics Calculation* Select first break time file: -----TRC:NN_PICK:PICK0001 Number of layers: ----------------------------------------------------1 Identification number: ----------------------------------------------1 Minimum fold: ---------------------------------------------------------1 Shooting Geometry: -----------------------------2D split spread V0 options: -------------------Compute V0 from uphole data INPUT REFRACTOR OFFSET?: ----------------------------. Edit the current flow as follows: Editing Flow: 4b.Yes Refractor Offset specification: --------User typein Enter SIN and refractor offsets: -----------------------------------------------------10:-1800--500.Yes TYPE of delaytime ALGORITHM: -Gauss-Seidel Number of iterations: ------------------------------------5 TYPE of delay time computation: ----------.Yes Final datum Elevation: -----------------------------800 Replacement method: -----------Refractor Velocity COMPUTE RESIDUAL STATICS:? ----------------------------No 10-14 ProMAX 2D Seismic Processing and Analysis Landmark .Yes First refractor smoothing: -----------No smoothing COMPUTE SOURCE and RECEIVER STATICS?: ----.Chapter 10: Refraction Static Corrections 1.No COMPUTE REFRACTOR DEPTH MODEL?: ------------.Yes Type of INITIAL velocity computation: ---.MEAN Smooth INITIAL velocities before output?: ---Yes Length of INITIAL velocity smoother: ----------201 Edit first break times (median velocity?: ------No COMPUTE DELAY TIMES?: ----------------------------------.500-1800/ COOMPUTE REFRACTOR VELOCITIES?: -------------. SIN REFR_OFF OFFNGE11 ---Far negative offset of refractor. edit the uphole times. COMPUTE REFRACTOR VELOCITIES. You could then either smooth in the database (Good to see immediate results of smoothing).Chapter 10: Refraction Static Corrections 2. 3. Select the first break time to use for the statics decomposition. In this exercise we’ll compute V0 from uphole times and manually type in the refractor OFFSET range. Select Refraction Statics Calculation* parameters. SIN REFR_OFF OFFPSE11 ---Far positive offset of refractor. These time picks will be in the TRC OPF and will normally be of the type NNPICK. INPUT V0 and REFRACTOR OFFSET. If you have output an edited pick file. you may wish to look at your model in the database before smoothing. it will be stored with an infotype of FBPICK. SIN REFR_OFF OFFNGS11 ---Near negative offset of refractor. The shooting geometry is 2D split spread. If you want to make a permanent change. Enter the number of layers to model. These database attributes may be edited. SIN VELOCITY V0INIT11 ----Weathering Velocity. Select the PICK0001 file. They may all be turned on for refraction statics computation or you may select to run one option at a time and view the output in the database. or define a smoother in the menu. The identification number will be 1 for the first run through the process. Landmark ProMAX 2D Seismic Processing and Analysis 10-15 . Three database entries are created in the SIN OPF: SIN REFR_OFF OFFPSS11 ---Near positive offset of refractor. The V0INIT11 is written over each time you rerun the module. in this case use one layer. There are 5 steps to Refraction Statics Calculation* described in the menu. With this subheading turned on a refractor velocity is calculated based on the first break times and the offset range from the previous step. 4. Although you can smooth the velocity model in the menu. SRF or CDP that does not meet the minimum fold (menu parameter) criterion. followed by receiver delay time estimates. Remember to examine this edited file. TRC F_B_PICK FBPEDIT1 ----Edited first break pick file.CDP velocity for 1st refractor. 10-16 ProMAX 2D Seismic Processing and Analysis Landmark . delay times for shots and receivers may be computed. these missing values are interpolated based on X and Y. CDP VELOCITY VCFIN011---. Once CDP velocity is available. Only the good picks will be included in this file. where X is the run identification number. and (optionally) finalized by CDP velocity updating. These database attributes may be edited. If any picks deviate more than the selected amount they will be killed. Three database entries are created. SIN DELAYTIM SDELAY11----Source Delay times. Values are not computed for any SIN.Chapter 10: Refraction Static Corrections There is also an option to edit the first break picks automatically by setting a deviation from the median velocity described by the offsets. SIN VELOCITY VSINIT11 ----Source velocity for 1st refractor. COMPUTE DELAY TIMES. starting with source delay time estimates. Three database entries are created. SRF DELAYTIM RDELAY11--. and set to NULL in a new first break picks database file TRC F_B_PICK FBPEDITX.Receiver delay times. Once the decomposition is complete for each refractor. This is done by iteration. 5. CDP VELOCITY VCINIT11 -.Final CDP velocities. interpolates refractor velocity into SIN and SRF. 7. computes source and receiver depths to the FINAL datum of 800 feet and outputs static values. SIN REFDEPTH SDEP_011---Source Refractor Depth. SIN GEOMETRY SSTAT00X ----Source statics.Chapter 10: Refraction Static Corrections 6. Two database entries are created. We have the choice of inputting a constant velocity or the bottom refractor velocity. SRF VELOCITY V0FIN011 ---Final Weathering Velocity. Landmark ProMAX 2D Seismic Processing and Analysis 10-17 . the first refractor depth in SRF may be projected into CDP. Optionally. The statics computation stage inputs refractor velocities and refractor depths. computes a depth model for sources and another for receivers. SRF VELOCITY VRFIN011. smoothed. SRF GEOMETRY RSTAT00X --. SIN VELOCITY VSFIN011 -. new V0 projected from SRF to SIN. COMPUTE SOURCE AND RECEIVER STATICS. SRF REFDEPTH RDEP_011--Receiver Refractor Depth. For this exercise choose a user specified value of 8000 ft/sec. projected back into SRF.Final Source velocity for 1st refractor.Final Receiver velocity for 1st refractor. and finally SIN and SRF depth models computed. COMPUTE REFRACTOR DEPTH MODEL..Receiver statics. V0 recomputed in SRF based on the smoothed depths. The depth model stage inputs delay times and refractor velocities in CDP. Six database entries are created. SIN VELOCITY V0FIN011 ---Final Weathering Velocity. It is important to note that the Datum Statics Apply process first checks to see if other statics have been applied to the traces by an earlier processing step. these header entries are updated and the integer multiple of a sample period portion of NMO_STAT is applied to the trace and the remainder is written to NA_STAT to be applied later. along with elevations from the database to compute NMO_STAT and FNL_STAT. C_STATIC is set to zero. 10-18 ProMAX 2D Seismic Processing and Analysis Landmark . and FNL_STAT is zero because your data will already be at the final datum. This process updates the statics trace headers and applies the shifts to each trace. Therefore.Chapter 10: Refraction Static Corrections Apply Refraction Statics The Datum Statics Apply program uses refraction statics computed by the Refraction Statics* or Refraction Statics Calculation* processes. Also. these statics are also removed and should be reapplied. The refraction statics to be applied must be calculated prior to running Datum Statics Apply. As with the previous methods. If statics are applied. if previous statics contained any hand statics or shot delay corrections. If the option to process to a final datum is selected. C_STATIC is zero. Datum Statics Apply is generally executed in a processing flow prior to velocity analysis. Datum Statics Apply first removes these statics returning the traces to their original recorded time reference. NMO_STAT becomes the static shifting traces to the final datum. Recall: NMO_STAT = S_STATIC + R_STATIC + C_STATIC. 2. The GRM method is not valid for this line since it is not split spread.) unless you want to change the smoother of N_DATUM. DRM Refraction Statics for Sources to Final datum.. or the replacement velocity. Datum Statics Apply will back out the elevation statics before it applies the refraction statics. • For Source statics.3-Apply Refraction Statics Add Delete Execute View Exit Disk Data Input Select dataset:-----------------------Shots-decon/elev statics Trace Read option:-------------------------------------------Get All ----Default all other parameters---- Datum Statics Apply Source datum statics database parameter: ---------------------------------------------SIN GEOMETRY SSTAT001 Receiver datum statics database parameter: ------------------------------------------SRF GEOMETRY RSTAT001 CDP datum statics database parameter: -------------------------------------------------CDP GEOMETRY C_STATIC Disk Data Output Output Dataset Filename: ------Shots-decon/refr statics ----Default all other parameters---NOTE: We do not have to recalculate the datum statics (. select your Source and Receiver statics... You will have an available list of parameters files. saved in Refraction Statics*. 1. Build the following flow: Editing Flow: 4b. In Datum Statics Apply.. the order is SIN and the Infotype is Geometry. You have the option of choosing the statics from any of the refraction statics calculation methods.Chapter 10: Refraction Static Corrections Apply Refraction Statics to your data.C_STATIC. Select one of the following statics files: GRM Refraction Statics for Sources to Final datum. the datum elevation. • • Landmark ProMAX 2D Seismic Processing and Analysis 10-19 . depending on your selection. Coordinate based. Use your previous flow “5. DRM Refraction Statics for Receivers to Final datum. Traces are shifted to the floating or final datum. 6. DLT Delay Time Refr. Add a new output dataset “Shots-decon/refr statics” 4.1-Stack” to stack the refraction corrected shots to a dataset “STK-refr statics”. • • • 3. 10-20 ProMAX 2D Seismic Processing and Analysis Landmark . Coordinate based. Display gathers with elevation statics applied instead of refraction statics and check these trace header values on the same trace. The GRM method is not valid for this line since it is not split spread. Select one of the following statics files: • GRM Refection Statics for Receivers to Final datum. 5.Receiver statics to Final datum from coordinate based method. Build a flow to display gathers with refraction statics applied and use the Header icon to check updated statics header entries. Statics-Receivers to Final datum. the order is SRF and the Infotype is Geometry.Chapter 10: Refraction Static Corrections • • DLT Refraction Statics to Final datum. Execute the flow.Source statics to Final datum from coordinate based method. Note the differences due to Datum Statics Apply. For Receiver statics. Chapter 10: Refraction Static Corrections Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • • What is the difference between Refraction and Elevation Statics How do you Calculate Refraction Statics When do you Apply Refraction Statics Landmark ProMAX 2D Seismic Processing and Analysis 10-21 . Chapter 10: Refraction Static Corrections 10-22 ProMAX 2D Seismic Processing and Analysis Landmark . This flow is used throughout the rest of the class to compare stack sections. Topics covered in this chapter: t Compare Stacks Landmark ProMAX 2D Seismic Processing and Analysis 11-1 .Chapter 11 Stack Comparisons In this chapter you will use Trace Display to compare two stacks. This technique is quite valuable in testing processing flows and parameters.Chapter 11: Stack Comparisons Chapter Objectives 5. Upon completion of this chapter you should: • Be able to graphically compare any two stacks 11-2 ProMAX 2D Seismic Processing and Analysis Landmark . Brute Stack In this chapter you learn a slick way to compare stack datasets. Landmark ProMAX 2D Seismic Processing and Analysis 11-3 . You may want to execute this flow again. Execute the flow.3-Compare Stacks Add Delete Execute View Exit Disk Data Input Select dataset: -----------------------------------STK-elev statics ----Default all other parameters---- Disk Data Insert Select dataset: ------------------------------------STK-refr statics ----Default all other parameters---- Automatic Gain Control ----Default all parameters---- Bandpass Filter Ormsby filter frequency values: -----------------.Chapter 11: Stack Comparisons Compare Stacks 1. use the animation tool to compare the stacks. After both stacks have been displayed.3-6-50-60 ----Default all other parameters---- Trace Display Primary trace LABELING header entry: --------------NONE Secondary trace LABELING header entry: ------------CDP ----Default all other parameters---2. The stack with elevation statics will appear first. Build the following flow to compare stacks: Editing Flow: 5. and display both stacks on a single screen. Use the Next ensemble icon to display the stack with refraction statics. Chapter 11: Stack Comparisons Chapter Summary Upon completion of this chapter you should be able to answer the following question: • How do you graphically compare two stacks 11-4 ProMAX 2D Seismic Processing and Analysis Landmark . Chapter 12 Velocity Analysis and the Volume Viewer Velocity Analysis provides comprehensive interactive velocity analysis, velocity quality control, and velocity field modification capabilities. Precomputing data at predefined locations is also supported to speed the interactive session. When used in the precomputed mode, the process reads in precomputed analysis data, as opposed to standard CDP-ordered data. This precomputed data is generated using Velocity Analysis Precompute. Preprocessing of data must be performed at the precomputing step. Topics covered in this chapter: t Velocity Analysis Precompute t Velocity Analysis t Volume Viewer/Editor Landmark ProMAX 2D Seismic Processing and Analysis 12-1 Chapter 12: Velocity Analysis and the Volume Viewer Chapter Objectives 6. Velocity Analysis Velocity analysis is a critical aspect of any processing workflow. This chapter explores one of ProMAX’s techniques of picking and quality controling velocities. Upon completion of this chapter you should: • • Comprehend the parameters input to Velocity Analysis Understand how to use the Velocity Analysis Viewer in conjunction with the Volume Viewer/Editor Be confident in picking reasonable stacking velocity functions • 12-2 ProMAX 2D Seismic Processing and Anlaysis Landmark Chapter 12: Velocity Analysis and the Volume Viewer Velocity Analysis Introduction Velocity Analysis is a InterProcess Communication tool (IPC tool); therefore, preprocessing of data can be performed in the same flow before passing the data on to the analysis. Velocity Analysis also allows random access to the dataset. With this feature, you can go back to the previously processed ensemble, rewind the data to the first CDP specified in the sort order for dataset, or go to any CDP in the dataset by specifying a new sort order. Velocity Analysis is used to quickly pick velocities with the semblance option. More detailed velocity information can be obtained by turning on the constant velocity strip option and the interval velocity display. Choice of the analysis locations is initially determined by selecting analysis locations using the Supergather Formation. Picks can be made on either the semblance plots or the constant velocity strips, and picks made on one display will appear on the other display. Velocity Analysis only processes single ensembles of data, such as CDPs or groups of CDPs. Creating supergathers prior to Velocity Analysis is often helpful to boost the fold in the ensembles and create more robust semblance calculations. Supergathers must be defined in a processing flow before input to Velocity Analysis or Velocity Analysis Pre-Compute. The Supergather Formation* Macro may be used to combine many CDPs. This will permit Velocity Analysis to read the combined CDPs for one analysis as one ensemble of data. Landmark ProMAX 2D Seismic Processing and Analysis 12-3 Chapter 12: Velocity Analysis and the Volume Viewer Velocity Analysis Precompute Precomputing data at selected locations is also supported to speed the interactive session. Velocity Analysis Precompute provides a means to prepare the data to be input to the Velocity Analysis module by calculating the semblance values, stacking the CDP traces to create the supergather, and creating CVS traces at predefined locations CDP. When used in the precomputed mode, Velocity Analysis reads in only the precomputed data, as opposed to standard CDP ordered data. Preprocessing of data must be performed at the precomputing step. Precomputing velocity analysis data can significantly speed up the interactive Velocity Analysis session, especially when a large number of CDPs are used to create the supergathers. 12-4 ProMAX 2D Seismic Processing and Anlaysis Landmark Chapter 12: Velocity Analysis and the Volume Viewer Precompute Velocity Analysis 1. Build the following flow to start Velocity Analysis Precompute: Editing Flow: 6.1-Velocity Precompute Add Delete Execute View Exit Supergather Formation* Read data from other lines/surveys?: ---------------------No Select dataset: -----------------------Shots-decon/refr statics Presort in memory or on disk?: -----------------------Memory Maximum CDP fold: ---------------------------------------------180 Minimum center cdp number---------------------------------825 Maximum center cdp number--------------------------------950 Cdp increment--------------------------------------------------------25 Cdps to combine-------------------------------------------------------9 Bandpass Filter Ormsby frequency filter values: -------------------3-6-50-60 ----Default all remaining parameters---- Automatic Gain Control ----Default all parameters for this process---- Velocity Analysis Precompute Disk Data Output This flow is continued on the next page Landmark ProMAX 2D Seismic Processing and Analysis 12-5 Chapter 12: Velocity Analysis and the Volume Viewer Editing Flow: 6.1-Velocity Precompute Add Delete Execute View Exit Supergather Formation* Bandpass Filter Automatic Gain Control Velocity Analysis Precompute Number of CDPs to sum into gather: --------------------------9 Apply partial NMO-to-binning:--------------------------------Yes Apply differential CDP mean statics?:---------------------Yes Absolute offset of first bin center: -------------------------27.5 Bin size for vertically summing offsets: -------------------55 Maximum offset: ---------------------------------------------6572.5 Use absolute value of offset for stacking?: --------------Yes Minimum semblance analysis value: -------------------7000 Maximum semblance analysis value: ----------------20000 Number of semblance calculations:--------------------------50 Semblance sample rate (in ms): ------------------------------20 Semblance calculation window (in ms): -------------------40 Number of stack velocity functions: -------------------------17 Number of CDPS per stack strip---------------------------------5 Scale stacks by number of live samples summed:---Yes Method of computing stack velocity functions:-----------------------------------------------------------Top/base range Velocity variation at time 0: ---------------------1000 Velocity variation at maximum time:---------3000 Velocity guide function table name:-----------------------------------------------------------------imported from ascii file Maximum stretch percentage for NMO: --------------------30 Long offset moveout correction?:-------------------------NONE Disk Data Output Output Dataset Filename: -----------------------------------------------------------------Precomputed Velocity Analysis 12-6 ProMAX 2D Seismic Processing and Anlaysis Landmark Chapter 12: Velocity Analysis and the Volume Viewer 2. Select your best prestack dataset for Supergather Formation. Supergather Formation is a macro that reads the data as CDP’s, and combines them into supergathers. Data should be preprocessed gathers without NMO. Set the Maximum CDP fold to 180 (9 CDPs times 20 fold per CDP). Set the Min and Max CDP centers to 825 and 950 respectively. Set the CDP increment to 25. This will give you six analysis locations with supergathers starting at CDPs 825, 850, 875, 900, 925, 950. 3. Apply a bandpass filter. For velocity analysis, it is usually desirable to limit the frequency range of the input data. Select Ormsby filter values of 3-6-50-60. 4. Apply Automatic Gain Control. For velocity analysis, a relatively short AGC window is usually desirable. The default value of 500 ms will work fine for this exercise. 5. Set parameters for Velocity Analysis Precompute. Set the number of CDPs to sum into gathers as 9, and set the bin sizes. Landmark ProMAX 2D Seismic Processing and Analysis 12-7 Chapter 12: Velocity Analysis and the Volume Viewer 6. Supergather input to Velocity Analysis has reduced spatial separation between traces compared to the original CDP gather Arrows indicate the direction of the Partial NMO One Group Interval Partial NMO and SUM Move the Traces to the NMO of the Bin Centers Full NMO and SUM Flatten the Traces to the Zero Offset Time of the Gather 12-8 ProMAX 2D Seismic Processing and Anlaysis Landmark . Select Yes to Apply partial NMO-to-binning. 9. Execute the flow. Landmark ProMAX 2D Seismic Processing and Analysis 12-9 . Create a new Disk Data Output file called “Precomputed Velocity Analysis”. Select minimum and maximum semblance values to 7000 and 20000.Chapter 12: Velocity Analysis and the Volume Viewer 7. Select Top/base range as the method of computing stack velocity functions. Velocity Analysis In this flow we will set the prameters for velocity analysis to use the precomputed data from the previous flow. 8. 10. and set the number of stack velocity functions to 17. 1.1 Automatically snap------------------------------------------No Maximum velocity % change for snapping: ----------5 --------------------------------------------------------------------------Maximum vertical change for snapping: ------------------40 Display horizon(s)?: -----------------------------------------------No Use neural network velocity picker?: -----------------------No Interact with other processes using PD?:-----------------Yes Get guide function from existing parameter table?---Yes Velocity guide function table name: ----------------------------------------------------imported from ascii file --------------------------------------------------------------------------------Maximum stretch percentage for NMO: --------------------30 Long offset moveout correction?:-------------------------NONE Interval velocity below last knee: ------------------------------0 Table to store velocity picks: -------vels from precompute Copy picks to next location------------------------------------No Submenu Controls >Volume Viewer/Editor*< 12-10 ProMAX 2D Seismic Processing and Anlaysis Landmark . Build the following Velocity Analysis flow: Editing Flow: 6. Contrast noise factor: ------------------------------------.0.2-Velocity Analysis Add Delete Execute View Exit Disk Data Input Select dataset: ------------Precomputed Velocity Analysis Trace read option:-----------------------------------------------Sort Interactive Data Access?:---------------------------------------Yes Select primary trace header entry:-------SG_CDP Velocity Analysis Select display DEVICE: -----------------------------This Screen Is the incoming data Precomputed?: ----------------------Yes Set which items are visible?---------------------------------No Set semblance scaling and autosnap parameters?:--No --------------------------------------------------------------------------Semblance normalization mode: ---Scale Time Slice Contrast power factor: ------------------------------------.Chapter 12: Velocity Analysis and the Volume Viewer 1. 3. and guide functions from previous velocity picks. 5. The submenu parameter settings will be retained and used even though they are not visible.Chapter 12: Velocity Analysis and the Volume Viewer 2. Both the visiblity and semblance parameters can also be changed interactively from within the velocity analysis tool. From this menu you can also change the trace scaling. a corresponding CDP gather or CDP supergather sorted by absolute offset. Set the Disk Data Input parameters as shown. The default settings will work fine so turn off the semblance submenu by clicking No for Set semblance scaling and autosnap parameters. Set the Velocity Analysis parameters. The parameter Set which items are visible works the same way. interval velocities derived from the RMS picks. When you first parameterize the Velocity Analysis process. NOTE: The Velocity Analysis parameters are only our initial guesses. Be sure to create a table to store velocity picks such as “vels from precompute”. a subset of the parameters will be visible so begin by setting the “global parameters” highlighted in the flow. and the varying velocity stack strip panels. The display shows a velocity semblance plot. The panel menus allows you to control several other items including the semblance scale. Once inside the Velocity Analysis Viewer we can change any of the parameters interactively. 4. select Yes for Set semblance scaling and autosnap parameters to display the semblance submenu. Next. Make sure to sort the input data by the user-defined header word SG_CDP. Execute the flow. Landmark ProMAX 2D Seismic Processing and Analysis 12-11 . the dynamic stack positive and negative polarity. • Previous ensemble: Step backward one ensemble and process. Rewind: Rewind the dataset and go back to the first ensemble as specified in the sort order. this button is inactive. this button is inactive.Chapter 12: Velocity Analysis and the Volume Viewer Velocity analysis window Velocity Analysis Icons • Next ensemble: Proceed to and process the next ensemble in the dataset. If you are currently processing the last ensemble in the dataset. If you are currently processing the first ensemble in the dataset. If you are currently processing the first ensemble of the dataset. this button is inactive. • 12-12 ProMAX 2D Seismic Processing and Anlaysis Landmark . and should be executed while you are running Velocity Analysis. If your workstation performance suffers such as slow redraws... The tool used for this is a standalone process called the Volume Viewer/Editor... NOTE: Your velocity picks are automatically saved to an RMS velocity ordered parameter file when you move from one location to the next or Exit the program. This icon works only when Velocity Viewer/Editor is running. Pick a stacking velocity function for the first ensemble. you can set the flow parameters so your Velocity Analysis display is automatically configured that way. and begin picking a function with MB1. You also have the option to save picks using the Table/Save Picks option. This can be accomplished by simultaneously viewing a color isovelocity display of the entire velocity volume. as outlined below. This will display the average of all of the functions that have been picked in the output table to date.. 6. Once you have determined your favorite settings. or the velocity stack strips display. Use the Next ensemble icon to move to the next analysis location After you pick the first location and move to the second you may want to overlay the function that you just picked as a second guide. Using the Volume Viewer As you pick velocities along a line using the Velocity Analysis tool. 7. ¦ Velocity Color Key. you may want to QC the picked velocity field. Landmark ProMAX 2D Seismic Processing and Analysis 12-13 . Activate the picking icon. turn off the more resource intensive attributes.. and vice versa. the picks are also displayed on the velocity strips.Chapter 12: Velocity Analysis and the Volume Viewer • Point Dispatcher(PD): save and send the velocity picks in the current ensemble to the Velocity Viewer/Editor. ¦ Interval Velocity.. You can do this by clicking on View ¦ Object visibility. You can pick in either the semblance display. and View ¦ Object visibility. ¦ Average of all CDPs (blue). As you pick velocities on the semblance plot. and you have told it to interact with Velocity Analysis. Experiment with some of the other display attributes such as View ¦ Object visibility. • 12-14 ProMAX 2D Seismic Processing and Anlaysis Landmark .Stacking (RMS) Velocity Select input volume: -------vels from precompute To which datum is the velocity volume referenced?:----------------------------------------------------Floating Datum Display seismic data?: ------------------------------------------Yes Select poststack data file: --------STK-refr statics To which datum are the stack data referenced?:------------------------------------------------------------Final Datum To which datum are the horizons referenced?:---------------------------------------------------------------Final Datum Interact with other processes using PD?: --------------. Also. 3.2-Velocity Analysis Add Delete Execute View Exit >Disk Data Input< >Velocity Analysis< Volume Viewer/Editor* Display DEVICE for cross-section: -------------This Screen Work in Time or Depth: -------------------------------------. Editing Flow: 6.Time Unit System: -----------------------------------------------DataBase Source of surface coordinate limits: ---------Seismic Data Source of depth coordinate limits: ------------Seismic Data Input Volume Type-----------------.Yes Display gather locations?:--------------------------------------Yes • Make sure you use the same velocity table that you are currently using in Velocity Analysis. Parameterize Volume Viewer/Editor as follows. Return to the ProMAX User Interface. Toggle off all processes and add Volume Viewer/Editor to the flow. make sure you select Yes to Interact with other processes using PD? This will allow the PD (point dispatcher) to communicate with Velocity Analysis. After picking and saving at least one velocity analysis location. iconify the Velocity Analysis Window.Chapter 12: Velocity Analysis and the Volume Viewer 1. 2. the display will contain zero values and the screen will be all blue and the velocity scale will be very large.Chapter 12: Velocity Analysis and the Volume Viewer 4. you will want to try different ways of arranging the windows on the screen until you have made an arrangement that is workable for you. you will only see a vertical color variation in the Cross Section window. Landmark ProMAX 2D Seismic Processing and Analysis 12-15 . Unless you have two screens. The following diagram illustrates one way to arrange the windows on the screen: Possible Window Arrangement If you have not picked any velocities. Execute the flow containing the Volume Viewer/Editor. If you have picked at least one velocity function. and return to the Velocity Analysis display. The Volume Viewer/Editor window will eventually appear. In the Volume Viewer/Editor window. In the Velocity Analysis display. click on the PD icon. click on the Next ensemble icon again. you can select a CDP and send it to Velocity Analysis. A “Volume Controls” window will appear. click on the “bow-and-arrow” PD icon to send the new information to the Volume Viewer/Editor. pick or modify the velocity function for the current location. 9. position the mouse cursor over a node. In the Velocity Analysis window. The velocity displayed in Volume Viewer/Editor updates in response to picks made in Velocity Analysis. 6.Chapter 12: Velocity Analysis and the Volume Viewer 5. This will display vertical lines in the Cross Section window indicating the positions of the Velocity Analysis centers already saved to the velocity table. but will automatically send the velocity picks just made to the Volume Viewer/Editor displays. This will not only move you to the next analysis location. The cursor should change from an “x” to an “o”. Velocity Analysis Pointing Dispather By activating this icon. 8. Click on the Cross-section Nodes button. and pick the next analysis location. then Ok. 12-16 ProMAX 2D Seismic Processing and Anlaysis Landmark . In the Velocity Analysis window. The locations of these lines are referred to as nodes. From the Velocity Viewer/Editor window. When you are finished picking this new analysis location. 7. This icon does not appear if No was selected for Interact with Velocity Analysis? in the Velocity Viewer/Editor menu. Click MB1 to retrieve that velocity function into the Velocity Analysis display. This allows random access to any of the precomputed and picked locations. You should now see a vertical line in the Cross Section window at the CDP location of the velocity function just picked. Clicking MB2 deletes that analysis location. click on View ¦ Volume Display. Any Velocity Analysis CDP location can be easily retrieved or deleted from Volume Viewer/Editor through the use of the mouse. With the PD icon activated. click on the Next ensemble icon. you may either use the “bow-and-arrow” PD icon to send the picks from Velocity Analysis to the Volume Viewer/Editor displays for QC before moving to the next analysis location. click on the File ¦ Exit/stop flow pull down menu in the velocity analysis and the File ¦ Exit pull down in the Volume Viewer/ Editor. Try moving to a previous location by selecting it in the Volume Viewer window. Continue picking velocities in Velocity Analysis until you finish all of the locations on this project. To finish picking. 11. or you may move directly to the next ensemble and your previous picks will be automatically sent to the Volume Viewer/Editor displays. Then in Velocity Analysis. Remember. first make sure that the “Point Dispatcher” PD icon in Volume Viewer is deactivated. 12.Chapter 12: Velocity Analysis and the Volume Viewer 10. Landmark ProMAX 2D Seismic Processing and Analysis 12-17 . Chapter 12: Velocity Analysis and the Volume Viewer Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • Do you understand the parameters input to Velocity Analysis? Can you operate the Velocity Analysis Viewer in conjunction with the Volume Viewer/Editor? Are you confident in picking a reasonable stacking velocity function? • 12-18 ProMAX 2D Seismic Processing and Anlaysis Landmark . it may still be necessary to remove residual near-surface traveltime delays that are the result of varying velocity and/or varying depth of the weathering layer. ProMAX offers several residual statics processes. All are surface consistent solutions except for the Trim Statics routines.Chapter 13 Residual Statics Corrections Although datum static corrections have been applied to remove travel-time effects of elevation changes along the seismic line. Topics covered in this chapter: t Autostatics Flowchart t Data Preparation for Input to Residual Statics t Calculation of Residual Statics t QC and Application of Residual Statics t External Model Autostatics Overview t External Model Autostatics Flowchart Landmark ProMAX 2D Seismic Processing and Analysis 13-1 . Chapter 13: Residual Statics Corrections Chapter Objectives 7. Residual Statics To correct for high frequency variations in the near surface weathering not solved by elevation/refraction statics or velocities. High frequency can be thought of as shorter than one cable length. Upon completion of this chapter you should: • • • • Know how to prepare data for input to Residual Statics Understand how Surface Consistent Statics are calculated Understand how Trim Statics are calculated Be able to build a Model Stack to pilot some of the statics routines 13-2 ProMAX 2D Seismic Processing and Analysis Landmark . some type of residual statics is almost always applied for land data. This chapter explores some of ProMAX’s techniques of calculating residual statics. noise reduction. Power Autostatics SIN:STATICS:SPWRxxxx SRF:STATICS:RPWRxxxx Landmark ProMAX 2D Seismic Processing and Analysis 13-3 . NMO. AGC) RMS Velocities 2. BPF. Pre-Process (geometry. deconvolution. refraction or elevation statics. gain recovery. Apply NMO and Sort to CDPs CDP Stack Pick Autostatics Horizon 3.Chapter 13: Residual Statics Corrections Autostatics Flowchart Autostatics Flowchart 1. Calculate Residual Statics Correlation Autostatics SIN:STATICS:SCORxxxx SRF:STATICS:RCORxxxx Max. you will need to create an enhanced stack as the model using any of the signal enhancement techniques available in ProMAX. the input to autostatics should have geometry information. This will be covered in the section on External Model Autostatics. Data preparation and horizon picking for residual statics In this exercise you are simply preparing a prestack dataset for input to autostatics. and NMO applied. as well as picking your autostatic horizons on poststack data. To execute an external model autostatics method. gain recovery. and scale the data with an AGC. deconvolution. noise reduction. you may want to filter unwanted high and low frequency noise by band limiting the input data. In addition to normal preprocessing. At this point in the processing sequence. refraction or elevation statics. 13-4 ProMAX 2D Seismic Processing and Analysis Landmark .Chapter 13: Residual Statics Corrections Data Preparation for Input to Residual Statics All of the residual statics process are standalone and require that all preprocessing be applied to the data and output to a disk dataset prior to executing the residual statics processes. This data is input into the residual statics process in a later flow. 6. 5.Chapter 13: Residual Statics Corrections 1. Landmark ProMAX 2D Seismic Processing and Analysis 13-5 .1-Data Prep for Res. Apply Bandpass Filter to remove the lowest and highest frequencies. 4. statics >Disk Data Input< >Trace Display< 2. Apply an AGC and bandpass filter to clean the data going into residual statics calculation. such as 5-10-40-50 Hz. Build the following flow: Editing Flow: 7.5-10-40-50 Disk Data Output Output Dataset Filename: ------CDP-input to res. Output your NMO corrected CDPs to a new file “CDP-input to res. select your best pre-stack data. 3. select your best RMS velocity parameter table. Execute the flow. In NMO.*/ Normal Moveout Correction SELECT Velocity parameter file: --vels from precompute Automatic Gain Control ----Default all parameters---- Bandpass Filter Ormsby filter frequency values: ---------------. statics”. Statics Add Delete Execute View Exit Disk Data Input Select dataset: -----------------------Shots-decon/refr statics Trace read option: -----------------------------------------------Sort Interactive Data Access?: ---------------------------------------No Select primary trace header entry: -----------------------CDP Select secondary trace header entry: -----------------NONE Sort order for dataset: -------------------------------------------. In Disk Data Input. A 500 ms AGC gate width is sufficient. 13-6 ProMAX 2D Seismic Processing and Analysis Landmark . Statics Add Delete Execute View Exit >Disk Data Input< >Normal Moveout Correction< >Automatic Gain Control< >Bandpass Filter< >Disk Data Output< Disk Data Input Select Dataset: -----------------------------------STK-refr statics Trace read option: --------------------------------------------Get All Trace Display Primary trace LABELING header entry: --------------NONE Secondary trace LABELING header entry: ------------CDP 8. 9. Execute the flow.Chapter 13: Residual Statics Corrections 7.1-Data Prep for Res. Residual statics processes require that reference horizons (autostatics horizons) are picked from a preliminary stack and saved in a parameter table. Edit the following flow: Editing Flow: 7. Input your refraction statics stack. Landmark ProMAX 2D Seismic Processing and Analysis 13-7 . Smash is the number of CDPs to sum along the horizon to form the model trace for correlation. Enter a gate width=100 (ms). select Picking ¦ Pick Autostatics Horizons. Gate width is symmetric about the picks. Picking Autostatics Horizon 11.. The gate width should be bigger than twice the maximum residual static expected. In swampy/marshy areas this may be a large value. For flatter areas smash values of 11 to 21 are valid.Chapter 13: Residual Statics Corrections 10.. For steeply dipping areas a smash of 3 to 5 should be used. Enter a new table name “horizon1” and select OK. Enter smash=11 (CDP traces). From the menu bar in Trace Display. Click on OK when finished. A Table Selector window appears. Additional horizons (up to 500) may be picked by clicking in the trace display area with MB3 and choosing a new layer. The residual statics processes automatically shifts these time horizons to the processing datum. NOTE: Autostatics horizons are picked from stacked data that has been shifted to the final datum. Notice also the new horizon is represented in the Pick Layers window with a number in parentheses. the same datum input CDP gathers are referenced to. Horizons may extend across the entire dataset or cover only a portion of the data. 13-8 ProMAX 2D Seismic Processing and Analysis Landmark . 13. Select Yes when asked to save your work. Too much overlap can lead abrupt edges to the static solution. Pick a horizon using MB1.Chapter 13: Residual Statics Corrections 12. You will be prompted to enter a new smash value and time gate for each horizon. CDPs not included in a horizon will not be included in residual statics calculations for that horizon. This identifies the center of the time gate. This process of applying C_STATIC to the horizons is automatic and transparent to the user. 14. About a 10 trace overlap should provide a smooth transition between static solutions. The residual statics process will average the static solutions in areas of overlapping windows. To quit and save the autostatics horizon parameter table select File ¦ Exit/Stop Flow. except the shifts are applied in the CDP domain. magnitude of statics problem. and thus the shifts are blind to surface consistency. These edge problems are often corrected by editing the erroneous values in the database.” The max power method has proven very robust for good and bad data areas. and merits of the residual statics method. The “CDP Trim Statics” works similar.Chapter 13: Residual Statics Corrections Calculation of Residual Statics ProMAX offers nine internal model surface consistent residual statics methods and three CDP consistent (trim) statics methods: • • • • • • • • • • • • Correlation Autostatics Cross Correlation Sum External Model Autostatics Cycle Skip Analysis Autostatics Differential Autostatics Gauss-Seidel External Model Autostatics Hybrid Genetic Algorithm /Steepest Ascent Autostatics Maximum Power Autostatics Steepest Ascent Autostatics Summed Differential Autostatics CDP Trim Statics: non surface consistent Horizon Trim Statics: non surface consistent Time Varying Trim Statics: non surface consistent The most commonly used surface consistent methods are “Correlation Autostatics” and “Maximum Power Autostatics. Most of the methods have some problems at the edges and low fold areas. If nothing seems to work use Gauss-Seidel External Model Autostatics. The max power simply maximize the power of the stack by shifting each trace and stacking for the maximum power. Parameter selection for each method is also based on data quality and magnitude of statics problem. Landmark ProMAX 2D Seismic Processing and Analysis 13-9 . The only downside to max power is that it is a little more expensive in terms of CPU usage. Choose a method based on data quality. receiver. Do you have any reversed traces? 13-10 ProMAX 2D Seismic Processing and Analysis Landmark . Upon completion.2-Calculate Residual Statics Add Delete Execute View Exit Correlation Autostatics* Select Trace data file: -------------CDP-input to res. Power Autostatics*< 2. Select your autostatic horizon and RMS velocity tables. 3. statics Select Autostatics HORIZON file: --------------------horizon1 Select Autostatics VELOCITY file: vels from precompute Maximum velocity error (percent): ----------------------------5. Select your NMO corrected CDP gathers as the input trace data to Correlation Autostatics. Execute the flow. channel and structure statics. An additional exercise at the end of this section describes the external model routines. 1. click on View from the Flow menu and look at the contents of the job. estimate: ------------25 Maximum statics allowed (milliseconds): -----------------20 Statics partitioning iterations: -----------------------------------4 Minimum live samples in a gate (percent): ---------------60 Seek/report reversed sources/receivers/channels: Yes Create a NEW database entry for each run?: -----------No >2D/3D Max. Correlation Autostatics* uses a Gauss-Seidel method to partition statics into velocities. Build the following flow: Editing Flow: 7. Gauss-Seidel External Model Autostatics and Cross Correlation Sum External Model Autostatics. as well as source.output file. estimate: ---------------------36 Minimum % of offset range for vel.Chapter 13: Residual Statics Corrections Autostatics calculation In this exercise. you will calculate residual statics using Maximum Power and Correlation Autostatics. Check the range of source and receiver statics values. Number of CDP’s for velocity smoothing: -----------------51 Minimum # of traces for vel. output file.2-Calculate Residual Statics Add Delete Execute View Exit >Correlation Autostatics*< 2D/3D Max. The Maximum static allowed is per iteration. Landmark ProMAX 2D Seismic Processing and Analysis 13-11 .10. Check to see if your solution has converged. Upon completion.-20 Final maximum static: --------------------------------------------20 Run ID: --------------------------------------------------------------0000 Report static values after each iteration?: ----------------No 5.Chapter 13: Residual Statics Corrections 4. Power Autostatics* Select Trace data file: -------------CDP-input to res.05 Maximum number of iterations: ------------------------------10 Minimum live samples in a gate (percent): ---------------60 Maximum static allowed (ms): -------------5. click on View from the Flow menu and look at the contents of the job. In 2D/3D Max. We start these values out low in order to keep the solution from immediately diverging. Editing Flow: 7.15. Also check the range of source and receiver statics values. Execute the flow. 6.7. statics Select Autostatics horizon file: -----------------------horizon1 RMS statics change convergence criteria: -------------0. receiver and channel statics by maximizing the CDP stack power. Power Autostatics* estimates source. input your NMO corrected CDP gathers. Select your autostatic horizon tables.20(6) Correlation accept percent: -------------------------------------10 Compute Statics for whole line?: ----------------------------Yes Use envelope of correlations?: --------------------------------No Apply previously computed residuals?: -------------------No Restrict offsets?: ----------------------------------------------------No Final minimum static: ------------------------------------------. Set the remaining parameters as indicated above. Edit the previous flow. 2D/3D Max. Power Autostatics*. Comparison of stacks with different residual statics methods applied. Comparison of stacks with and without residual statics applied. 13-12 ProMAX 2D Seismic Processing and Analysis Landmark .Chapter 13: Residual Statics Corrections QC and Application of Residual Statics Quality control of residual static results can be achieved by several methods: • • • Utilizing the Database display tool. Select SRF order. Select Database ¦ Get from the XDB display. and the two statics files RCOR000 & RPWR000. and then select Database ¦ XDB Database Display from the main DBTools menu. 1. Database plot of Receiver statics Landmark ProMAX 2D Seismic Processing and Analysis 13-13 . 2. Statics infotype.Chapter 13: Residual Statics Corrections Compare Static Solutions in the Database A quick QC tool is to examine the computed static values with the Database display tool. From the Flows menu select the Database option. 3. For more information see the Residual Statics helpfile. Computed static values from several methods can be plotted simultaneously for comparison. Quality Factors can be used as a criteria for zeroing statics values or editing shots and receivers. The source (SIN) and receiver (SRF) statics for Maximum Power Autostatics are SPWR0000 and RPWR0000. Values can then be zeroed or edited from this database display. Quality factors from several methods can be displayed simultaneously to compare reliability of the computed statics.Chapter 13: Residual Statics Corrections The source (SIN) and receiver (SRF) statics for Correlation Autostatics are SCOR0000 and RCOR0000. Quality Factors computed by each method are also output to the database. Statics with low quality factor values relative to neighboring values can be zeroed or the receivers could be edited. and R_CQ0000. See mouse button helps for instruction. The quality factor file naming convention is S_CQ0000. 13-14 ProMAX 2D Seismic Processing and Analysis Landmark . Quality factors can be used to weight traces before CDP stack. Power Autostatics. It uses the Screen Display process. 2. Execute (with MB2) and use the screen swap feature to compare stacks. Build the following flow: Editing Flow: 7.3-Compare Autostatics Stacks Add Delete Execute View Exit Compare Autostatics Stack SELECT input trace data file: --CDP-input to res. Execute this flow again (with MB2) using the Max. Landmark ProMAX 2D Seismic Processing and Analysis 13-15 . statics SPECIFY the input CDP range(s): ----1-100000/ Temporary SCRATCH data file: -----------------------Scratch Automatically delete this file upon completion?: ----------------------------------------------------------------Yes Normal database entry naming mode?: -----------------Yes Type of residual statics to apply: -------------------------------------------------------Correlation Autostatics Select display DEVICE: -----------------------------This Screen Number of traces per display screen: --------------------215 This is a stand-alone macro that enables you to compare a preliminary stack without residual statics to a stack with residual statics.Chapter 13: Residual Statics Corrections Compare Autostatics Stacks 1. 3. Chapter 13: Residual Statics Corrections Compare two or more Autostatics Stacks 1.3-Compare Autostatics Stacks Add Delete Execute View Exit >Compare Autostatics Stack< Disk Data Input Select dataset: -----------------------CDP-input to res. Use the following flow to get started: Editing Flow: 7. Power Autostatics ENDIF Apply Fractional Static Automatic Gain Control Bandpass Filter Ormsby filter frequency values: -------------------3-6-50-60 CDP/Ensemble Stack Trace Display Primary trace LABELING header entry: ---------------None Secondary trace LABELING header entry: ------------CDP 13-16 ProMAX 2D Seismic Processing and Analysis Landmark . Build a flow for comparing stacked results from two or more statics methods. statics Trace read option: --------------------------------------------Get All Reproduce Traces Trace grouping to reproduce: --------------------------All Data Total number of datasets: ----------------------------------------2 IF Apply Residual Statics Type of residual statics: -----------Correlation Autostatics Trace Display Label Trace label:------------------------------Correlation Autostatics ELSE Apply Residual Statics Type of residual statics: ----------Max. Power Autostatics Trace Display Label Trace label:-----------------------------Max. you can apply trace mixing. For example. statics computation.Chapter 13: Residual Statics Corrections External Model Autostatics Overview ProMAX currently offers two surface consistent autostatics routines for use with an external model (pilot). correlation computation. 2D filtering. and statics application. these may also be applied directly to the data as external model trim statics. The input to the external model building can be any stack of the dataset. A typical External Model Autostatics job flow consists of four phases: external model building. Both require using the External Model Correlation tool which correlates prestack traces with the model. Landmark ProMAX 2D Seismic Processing and Analysis 13-17 . Another method would be to use the Eigen Stack process to produce the model stack. This allows you to use the data enhancement techniques available in ProMAX to improve the model stack. or F-X decon to a brute stack to generate the model stack. Since correlation pick times can be written to the TRC database. AGC) RMS Vels 2. refraction or elevation statics. Pre-Process (geometry.Chapter 13: Residual Statics Corrections External Model Autostatics Flowchart External Model Autostatics Flowchart 1. deconvolution. NMO. EMC Xcor Sum SIN:STATICS:SPEMxxxx SRF:STATICS:SPEMxxxx 13-18 ProMAX 2D Seismic Processing and Analysis Landmark . noise reduction. EMC Gauss Seidel Eigen Matrix Time Gate TRC STATICS TRM0001 Correlations (trace data) 3. External Model Correlation Autostatics Horizon 5b. Eigen Stack 4. Apply NMO and Sort to CDPs SIN:STATICS:SGEMxxxx SRF:STATICS:SGEMxxxx 5a. BPF. gain recovery. The cost of this process.Chapter 13: Residual Statics Corrections Create Eigen Stack Eigen Stack process uses the Eigen vector decomposition techniques to isolate the principle component of the trace matrix from a supergather of pre-stack traces. Input Traces on CDP with NMO applied Conventional Stack Model Trace Eigen Stack Model Trace Principal Component input traces Cartoon of Eigen Stack Decomposition Landmark ProMAX 2D Seismic Processing and Analysis 13-19 . These wavelets are time shifted due to near surface velocity variations. Conceptually. The Eigen Stack process attempts to make the stacked trace wavelet that is as similar as possible to the wavelet of the pre-stack traces. is that some of the structural information may be lost. however. Typically we measure these time variations by cross correlating the pre-stack traces with a stacked trace. the wavelet on the stack trace after eigen stack is more similar to the wavelets on the prestack data than a conventional stack. Note that this is the same technology as the government uses for pattern recognition in scanning retinas or for enhancing faces on photographs. Theory says that all of the wavelets recorded from a reflection point are the same. This should improve the cross correlation process by creating a higher resolution pilot trace. Some writings may refer to an Eigen stack as a K-L transform. 4-Eigen Stack Add Delete Execute View Exit Disk Data Input Select dataset: -----------------------CDP-input to res. 13-20 ProMAX 2D Seismic Processing and Analysis Landmark . Build the following flow to pick an eigen matrix time gate on NMO corrected CDP gathers.Chapter 13: Residual Statics Corrections You first need to pick a time gate that will be used in the Eigen Stack process: 1. Input a range of CDP gathers and execute the flow. Editing Flow: 7. statics Trace read option: -----------------------------------------------Sort Interactive Data Access?: --------------------------------------Yes Select primary trace header entry: -----------------------CDP Sort order for dataset: ----------------------------800-950(25)/ >Eigen Stack< >Disk Data Output< Trace Display Number of ENSEMBLES (line segments)/screen: -----10 Primary trace LABELING header entry: ----------------CDP Secondary trace LABELING header entry: -----------None 2. Save picks and exit the Trace Display. From the Trace Display menu bar. 5. If the CDP gathers are not flat you may have a problem with your velocities..Chapter 13: Residual Statics Corrections 3. Landmark ProMAX 2D Seismic Processing and Analysis 13-21 . Use MB3 inside of the Trace Display area to select a new layer for the bottom of the window. and pick a window from a data area that has a high Signal/Noise ratio. Make sure that your window includes the area of interest. Input a gate name like “eigen gate”.. This display is also a good QC to check your velocities. Select a secondary key of CDP. select Picking ¦ Pick Miscellaneous Time Gates. 6. Pick Time Gate 4. 13-22 ProMAX 2D Seismic Processing and Analysis Landmark .4-Eigen Stack Add Delete Execute View Exit >Disk Data Input< Disk Data Input Select dataset: -----------------------CDP-input to res. In Disk Data Output.Chapter 13: Residual Statics Corrections 7. statics Trace read option: --------------------------------------------Get All Eigen Stack Mode: --------------------------------------------Output Eigenstack Get matrix design gates from DATABASE?: ------------Yes SELECT design gate parameter file: ------------eigen gate Type of Computations?: ---------------------------------------Real Horizontal window width: ----------------------------------------5 Number of iterations: -----------------------------------------------0 Apply final datum statics after stack?: ------------------Yes Disk Data Output Output Dataset Filename: ---------------------------STK-eigen >Trace Display< The Eigen Stack process stacks flat events in a CDP gather. Edit the flow to generate an Eigen Stack. output a new dataset “STK-eigen”. Editing Flow: 7. Events with large trace to trace moveout will not be included in the output Eigen Stack. This is used for subsequent input to the external model correlation builder. Execute the flow. 8. 9. Edit the flow to pick autostatics horizons on your Eigen Stack. Editing Flow: 7. Execute the flow. Landmark ProMAX 2D Seismic Processing and Analysis 13-23 .Chapter 13: Residual Statics Corrections 10.4-Eigen Stack Add Delete Execute View Exit >Disk Data Input< >Disk Data Input< >Eigen Stack< >Disk Data Output< Disk Data Input Select dataset: -------------------------------------------STK-eigen Trace read option: --------------------------------------------Get All Trace Display Primary trace LABELING header entry: ---------------None Secondary trace LABELING header entry: ------------CDP 11. Enter smash=1 (in traces) and the gate width=300 ms and click on OK. give it a value of 1. the smash is not used. Pick horizon for Autostatics • • Enter a new table name and click on OK.. select Picking ¦ Pick Autostatics Horizons.. The pilot traces have already been somewhat “smashed” together by creating the Eigen Stack. Therefore. For an external model.Chapter 13: Residual Statics Corrections 12. From the menu bar in Trace Display. 13-24 ProMAX 2D Seismic Processing and Analysis Landmark . Horizons may extend across the entire dataset or cover only a portion of the data. Additional horizons (up to 500) may be picked by clicking MB3 in the trace display area and choosing a new layer. Save your autostatics horizon picks and exit Trace Display. You will be prompted to enter a new smash value and time gate for each horizon. 15. NOTE: Autostatics horizons are picked from stacked data that has been shifted to the final datum. the same datum input CDP gathers are referenced to. This process is automatic and transparent to the user. The residual statics processes automatically shift these time horizons to the processing datum. This identifies the center of the time gate. Landmark ProMAX 2D Seismic Processing and Analysis 13-25 . 14. To automatically move picks to the nearest peak or trough. click with MB3 in the data area and choose the appropriate snap. CDPs not included in a horizon are not included in residual statics calculations for that horizon. 13. Notice also the new horizon is represented in the Pick Layers window with a number in parentheses.Chapter 13: Residual Statics Corrections Pick a horizon using MB1. 5-External Model Correlations Add Delete Execute View Exit Disk Data Input Select dataset: -----------------------CDP-input to res. Select Eigen Stack for the model trace dataset and select your autostatics horizons for the Horizon file. 13-26 ProMAX 2D Seismic Processing and Analysis Landmark . Build this flow to generate correlations: Editing Flow: 7. 18. Select External Model Correlation parameters.Chapter 13: Residual Statics Corrections 16. The correlation trace data is used in EMC Autostat: Xcor Sum*. In Disk Data Output. Execute the flow. In Disk Data Input. input the NMO corrected CDP gathers. 20. output the correlation trace data. 19. statics Trace read option: --------------------------------------------Get All External Model Correlation Select model trace dataset: -------------------------STK-eigen Use autostatics horizon or gate file: --------------HORIZON Select autostatics horizon file: ------EMC horizon Minimum live samples in a gate(percent): ----------------60 Maximum static shift: ---------------------------------------------20 Write correlation pick TIMES to the database?: -------Yes Write correlation pick AMPLITUDES to the database?: ----------------------------------------------------------------Yes Write quality control estimates to the database?: ----Yes Database mode: ---------------------------------Overwrite/ New Enter 4 Digit ID number:------------------0001 Disk Data Output Output Dataset Filename: -------------------------correlations 17. You can graphically check the range of source and receiver statics values in the database with DBTools or XDB Database Display. receiver (SRF). Landmark ProMAX 2D Seismic Processing and Analysis 13-27 . and structure (CDP) statics. Build the following flow to calculate your residual statics using EMC Autostat: Gauss-Seidel*: Editing Flow: 7. These time shifts will be decomposed into the source (SIN). 23.STATICS . Upon completion. Max trace offset MAGNITUDE for inclusion: ----999999. click on View from the Flow menu and look at the contents of the job. Execute the flow.TRC:STATICS: TRM_0000 Statics partitioning iterations: -----------------------------------7 Maximum source or receiver static: -------------------------20 Min trace offset MAGNITUDE for inclusion: ---------------0.output file. Weight solutions by pick quality factors: ----------------Yes Alpha trimmed mean percentage for pick exclusion:--40 Length of the CDP structure smoothing: ---------------------3 Dampen the structure term at low fold?: ----------------Yes Create a NEW database entry for each run?: -----------No >EMC Autostat: Xcor Sum*< 22. For Gauss-Seidel.TRM_0000 from the Ordered Parameter Files.Chapter 13: Residual Statics Corrections 21.6-EMC Autostatics Add Delete Execute View Exit EMC Autostat: Gauss-Seidel* Select TRC database correlation pick entry:----------------------------------------------. select TRC . input the correlation trace data that was output from the External Model Correlations flow. Editing Flow: 7.3-Compare Autostatics Stacks” to do your comparisons.Chapter 13: Residual Statics Corrections 24. Upon completion. Execute the flow.6-EMC Autostatics Add Delete Execute View Exit >EMC Autostat: Gauss-Seidel*< EMC Autostat: Xcor Sum* Input correlations from Tape or Disk?: ------------------Disk Select input correlation file:-------------Statics-correlations First statics computation domain: ------------------------CDP Second statics computation domain: -----------------Source Third statics computation domain: -----------------Receiver Fourth statics computation domain: -------------------NONE Adjust correlations by a previous SOURCE static: ----No Adjust correlations by a previous RECEIVER static: -No Adjust correlations by a previous CDP RESIDUAL STRUCTURE?: -------------------------------------------No Method for correlation summing: ------Min/Max Exclude Maximum source or receiver statics: ------------------------20 Create a NEW database entry for each run?: -----------No 25. Use the XDB Database Display and flow “7. In the database you will see SPEM0000 for both source and receiver statics calculated using the Xcor Sum and SGEM0000 for the source and receiver statics from Gauss-Seidel. In Xcor Sum. 27. 13-28 ProMAX 2D Seismic Processing and Analysis Landmark . 26. QC your results as you did earlier in this chapter. Edit the previous flow to use EMC Autostat: Xcor Sum*.output file. click on View from the Flow building menu and look at the contents of the job. These correlations are summed and then the maximum is picked within the various domains in order to derive the statics. Check the range of source and receiver statics values. */ Apply Residual Statics Type of residual statics to apply: ----EMC Gauss-Seidel Normal Moveout Correction SELECT Velocity parameter file: --vels from precompute Disk Data Output Output Dataset Filename: ---------CDP-decon/refr/resid CDP/Ensemble Stack Trace Display Label Trace label: ----------------------------------------EMC GS Statics Disk Data Output Output Dataset Filename: ---------STK-decon/refr/resid Trace Display Primary trace LABELING header entry: ---------------None Secondary trace LABELING header entry: ------------CDP 29.Chapter 13: Residual Statics Corrections 28. Landmark ProMAX 2D Seismic Processing and Analysis 13-29 . 30. After comparing the various autostatics solutions. When you are finished viewing the stack in Trace Display. build the following flow to apply the best solution. Fill in the parameters as listed above.7-Apply Residual Statics Add Delete Execute View Exit Disk Data Input Select dataset: ------------------------Shot-decon/refr statics Trace read option: -----------------------------------------------Sort Select primary trace header entry: -----------------------CDP Sort order for dataset: -------------------------------------------. select File ¦ Exit/Continue Flow. and then execute the flow. Editing Flow: 7. Chapter 13: Residual Statics Corrections Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • • • • Can you prepare data for input to Residual Statics What does it mean to be Surface Consistent How are Surface Consistent Statics calculated How are Trim Statics calculated Can you build a Model Stack to pilot some of the statics routines 13-30 ProMAX 2D Seismic Processing and Analysis Landmark . This collapses the CMP smear induced by dipping reflectors. Topics covered in this chapter: t Common Offset Binning t DMO t Final Stack Landmark ProMAX 2D Seismic Processing and Analysis 14-1 . but the stacking velocities picked after applying DMO are dip independent. Not only is the imaging of these dipping reflectors enhanced. the trace data are typically grouped into offset bins using the Trace Binning process.Chapter 14 Dip Moveout (DMO) Dip Moveout is also known as prestack partial migration where each data sample is migrated to its zero offset position. processes using Kirchhoff and F-K implementations of DMO are available to perform the prestack partial migration. Once the data is binned. Also. Before DMO is applied to the data. This improves velocities for stacking and migration. lateral resolution is increased and coherent noise is attenuated. The DMO processes itself is quite simple. however.Chapter 14: Dip Moveout (DMO) Chapter Objectives 8. Upon completion of this chapter you should: • • • Be able to Common Offset Bin data for input to DMO Be familiar with some of the input parameters to DMO Understand the basic theory of what DMO does to the data 14-2 ProMAX 2D Seismic Processing and Analysis Landmark . migration of dipping reflectors and noise reduction. the prep of the input data can be a little tricky to the new user. Dip Moveout (DMO) The advent of DMO in the 80’s has greatly improved velocity calculation. DMO improves the data because it migrates each sample to its zero offset position. This collapses the CMP smear induced by dipping reflectors. we select traces belonging to common offset planes before applying DMO.200. 800.. 400. For asymmetric split spreads. the group interval is 100 m. In general the rules of thumb for DMO offset bin spacing are: • • • Marine: OFB = 2 X Shot Interval Land Split Spread: OFB = 1 X Shot Interval Land End On: OFB = 2 X Shot Interval It is relatively simple to determine the center of the first common offset bin. In this step.. or 450 m... may place two or more traces per CDP within a given DMO bin. and 300 m is the distance to the first group. 600. The shot-receiver offsets within this survey would be: 300. Since the shot interval of 200 m yields a bin increment of 400 m..200. 450 850 1250 Skidded shots.. Within the DMO process. Landmark ProMAX 2D Seismic Processing and Analysis 14-3 . For offend shooting. See diagram below: 300 400 500 600 700 800 900 1000 1100 1200 1300 1400... the data will determine which interval is appropriate. A rule of thumb is to build common offset binning to create a maximum number of bins. the shot interval should work. the center of your first offset bin would lie midway between 400 and 500... Your DMO offset bins would now be 450 +/. 1250 +/. etc.. yet still have 100% CDP coverage in both the common offset section and each bin.Chapter 14: Dip Moveout (DMO) Common Offset Binning Common offset binning is a critical part of the DMO process. Trace Binning requires a list of bin centers and bin increments. For symmetric split spread geometries. Common offset planes can be created with the Trace Binning process.. traces within the same DMO bin having identical CDP numbers are stacked together prior to DMO. 850 +/200. assume that we have a survey with off-end shooting where the shot interval is 200 m. or other irregular shooting geometry. 500... For example. the minimum offset bin increment is typically specified as either twice the shot interval or the nominal change in offset from trace to trace within a CDP. 700. 900. traces with the same magnitude offset are combined in the same ensemble. This may become important for lines that were collected with a regular. For datasets where the geometry is irregular and it is difficult to get good population of offset planes. If absolute value of offset is used. Ensemble DMO in the T-X Domain should be run on common shot ensembles. but asymmetric split spread geometry. Recall that the first few shots on the line resembled off-end shooting. the recommended approach is to use Trace Binning as a function of absolute offset followed by F-K DMO on common offset ensemble. and the last few shots were the normal split spread geometry. We will then look at several database and trace displays to check the binning parameters. Bin centers may be based on either the signed offset or the absolute value of the offset.Chapter 14: Dip Moveout (DMO) For regular shooting geometry. You also have the opportunity to vary the width of the offset bins (the bin increment) as a function of trace offset. 14-4 ProMAX 2D Seismic Processing and Analysis Landmark . you will compute common offset bin centers using the off-end shooting assumptions. Determine trace binning parameters In this exercise. Chapter 14: Dip Moveout (DMO) 1. Use Disk Data Input to sort the data first by offset bin number (from the Alternate List of header words) and then sort by CDP. Build the following flow to view the first offset bin in your survey: Editing Flow: 8. Maximum traces per output ensemble: ------------------215 Warnings if max traces/ensemble exceeded?: --------Yes Select PRIMARY Trace Order Header Word: ----OFB_NO Average the X and Y coordinates of primary key?: ---No Select SECONDARY Trace Order Header Word: -----CDP Output trace secondary key order: --------------Ascending Print results?:---------------------------------------------------------No Pad Traces Header word to use for padding: --------------------------CDP Spacing of header value: ------------------------------------------1 Remove traces?: ----------------------------------------------------No Explicitly define the bounds of header values?: ------Yes First trace header value: --------------------------------------775 Last trace header value: ---------------------------------------989 Trace Display Primary trace LABELING header entry: ----------OFB_NO Secondary trace LABELING header entry: ------------CDP 2.1-DMO Binning Add Delete Execute View Exit Disk Data Input Select dataset: --------------------------CDP-decon/refr/resid Trace read option: -----------------------------------------------Sort Interactive Data Access?: ---------------------------------------No Select primary trace header entry: -----------------OFB_NO Select secondary trace header entry: --------------------CDP Sort order for dataset: ------------------------------------------*:*/ Ensemble Stack/Combine Type of operation: -------------------------Combine and Stack Input ensembles per output ensemble: ----------------------1 How are trace headers determined: ----------------Average Secondary key bin size: ------------------------------------------1. Landmark ProMAX 2D Seismic Processing and Analysis 14-5 . Pad missing CDPs with Pad Traces. Use Ensemble Stack/Combine to combine offset bins. we will only display the first offset bin. and stack any CDPs which are the same. it would be desirable to 14-6 ProMAX 2D Seismic Processing and Analysis Landmark . We will use this process later to combine more than one offset bin for display. 5. Since DMO operates in the offset domain. Execute the flow. Notice that there are very few live CDPs for this single offset bin. This process will insert a dead trace anytime the spacing between CDPs is greater than 1. and CDP. so set the number of input ensembles/output ensemble to 1. Set the primary and secondary labeling headers in Trace Display to OFB_NO. 4. 6.Chapter 14: Dip Moveout (DMO) 3. For this first exercise. 5 357.5 412. Execute the flow. 10. The offset bin spacing for this line is 55 ft..5 and 247.. 7.5 82.5 ft. 220 660 For an offset bin width of 440 ft. the average shot interval is 220 ft. For this geometry.5 137. Landmark ProMAX 2D Seismic Processing and Analysis 14-7 . apart.5 302. so the source-receiver offsets would be: 27.5 192.. Editing Flow: 8.5 467. so the first guess at a DMO offset bin width (using the off-end assumption) would be 220 * 2 = 440 ft... The near offset of this data is 27. 8. the center of the first bin would lie halfway between 192.5. so 8 offset bins would equal 440 ft. This is the reason that we merge several offset bins prior to performing DMO. Modify the flow to display the data with a bin width of 440 ft.Chapter 14: Dip Moveout (DMO) have offset bins that contain live traces for nearly all CDPs.5 or at 220 ft.1-DMO Binning Add Delete Execute View Exit Disk Data Input Ensemble Stack/Combine Input ensembles per output ensemble: ----------------------8 Average the primary key values?: -------------------------Yes Pad Traces Trace Display 9. and the traces are 55 ft. Compute first guess at bin width and center of first bin.5 247. Chapter 14: Dip Moveout (DMO) Notice that most of the CDP locations are filled by live traces. (4 offset bins) you would see that a width of 220 ft. Create the greatest number of offset bins to enhance DMO velocity analysis. This is what we want for DMO binning. is adequate for the near offsets. but too small at the farther offsets. If you were to display the data with a bin width of 220 ft. Remember that we have two conflicting goals in our DMO binning process: • • Create continuous CDP coverage in the offset bins to eliminate DMO artifacts. 14-8 ProMAX 2D Seismic Processing and Analysis Landmark . Landmark ProMAX 2D Seismic Processing and Analysis 14-9 . 14. In marine shooting where the first channel is farthest from the boat. For example. all of the offsets are negative. and the OFFSET attribute.. Permanently write AOFFSET to the database by selecting Database Commit. First we need to transfer the AOFFSET header to the database: Database ¦ Edit ¦ Attribute ¦ Apply a Function.. Type in “AOFFSET GEOMETRY” for the result attribute and then select OK. 13. You can now use MB2 to drag OFFSET from the DBTools window to the Tabular View Window.. AOFFSET and then OK. 12. and only the negative DMO bins would be populated. Be patient the more data you put into the database. in split spread shooting. for every positive offset bin that is defined. the longer the initial delay when you first execute the database. +660. -660. 15. For a QC that the function worked choose View Tabular. -220. Remember.Chapter 14: Dip Moveout (DMO) 11. Now lets go into Database ¦ XDB Database Display. the above example would contain DMO bins +220. if OFFSET is used.. Choose the abs function. Next we will view the DMO binning parameters in the database. Close the Tabular View when satisfied. a negative offset bin is also created. The XYGraph using AOFFSET will look similar to the following: Check the offset bin centers by looking at the graphs and verifying that each offset bin is evenly populated with CDPs. Plot two 3D XYGraphs. Use the Grid tool to analyze your bins on the display. modify the cell size.Chapter 14: Dip Moveout (DMO) 16. SRF and the second will be TRC: AOFFSET. Select Grid ¦ Display. A general rule is to simultaneously process like offsets. and generate spider or histogram plots 14-10 ProMAX 2D Seismic Processing and Analysis Landmark . CDP. Also determine if it is appropriate to combine the traces by absolute offset or if the negative offsets should be processed separately from the positive offsets. CDP. This will generate new icons to rotate and move the grid. The first will be TRC: OFFSET. SRF. For this data.Chapter 14: Dip Moveout (DMO) of the cells. Now select Grid ¦ Parameterise. and see how your CDPs increment within each bin. Click on the Green Light icon. Notice that the near offsets would only need a bin width of 220 ft.You should have 15 offset bins displayed. the far offset bin center is 6380. The “dx” should be the offset bin spacing. If AOFFSET is used. the far offset bin centers are -3300 and +6380. and fill in the values as displayed. Click MB3 on the top left icon in XYGraph. with a bin increment of 440. and we have 15 offset bins. for continuous CDP coverage. and we have 23 bins. but the far offsets need a bin width of Landmark ProMAX 2D Seismic Processing and Analysis 14-11 . if OFFSET is used. the near offset bin center is 220. the near offset bin centers are -220 and +220. The “dy” should be the length of the line in CDP’s. “ny” to 215. If you change “dy” to 1. 14-12 ProMAX 2D Seismic Processing and Analysis Landmark . From this display you can zoom in and QC that each offset bin has cells populated with continuous CDPs. and “Y origin” to 775 you will see a tight grid with a cell size of one CDP.Chapter 14: Dip Moveout (DMO) 440 ft. Build the following flow: Editing Flow: 8.1760-6160(440) Binned header entry values: ----------------------------------------------.Enter DMOOFF First Header Entry: -------------------------------------DMOOFF Disk Data Output Output Dataset Filename: ---CDP-dmooff/input to DMO 2. input the NMO corrected gathers with a primary header entry of CDP and a secondary header entry of AOFFSET.110-1430(220).Chapter 14: Dip Moveout (DMO) Assign DMO offset bins to the data In this exercise you will offset bin the data using the Trace Binning process. apply NMO in preparation for DMO.110-1430(220).1760-6160(440) Set OFFSET and AOFFSET headers to bin center: --Yes Database/Header Transfer Direction of transfer: ------------------------------------------------------------Load FROM Trace header TO database Number of parameters: --------------------------------------------1 First database parameter: -------------------------------------------------------TRC:Geometry:New . 1. In Disk Data Input.2-Assign DMO Offset Bins Add Delete Execute View Exit Disk Data Input Select dataset: --------------------------CDP-decon/refr/resid Trace Read Option: ----------------------------------------------Sort Interactive Data Access?: ---------------------------------------No Select primary trace header entry: ------------CDP Select secondary trace header entry: AOFFSET Sort order for dataset: -------------------------------*:*/ Trace Binning Header entry to bin: ------------------------------------AOFFSET Binned header entry: -----------------------------------DMOOFF Binned entry format: -------------------------------------------Real Header entry bin centers: ---------------------------------------------------. and QC the output common offset ensembles. Landmark ProMAX 2D Seismic Processing and Analysis 14-13 . Output the gathers to a new dataset “CDP-dmooff/input to DMO”. Enter the bin centers from 110 to 1430 with an increment of 220. 14-14 ProMAX 2D Seismic Processing and Analysis Landmark . 6.Chapter 14: Dip Moveout (DMO) 3. 4. 5. Output the same values to a new header entry called DMOOFF. If you plan to further process the DMO gathers. If you wish you can vary the bin spacing more along the line. Transfer the DMOOFF header to the database by setting a new database value DMOOFF (floating point). yet still have 100% CDP coverage. you may want to set the OFFSET header word equal to DMOOFF values. Execute the flow. Remember our primary goals are to have the maximum number of bins. The discussion at the beginning of this section describes how to calculate these numbers.and bin centers from 1760 to 6160 with an increment of 440 based on the absolute offset. 8. Landmark ProMAX 2D Seismic Processing and Analysis 14-15 . Now lets QC the DMO offset bin centers in the database.CDP. Each DMO offset bin will now be displayed in a different color. select Color ¦ Edit. since its label will be an 8 digit unix parsed name. You may have to use the mouse button help on the bottom left of the window to help you locate which database entry is DMOOFF. and select the contrast.Chapter 14: Dip Moveout (DMO) 7. When selected click Display. From the color editor menu select File ¦ Open. From the XYGraph menu.rgb color file.DMOOFF. Select Database ¦ XDB Database Display ¦ 3D ¦ XYGraph ¦ TRC:AOFFSET. Edit the 8.1 flow to display the results of your DMO binning: Editing Flow: 8. It is used here to stack all like numbered CDPs within the same offset panel.*:*/ Ensemble Stack/Combine Type of operation: --------------------------------------Stack only How are trace headers determined?: --Average Secondary key bin size: -------------------------------1 Maximum traces per output ensemble: ------------------215 Warnings if max traces/ensemble exceeded?: --------Yes Select PRIMARY Trace Order Header Word: ---DMOOFF Average the X and Y coordinates of primary key?: ---No Select SECONDARY Trace Order Header Word: -----CDP Output trace secondary key order: --------------Ascending Pad Traces Header word to use for padding: --------------------------CDP Spacing of header value: ------------------------------------------1 Remove traces?: ----------------------------------------------------No Explicitly define the bounds of header values?: ------Yes First trace header value: --------------------------------------775 Last trace header value: ---------------------------------------989 Trace Display Primary trace LABELING header entry: ---------DMOOFF Secondary trace LABELING header entry: ------------CDP 10. The Ensemble Stack/Combine step should be used when DMOOFF has been built from AOFFSET. In Disk Data Input.DMO Binning Add Delete Execute View Exit Disk Data Input Select dataset: --------------------CDP-dmooff/input to DMO Trace Read Option: -------------------------------------------SORT Interactive Data Access?: ---------------------------------------No Select primary trace header entry: ----DMOOFF Select secondary trace header entry: --------CDP Sort order for dataset: -----------------------------.1. In Trace Display annotate DMOOFF and CDP. input the gathers sorting on DMOOFF:CDP.Chapter 14: Dip Moveout (DMO) 9. 14-16 ProMAX 2D Seismic Processing and Analysis Landmark . This display will show how many CDP traces exist per bin and will also show any gaps or unpopulated CDPs in the offset plane. Are the trace gaps in the DMO offset panels reasonable? If not you will need to adjust you offset binning parameters and re-run flow 8. Landmark ProMAX 2D Seismic Processing and Analysis 14-17 . 12.Chapter 14: Dip Moveout (DMO) Use pad traces to insert a dead trace whenever the spacing between CDPs is greater that 1. 11. Execute the flow.2. Common Offset F-K DMO works in F-K space using the Stolt stretch technique to account for vertical velocity variations. such as common shot gathers. or common offset data. This process may be run in the shot mode for datasets with irregular shooting geometries instead of the F-K DMO. In a typical processing sequence. NMO DMO Inverse NMO Velocity Analysis Re-iterate this process until the difference between input and output velocities in velocity analysis is small. try the following sequence.Chapter 14: Dip Moveout (DMO) DMO Both F-K and integral DMO methods are available in ProMAX. which can be applied to arbitrary ensembles of input traces. common receiver gathers. Ensemble DMO in the T-X Domain is a Kirchhoff implementation. The data should be binned into common offsets in preparation for this process. Since DMO may enhance stacking velocity picks. DMO follows statics and NMO. 14-18 ProMAX 2D Seismic Processing and Analysis Landmark . input the gathers using DMOOFF as the primary sort key and CDP as the secondary key. In Disk Data Input. Select Common Offset F-K DMO parameters. 1.*:*/ Common Offset F-K DMO CDP interval: ------------------------------------------------------27.5 Typical common-offset trace spacing: -------------------27. Landmark ProMAX 2D Seismic Processing and Analysis 14-19 . 3.3-DMO Add Delete Execute View Exit Disk Data Input Select dataset: --------------------CDP-dmooff/input to DMO Trace Read Option: ------------------------------------------SORT Select primary trace header entry: ----DMOOFF Select secondary trace header entry: --------CDP Sort order for dataset: -----------------------------.6 Maximum memory to use (in Mbytes): -----------------------4 Re-apply trace mutes?: -----------------------------------------Yes Re-kill dead traces?: ---------------------------------------------Yes Disk Data Output Output Dataset Filename: -----------------------DMO-gathers Disk Data Input Select dataset: ---------------------------------------DMO-gathers Trace Read Option: ------------------------------------------Get All Trace Display 2. Header entry to use for offsets: ---------------------DMOOFF Maximum frequency (in HZ): -----------------------------------80 Perform dip filtering?: -------------------------------------------Yes Get RMS velocities from database?: -----------------------Yes Select RMS velocity file: --vels from precompute DMO stretch factor: -----------------------------------------------0.5 Maximum number of CDPs in dataset: ------------------215 Maximum offset in data: ------------------------------------6600. Build the following flow: Editing Flow: 8.Chapter 14: Dip Moveout (DMO) Apply DMO to the data. 14-20 ProMAX 2D Seismic Processing and Analysis Landmark . 4. select File ¦ Exit/Continue Flow. build a flow that sorts the data to CDP and views the gathers. otherwise the job will stop without outputting the entire dataset. and view the common offset planes after DMO. 6. label DMOOFF and CDP. In Disk Data Output. In Trace Display. After viewing a few of the offset planes after DMO. output the DMO applied data. 7. change the Trace Display ensembles per screen to 215 and execute. Execute the flow. 8. Remember to select the continue flow option. Optional: After the DMO job finishes. Change the sort to CDP in Disk Data Input. In a typical processing sequence you would apply inverse NMO and repick velocities. Toggle off the first three processes in the above flow.Chapter 14: Dip Moveout (DMO) Input the same velocity field used to NMO correct the input gathers. 5. Use your flow “11-Compare Stacks” to examine the differences between the DMO stack. Landmark ProMAX 2D Seismic Processing and Analysis 14-21 . it probably resulted from a bad trace.4-DMO Stack Add Delete Execute View Exit Disk Data Input Select dataset: ---------------------------------------DMO-gathers Trace Read Option: -------------------------------------------SORT Interactive Data Access?: ---------------------------------------No Select primary trace header entry: ------------CDP Sort order for dataset: ---------------------------------*/ CDP/Ensemble Stack ----Default all parameters---- Trace Display Label Trace label: ----------------------------------------------DMO Stack Disk Data Output Output Dataset Filename: ----------------------------STK-dmo Trace Display Primary trace LABELING header entry: ---------------None Secondary trace LABELING header entry: ------------CDP 2. and the regular stack. Optional: Replace Common Offset F-K DMO with Ensemble DMO in the T-X Domain. 5. Build the next flow to stack results. Editing Flow: 8.Chapter 14: Dip Moveout (DMO) Final Stack 1. Ensemble DMO in T-X Domain process will output as many traces per CDP per bin as were input by producing copies of the output traces. or apply an AGC prior to DMO. You could either go back and kill the bad trace. In Disk Data Input. 4. Select an output dataset name. 3. If you notice any large artifacts from the DMO process. Execute the flow. and examine the stack. 6. input your DMO data in CDP sort order. Build and execute a flow to compare the output gathers and stacks. Chapter 14: Dip Moveout (DMO) Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • • Can you Common Offset Bin data for input to DMO Are you familiar with the input parameters to DMO Do you understand the basic theory of DMO 14-22 ProMAX 2D Seismic Processing and Analysis Landmark . trace mixing. Dynamic S/N Filtering. You can use these processes in conjunction with windowed processing to limit the signal enhancement processing over a specific time window. and BLEND t Trace Math Landmark ProMAX 2D Seismic Processing and Analysis 15-1 . In this chapter we will cover F-X Decon and Dynamic S/N Filtering as well as techniques to subtract adjacent traces (Trace Math) and to add back (BLEND) a proportion of the original data to the processed data. F-K and bandpass filtering. Topics covered in this chapter: t F-X Decon.Chapter 15 Poststack Signal Enhancement ProMAX offers a variety of poststack signal enhancement tools including eigenvector filtering. This chapter explores some of ProMAX’s techniques of reducing noise and enhancing signal in poststack data. PostStack Signal Enhancement To further clean up and optimize the stack. Upon completion of this chapter you should: • • Be familiar with F-X Decon and Dynamic S/N Filtering techniques Understand how to use Trace Math to enhance stacks 15-2 ProMAX 2D Seismic Processing and Analysis Landmark . some type of poststack signal enhancement is almost always applied.Chapter 15: Poststack Signal Enhancement Chapter Objectives 9. Chapter 15: Poststack Signal Enhancement F-X Decon, Dynamic S/N Filtering, and BLEND F-X Decon is a tool designed to attenuate random noise on your stack. This process transforms data from time and distance to frequency and distance. Each sample in the transformed data has both real and imaginary components. Events with similar dip appear as complex sinusoids along a given frequency slice. Therefore, the signal is predictable. F-X deconvolution uses a complex prediction filter to predict the signal one trace ahead, across the frequency slice. Any difference between the predicted waveform and the actual waveform is considered noise and removed. Similar to F-X Decon, Dynamic S/N (Signal to Noise) Filtering transforms the data into frequency and distance and calculates noise in the same manner as described above. However, Dynamic S/N Filtering applies an amplitude only convolutional filter to each trace based on the signal to noise ratio. Therefore, unlike F-X Decon, there is little mixing or lateral smearing of data. BLEND is a tool which is useful for attenuating the effects of a given process by adding or subtracting a chosen ratio of input data to the processed data. Signal Enhancement In this exercise, you will compare the results of your residual statics stack, with stacks that are processed with signal enhancement techniques. Landmark ProMAX 2D Seismic Processing and Analysis 15-3 Chapter 15: Poststack Signal Enhancement 1. Build the following flow: Editing Flow: 9.1-Poststack Enhancement Add Delete Execute View Exit Disk Data Input Select dataset: ---------------------------------------------STK-dmo Reproduce Traces Trace grouping to reproduce: --------------------------All Data Total Number of datasets: ----------------------------------------4 IF Trace Display Label Trace label: ------------------------------------------Original Input ELSEIF SPECIFY trace list: ---------------------------------------------------2 Trace Display Label Trace label: -------------------------------------------------FX Decon F-X Decon TYPE of filter: ------------------------------------Wiener Levinson Percentage of white noise: ---------------------------------------0. Horizontal window length: -------------------------------------50 Number of filter samples: -----------------------------------------5 Time window length: -----------------------------------------1000 Time window overlap: ------------------------------------------100 F-X filter start frequency: -----------------------------------------3 F-X filter end frequency: -----------------------------------------90 Re-apply trace mute after filter?: ---------------------------Yes ELSEIF Trace Display Label BLEND F-X Decon ELSEIF Trace Display Label Dynamic S/N Filtering ENDIF Disk Data Output Automatic Gain Control Trace Display 15-4 ProMAX 2D Seismic Processing and Analysis Landmark Chapter 15: Poststack Signal Enhancement Editing Flow: 9.1-Poststack Enhancement Add Delete Execute View Exit Disk Data Input Reproduce Traces IF Trace Display Label ELSEIF Trace Display Label F-X Decon ELSEIF SPECIFY trace list: ---------------------------------------------------3 Trace Display Label Trace label: --------------------------------------FX Decon/Blend BLEND Ratio of processed/original: ----------------------------------1:2 F-X Decon ----Use same parameters as the previous F-X Decon---- ELSEIF SPECIFY trace list: ---------------------------------------------------4 Trace Display Label Trace label: ------------------------------Dynamic S/N Filtering Dynamic S/N Filtering Horizontal window length: -------------------------------------20 Time window length: -----------------------------------------1000 Time window overlap: ------------------------------------------100 F-X filter start frequency: -----------------------------------------3 F-X filter end frequency: -----------------------------------------90 Re-apply trace mute after filter?: ---------------------------Yes ENDIF Disk Data Output Output Dataset Filename: -----STK-signal enhancement Automatic Gain Control ----Default all parameters---- Trace Display Primary trace LABELING header entry: ---------------None Secondary trace LABELING header entry: ------------CDP Landmark ProMAX 2D Seismic Processing and Analysis 15-5 Chapter 15: Poststack Signal Enhancement 2. In Disk Data Input, input your residual statics stack. 3. Make four copies of your stack with Reproduce traces and choose a trace grouping of All Data. 4. Set up an IF-ELSEIF-ENDIF conditional with Trace Display Labels to easily compare the results of the different signal enhancement tools with your original stack. Enter the Repeat number to pass through this portion of the flow. Please refer to the chapter on parameter analysis if you are not familiar with the IF-ENDIF conditional logic. 5. Select F-X Decon and Dynamic S/N Filtering parameters. Refer to the online helpfiles for parameter selection of these processes. Note that the BLEND function applies to the process immediately following. 6. Output the four copies of the dataset with Disk Data Output. This dataset will be used in the next flow. 7. Execute the flow. View the 2D filtered data, and compare the stacks using the animation tool. Which dataset looks the most mixed? 15-6 ProMAX 2D Seismic Processing and Analysis Landmark Chapter 15: Poststack Signal Enhancement Trace Math Trace Math will allow you to add, subtract, multiply or divide adjacent traces, or apply a scalar to the traces. We will use this process to subtract stacks created using different processing techniques. Use Trace Math to view differences between stacks 1. Create the following flow: Editing Flow: 9.2-Trace Math Add Delete Execute View Exit Disk Data Input Select dataset: ---------------------STK-signal enhancement Trace Read Option: ----------------------------------------------Sort Select primary trace header entry: ------------CDP Select secondary trace header entry: --REPEAT Sort order for dataset: ---------------------------*:2,1/ Trace Math MODE of operation: ---------------------------------Trace/Trace TYPE of trace/trace operation: ------------Subtract Traces Honor ensemble boundaries: ----------------------------------No Trace Display Label Trace label: --------------------------------------FX Decon - Input Trace Display Primary trace LABELING header entry: ---------------None Secondary trace LABELING header entry: ------------CDP 2. In Disk Data Input, input the file you just created, and select the FX Decon copy, and the Original Input copy. 3. In Trace Math, select Trace/Trace for the mode of operation, and Subtract Traces. 4. In Trace Display Label, indicate which stacks have been subtracted. 5. Execute the flow. Landmark ProMAX 2D Seismic Processing and Analysis 15-7 Chapter 15: Poststack Signal Enhancement A display representing the difference between the two stacks appears on your screen. Ideally all of the energy in this difference display would be noise that was removed by the FX Decon. The presence of actual signal in this display might indicate a need to try different parameters in the FX Decon. 6. Experiment with the different trace scaling methods from within Trace Display. 15-8 ProMAX 2D Seismic Processing and Analysis Landmark Chapter 15: Poststack Signal Enhancement Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • Are you comfortable with F-X Decon and Dynamic S/N Filtering Are you comfortable with Trace Math Landmark ProMAX 2D Seismic Processing and Analysis 15-9 Chapter 15: Poststack Signal Enhancement 15-10 ProMAX 2D Seismic Processing and Analysis Landmark . using two different velocity tools. Topics covered in this chapter: t Velocity Viewer/Point Editor t Velocity Manipulation Landmark ProMAX 2D Seismic Processing and Analysis 16-1 . Modeling Preparation of your velocity field for migration is a crucial step in the imaging process. we will discuss how to edit and modify velocity fields. You may need to smooth the field in space and/or time and change the field type from a stacking (RMS) field to an interval velocity field. Manipulation of velocity fields is necessary for other purposes such as seismic trace inversion. Editing. In this chapter. finite difference modeling and time to depth conversion.Chapter 16 Velocity: QC. You will also need to convert your velocities from the floating processing datum to the final flat datum. Editing. Upon completion of this chapter you should: • • Be able to use the Velocity Viewer/Point Editor Be able to Manipulate the Velocities to various formats 16-2 ProMAX 2D Seismic Processing and Analysis Landmark .Chapter 16: Velocity: QC. You will also need to convert your velocities from the floating processing datum to the final flat datum. PostStack Migration Velocity Modeling Preparation of your velocity field for migration is a crucial step in the imaging process. Modeling Chapter Objectives 10. In this chapter. using two different velocity tools. You may need to smooth the field in space and/or time and change the field type from a stacking (RMS) field to an interval velocity field. we will discuss how to edit and modify velocity fields. x). enabling you to scan through a velocity field. This tool also lets you smooth the velocity field and convert stacking velocities to interval velocities. you will edit and smooth a velocity field that was created with the Velocity Analysis tool. and Finite Difference Migrations need Vint(t. Modeling Velocity Viewer/Point Editor Velocity Viewer/Point Editor is a stand-alone module.x). Remember that FK Migrations need Vrms(t. Phase Shift Migrations need Vint(t). A typical use of this tool is to analyze velocities for anomalous points that need editing. and analyze the interpolation between the control points. Editing. and convert to interval velocity In this exercise. Landmark ProMAX 2D Seismic Processing and Analysis 16-3 . identify and edit velocity control points. You will then convert the RMS velocities to interval velocities in time. Smooth RMS velocities.Chapter 16: Velocity: QC. unrealistic velocities are frequently computed when converting stacking velocities to interval velocities. These edited velocity fields will be used in the chapter on migrations later in the manual. This tool ensures that a reasonable velocity field is passed to the migration. In particular. Chapter 16: Velocity: QC. Select Velocity Viewer/Point Editor parameters. 16-4 ProMAX 2D Seismic Processing and Analysis Landmark . Modeling 1. Editing. 3. Build the following flow: Editing Flow: 10. Execute the flow. Maximum depth (or time) of velocity field to edit: --------0 2. Select an output name of “Smoothed for FK Mig” for the RMS velocities and “Converted Stacking Vels” for the interval velocities.1-Velocity Editing Add Delete Execute View Exit Velocity Viewer/Point Editor* Select the type of field you wish to edit: --------------------------------------------------------Stacking (RMS) Velocity Do you wish to edit an existing table?: -------------------Yes Select input velocity database entry: ----------------------------------------------------vels from precompute Do you wish to specify the bounds of the field?: ------No Select output velocity database entry: ---------------------------------------------------------------Smoothed for FK Mig Specify an alternative name for the output interval velocity?: -------------------------------------------------Yes Select output Interval velocity database entry: ----------------------------------Converted Stacking Vels Minimum depth (or time) of velocity field to edit: --------0. Select Stacking (RMS) Velocity field as the type of field to edit. A velocity control point generally consists of a vertical group (or function) of velocity-time pairs at a certain CDP location. To view these control points. the function does not change as the mouse moves across the velocity locations. Edit velocity control points.Chapter 16: Velocity: QC. Move the mouse pointer from location to location and watch as the blue function changes in the edit window. Click MB2 near one of the locations to freeze the function in the edit window. click on the Edit Vel Function icon and move your mouse into the velocity field. Landmark ProMAX 2D Seismic Processing and Analysis 16-5 . Modeling Edit Edit Vel Function Function to Edit(Pink) Function to Compare(Blue) Interval Velocity 4. you must edit the control points that define the velocity. Editing. To edit the velocity field. You will also notice that the function nearest the mouse pointer changes from a solid line to a dashed line. 7. the velocity field can be updated by clicking on the Update button on the top of the edit window. Click the Edit icon on the right of the edit window. apply a general smoothing. and follow the mouse button help to edit the pink function. This saves the “Smoothed for FK MIg” file to disk for use in the FK Migration. Once your velocity field has been edited to your satisfaction.Chapter 16: Velocity: QC. From the menu bar select Modify ¦ Smooth Velocity field. Smoothing Parameter window 6. This brings up the Smoothing Parameters window. 16-6 ProMAX 2D Seismic Processing and Analysis Landmark . then re-smooth the velocities. Once your velocity field is sufficiently smooth. Editing. Examine the results of the smoothing process. select Modify ¦ Undo last change. Enter the smoothing parameters as indicated above. select File ¦ Save table to disk. If you want to undo the smoothing and try again with different parameters. You should now have a blue line and a pink line in the edit window. Modeling Click MB1 near a different velocity location. After editing. 5. and select OK. Modeling 8. If there are large anomalies in the interval velocity field. Editing. you may compute and display Interval Velocities by selecting Modify ¦ Convert RMS to Interval Velocity ¦ Smoothed gradients Dix equation. and then convert to interval velocities again. Once you are satisfied with your interval velocity field. you may need to select Modify ¦ Undo last change. You can also directly edit and smooth this interval velocity field in the same manner as described above for the RMS velocities.Chapter 16: Velocity: QC. 9. This will save the “Converted Stacking Vels” file to disk for use in the FD Migration. Landmark ProMAX 2D Seismic Processing and Analysis 16-7 . select File ¦ Save table to disk and exit. After you have saved your smoothed velocity field. perform more editing on the RMS field. Shift smoothed RMS velocities to final datum In this exercise. Editing. datumize velocities. you will output three new velocity functions. Modeling Velocity Manipulation Velocity Manipulation is used to convert one type of velocity to another. apply a percentage. 16-8 ProMAX 2D Seismic Processing and Analysis Landmark . and/or smooth velocities. you will shift your smoothed RMS velocity field to final datum for later use in F-K migration. an interval velocity field shifted to final datum. The new functions will be a RMS field shifted to final datum. and a single average interval velocity function shifted to final datum.Chapter 16: Velocity: QC. In this section. Landmark ProMAX 2D Seismic Processing and Analysis 16-9 . Select Stacking (RMS) velocity for both the input and output types.1-Velocity Editing Add Delete Execute View Exit >Velocity Viewer/Point Editor*< Velocity Manipulation* Type of velocity table to input:--Stacking (RMS) Velocity Get velocity table from database?: -------------------------Yes Select input velocity database entry: -----------------------------------------------------Smoothed for FK Mig Combine a second velocity table with the first?: -------No Resample the input velocity table(s): -----------------------No Shift or stretch the input velocity table?: ------------------No Adjust velocities to the final datum?: ---------------------Yes Maximum percentage to change velocities during datuming: --------------------------------------------------30 Type of parameter table to output:----------------------------------------------------------------Stacking (RMS) Velocity Select output velocity database entry: ------------------------------------Smoothed at datum for FK Mig Spatially resample the velocity table?:---------------------No Output a single average velocity table?: ------------------No Smooth velocity field?: -------------------------------------------No Vertically resample the output velocity table?: ---------No Adjust output velocities by percentages?: ----------------No 2. Modeling 1.Chapter 16: Velocity: QC. you could QC the file by inputting the field into the Velocity Viewer/Point Editor. Editing. Select your smoothed velocity field as input. 3. Select Yes to “Adjust velocities to the final datum?” 4. Once you have created the new velocity table. and assign a output name. Execute the flow. Edit your flow: Editing Flow: 10. Execute the flow. Select Yes to “Adjust velocities to final datum?” 4.Chapter 16: Velocity: QC. you will shift your interval velocities to final datum for later input to FD migration. Select Interval Velocity in time as the input and output table types. Once you have created the new velocity table.1-Velocity Editing Add Delete Execute View Exit >Velocity Viewer/Point Editor*< Velocity Manipulation* Type of velocity table to input:--Interval Velocity in time Get velocity table from database?: -------------------------Yes Select input velocity database entry: ------------------------------------------------Converted Stacking Vels Combine a second velocity table with the first?: -------No Resample the input velocity table(s): -----------------------No Shift or stretch the input velocity table?: ------------------No Adjust velocities to the final datum?: ---------------------Yes Type of parameter table to output:-----------------------------------------------------------------Interval Velocity in time Select output velocity database entry: ---------------------------------Converted vels at datum/FD Mig Spatially resample the velocity table?:---------------------No Output a single average velocity table?: ------------------No Smooth velocity field?: -------------------------------------------No Vertically resample the output velocity table?: ---------No Adjust output velocities by percentages?: ----------------No 2. 3. Editing. Edit your flow to output interval velocities at final datum: Editing Flow: 10. and assign an output file name. 16-10 ProMAX 2D Seismic Processing and Analysis Landmark . Modeling Shift interval velocities to final datum In this exercise. you could QC the file by inputting the field into the Velocity Viewer/Point Editor. Read in your interval velocity file. 1. Select No to “Adjust velocities to final datum?”. and assign an output filename. and select Yes to “Output a single average velocity table?” 4. Modeling Output a single interval velocity function In this exercise you will output a single interval velocity function in time to be used in Phase Shift migration. Landmark ProMAX 2D Seismic Processing and Analysis 16-11 . Execute the flow. 3.1-Velocity Editing Add Delete Execute View Exit >Velocity Viewer/Point Editor*< Velocity Manipulation* Type of velocity table to input:--Interval Velocity in time Get velocity table from database?: -------------------------Yes Select input velocity database entry: -----------------------------------Converted vels at datum/FD Mig Combine a second velocity table with the first?: -------No Resample the input velocity table(s): -----------------------No Shift or stretch the input velocity table?: ------------------No Adjust velocities to the final datum?: ----------------------No Type of parameter table to output:-----------------------------------------------------------------Interval Velocity in time Select output velocity database entry: ------------------------------------One Function at datum/PS Mig Spatially resample the velocity table?:---------------------No Output a single average velocity table?: -----------------Yes Smooth velocity field?: -------------------------------------------No Time step sizes for the output velocity table: ------------30 Adjust output velocities by percentages?: ----------------No 2. Editing.Chapter 16: Velocity: QC. Select Interval Velocity in time as the input and output table types. Read in your interval velocities at final datum. 1. Edit your flow to output a single average function: Editing Flow: 10. Chapter 16: Velocity: QC. Editing. Modeling Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • Are you comfortable with the Velocity Viewer/Point Editor Can you Manipulate the Velocities to various formats 16-12 ProMAX 2D Seismic Processing and Analysis Landmark . Finite Difference. Reverse Time.Chapter 17 PostStack Migration The ProMAX suite of 2D migration tools includes pre and poststack time and depth migration and migration velocity analysis. The available poststack migrations are of the F-K. To aid in this selection. and Kirchhoff types. The goal is to migrate the stack section with the most appropriate poststack migration process. Topics covered in this chapter: t Poststack Migration Processes t Tapering t Poststack migration using: • • • FK migration Phase Shift migration FD migration Landmark ProMAX 2D Seismic Processing and Analysis 17-1 . this chapter includes a brief description of the processes. Phase Shift. The Reference Manual and cited references give further detail. Upon completion of this chapter you should: • • Understand Tapering and other Migration Parameters Be familiar with running FK.Chapter 17: PostStack Migration Chapter Objectives 10. To aid in this selection. PostStack Migration Velocity Modeling The ProMAX suite of 2D migration tools includes pre and poststack time and depth migration and migration velocity analysis. and FD Migrations 17-2 ProMAX 2D Seismic Processing and Analysis Landmark . this chapter includes a brief description of the processes. The goal here is to migrate the stack section with the most appropriate poststack migration process. Phase Shift. the following is a summary of the poststack migrations and how they handle changes in velocity and dip: PostStack Migrations Migration Name Category Type Velocity V(x) V(t/z) Steep Dip Fair Good Fair Good Fair Good Good Good Good Good Excel.Eikonal Max. workload.z) Poor None Fair Fair Fair Fair None Good Fair Good Excel.0 14. To help you decide on the optimal migration for a given situation.t) VINT(x.t) VINT(t) VINT(x.0 64.0 10.0 Memory Stolt F-K Phase Shift Fast Explicit FD Time Steep Dip Explicit FD Time Kirchhoff Time Reverse Time T-K Explicit FD Depth Kirchhoff Depth F-K Phase Shift FD FD (70 deg) FD (50 deg) Kirchhoff Reverse Time FD Imp.z) VINT(x.t) VINT(x. Rel Times 0.Chapter 17: PostStack Migration PostStack Migration Processes Choosing a poststack migration process can be difficult. Mult.5 21. dataset.3 12. and processing parameters. You must weigh CPU time. Often.6 2.Amp.z) VINT(x. NOTE: These tests were run on an IBM 370 RS6000 system.6 21. Poor Good Good Good Good Good Good Good Good Good Excel.t) VRMS(x. accuracy of velocity structure. a number of different migrations must be run in order to compare results. and other factors.t) VINT(t) VINT(x. Landmark ProMAX 2D Seismic Processing and Analysis 17-3 . Time Time Time Time Time Time Time Depth Depth Depth Depth VRMS(x.2 1.0 9. steepness of imaging dip.7 7. Arr. in order to choose the most appropriate process.z) VINT(x. Your times will depend on your specific environment. 17-4 ProMAX 2D Seismic Processing and Analysis Landmark . Upper edge taper default is 2 traces Bottom Lower edge taper default is 20 traces taper default is 200ms A Hamming taper is used. which consists of a cosine weighting that varies from 100% to 8% over the length of the horizontal taper. The bottom taper goes from 100% to 0%. as migration artifacts originating deeper in the section tend to move a longer distance. it allows you the change the tapering values. This does not turn off the taper. instead. there is a parameter that asks if you want to change the default tapering.Chapter 17: PostStack Migration Tapering Tapering is automatically applied to samples at the bottom and edges of the seismic section prior to migration. This prevents migration artifacts due to the abrupt truncation at the bottom of the input section (see diagram below). The magnitude of the edge taper should normally increase with depth. In the migration processes. If you have steeply dipping events near the edge of your data you may want to pad traces rather than the taper the edges. you will run a FK migration on your data. smoothed. Landmark ProMAX 2D Seismic Processing and Analysis 17-5 . shifted to datum). a pre-processed input velocity parameter table (edited. you should have your best stacked dataset with statics and velocities applied. and an idea of the types of migrations you would like to run. Apply FK migration In this exercise.Chapter 17: PostStack Migration Poststack Migration At this point. Build the following flow: Editing Flow: 10.2-FK Migration Add Delete Execute View Exit Disk Data Input Select dataset: -------------------------------------------------STK-dmo Memory Stolt F-K Migration Minimum CDP to migrate: ------------------------------------------775 Maximum CDP to migrate: -----------------------------------------989 CDP interval (ft or meters): ---------------------------------------27.5-10-60-70 Automatic Gain Control ----Default all parameters---- Trace Display Primary trace LABELING header entry: ------------------NONE Secondary trace LABELING header entry: -----------------CDP 2. In Disk Data Input.5 Maximum frequency to migrate (in Hz): ------------------------80 Get RMS velocities from database?: ----------------------------Yes Select velocity file: -Smoothed at datum for FK Mig Number of traces to smooth velocity field over: ---------------0 Percent velocity scale factor: ---------------------------------------95 Stolt stretch factor: ----------------------------------------------------0.Chapter 17: PostStack Migration 1.6 Apply Stolt obliquity correction?: --------------------------------Yes Change maximum memory usage?: -----------------------------No Change the default tapering?: -------------------------------------No Re-apply trace mutes?: ----------------------------------------------Yes Re-kill dead traces?: --------------------------------------------------Yes Trace Display Label Trace label: -------------------------------------------------FK Migration Disk Data Output Output Dataset Filename: -------------------------------MIG-fk mig Bandpass Filter Ormsby filter frequency values: --------------------. 17-6 ProMAX 2D Seismic Processing and Analysis Landmark . input your best (DMO) stack dataset. 5. select File ¦ Exit/Continue flow. Set the velocity scaling factor. Set FK migration parameters. Landmark ProMAX 2D Seismic Processing and Analysis 17-7 . 4. Select your smoothed velocity field at final datum. After examining your migration in Trace Display. Normal ranges are 85-100 percent. Execute the flow.Chapter 17: PostStack Migration 3. 5 Minimum frequency to migrate (in Hz): ------------------------------0 Maximum frequency to migrate (in Hz): ---------------------------80 Get INTERVAL-velocity-versus-time function from database?: -----------------------------------------------------Yes Select velocity file: ---One Function at datum/PS Mig Percent velocity scale factor: ------------------------------------------95 Migrate dips: -------------------------up to and beyond 90 degrees Maximum amount of memory (in Mbytes): -----------------------16 Change the default tapering?: ----------------------------------------No Re-apply trace mutes?: -------------------------------------------------Yes Re-kill dead traces?: ----------------------------------------------------Yes Trace Display Label Trace label: ----------------------------------------------------PS Migration Disk Data Output Output Dataset Filename: ---------------------------------MIG-ps mig Bandpass Filter Ormsby filter frequency values: -----------------------. and add Phase Shift Migration: Editing Flow: 10.3-Phase Shift Migration Add Delete Execute View Disk Data Input Select dataset: ----------------------------------------------------STK-dmo Phase Shift Migration Minimum CDP to migrate: --------------------------------------------775 Maximum CDP to migrate: --------------------------------------------989 CDP interval (ft or meters): ------------------------------------------27. 3. Copy your previous flow. input your best (DMO) stack dataset.Chapter 17: PostStack Migration Apply Phase Shift Migration 1. Select Phase Shift migration parameters. In Disk Data Input.5-10-60-70 Automatic Gain Control ----Default all parameters---- Trace Display Primary trace LABELING header entry: ---------------------NONE Secondary trace LABELING header entry: --------------------CDP 2. 17-8 ProMAX 2D Seismic Processing and Analysis Landmark . Execute the flow. 4. After examining your migration in Trace Display. 5. Set the velocity scaling factor.Chapter 17: PostStack Migration Select your smoothed velocity field at final datum. Normal ranges are 85-100 percent. select File ¦ Exit/Continue flow. Landmark ProMAX 2D Seismic Processing and Analysis 17-9 . Chapter 17: PostStack Migration Apply FD Migration 1. time velocity file: ---------------------------------------------------Converted vels at datum/FD Mig Change paneling parameters?: --------------------------------------No Change the default tapering?: ----------------------------------------No Retain input sample rate?: --------------------------------------------Yes Re-apply trace mutes?: -------------------------------------------------Yes Re-kill dead traces?: ----------------------------------------------------Yes Trace Display Label Trace label: ---------------------------------------------------FD Migration Disk Data Output Output Dataset Filename: ---------------------------------MIG-fd mig Bandpass Filter Ormsby filter frequency values: -----------------------. Copy your previous flow. and add FD Migration: Editing Flow: 10. 17-10 ProMAX 2D Seismic Processing and Analysis Landmark .5-10-60-70 Automatic Gain Control ----Default all parameters---- Trace Display Primary trace LABELING header entry: ---------------------NONE Secondary trace LABELING header entry: --------------------CDP 2.4-FD Migration Add Delete Execute View Disk Data Input Select dataset: ----------------------------------------------------STK-dmo Fast Explicit FD Time Mig. CDP interval (ft or meters): ------------------------------------------27.5 Maximum frequency (in Hz): -------------------------------------------80 Time step for migration diffraction term: ---------------------------0 Percent to pad trace length: --------------------------------------------30 Get interval velocities from database?: --------------------------Yes Select interval vs. input your best (DMO) stack dataset. In Disk Data Input. Execute the flow.3-Compare Stacks”. Landmark ProMAX 2D Seismic Processing and Analysis 17-11 . 5. Select FD migration parameters.Chapter 17: PostStack Migration 3. 4. Choose to retain input sample rate. select File ¦ Exit/Continue flow. to compare the various migration datasets to the input stack. Use your previous flow “5. Select your interval velocity field at final datum. Compare Migrations 1. After examining your migration in Trace Display. Chapter 17: PostStack Migration Chapter Summary Upon completion of this chapter you should be able to answer the following questions: • • Do you understand Tapering and other Migration Parameters Are you comfortable running FK. and FD Migrations 17-12 ProMAX 2D Seismic Processing and Analysis Landmark . Phase Shift. Appendix 1 Additional Geometry Information This chapter contains appendix additional information on the geometry assignment processes. Topics covered in this chapter: t Geometry Core Path Overview t Details of the Geometry Programs t Pre-Geometry Database Initialization t Inline Geometry Header Load after Pre-Initialization Landmark ProMAX 2D Seismic Processing and Analysis 1-1 . and x.y information in the headers. and station information exist in the headers and do you want to use it? * Do you want to minimize the number of times that you have to read the data? * Do I have “Valid Trace Numbers”? Table Diagram Question Is shot and receiver station.Appendix 1: Additional Geometry Information Geometry Core Path Overview How to Decide on the Primary Geometry Path Vector Diagram OPTIONS * Pre-Initialization no yes * Full Extraction no no yes * From Field Notes and Survey no yes QUESTIONS * Does Shot and Receiver X. Y. do you want to use it? Do you want to minimize the number of times to read the data? Answer Yes Option Full Extraction No Yes Ask the next question From Field Notes and Survey No Partial Extraction 1-2 ProMAX 2D Seismic Processing and Analysis Landmark . Yes Inline Geom Header Load by valid trace number. The following question determines how to match a trace in the data file to a trace in the database: Question Was a Full or Partial Extraction used to create the database and a new output file written? Answer No Option Inline Geom Header Load by Chan and other trace header words. Landmark ProMAX 2D Seismic Processing and Analysis 1-3 . the information contained in it is transferred to trace headers.Appendix 1: Additional Geometry Information Transferring the Database to Trace Headers When the database is completed. The outcome from running this program is to have a database and a data file that "match". We will see that this program is one of the ways that the "valid trace number" can be generated by running it in either the Partial or Full extraction modes. Another program that may be used in the geometry assignment procedure is called Extract Database Files.Appendix 1: Additional Geometry Information Details of the Geometry Programs In this section we will look in detail at the functions performed by the main programs used in the geometry assignment process. • 1-4 ProMAX 2D Seismic Processing and Analysis Landmark . In order to utilize the "valid trace number" we will have to spend some time discussing it’s origin and how it can be used. One of the options is to use a specific trace header word called the "valid trace number". The specific processes that will be addressed are: • • • Inline Geom Header Load Extract Database Files Geometry Header Preparation Inline Geom Header Load is the main program used to assign geometry values to individual trace headers from the OPF database files. One of the main issues related to this geometry assignment procedure is to define how a trace in a data file will be identified in the Trace Ordered Parameter file. We will look specifically at how it can be used when dealing with the problem of duplicate Field File Identification Numbers. This program can be used for a variety of different purposes. Steps Performed by Inline Geom Header Load • Inline Geom Header Load is the program that populates the trace headers of an input data file with the geometry information stored in the database. Geometry Header Preparation is another program that may be selected in the geometry assignment procedures. After a successful run each trace will also be assigned the "valid trace number" if it was not pre-assigned using Extract Database Files. The "valid trace number" is simply a ProMAX trace header word. an individual midpoint X and Y location and many other values that are single numbers. • • • • Landmark ProMAX 2D Seismic Processing and Analysis 1-5 . or may not be different for every trace. SRF (receiver) and CDP. A "valid trace number" combined with matching geometry is a flag that will allow fast random access sorting of disk datasets. to read the "valid trace number" from the input trace header. Every trace in the TRC database is assigned to a single SIN (shot). • Understanding this will help us decide on the "best" course of action for our data. This is a unique number for each trace in the line or 3D project. let’s make sure that we understand the idea of the "valid trace number". • There are two major options in this program pertaining to how to identify a trace in the input data file with a trace in the database. Once a trace in a data file has been identified in the Trace OPF. Every trace in the database is numbered from 1 to N. Every trace has an individual Shot to Receiver Offset distance. the information in all of the OPF’s for that trace is copied to the trace header.Appendix 1: Additional Geometry Information • This means that every trace in the output data file exists in the database and there is a one to one correspondence in all values in the trace header to those in the database. to read the recording channel number (automatic) and 1 or 2 trace header words that can uniquely identify this trace as having originated from a unique shot (SIN) that exists in the shot database. where N is the total number of individual traces in the database. These options are: 1. Valid Trace Numbers Before we proceed. or 2. that may. In this case the "valid trace number" is pre-assigned. Steps Performed By Extraction The steps performed by the extraction options are: Pre-Geometry Initialization (or partial extraction) which is sometimes used when no receiver information exists in the incoming headers. The last thing that happens is that the traces are "stamped" as matching the database. You may consider using Extract Database Files if there is sufficient information in the trace headers that can be transferred to the database which will save time and increase accuracy of the geometry definition process. • The "valid trace number" is a unique number for every trace and is stored in the trace header as TRACE_NO. If it is not pre-assigned. the Inline Geom Header Load process will create it after it determines which trace in the database corresponds to a trace in a data file. Valid Trace Number Origin Where does the "valid trace number" trace header word come from? Luckily.Appendix 1: Additional Geometry Information • Inline Geom Header Load matches the current trace being processed to the database and then copies all of the trace dependent values as well as the other order values to the trace header. • The Extract Database Files program writes this trace header word after it reads and counts a trace that it is entering into the TRC database. Partial Extraction counts each of the following: • the number of traces encountered 1-6 ProMAX 2D Seismic Processing and Analysis Landmark . This trace header word continues to exist ONLY if you write a new trace file after the extraction procedure. the answer to this is very simple. A common question that arises concerns the decision to pre-assign the "valid trace number" using Extract Database Files or to rely on the alternate header identification on the first read of the input data. The extraction may be run in either the partial extraction or full extraction modes depending on what information is available in the trace headers of the input data. After the Spreadsheets are complete. you can continue with the next step of loading the geometry information from the databases to the trace headers. With the database complete. AND have not altered the number of traces in the database. Between Extraction and Geom Load After running Extract Database Files in either mode there are many steps that need to be completed prior to running the Inline Geom Header Load. You may elect to address a trace by it’s "valid trace number" Landmark ProMAX 2D Seismic Processing and Analysis 1-7 . This mapping will be performed by Inline Geom Header Load after the database is completed.Appendix 1: Additional Geometry Information • the number of shots encountered • the number of traces per shot and then • writes the trace count number and SIN to the trace header Full Extraction is used when you want to extract the shot and receiver location and coordinate information from the incoming headers. AND written a new trace data file. More work will generally need to be done in the Spreadsheets to input the remaining information. the next step would be to complete the CDP binning procedures and then finalize the database. The extraction only partially populates the database. Full Extraction counts each of the following: • the number of traces encountered • the number of shots encountered • the number of traces per shot • the number of receivers encountered • the number of traces per receiver and then • writes the trace count number and SIN to the trace header IF you have run the extraction in either mode. you now have “valid trace numbers” in the headers of the output data set which you can use to map a trace in a data file to a trace in the database. Geometry Load Procedures For the first option. the key to the second option is that you need to identify which shot a trace came from by a "unique" combination of header words for that shot. the TRACE_NO is copied to the headers and the steps outlined in the first option are performed. cdp. Again. The appropriate values from those orders are then copied to the trace headers as well. inline.Appendix 1: Additional Geometry Information assigned during the extraction or you may read a combination of trace headers to identify the trace. receiver. Inline Geom Header Load does not know exactly which TRACE_NO it is looking for. 2) it copies the appropriate TRC order values to the trace header and then 3) finds the shot. Given that this mapping is unique. and offset bin for that trace. In the second option. crossline. Once the entry is found. 1-8 ProMAX 2D Seismic Processing and Analysis Landmark . the program now knows which SIN and CHAN to look for in the TRC database. Inline Geom Header Load operates as follows: 1) it identifies the TRACE_NO of the incoming trace and finds that trace in the TRC database. It does know which channel and shot to look for based on the header word(s) that you selected. An SRF OPF could be created. selecting Yes to the option for PreGeometry Extraction.Appendix 1: Additional Geometry Information Pre Geometry Database Initialization Note: In general. Basically this process counts how many traces.Pre-Init Path O.B. Therefore. Notes UKOOA ASCII Field Data SEG-? Input Manual Input UKOOA Import Spreadsheet Import Database Import Geometry Spreadsheet Ordered Parameter Files Marine Data SSD correction Seismic Data (ProMAX) Inline Geom Header Load Extract Database Files Seismic Data (ProMAX) Builds TRC and SIN OPF’s only Pre Geom Init = yes Disk Data Output Valid Trace Numbers Overwrite Trace Headers Seismic Data (ProMAX) Landmark ProMAX 2D Seismic Processing and Analysis 1-9 . it can build the TRC and SIN ordered database files. and recording channels were present for each input FFID. and may or may not have any information in it. To create a minimum set of entries in the SIN and TRC Ordered Parameter files. this process is not recommended for medium to large volume 3D projects. Partial Extraction Flow Chart Disk Output . different FFIDs. based upon the information found in the trace headers of the data passed through the flow. number of channels are written to the database.Appendix 1: Additional Geometry Information This option may be appropriate for relatively small datasets which only have FFID and CHAN in the input trace headers. number of shots. This information will be extracted. In so doing. In the following example. Selecting this option will also stamp the output dataset with “valid trace numbers”. This option should be used when reading the field data and writing the data to disk for the first time. you will assume that only the FFID and recording channel number exist in the incoming trace headers. and are then available when the geometry is completed. This is an important concept for the Inline Geom Header Load process. using the perform pre-geometry database initialization option in Extract Database Files. such as FFID. information. 1-10 ProMAX 2D Seismic Processing and Analysis Landmark . which allows you to process with trace headers only and overwrite the dataset with updated geometry from the database files. 1-Pre-Geom Initialization Add Delete Execute View Exit SEGY Input Type of storage: --------------------------------------. 2. File?: ----------------------------------------New Record length to output: ------------------------------------------0.Appendix 1: Additional Geometry Information Pre Geometry Initialization flow 1. Trace sample format: ----------------------------------------16 bit Skip primary disk Storage?: -----------------------------------No 3. Enter the parameters for the SEGY-Input process: Enter the full path name to the SEGY input dataset as described by the instructor. Landmark ProMAX 2D Seismic Processing and Analysis 1-11 . Build the following flow: Editing Flow: A1. or Existing. 4. select to identify which traces belong to which shots and receivers as follows: Sources: identify by FFID. In Extract Database Files. There are 120 traces per ensemble.Disk Image Enter DISK file path name: ---------------------------------------------------------------/misc_files/2d/segy_0_value_headers MAXIMUM traces per ensemble: ---------------------------120 Remap SEGY header values: -------------------------------.NO Extract Database Files Is this a 3D survey: ------------------------------------------------No Data Type: --------------------------------------------------------LAND Source index method: -----------------------------------------FFID Receiver index method: ------------------------------STATIONS Mode of operation: ----------------------------------OVERWRITE Pre-geometry extraction?: --------------------------------------Yes Disk Data Output Output Dataset Filename: ----------------”Shots-raw data” New. Make a new line called “from pre-initialization”. The only OPF files that should exist are LIN. verifying the number of records in the dataset. and the FFID range. the number of channels/record. the next steps would be to complete the Sources. 9. This initializes the SIN and TRC domains of the Ordered Parameter Files. 7. and allows for the use of overwrite mode when performing the Inline Geom Header Load step later. 6. 1-12 ProMAX 2D Seismic Processing and Analysis Landmark . SIN. Execute the flow. Check the OPFs. and TRC. Receivers and Patterns Spreadsheets and perform the CDP binning similarly to the sequence used in Chapter 1: Geometry Assignment. After the Flow Completes 8. If SRF exists. this means that you identified traces for receivers by coordinates. Complete the Spreadsheet In this sequence. You will also find that the SRF OPF has 1 value in it. enter the name for a new output file. Exit the flow building level and select Database from the global command line. select Yes for the option Pre-geometry extraction. stamps the dataset with valid trace numbers. 5. In Extract Database Files. such as “Shots-raw data”. In Disk Data Output.Appendix 1: Additional Geometry Information Receivers: identify by STATIONS. or Existing. build the following flow: Editing Flow: A1. Trace sample format: ----------------------------------------16 bit Skip primary disk Storage?: -----------------------------------No 2. File?: --------------------------------Overwrite Record length to output: ------------------------------------------0. we ran the Extract Database Files process in the preinitialization mode. enter your input shot dataset. In this sequence. we will read the output data from the preinitialization step and identify a trace relative to its “valid trace number” with respect to the database. If the geometry in the database looks good.2-Load Geom to Headers and QC Add Delete Execute View Exit Disk Data Input Read data from other lines/surveys: ----------------------No Select Dataset: --------------------------------”Shots-raw data” Trace read option: --------------------------------------------Get All Read the data multiple times?: -------------------------------No Process trace headers only?: ---------------------------------Yes Override input data’s sample interval: --------------------No Inline Geom Header Load Match by valid trace number?: ------------------------------Yes Drop traces with NULL CDP headers?: --------------------No Drop traces with NULL receiver headers?: ---------------No Verbose Diagnostics?: --------------------------------------------No Disk Data Output Output Dataset Filename: ----------------”Shots-raw data” New. Load Geometry to Trace Headers 1. Here. we only process the trace headers. In Disk Data Input.Appendix 1: Additional Geometry Information Inline Geometry Header Load after Pre Initialization In this sequence. Landmark ProMAX 2D Seismic Processing and Analysis 1-13 . 1-14 ProMAX 2D Seismic Processing and Analysis Landmark . you have a “valid trace number” to identify a trace. In the Extract Database Files path. You must then correct the situation by changing the geometry found in the OPFs. You have binned all traces. the Inline Geom Header Load process operates on a sequential trace basis. We will use the overwrite option in conjunction with trace header only processing in the Disk Data Input. In Disk Data Output. do not drop any traces. therefore. Unless you have a problem. Since the traces were read and counted with Extract Database Files. 4. The Inline Geom Header Load process will fail if these numbers do not correspond. match the traces by their “valid trace numbers”. output to the same dataset as specified in Disk Data Input. and includes a check to verify that the current FFID and channel information described in the OPFs matches the FFID and channel information found on each trace of each ensemble. there is no need for verbose diagnostics. Execute this flow. or possibly by changing the input dataset attributes. In Inline Geom Header Load.Appendix 1: Additional Geometry Information 3. 5. Examples include: Velocity Analysis. and Velocity Quality Control. Topics covered in this chapter: t Create Supergather t Create Supergather and Horizontally Stack Landmark ProMAX 2D Seismic Processing and Analysis 2-1 . This exercise is useful to help understand the mechanism employed in creating supergathers in these various processes. ProMAX incorporates the functionality to create supergathers in a number of analysis and quality control processes. Interactive Velocity Analysis.Appendix 2 Supergathers Supergathers are ensembles which were created by combining two or more regular CDPs to form a single ensemble. and any other processes which might benefit from reduced spatial separation between traces in a CDP gather. post-NMO mute definition. Supergathers are commonly used for velocity analysis and quality control. 1. In Disk Data Input.850-852/ Automatic Gain Control ----Default all parameters---- >Ensemble Stack/Combine< Trace Display Number of ENSEMBLES (line segments)/screen: -------3 Primary trace LABELING header entry: ----------------CDP Secondary trace LABELING header entry: ------OFFSET 2.” In other words. how the traces are grouped.Appendix 2: Supergathers Create Supergather Creating supergathers is really a matter of redefining a trace flag which establishes the “end-of-ensemble. 2-2 ProMAX 2D Seismic Processing and Analysis Landmark . mutes. or offset gather. if a process redefines the value for the END_ENS header word. and gain. The following exercise will illustrate how you may control trace grouping with a process called Ensemble Stack/ Combine. such as shot record. then it is able to regroup the traces. CDP. When END_ENS = 1. such as edits. this alerts any process that the last trace in an ensemble has been reached. Sort by CDPs 850-852. Editing Flow: A2. This way. The header word is called the End-of-ensemble flag (END_ENS) and its value is either 1 or 0 (one or zero). select a dataset with some initial processing applied. Build a simple flow to input and display three CDPs.1-Create Supergather Add Delete Execute View Exit Disk Data Input Select dataset: ----------------------------------Shot-decon/elev Trace read option: -----------------------------------------------Sort Interactive Data Access?: ---------------------------------------No Select primary trace header entry: -----------------------CDP Sort order for dataset: -------------------------------. In Trace Display. Also.Appendix 2: Supergathers 3. Your screen should look similar to the following: Landmark ProMAX 2D Seismic Processing and Analysis 2-3 . set the Number of ensembles/screen large enough to allow all three CDPs on the screen at one time. Execute the flow. label primary and secondary header entries as CDP and OFFSET in the Trace Display menu. 4. Use the Header icon to display several trace headers.Appendix 2: Supergathers 5. Be sure to check the last trace in any one of the ensembles. What is different? 2-4 ProMAX 2D Seismic Processing and Analysis Landmark . The value of the End-of-ensemble flag (END_ENS) header word can change from trace to trace. 1-Create Supergather Add Delete Execute View Exit Disk Data Input Automatic Gain Control Ensemble Stack/Combine Type of operation: ---------------------------------Combine Only Input ensembles per output ensemble: ----------------------3 Maximum traces per output ensemble: --------------------60 Warnings if max traces/ensemble exceeded?: --------Yes Select PRIMARY Trace Order Header Word: ----------CDP Average the primary key values?: ---------------------------No Average the X and Y coordinates of primary key?: --No Select SECONDARY Trace Order Header Word: -------------------------------------------------------------------OFFSET Output trace secondary key order: --------------Ascending Trace Display Landmark ProMAX 2D Seismic Processing and Analysis 2-5 . Select Combine only for the Type of Operation.Appendix 2: Supergathers 6. Editing Flow: A2. inputting three ensembles per output ensemble. Activate Ensemble Stack/Combine in your flow to create one superCDP. select primary and secondary header words as OFFSET. Also in this menu. This option will only reset the END_ENS flag for the first three CDPs so that the result is one single CDP. Execute the flow and compare your results to the original. 2-6 ProMAX 2D Seismic Processing and Analysis Landmark . It should look similar to the following: You might use this type of operation to create a super-CDP with better offset coverage prior to Velocity Analysis.Appendix 2: Supergathers 7. Editing Flow: A2.Appendix 2: Supergathers Create Supergather and Horizontally Stack 1. Landmark ProMAX 2D Seismic Processing and Analysis 2-7 . Modify Ensemble Stack/Combine to use the Combine and Stack option for the type of operation. Set this value to 350. The reason for NMO will be clear in the next step. Insert NMO into the Create Supergather flow. After making this selection you will see a new parameter called Secondary Key Bin Size which was previously hidden.2-Create & Stack Supergather Add Delete Execute View Exit Disk Data Input Normal Moveout Correction SELECT Velocity parameter file: --------------------------------------------------------------------imported from ascii file Automatic Gain Control Ensemble Stack/Combine Type of operation: -------------------------Combine and Stack Input ensembles per output ensemble: ----------------------3 How are trace headers determined?: --------------Average Secondary key bin size: ---------------------------------------350 Maximum traces per output ensemble: --------------------60 Warnings if max traces/ensemble exceeded?: --------Yes Select PRIMARY Trace Order Header Word: ----------CDP Average the primary key values?: ---------------------------No Average the X and Y coordinates of primary key?: ---No Select SECONDARY Trace Order Header Word: -------------------------------------------------------------------OFFSET Output trace secondary key order: --------------Ascending Trace Display 2. The velocity function you use is not too critical. Appendix 2: Supergathers 3. Execute the flow. Notice the difference between this display and your last. Why are they different this time? One observation that should jump out is that there are fewer traces on the screen. You might use this type of operation to reduce the amount of data going into a Prestack Migration. The summation is dependent on which header word you select as a secondary key. and by the secondary key bin size. 2-8 ProMAX 2D Seismic Processing and Analysis Landmark . This is due to the summation of adjacent traces performed by the Stack portion of the Combine and Stack option. Topics covered in this chapter: t CVS (Constant Velocity Stack) Analysis t IVA (Interactive Velocity Analysis) Landmark ProMAX 2D Seismic Processing and Analysis 3-1 . ProMAX has several other velocity analysis options available. Two of these methods will be covered in this chapter.Appendix 3 Alternate Velocity Analysis Methods Besides the ‘Velocity Analysis’ tool covered earlier in this book. Then Stack Display can be used to display and pick the velocities the same way as done with the macro. In this case you may want to use the process Constant Velocity Stacks to create and output the CVS panels ahead of time. 3-2 ProMAX 2D Seismic Processing and Analysis Landmark . Random picks can be made on any constant velocity stack panel and a final gridded velocity table is output. Horizons may be easier to track if the whole section is seen. Constant velocity stacks of the entire line or a subset are produced for a specified range of velocities.Appendix 3: Alternate Velocity Analysis Methods CVS Analysis CVS Analysis is a macro process. CVS can be helpful in areas of complex structure where velocity trends can change along the seismic section. Creating constant velocity stacks can be a time consuming event especially if you have a large dataset with many panels to create. apply an AGC prior to stacking with constant velocities. In CVS Analysis.Appendix 3: Alternate Velocity Analysis Methods 1. maximum velocity and number of velocity panels. use all the CDPs in the line. For this exercise. Sort to CDP and include the range of CDPs to be stacked. A Disk Data Input step is required since it is not included within the macro. Data should be preprocessed gathers without NMO and should have a bandpass filter and scaling function applied. Build the following flow: Editing Flow: A3. Select Disk Data Input parameters. Enter 7000 . 3.1-CVS Add Delete Execute View Exit Disk Data Input Select dataset: -----------------------Shots-decon/refr statics Trace read option: -----------------------------------------------Sort Interactive Data Access?: ---------------------------------------No Select primary trace header entry: -----------------------CDP Sort order for dataset: ---------------------------------------------*/ CVS Analysis Apply AGC to the data?: ---------------------------------------Yes AGC operator length: --------------------------------------------500 Maximum wavelet stretch: --------------------------------------30 Velocity input option: ----------------------------------Calculated Minimum velocity: ----------------------------------------------7000 Maximum velocity: -------------------------------------------17000 Number of velocity panels: -------------------------------------16 Select display DEVICE: -----------------------------This Screen Number of trace per display screen: ----------------------215 Do you wish to SCROLL your data?: -----------------------No Trace scaling option: -----------------------------------Individual SCALAR for sample value multiplication: ------------------1. Landmark ProMAX 2D Seismic Processing and Analysis 3-3 . Specify the minimum. 2.15000 ft/sec for an velocity range and create 16 panels. Click on Pick ¦ CVS/CVM panels ¦ Create new file and name it “cvs vels”. 3-4 ProMAX 2D Seismic Processing and Analysis Landmark . Activate the CVS/CVM picking mode. such as Individual. The last constant velocity panel will appear along with 16 screen swap boxes in the upper right of the display. The display will appear in the old Stack Display tool. 6. Select the number of traces to display per screen and an appropriate trace scaling option. Execute the flow with MB2. Selecting Individual as the trace scaling option will make sure that spikes do not dominate the display.Appendix 3: Alternate Velocity Analysis Methods 4. Click on the Pick icon to create a pick table. 5. 7. move the cursor back and forth within the stacked section.Appendix 3: Alternate Velocity Analysis Methods Move the cursor to the screen swap boxes in the upper right hand corner of the display and use MB2 to enable picking of the CVS panels. click MB1 in the screen swap boxes and then click MB2 in the screen swap boxes. To correct this error. While holding down MB2. Move your cursor into the displayed stacked section. you are not in CVS/CVM picking mode. If you don’t see the scroll icon and your cursor remains in the screen swap boxes. NOTE: You should see all the icons disappear except for the scroll icon and you should be able to move your cursor into the data area. This will enable the screen swapping. Pick velocities on the display by using MB1. 8. Landmark ProMAX 2D Seismic Processing and Analysis 3-5 . You should see the scroll icon remaining and you should be able to move your cursor into the data area. You can manually enter a velocity value at your cursor location by double clicking MB1. One file contains just the picks you made in the CVS Analysis display. Click the red Stop icon to exit the display. To finish picking. This can be useful if the desired velocity falls between the displayed panel velocities.Appendix 3: Alternate Velocity Analysis Methods Once you have found a velocity panel that stacks an event best. Hit enter to accept. 3-6 ProMAX 2D Seismic Processing and Analysis Landmark . NOTE: Upon exiting the CVS Analysis display. The second file is a fully interpolated velocity table based on the sparse picks you made on-screen. use MB1 to make a pick and to display it on-screen. two velocity tables are written to disk. click MB1 on any of the screen swap boxes in the upper right hand corner of the display. 9. A pop-up box will appear in the upper left hand corner of the display. You may now type in a velocity value. 10. Choose “Save all work to the database before quitting”. With the use of active image. Consult the Reference Manual for more specific details about a particular operation. velocity fans. Landmark ProMAX 2D Seismic Processing and Analysis 3-7 . stacks. gathers and an isovel plot for interactive picking of a velocity field. you see the appearance of real time moveout and stacking as the cursor is moved within the velocity fans. this exercise is designed to teach you the basic functionality of the program.Appendix 3: Alternate Velocity Analysis Methods Interactive Velocity Analysis (IVA) Interactive Velocity Analysis is a standalone process that allows comprehensive velocity analysis and quality control of a new or existing velocity field. IVA combines displays of semblances. Since IVA has many options and interactive capabilities. 75 3-8 ProMAX 2D Seismic Processing and Analysis Landmark . Build the following flow: Editing Flow: A3. below last knee: ----------------------------17500 Maximum Frequency: ---------------------------------------------70 Number of functions: ----------------------------------------------17 Span in CDPs for flip stack panels: --------------------------7 NMO Stretch Percent to allow: ---------------------------------30 Horizontal Enlargement Factor: ---------------------------0.75 Vertical Enlargement Factor: --------------------------------0.5 Maximum Offset bin center: --------------------------------6500 Common Offset bin center Inc: --------------------------------55 Common Offset bin Width: --------------------------------------55 Adjacent CDPs in Super Gather: -------------------------------9 Input (Initial) Velocity Table: -----imported from ascii file Output Velocity Table: ------------------------------------IVA vels Provide CDP mute Table?: --------------------------------------No Provide Horizon DATA Table?: --------------------------------No Minimum velocity: ----------------------------------------------7000 Maximum velocity: -------------------------------------------17000 Velocity Uncertainty at Tzero: -------------------------------900 Velocity Uncertainty at Tmax: -----------------------------3600 Interval Vel.2-IVA Add Delete Execute View Exit Interactive Vel Analysis* Operation Mode: --------------------------------Fully Interactive Input trace data file: --------------Shots-decon/refr statics Minimum CDP on line: ------------------------------------------775 Maximum CDP on line: -----------------------------------------989 Increment CDP on line: ---------------------------------------------1 Dataset CDP Restriction: ------------------All available data Super Gathers Options: -----------------------Common Offset Minimum Offset bin center: ----------------------------------27.Appendix 3: Alternate Velocity Analysis Methods 1. The output table is continuously updated as each new velocity function is picked. The same can be done for a horizon data table. However. Fully Interactive allows you to choose random locations once IVA is displayed and does not involve any precomputation. Velocity Uncertainty at Tzero and Tmax basically defines the bounds of your velocity fan. The menu asks for a minimum and a maximum velocity of interest plus an interval velocity below the last picked time or knee. 5. 6. 3. Select Fully Interactive for the Operation Mode. Precompute then Interactive allows you to specify CDPs at which to precompute analyses. or one can be created and interactively picked once IVA is running. It is not a filter. For example the default uses 900 ft/sec for Tzero meaning the fan will be no wider than 1800 ft/sec (900 on each side of the reference function) at Tzero. other random locations can still be selected. Supergathers can also be created for analysis. 4. you can move between locations more quickly. A post NMO mute table can be supplied provided it was created as a function of CDP:AOFFSET. Select or create the Input (Initial) and Output velocity Table. Enter velocity information and maximum frequency of data. Landmark ProMAX 2D Seismic Processing and Analysis 3-9 . Select your range of data to process. IVA allows the selection of a specific range of CDPs to process or All Available Data. The maximum frequency of the data is requested simply to internally resample the data to optimize screen resolution and execution time. 70 Hz is reasonable for this data. Once IVA is displayed.Appendix 3: Alternate Velocity Analysis Methods 2. For this data use a velocity range of 7000-17000 ft/sec and an interval velocity of 17500 ft/sec. The input velocity table and the output velocity table can be the same file or a new output table can be added. Provide a CDP Mute Table and/or a Horizon Data Table. Appendix 3: Alternate Velocity Analysis Methods 7. Enter the number of velocity functions and number of CDPs for the stack panels. As the number of velocity functions increases, the resolution improves, but the run time and resource requirements also increase. For this data, you can get adequate resolution using 15-17 velocity functions and 7 consecutive CDPs in the stack panels. 8. Execute the flow with MB2. The initial display includes a semblance plot, an isovel plot and a portion of the data stacked with the input velocity table. 9. Scan your data. The portion of the stacked data displayed is defined by the rectangle box in the isovel plot. Use MB3 with the cursor located in either the stack or the isovel to scroll through the data. Clicking on MB3 will 3-10 ProMAX 2D Seismic Processing and Analysis Landmark Appendix 3: Alternate Velocity Analysis Methods quickly jump to a new location on the isovel plot. The size of the box in the isovel plot is controlled by the Horizontal and Vertical Enlargement Factor. NOTE: The mouse button helps are very important in this process because they change according to where the cursor is located on the screen. 10. Select your CDP analysis location by clicking MB2 for a previously picked location or MB1 for a new location. CDP numbers are displayed below the stack section along with time and velocity. Use MB1 to pop up a menu with analysis mode options. Select Semblance, Stacks and Gathers. In the lower right corner of the screen the Notification Window shows that the stack, semblance and gather images are being computed. 11. Click on Config and select Expand/UnExpand Top. This option appears below the semblance plot and allows the reconfiguration of the display. Eliminate the isovel plot to allow more room for the semblance, stack and gather. Landmark ProMAX 2D Seismic Processing and Analysis 3-11 Appendix 3: Alternate Velocity Analysis Methods 12. Begin picking the velocity function by clicking on Pick. Select Velocity Function from the Pick Operation menu. A message appears in the notification window that reads “Picking Function Auto_scroll enabled.” You can freely scroll the mouse up and down the display. MB1 adds a control point (knee) to your function and MB3 deletes a control point. As you move the cursor within the calculated functions, the active screen images change within the flip stack and gather. Once you have finished picking your velocity function, while keeping the cursor within the semblance plot, use MB2 to save and write the function to the velocity table. Go back to the Config option and UnExpand your window. Your function is displayed as a downline in the isovels plot. Start again and select a new CDP location for analysis. 13. Changing the velocity bounds of your fan is possible by using the Vbound option located to the right of Pick. Click here and the notification window reads “Picking Vbound 1. Auto_scroll enabled.” Use MB1 to add control points to the lower vbound (left side). When you are finished, click MB2 and the notification window reads “Picking Vbound 2. Auto_scroll enabled.” Use MB1 to select your control points for the upper vbound. When finished, MB2 recomputes a new velocity fan with new gather and stack panels. 14. Mute Analysis can be run at any CDP location. Click on your analysis location. When the Analysis Mode menu pops up, select Mute Analysis. Wait for the computations to complete. Follow the same instructions as picking a function, click on the Pick option and select Top Mute from the menu. You will notice in the gather display that mute points have already been selected. To choose your own mute, use MB1 to select time/aoffset points. When finished, use MB2 to save the output. Gathers and stacks are recalculated and you are prompted to Update the Semblance. A mark is displayed on the isovel where the analysis was done. Your mute is saved in the Parameter File menu for Mute Gates and is automatically labeled as IVA with a time/date stamp. 15. Restack Line. To restack your line with the new velocities, click on Action and select Restack Line from the popup menu. The notification window informs you that your CDPs are being restacked. 3-12 ProMAX 2D Seismic Processing and Analysis Landmark Appendix 3: Alternate Velocity Analysis Methods 16. Exit. When you are ready to exit IVA, use the Exit located at the bottom of the screen. Select from the menu to either save to the database or to abort the IVA session. Your velocity table can be found in the Parameter Files for RMS (stacking) Velocity menu. Landmark ProMAX 2D Seismic Processing and Analysis 3-13 Appendix 3: Alternate Velocity Analysis Methods 3-14 ProMAX 2D Seismic Processing and Analysis Landmark Appendix 4 Database/Header Manipulation The database is critical to ProMAX. Many processing attributes, such as statics and first break picks are kept in the database. In this chapter we examine the links between the database and the trace headers by determining first break linear moveout corrections. We will also create and alter trace headers and database attributes. Topics covered in this chapter: t Header Manipulation Processes Landmark ProMAX 2D Seismic Processing and Analysis 4-1 Appendix 4: Database/Header Manipulation Header Manipulation Processes This exercise uses the following ProMAX Header Manipulation processes: • Trace Header Math: Trace header math has four modes of operation. The first three allow you to modify and/or create trace headers and the last changes global runtime attributes of the data, such as forcing the time to be depth. We will use the application called Fixed Equation Mode which allows us to create or modify headers using a mathematical function on existing header entries and constants. Database/Header Transfer: This process transfers up to 8 values at a time between the database and the trace headers. The transferred value can be loaded into an existing database attribute or trace header name, or you can create your own names. However, if you create your own database attribute, a random number represents the database name and the description is what you typed in. This random number can be changed to a meaningful name using the new/copy option in the database. Header Statics: This process applies statics to traces from header words or applies bulk shift statics. • • Apply a Linear Moveout Correction In this exercise, you will compute and apply a linear moveout (LMO) correction to the data. This will create a new trace header that you can transfer to the database. Finally you will view your new attribute in the database. 4-2 ProMAX 2D Seismic Processing and Anlaysis Landmark Appendix 4: Database/Header Manipulation 1. In Disk Data Input. input your raw shots with applied geometry.Enter LMO First Header Entry: ---------------------------------------------LMO Header Statics Bulk shift static: ------------------------------------------------------0 What about previous statics?: ---Add to previous statics Apply how many static header entries?: -------------------1 First Header word to apply: ---------------------------------LMO HOW to apply header statics?: -----------------------------Add Apply Fractional Static Trace Display Specify display END time: ------------------------------------500 Number of display panels: ---------------------------------------4 2. Landmark ProMAX 2D Seismic Processing and Analysis 4-3 . Build the following flow: Editing Flow: A4.1-Trace Header/Database Manip Add Delete Execute View Exit Disk Data Input Select dataset: ----------------------------Shots-with geometry Trace Header Math Select mode: ----------------------------------------Fixed equation DEFINE trace header equation: ----------------------------------------------------LMO=100-(AOFFSET/8000)*1000 Database/Header Transfer Direction of transfer: ---From Trace header to database Number of parameters: --------------------------------------------1 First database parameter: -------------------------------------------------------------TRC:Geometry:New . 8000 is the refractor velocity. 5. View your new LMO attribute in the database. 7. 1000 converts seconds to ms. For “First database parameter” select TRC: Geometry: New to enter a name for your LMO static header and make it Floating Point. Select Database/Header Transfer parameters. Execute the flow. the final LMO corrections are fairly large negative numbers. For “First Header entry” select User Defined and enter LMO. to the previous statics. In Trace Header Math. 6. Except for the near offsets. and observe the effects of the LMO.(AOFFSET/8000) * 1000 where: 100 is a bulk shift to move the trace samples away from time zero by 100 ms. 4. created in the Trace Header Math. You may find that setting this display to four panels. 4-4 ProMAX 2D Seismic Processing and Anlaysis Landmark .Appendix 4: Database/Header Manipulation 3. and limiting the time range from 0 to 500 ms is useful. Select to Load FROM trace header TO database. 8. Select Header Statics parameters. Set the Trace Display parameters. Add the LMO header entry. The following equation creates the LMO static time: LMO = 100 . create a static for applying a linear moveout correction to your data. Appendix 5 Training Summary This summary may be used as a quick reference for some of the most useful charts of information you have worked with during the week. Topics covered in this chapter: t Reference Tables t Reference Graphs t Flows and Data Summaries Landmark ProMAX 2D Seismic Processing and Analysis 5-1 . Contains information varying by offset bin number. Contains information varying by surface receiver location. Contains information describing the recording patterns. TRC (Trace) SRF (Surface location) SIN (Source Index #) CDP (Common Depth Point) CHN (Channel) OFB (Offset Bin) PAT (Pattern) The Ordered Parameter Files database stores information in structured categories. such as source x. nearest surface location. such as FB Picks. such as CDP x. surface location elevations. nearest surface location to source. such as channel gain constants and channel statics. representing unique sets of information applying to an individual line. such as surface consistent amplitude analysis. Contains information varying by CDP location. known as Orders.y coordinates. source statics.y coordinates. such as surface location x. source elevations. 5-2 ProMAX 2D Seismic Processing and Anlaysis Landmark . type of units. OFB is created when certain processes are run. number of traces received at each surface location. CDP elevation.Appendix 5: Training Summary Reference Tables Organization of Ordered Parameter Files LIN (Line) Contains constant line information. total number of shots. source type. Contains information varying by source point. CDP fold. source uphole times. and receiver fold. Contains information varying by trace. such as surface consistent amplitude analysis. surface location statics. source-receiver offsets. such as final datum. Contains information varying by channel number.y coordinates. trim statics. t) VRMS(x. Mult.6 21. Rel Times 0.5 21.t) VINT(t) VINT(x. Arr.0 10.3 12. the above table is a summary of the poststack migrations and how they handle changes in velocity and dip.2 1.t) VINT(t) VINT(x.z) VINT(x.7 7.z) VINT(x. Poor Good Good Good Good Good Good Good Good Good Excel. To help you decide on the optimal migration for a given situation.z) VINT(x.6 2.t) VINT(x.t) VINT(x.0 9.Eikonal Max. Landmark ProMAX 2D Seismic Processing and Analysis 5-3 .z) Poor None Fair Fair Fair Fair None Good Fair Good Excel.0 14.Appendix 5: Training Summary PostStack Migration Summary Migration Name Category Type Velocity V(x) V(t/z) Steep Dip Fair Good Fair Good Fair Good Good Good Good Good Excel.Amp. Time Time Time Time Time Time Time Depth Depth Depth Depth VRMS(x.0 Memory Stolt F-K Phase Shift Fast Explicit FD Time Steep Dip Explicit FD Time Kirchhoff Time Reverse Time T-K Explicit FD Depth Kirchhoff Depth F-K Phase Shift FD FD (70 deg) FD (50 deg) Kirchhoff Reverse Time FD Imp.0 64. Appendix 5: Training Summary Datum Statics Apply For Elevation Statics 1) Remove previously applied statics if TOT_STAT not equal 0 For Refraction Statics 1) Remove previously applied statics if TOT_STAT not equal 0 2) Compute S_STATIC and R R_STATIC to Final Datum 3) Compute N_DATUM (smooth surface / processing datum) 4) Partition the statics into PRE and POST NMO terms ----.FNL_STAT (post) 5) Apply the PRE NMO term NMO_STAT 6) Update NA_STAT and TOT_STAT in the Trace Headers 2) COPY refraction statics to S_STATIC and R_STATIC 3) Compute N_DATUM (smooth surface / processing datum) 4) Partition the statics into PRE and POST NMO terms ----.NMO_STAT (pre) ----.NMO_STAT (pre) ----. Refer to the following “Datum Statics Terminology” graph for a further description of the statics variables. 5-4 ProMAX 2D Seismic Processing and Anlaysis Landmark .FNL_STAT (post) 5) Apply the PRE NMO term NMO_STAT 6) Update NA_STAT and TOT_STAT in the Trace Headers ProMAX uses the above logic when applying datum statics. Appendix 5: Training Summary Reference Graphs Datum Statics Terminology S. CDP Receiver N_DATUM Surface Elevation Vweathering NMO_STAT NMO_STAT Shot Base Weathering Vreplacement S_STATIC F_DATUM FNL_STAT C_STATIC R_STATIC Database Attributes: N_DATUM = floating datum F_DATUM = final datum S_STATIC = (F_DATUM .C_STATIC TOT_STAT = cumulative applied statics NA_STAT = statics less than one sample period which are not-yet-applied (If TOT_STAT = 21.UPHOLE C_STATIC = 2 * [(N_DATUM .F_DATUM) / DATUMVEL] Trace Header Values: N_DATUM = floating datum NMO_STAT = S_STATIC + R_STATIC + C_STATIC FNL_STAT = .ELEV + DEPTH) / DATUMVEL] .2 ms. and the sample period is 4 ms.P. NA_STAT = 1.2 ms) Landmark ProMAX 2D Seismic Processing and Analysis 5-5 .ELEV + DEPTH) / DATUMVEL R_STATIC = [(F_DATUM . Notes ASCII Field Data Manual Input UKOOA Import Spreadsheet Import Database Import SEG-? Input Seismic Data (ProMAX) Extract Database Files Inline Geom Header Load Geometry Spreadsheet Ordered Parameter Files Disk Data Output Inline Geom Header Load Valid Trace Numbers Overwrite Trace Headers Seismic Data (ProMAX) Disk Data Output Seismic Data (ProMAX) 5-6 ProMAX 2D Seismic Processing and Anlaysis Landmark .Appendix 5: Training Summary Geometry Assignment Map All Possible Geometry Assignment Paths UKOOA O.B. exe super_exec.exe from command line /frame /sdi /3rd party software /lib lib*.exe from program /bin *.dat /scratch /queues /data /area /line (or $PROMAX_DATA_HOME) Landmark ProMAX 2D Seismic Processing and Analysis 5-7 ./ProMAX) /sys /exe exec.a /plot /help /port /promax *.rgb-colormaps ProMax_defaults /bin start-up executable config_file product install.help -ASCII help Application window /promax3d managers /promaxvsp /menu /promax *.Frame help /etc /lib/X11/app-defaults *..exe *.doc pvmhosts qconfig license..Appendix 5: Training Summary Promax Directory Structure $PROMAX_HOME (default=.lok .menu Processes /promax3d /promaxvsp /misc *_stat_math *. SIN Database subdirectory and a non-spanned file /OPF.output packet.SRF Database subdirectory and a span file /OPF.ELEV Understanding the ProMAX directory structure and file naming conventions will be crucial for debugging flows and managing disk space.job /OPF.Appendix 5: Training Summary Promax Data Directories PROMAX_DATA_HOME or /Data /Area DescName Project Area subdirectory and its files /Line DescName 17968042TVEL 31790267TGAT 36247238TMUT 12345678CIND 12345678CMAP /12345678 HDR1 HDR2 TRC1 TRC2 /Flow1 DescName TypeName job. 5-8 ProMAX 2D Seismic Processing and Anlaysis Landmark .GEOMETRY.GEOMETRY.SRF #s0_OPF60_SRF.ELEV 4) /OPF.SIN 1) Parameter Table files Index and Map Dataset files 2) Dataset subdirectory and Header and Trace Dataset files 3) A Flow subdirectory and its files OPF60_SIN. Appendix 5: Training Summary Flows and Data Summaries Flows Upon completion of the course your flows menu should look similar to the above. Landmark ProMAX 2D Seismic Processing and Analysis 5-9 . Appendix 5: Training Summary Datasets: Seismic Upon completion of the course your processing should have created the above datasets. Note: how the naming convention allows for clues as to the datasets contents. 5-10 ProMAX 2D Seismic Processing and Anlaysis Landmark . trim statics. Landmark ProMAX 2D Seismic Processing and Analysis 5-11 .Appendix 5: Training Summary Datasets: OPF-TRC The TRC “trace” database is the largest of the Ordered Parameter Files since it contains information varying by trace. source-receiver offsets. variable/info type. and variable description. Note: the format in the database table is variable name. such as FB Picks. surface location elevations. number of traces received at each surface location and receiver fold. surface location statics.Appendix 5: Training Summary Datasets: OPF-SRF The SRF “receivers” OPF contains information varying by surface receiver location. such as surface location x. 5-12 ProMAX 2D Seismic Processing and Anlaysis Landmark . y coordinates. y coordinates. such as source x. nearest surface location to source. source uphole times. Landmark ProMAX 2D Seismic Processing and Analysis 5-13 .Appendix 5: Training Summary Datasets: OPF-SIN The SIN “source” OPF contains information varying by source point. and source statics. source elevations. Appendix 5: Training Summary Datasets: OPF-CDP The CDP OPF contains information varying by CDP location. CDP elevation. y coordinates. 5-14 ProMAX 2D Seismic Processing and Anlaysis Landmark . such as CDP x. and CDP fold nearest surface location. Datasets: OPF-OFB The OPF “offset bin” OPF contains information varying by offset bin number. such as channel gain constants and channel statics.Appendix 5: Training Summary Datasets: OPF-CHN The CHN “channel” OPF contains information varying by channel number. such as surface consistent amplitude analysis. such as surface consistent amplitude analysis. OFB is created when certain processes are run. Landmark ProMAX 2D Seismic Processing and Analysis 5-15 . 5-16 ProMAX 2D Seismic Processing and Anlaysis Landmark .Appendix 5: Training Summary Datasets: OPF-PAT The PAT “pattern” OPF contains information describing the recording patterns. Landmark ProMAX 2D Seismic Processing and Analysis 5-17 .Appendix 5: Training Summary The End ProMAX 2D Seismic Processing and Analysis I hope the class was beneficial. wlf. Appendix 5: Training Summary 5-18 ProMAX 2D Seismic Processing and Anlaysis Landmark .
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