SEDIMENTARY BASINS OF INDIA, CATEGORIZATION AND HYDROCARBON POTENTIAL BY N.S.RANA CG, KDMIPE, ONGC DEHRADUN --/--/2013 The Indian scenario of Sedimentary Basins India is having vast Onland and Offshore area covered with sedimentary rocks. (Total: 3.14 million Sq Km, ie. 4.07% of the world’s total sedimentary area) WHAT IS SEDIMENTARY BASIN ? Sedimentary basins are Geosynclines, creating accommodation space for infilling the sediments. Sedimentary basins occur in diverse geological settings usually associated with plate tectonic activity. THE SEDIMENTARY BASINS WORLD WIDE . UNDERSTANDING ON THE EVOLUTION OF THE BASINS. WITH THE DEVELOPMENT OF PLATE TECTONICS. .EXPLAINED IN TERMS OF GEOSYNCLINAL THEORY. THEIR STRUCTURAL STYLES AND ASSOCIATED LITHOFACIES HAVE BECOME MUCH CLEARER.TILL 1960. . Sedimentation pattern in half graben set up . Sedimentary Depositional Environments (Clastics) The figure shows schematic representation of sedimentary environments which can be grouped as: Continental Transitional Marine 7 7 . Sedimentary Depositional System in Offshore . Indian Sedimentary Basins Explored / Unexplored Basin Area . 1976) GEOMETRIC SHAPE AND SIZE OF THE BASIN NATURE OF THE SEDIMENTARY FILL THE STRUCTURAL STYLES AND THE THERMAL HISTORY .EVOLUTION OF A SEDIMENTARY BASIN FOUR INDEPENDENT FACTS (DICKINSON. STAGES OF DEVELOPMENT AND EVOLUTION OF HYPOTHETICAL SEDIMENTARY BASIN A number of basins formed in extensional settings can undergo inversion. . which has accounted for a number of the economically viable oil & Gas reserves on earth. 35 million sq. km. the sedimentary area has been estimated about 1. The sedimentary basins of India. .Sedimentary Basins Of India Total 26 sedimentary basins have been recognized and they are divided into four categories based on their degree of hydrocarbon prospectivity. km.14 million sq. In the deep water offshore beyond the 200m isobath. area is about 1. onland and shallow offshore. up to the 200m isobath.79 million sq. The total area of sedimentary basins in Indian scenario works out to 3. km. CATEGORIZATION OF INDIAN SEDIMENTARY BASINS Category. Category – III basin comprises with no significant oil & gas shows but which are considered to be prospective on G&G analysis. These basins are: Kutch-Sourashtra & MBA( Mahanadi. Tripura. Ie. Cauvery and Krishna-Godavari Basins. Vyndhyan basin etc. Bombay offshore. It includes the basins which bear an analogy with hydrocarbon producing basins in the world. Cuddapah & Chattisgarh Syncline etc. Bangal & Andaman) Basins. These are mainly todays Frontier basins : Himalayan foreland. Ganga Basin. Category – IV basin comprises uncertain prospects. Cambay. These basins are: Assam shelf. Category – II basin comprises with occurrence of hydrocarbons but from which no commercial production has been obtained yet. . Deccan Plateau.I Basin is the petroliferous basins with proved hydrocarbon reserves and where commercial production has already started. I 2 6 1 BASINS WITH COMMERCIAL HYDROCARBONS PRODUCTION. 6. 7. 2. 1. 4. 3. 5. CAMBAY ASSAM SHELF BOMBAY OFFSHORE KRISHNA-GODAVARI CAUVERY ASSAM-ARAKAN FOLD BELT RAJASTHAN 3 4 5 .7 CATEGORY. 500 53.16.000 24.000 Rajasthan .000 1.000 55.000 1.000 52.16.000 Krishna Godavari 28.26.500 Cauvery 25.Category-I (Proven Commercial Productivity) Basin Name Assam-Arakan Onland Area Offshore Area Total 1.26.16.000 Cambay 51.000 - 1.16.000 Mumbai Offshore - 1.000 30.000 2.000 - 1. II BASINS WITH KNOWN ACCUMULATION OF HYDROCARBON BUT FROM WHICH NO COMMERCIAL PRODUCTION. ANDAMAN-NICOBAR . KUTCH 9. MAHANADI 10. 8.CATEGORY. 000 14.000 Mahanadi 55.000 41.000 13.000 .000 47.000 Andaman Nicobar 6.Category-II (Identified Prospectivity) Basin Name Onland Area Offshore Area Total Kutch 35.000 48.000 69. . 13. 15. 15 HIMALAYAN FOOTHILLS GANGA BASIN VINDHYAN KUTCH-SAURASHTRA KERALA-KONKAN-LAKSHWADEEP BENGAL Today’s frontiers may tomorrows cat.11 CATEGORY-III 14 BASINS GEOLOGICALLY CONSIDERED PROSPECTIVE WITH HYDROCARBONS. 11. 14. 13 12 16 . 16. I……. 12. 62.000 - 1.000 - 94.000 89.000 - 30.Category-III (Potentially Prospective Basins) Basin Name Bengal Ganga Valley Himalayan Foreland Kerala-Konkan Lakshdweep Saurashtra Vindhyan Onland Area Offshore Area Total 57.62.000 1.000 94.000 32.000 52.86.000 30.000 .000 1.000 28.000 80.86.000 - 1. 23. 21.SOUTH REWA. 24. 18. 19. 26.CATEGORY. 17.KALADGI CUDDAPAH PRANHITA.DAMODAR NARMADA DECCAN SYNECLISE BHIMA. 22. 25.IV BASINS WITH UNCERTAIN PROSPECTS WHICH MAY BE PROSPECTIVE ON ANALOGY WITH SIMILAR BASIN IN THE WORLD. 20.ZANSKAR SATPURA. KAREWA SPITI.GODAVARI BASTAR CHATTISGARH . . 000 2.000 - 22.000 - 32.73.73.000 - 2.000 8.000 Chattisgarh Cuddapah Deccan Syncline Karewa Narmada PranhitaGodavari .000 3.700 17.700 17.500 32.000 Satpura-South Rewa-Damodar 46.000 39.500 - 8.000 - 3.000 Spiti-Zanskar 22.000 39.000 - 46.000 15.000 - 15.000 - Total 5.Category-IV (Potentially Prospective ) Basin Name Bastar Bhima-Kaladgi Onland Offshore Area Area 5. DEEP WATER BASINS WESTERN OFFSHORE BASIN Mumbai Offshore and Kerala Kankan Offshore In Western offshore basin the reservoirs are mainly carbonates and maximum production of oil is from this basin. . .DEEP WATER BASINS EAST COAST OFFSHORE BASINS Cauvery Offshore KG Offshore and MBA Offshore In East cost offshore the reservoirs are mainly Clastics and & rich in gaseous hydrocarbon. Indian Sedimentary Basins Deepwater: 1.Km .000 Sq.350. ASSAM AND ASSAM-ARAKAN BASIN * ASSAM SHELF * ARAKAN FOLD BELT . . WESTERN ONLAND BASIN Rajsthan Basin Cambay Basin Kutch Basin Saurastra Basin . Rajasthan Basin( Jaisalmer. Bikaner-Nagour and Barmer Basins) . KHARTAR. .THE RAJASTHAN SHELF IS CARVED OUT INTO A NUMBER OF BASINS • JAISALMER BASIN • BIKANER-NAGAR BASIN • BARMER BASIN MAJOR OIL AND GAS FIELDS GHOTARU. SADEWALA TIBBA. BANIKA. MIAJALAR. CHINNEWALA TIBBA. BAKHRI TIBBA. . km.000 sq.THE CAMBAY BASIN : The Cambay Basin occupies an area of approximately 54. The Cambay Shale is the main source rock in this basin. . CAMBAY BASIN DIVIDED INTO FIVE TECTONIC BLOCKS FORM NORTH TO SOUTH: 1. SANCHOR – PATAN BLOCK 2. MEHSANA – AHMEDABAD BLOCK 3. TARAPUR – CAMBAY BLOCK 4. JAMBUSAR – BROACH BLOCK 5. NARMADA – TAPTI BLOCK CAMBAY BASIN MAJOR OIL FIELDS OF CAMBAY BASIN MEHSANA BLOCK- N. KADI, SANTHAL, BALOL, SOBHSAN, NANDASAN, LINCH, JOTANA, BECHRAJEE, LANGHNAJ, MANSA, MEWAD etc. AHMEDABAD BLOCKKALOL, WADU- PALIYAD, NAWAGAM, NANDEJ, AHMEDABAD, WASNA, JHALORA, SANAND, LIMBODRA, GAMIJ, ASMALI etc. ANKLESHWAR BLOCKANKLESHWAR, MOTERA, SISODRA, KIM, KOSAMBA, GANDHAR, PAKHAJAN, NADA, DABKA, JAMBUSAR, PADRA, KARZAN etc. WESTERN OFFSHORE BASIN Mumbai Offshore Basin & Keraka-Konkan Offshore Basin BOMBAY OFFSHORE BASIN: It lies in region of Western continental shelf of India and forms an important hydrocarbon bearing province. It is extending from Saurashtra Coast in the North to Vengurla arch near Goa in the South covering an area of about 1,20,000 sq.km. up to 200 m isobaths. Tectonically the basin can be subdivided into Surat depression, Bombay High, Ratnagiri block, Shelf margin basin and the Shelf-edge basement arc. Bombay Offshore Basin is producing nearly 70% oil and gas of India’s total hydrocarbon production. Major reservoirs are the Carbonates. WESTERN OFFSHORE BASIN(Mumbai Offshore) . MID MIOCENE EARLY MIOCENE . LATE OLIGOCENE EARLY OLIGOCENE . MID-LATE EOCENE LATE PALEOCENE-EARLY EOCENE . Prospects in Bombay Offshore Basin Dry Gas Oil . EAST COAST BASINS CAUVERI Basin KG-PG Basin MBA Basin . 000 sq. . Mannar sub-basin. The basin is subdivided into six sub-basin:1.CAUVERY BASIN The Cauvery Basin encompasses an area of 55. Tranquebar 3.Ariyalur Pondicherry 2. km. Thannjavur 4. Nagapatinam 5. Ramnad Palk Bay 6. Ariyalur-Pondicherry sub-basin Madanam horst Tranquebar sub-basin Kumbakonam horst Karaikal horst Nagapattinam sub-basin Tanjore sub-basin Pattukottai horst Mandapam horst Ramnad sub-basin Bouguer Gravity Anomaly Map of Cauvery Basin . GENERALISED STRATIGRAPHY OF CAUVERY BASIN . Kumbakonam ridge Tranquebar sub-basin Karaikal ridge Nagapattinam Sub-basin Vedaranyam ridge Pattukottai 10/09/15 ridge 3D view at Basement level showing various structural elements 47 . . KUTHALAM. KOVILKALAPPAM. PUNDI. VIJAYAPURAM. KAMLAPURAM. KUTHANALUR. NANNILAM.MAJOR OIL AND GAS FIELDS OF CAUVERI BASIN NARIMANAM. RAMNAD etc. BHUVNAGIRI. TIRVARUR. MATTUR. ADIYAKKAMANGALAM. KA ZA KA IKA LU RH PL KMT PF AU LT N H TA NU KU HI G IL LI GR AB E GR AB EN BA NT UM IGH GU DI VA DA BA PA TL A HI GH KG-PG Basin . . The basin contains about 7km thick sediments with several cycles of deposition and H/C occurrences ranging from PermoTriassic(Gondwana) to Plio-Pleistocene age .000 sq. Its onland part covers an area of 28. km up to 1000 m isobath.KRISHNA GODAVARI BASIN The Krishna Godavari Basin is a proven petroliferous basin of continental margin located on the east coast of India. km and the offshore part covers an area of 25.000 sq. Geological map: KG-PG Basin 30’ 800 00’ 820 30’ 820 00’ 30’ 810 00’ G E O L O G IC A L & T E C T O N IC M A P O F K R IS H N A -G O D A V A R I B A S IN 5 170 30’ 0 + SC A LE 10 30 50km + 170 30’ Tuni K h a m m a m p e tt P o la v a r a m P it h a p u r a m C h in ta la p u d i + 170 00’ + + + R a ja h m u n d r y + J a g g a y y a p e ta N u z v id + K A K IN A D A 170 00’ N u z iv d E LL O R E K a ik a lu r V IJ A Y A W A D A 30’ 30’ S a t t er nn aa pp aa l l el e G u n tu r + 160 00’ P a ru c h u ru + + + A v a n ig a d d a + + 0 16 00’ N iz a m p a tn a m A dd anki 30’ + O n g o le K S -3 + 30’ 0 15 00’ + 0 P L I O C E N E TO R E C E N T M IO C E N E TO P L IO C E N E T R A P W ITH IN T E R T R A P P E A N S / IN F R A T R A P P E A N S L O W E R E O C E N E TO P A L A E O C E N E T IR U P A T H I .VEM AVARAM K a v a li 14 30’ A L L U V IU M RA J AHM UN D RY + L O W E R C R E TA C E O U S UPPER G O N D W A N A G O LLA PA LLI .P A V A L U R + RA G HAVA PURA M .P A K H A L-S U L L A V A I P R E C A M B R A IN . E B G SR B C C H EN N A I 30’ 810 00’ 30’ 820 00’ 150 00’ 820 30’ 140 30’ .P R E C A M B R IA N N e llo r e 800 00’ LO W E R G O N D W A N A D R A W IN G S E C T IO N E & D .BU D A V A D A U P P E R J U R A S S IC C H IN TA L A P U D I U P P E R P E R M IA N TO L O W E R T R IA S S IC TA L C H IR / B A R A K A R L O W E R P E R M IA N C U D D A P A H .E A R L Y P A L A E O Z O I C M E TA M O R P H IC S ( D h a rw a r ’s ) A R C H A E A N . Geological/ Geophysical Surveys: ONGC has carried out detailed geological mapping in the area covering 4220 sq. . km since 1959. in onland part have been carried out by ONGC over an area of 19. Prakla Seismos and GSI acquired the gravitymagnetic data for ONGC. M/s.Gravity-Magnetic surveys. Composite Bouguer gravity & composite magnetic anomaly map . km. In offshore area.200 sq. BASIN FILL MAP – KRISHNA GODAVARI BASIN . 3.KRISHNA GODAVARI BASIN : This basin is divided into six sub-basins: 1. East Godavari sub-basin. Krishna sub-basin. 5. Mandapeta Sub-basin. 4. K. Nizamapatnam sub-basin & 6. 2. . Offshore sub-basin: -shallow offshore. West Godavari sub-basin. -deep offshore and -ultra-deep offshore.G. C H E N N A I. P E L .A .D W . D R A W IN G S E C TIO N . S R B C .D W . .III G AS G D -1 -1 RELEA SE D RAVVA & G O D A VA RI C LA Y P LA Y G O D A VA R I C LA Y (P L IO C E N E ) P L A Y G S-3 8 R A V V A P LA Y K G -O S-D W K G . .E G S-8 M A S U L IP A T N A M G 1 I N D E X O IL K G .F KV G S-2 9 G 2 G S-1 5 K G .IV 1 -B M A I.G RA LP M P B H IM A V A R A M LG A M A LA P U R A M AC PS G M I.K A K IN A D A M D K R IS H N A G O D A V A R I B A S IN 10 0 10 20KM EM M W YA N A M G R PM K K-1 2 SU 1 -A EG TP M L PO EL RZ LS KK VA AP M R NG I.B M G BN KP SI G S -2 3 -4 G S-2 3 RA V VA KW I.W E S T M W M A N D A P E TA .K G 1 .A KZ M M I.D W .M A R ’0 3 M A TS Y A P U R I / V A D A PA R U P LA Y F IE L D N A M E S : K D -1 -1 AC A C H A N TA KV K E SA V A D A SU PA LE M M M M U M M ID I V A R A M AP A D IV I P A L E M KW K E S A N A P A L L I.E X TN .W E S T P A S A R A L A P U D I/ P A L A K O L LU P L A Y BN B A N D A M U R U L A N K A .O S .O S . .O S .P L A Y .N O R TH LP LA N K A P A LE M NG N A N D IG A M A TIR U P A TH I P L A Y EG E N U G U PA LLI LG L IN G A L A PS PA SA R LA PU D I EL E L A M A N C H IL L I LS LA KSH M A N ESW A R A M PM PEN UM A D AM EM EN DA M URU M P M E D A PA D U PO PO N N AM AN AD A G R G O KA RN A PURAM M D M A N D A P E TA RA RAN G APURAM G M G O PA V A R A M M G M A G A TA P A L L I RZ R A ZO LE KK K A IK A L U R M A M A H A D E V A P A TN A M SI S IR I G A TTA P A L L E KZ K A ZA M R M O RI SU S U R Y A R A O P E TA KP K E SA N A P A LL I M L M U L IK IP A L L I TP TA TI P A K A VA V A D A LI RA G H AVA PURA M P LA Y K A N U K O LLU P LA Y N A N D IG A M A P L A Y G O LLA PA LLI P LA Y M A N D A P E TA P L A Y E & D . . deposited as basin fan floor complexes. Deposited as alluvial fans/ braided fluvial fans. . deltaic fan 58 under marginal marine environment.Hi gh Ka ik in e Ka Hi za gh Alluvial Fan Sh ch all an ow ne m l ar Ba p at la Hi gh Fan Delta ula r F po luv ba in ia rs t l Envisaged Depositional Model The environment of deposition has been envisaged to be fluvial to transitional during the earlier period of graben formation and transitional to marginal marine during the later stages. slope fan complexes. Sands within the syn rift are derived from the rift shoulders. Also. prograding as lobes with intervening lacustrine facies. Mandapeta. Bantumilli. Pasarlapudi. so far 141 prospects have been probed by 375 exploratory wells by ONGC. Enugupalli. Magatapalli.More than 225 prospects have been probed by drilling of more than 557 exploratory wells. In onshore. In offshore. Mori. Achanta. Kesavadasapalem. Gokarnapuram. so far more than 84 prospects have been probed by 182 exploratory wells . Hydrocarbon accumulations have been proven in 75 of these prospects (22 oil & 53 gas). Mullikipalle. . out of which 11 oil & gas pools and 31 gas pools have been discovered and most of them are on production. Lingala. Narsapur. The gas discoveries are Adavipalem. Chintalapalli. Endamuru. Tatipaka-Kadali. Notable oil discoveries are Kaikalur. Penumadam. Gopavaram. Suryaraopeta. Nandigama. Lakshamaneshwaram. Rangapuram and Sirikattapalli. Razole. Ponnamanda. Elamanchili. Hydrocarbon accumulations have been proved in 33 of these prospects (11 oil & gas and 22 gas prospects). and Kesanapalli West. Vadali. Kesanapalli. MIOCENE DELTAIC SANDS (OFFSHORE).000 & OFFSHOE24.UP (OFFSHORE).28. .000) COMPOSITE BASIN 46. 000 Sq.22 (O+OEG) RESOURCES. PLIOCENE PINCHOUTS.Km (ONLAND.AREATYPERESERVES- 52.1130 MMt EXPLORATION OBJECTIVES MESOZOIC STRUCTURAL PROSPECTS ASSOCIATED WITH RIDGES (ONSHORE). ROLLOVER ANTICLINES (OFFSHORE). EOCENE DELTAIC SEQUENCE ON SHALLOWER SHELF (OFFSHORE). PALEOCENE/ EOCENE CARBONATE BUILD. IG IB DWN-U-1 Oil Gas . KG LOCATION MAP WITH DEEP WATER NELP BLOCKS . 1 22A.24 G.6 EL.3 AK .1 15.1 GS.38.PG BASIN CROSS TREND MAJOR FAULT AT BASEMENT LEVEL PROJECT : PS C UBE.2.1 BMP.1 BN .1 MD V.20.5 31 DWN -M-1 GS.1 GM.8 4 KW.4.2 DWN-D-1 GS.1 MA.29.1 23.1 21 19 20 SLP -1 PNL-1 15 MD -4 KG.3 LK.1 KM.4.1 SRP.D WN .1 KG-DWN -98/4-A-1 KMG.1 GS.1 24 PS.8 MW-9 KT-3 KI.39.29.1.1 1 5 2 GS.37.98/4-K-1 N M.1 PKR .1 MVD -1 15 GPM.1 GD-2-1 16° 00' GD .1.1A SR-4 EP.1 GS.1 9 GS.1 PR P.1 N G-6 T en ali MR .13.1 KC .15.1.1 PAL.1 MPD .1 KA.1 MB.2.1.1 N DV.2 14 N G.10 43.1 15.2 C P.1 SI.1 9 GS .1 VMD .12. April 2007 DRY OIL GAS 80° 00' 81° 00' 82° 00' 83° 00' 84° 00' 85° 00' SC ALE : 5 0 10 20 Km.1 YS.1 PM.1 N I.1 9 DWN-W-1 BD P.1 R.1 PO.1 O NGOLE KS-3-1 9 GOLLAPALLI S ANDSTONE 8 MALERI 7 UPP ER KAMTHI/CHINTALAPUDI 6 MIDDLE KAMTHI 5 LOWER KA MTHI 4 BARAKAR KD-3-1A KR I-1-1 Fig .2 GS.1 VA-1A MAC HI LIPATNAM GS.4 G.3.1 S a marlakota 12 13 9 14 K ovvur 17° RAJ AHMUNDRY 00' 14 10 K BS.1 BT.1 SR-2 GM.1 SV.4.1 23.1.1 J NL.1.1 9 22B.1 RA .3 AGE 3 TALCHIR 2 PAKHAL 1 ARCHAEAN P LEISTOCENE TO HOLOCENE MIOCE NE TO PLIOCENE P ALEOCENE TO EARLY EOCENE E ARLY PALEOCENE UPPER CRETACEOUS LOWER CRETACEOUS LATE JURASSIC TO EARLY CRE TACEOUS MIDDLE TO UPPER TRIASSIC LOWER TRIASSIC TO UPPE R PERMIAN -do-doP ERMIAN UPPER CARBONIFEROUS TO LOWER PERMIAN LOWER PROTEROZOIC E ARLY PRECAMBRIAN 14 98/2-UD-1 14 LEGEND KS-4-1 15° 00' 5 OUT CROPS MEGA TECTONIC ELEMENTS KG .1.41.3 GS.2 MB.11.1 B BK.21.1 PA.19 GJP .2 SN .5 PV.4.49-2 GS.1 KK.1 KTL.1 15 VM.MEGA TECTONIC MAP OF KG-PG BASIN 81° 00' 80° 00' 83° 00' 82° 00' 84° 00' 85° 00' SRIKAKULAM VIJ AYANAGARAM 18° 00' 3 1 3 18° 00' 3 8 3 4 5 2 5 3 2 7 3 7 2 1 1 3 7 2 1 3 VISAKHAPATNAM 1 3 Bhadrac halam 4 2 3 5 3 4 5 4 4 3 1 4 2 1 5 3 KG-OSN -97/1-A-1 1 4 3 3 Kot hagudem 1 1 4 3 6 4 1 5 2 KG.D WN . By : R J Michael.1 TP.1 G.D wg.1 23.1 N G.1 GSKW .1 VNT.1 PS.3 DWN-Q-1 DWN-R-1 Annapurna-2 G.12 KT .1 KZ.9 17 13 7 EM.6 15.11 LG.1 SSY.1 PLK.1 VA-2 VA-3 D WN-U-1 G.5 MP.5 TU-1 MAI.1A R A.1 AKP .1 27 A P.5.3 MODI.1 GS.1 IP.1 50.3.16 K NK.25 R .1.5 D P.1A TNK.1 16° 00' G.2 A D.1 D S.1A KAKINADA 9 13 7 EM.19.1 GS.1 N U.1 GS.1 11 VLP.15.2 LM.E.1 G.2 SU .1 1 KB-4-1B 7 5 4 KHAMMAM 4 3 4 3 5 11 15 7 9 1 15 11 14 14 11 15 9 1 13 9 7 7 1 17° 00' 11 10 K B.1 5 A MP.1 KV-7 GS.1 PT .1 29 SR.1.1 G.1 3 GN .14.2.1 2 MY.1 15 ALLUVIUM 14 RAJ AHMUNDRY SA NDSTONE 13 TRAP WITH INTER TRAPPEANS 12 INFRATRAP PEAN 11 TIRUPATHI SANDSTONE 10 RAGHAVAPURAM SHALE KD .1A AGL.10.2 OUTCROP LEGEND GS.1 PR .2.4 VD .1 W M.1 WM.1 KK.1 SM.1 2 BT.1 GS.8 SKP.10 9 KKD.1 BT.25.5-1 MPL.1 ELURU BV-1 9 MD .1 CP.1 NS.1 KK.1 KK.1 GR .1 FORMATION GS.1 BML.2 KV.1 K D.9 K Z.1 GS.8.22.1 MA.1 NMK.4.29.1 GS.1.1 GD.1 N G.14 AB.1 MM.4.11 GS. Ass t.1 LG.P-1 DWN-A-1 G.1.1 G.1 MW.3 G.1 VD P.1 GS.1 MN .2.3.1 C PK.2 KK.2 3 2 6 G.3 VND .1 KZ.1 SU.1A G.1 MG.1 GD.9 15.2 GS.2 GUNTUR LP.1 VIJAYAWADA 4 15 14 11 KK .4 6 MW.1 RP.1 KD .1 PM.5.1 GRZ.1 GS.6 YS.1 R Z.1 D KR -1 MW .1 15.1 GS.17.4 12 8 GS.98/5-L-1 5 7 3 1 7 4 3 7 7 5 1 1 ASP.5 D G.1-3 KD.1 MA.1 VV-2 VV-1 PR-2 VN K.1 LLP.1 G.1 MD .1 KP.1 46.1 MK.1.1 AC .1 9 KMP.1 EL.1 D WN.49.1 PKP.Officer 15° 00' .6-1 Bapat la Nizam patnam GD-3-1 PD P.1. 000 Sq. In the land part. Its boundaries in the north. having an area of about 14000 Sq. and south are marked by outcrops of Precambrian rocks and in the east the basin extends into Bay of Bengal.Km. .MBA Basins The Mahanadi Basin is located on the eastern sea board of India and covers the coastal districts of Orissa State and adjoining offshore areas in Bay of Bengal.Km. west. it covers an area of about 55. MAHANADI MAP WITH NELP BLOCKS . Bangal Onland Basin Bangal Offshore Basin . Andaman Offshore Basin . Hydrocarbon Potential & Prospectivity of sedimentary Basins . oil & gas pools in a sedimentary basin There could be several prospects in sedimentary basin Size of prospect very from few sq km to thousands of sq km.What is a Prospect ? Independent accumulation of oil. gas. . Prospects Identification To identify the possible hydrocarbon locales/area through Integrated Interpretation of multi-disciplinary data (Geological and Geophysical data) . Types of Prospects: • Oil prospect • Gas prospect • Oil & Gas prospect . Geological Aspects: Prospect Analysis Source Rock Evaluation Presence of Reservoir Rocks Presence of Cap rock or Seals Traps ( Structural / Stratigraphic) H/C charges and Timing . There should be adequate reservoir rocks for holding this oil.REQUIREMENTS FOR HYDROCARBON ACCUMULATION • In a basin there must be adequate thickness of sediments. • There must be adequate organic material trapped in those sediments. • There should be adequate sealing above reservoir rocks to form traps. • Once oil is generated it migrates out of the source rocks. . There should be conditions of burial and favourable temperature long enough for generation of oil. • When the Kerogen is further heated with time. the chains of HC break away from the Kerogen and form waxy and viscous crude oil.Source Rock • Rocks that contain sufficient amount of Kerogen are called Source Rock • When a source rock starts generating oil and gas then it is said to be mature. . Source Rock Evaluation Total quantity of organic matter Type of organic matter Maturity of organic matter Generative capacity of the basin . Reservoir Rocks: The essential element of petroleum accumulation is Reservoir and essential features of a reservoir rock is Porosity i.e its ability to store fluid. Sandstones: 59% Carbonates: 40% & Other fractured rocks: 1% . POROSITY : The total sum of opening or voids that occur within a rock. . Usually expressed as a decimal percent. Porosity is denoted by phi (ф) and is given by the equation ф = Bulk Volume – Grain Volume x 100 Bulk Volume EFFECTIVE POROSITY : Porosity that is available for storage of fluids. and enough permeability to transmit flow of hydrocarbons.RESERVOIR ROCKS A rock with enough porosity to be capable of storing economic quantities of petroleum. Poor 10-15% .Good >20% .Very good Practical cut off for oil Sandstone ~8% Limestone ~5% For gas the cut off is lower .Negligible 5-10% .What is good porosity? 0-5% .Fair 15-20% . The geographical extent of seal rocks defines the effective limits of the Petroleum system.Cap Rocks The cap/seal rocks have pore throats too small and poorly connected to allow the passage of hydrocarbons. . . Petroleum expelled from an active source rock (Primary migration) migrate along a fault plane or a permeable carrier bed (secondary migration to a porous reservoir rock) capped or surrounded by a comparatively impervious seal that together form a trap.Traps Traps are the geometric arrangement in which petroleum accumulation takes place. Prospect types: Structural prospect (Structural Entrapment ) Stratigraphic Prospect (Entrapment is stratigraphic) Stati-structural prospect (Entrapment combination of structural & stratigraphic) . GAS AND WATER .ANTICLINAL TRAP SHOWING DISTRIBUTION OF OIL. Structural Prospect: Fault Trap . Structural Prospect: Salt Dome . Stratigraphic Prospect: . Stratigraphic Prospect: . Stratigraphic Prospect: Diagenetic traps: This area more common in carbonate reservoirs which are more easily affected by cementation. dissolution and dolomitization. These post-depositional processes lead to a lateral change in reservoir quality to acts as the trapping mechanism . Structural Prospect: Fold Trap . Oil & Gas accumulations are governed by an intricate mechanism of generation. migration and entrapment with uniquely subjective boundary conditions that are not so exacting . Ch o e y” h t h t r r e fo cov s i d .l e v g a r n t i h r c o r / a nd e s s r a e f y b f o hl o t m c g a e “a rou sak .