Untapped Vast Hydrocarbon Resource Potential of Deep Water basins in India

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1 Untapped Vast Hydrocarbon Resource Potential of Deep Water basins in India Dev Dutt Sharma, Principal Geologist, Oilex Limited, Australia ABSTRACT India is the fourth largest consumer of hydrocarbons and fifth largest importer in the world, importing about 75% of its requirement. Hydrocarbons contribute to about 40% of energy requirement in India. This large demand-supply gap is not because of lack of resources but due to domestic exploration and production activities are not keeping pace with the growing demand. Out of 3.14MMkm 2 area of 26 sedimentary basins in India, 1.39MMkm 2 lies in onshore and 0.40MMkm 2 in offshore shallow water, while 1.35MMkm 2 is in three deep water (>200m isobath to EEZ) areas along the east coast in Bay of Bengal, west coast in Arabian Sea and south-east in Andaman sea which offers vast hydrocarbon resource potential as we have just touched the tip of iceberg by initiating exploration and production activities and major surprises are yet to come. Since the first encouraging giant gas discovery of KG-D6 in deep water along east coast in KG basin during 2002, a number of discoveries followed in deep water exploration blocks offered through NELP bidding rounds, especially in east coast basins of Bengal, Mahanadi, Cauvery and Andaman also besides KG basin which are quite exciting and challenging and thus indicate the high prospectivity of Indian deep water basins. The new discoveries are more of gas than oil worldwide and so as the case with India. Recent discovery of giant Leviathan gas field in deep water of Mediterranean Sea in Israel during 2010 estimating about 17tcf of gas and 600MMb of oil is considered as world s largest in last decade after India s KG-D6 in As per USGS estimates, Levantine Basin comprising Leviathan Field holds mean recoverable reserves of 1.7Bb of oil and 122tcf of gas. Similarly, recent deep water gas discoveries in Rovuma Basin, Mozambique are estimated to hold about 100tcf of recoverable gas. There are no separate estimates for hydrocarbon resource of deep water basins in India either by USGS or other international agencies, may be due to unavailability of data. However, estimates by the author during 2003 after encouraging deep water gas discoveries in KG basin though the study entitled, India s emergence towards self sufficiency in hydrocarbons with new E&P opportunities total hydrocarbon resources in Indian basins prognosticated at 32 billion tons with recoverable resources of 12 billion tons, which was substantiated by DGH also. KDMIPE, ONGC estimated hydrocarbon resources in deep water basins at 7 billion tons, while DGH estimates are of 9 billion tons. However, the author s study indicates 35

2 that Indian deep water basins hold about 11 billion tons of hydrocarbon resources of which 7 billion tons oil and 4 billion tons oil equivalent gas. Of these, recoverable resources are conservatively estimated at about 1 billion tons of oil and 3 billion tons oil equivalent of gas, which comes to 3 trillion m 3 of gas or 106 tcf of recoverable gas. If developed, this has gas production potential of about 410 MMm 3 /d for 20 years, against the projected gas demand of about 550MMm 3 /d as per Hydrocarbon Vision 2025 by Govt. of India. This shows that deep water basins of India have enormous potential which can contribute to about 75% of growing demand alone by Though countries like Brazil and India having geologically similar prospective acreage started awarding exploration blocks through PSC s almost at the same time during 1997 and 1998, E&P activities in Brazil were fast, which contributes to about 22% of world deep water production and that is expected to grow 50% by Thus, we have to accelerate our E&P activities in indigenous basins, with special focus on deep water basins, which have prolific production potential to bridge the demand-supply gap and reduce the imports to relieve the burden of foreign exchange crunch. Bay of Bengal is visualised to be another Gulf of Mexico or Campos basin of Brazil for India while considering regional geological analogy of Gulf of Mexico, Brazil and West Africa which is golden corridor of discovery in Atlantic Sea similar to Bay of Bengal, Indonesia and Australia and that is going to be emerged as golden corridor of discovery in Indian Ocean with new E&P activities. Similarly, West Coast Deep Water area of India in Arabian Sea comprising Kutch-Saurashtra, Mumbai-Ratnagiri and Kerala- Konkan basins is suitably located along golden corridor of discovery of Mozambique, Tanzania and India but yet to be proved. We have to intensify our deep water exploration activity along west coast while chasing the leads from shallow water discoveries like Kutch-Saurashtra and producing fields like Mumbai-Bassein as Indus delta is extending far deep into the Arabian Sea like Ganges in Bay of Bengal. 36

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29 About the Author Mr. Dev Dutt Sharma, holds M.Sc. degree in Geology, additionally MBA with over 32 years of integrated experience in upstream oil & gas from exploratory discovery of a new prospect to field appraisal and development resulting in reserves accretion and production enhancement while working with national and international oil companies of repute like ONGC, Reliance Industries and Qatar Petroleum from Geologist to Senior Management level. He has given special thrust to gas exploration in India from both conventional and unconventional resources like Coalbed Methane, Tight Gas Sands and Shale Gas having low resistivity and low permeability while adopting innovative concepts and new technologies of formation evaluation and reservoir development. His pioneering works include exploration of Unconventional Shale reservoirs of Cambay Basin in Wadu-Kalol, Sanand-Jhalora, Indrora-Limbodra, Nandej-Nawagam etc. while applying new concept of Shale Resistivity Ratio for identification of commercial zones within the monotonous shale section and new technologies of directional drilling, cluster drilling and stimulation/ hydrofracturing. He has been associated with mega research projects like Standardisation of Stratigrahy of Cambay Basin and Evaluation of its Hydrocarbon Potential while giving thrust to shallow Oilgo-Miocene Babaguru and Tarapur formations and deeper Eo-Paleocene Cambay Shale and Olpad formations including fractured Deccan Trap reservoir. Presently, he is associated with Oilex Ltd for development of Tight Hydrocarbon reservoirs in Cambay Field, the first discovery field of Cambay Basin by applying new technologies of formation evaluation, horizontal drilling, multistage fracturing and microseismic monitoring for production enhancement, which have wider application in other basins of India also like Krishna-Godavari, Cauvery, Assam-Arakan, Rajasthan, Gondwana and Vindhyan having tight hydrocarbon reservoirs. 63