Kumar, B.¹, D.J. Patil¹, G. Kalpana¹, C. Vishnu Vardhan¹ 
(1) National Geophysical Research Institute, Hyderabad, India

ABSTRACT: Geochemical Prospecting of Hydrocarbons in Frontier Basins of India

India has 26 sedimentary basins with a basinal area of approximately 1.8x10⁶ Sq. Km.(excluding deep waters), out of which seven are producing basins and two have proven potential. Exploration efforts in other basins, called as frontier basins are in progress. These basins are characterized by varied geology, age, tectonics and depositional environments. Hydrocarbon shows in many of these basins are known and in few basins oil and gas have flowed in commercial /non-commercial quantities. Within the framework of India Hydrocarbon Vision – 2025 and New Exploration Licensing Policy, there is a continuous increase in area under active exploration. The asset management concept with multi-disciplinary teams has created a demand for synergic application of risk reduction technologies including surface geochemical surveys. 
National Geophysical Research Institute (NGRI), Hyderabad, India has initiated/planned surface geochemical surveys comprising of gas chromatographic and carbon isotopic analyses in few of the frontier basins of India. The adsorbed soil gas data in one of the basin (Saurashtra basin, Gujarat) has shown varied concentrations of methane to butane. The C₁ concentration varies between 3 to 766 ppb and C₂₊ 1 to 543 ppb. This basin has thin soil cover and the Mesozoic sediments (probable source rocks), are overlain by thick cover of Deccan Trap at places. The scope and perspective of geochemical surveys in frontier basins in India will be presented and discussed.

AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.