A Relook on Structural Style and Sedimentation Pattern: Implications on Lithostratigraphy and Hydrocarbon Prospectivity for Already Explored and New Plays of Krishna-Godavari and P-G Graben, India

Rawat, Sushma¹, K.B Trivedi² (1) Oil and Natural Gas Corporation Ltd, Dehradun, India (2) GNPOC, Khartoum, Sudan

Krishna-Godavari basin is marked by a conspicuous bite on eastern seaboard of India. It has evolved as a result of Mesozoic rift and subsequent drift of Indian plate after breakup of Eastern Gondwanaland. The structural grain of basin is aligned parallel to North-East aligned passive continental margin. The tectono-sedimentation cycles are very well depict­ed in stratigraphic record and each stage has contributed for components of different petro­leum system. Till now five petroleum systems are being identified, which are under active exploration and development in this basin.

The sedimentation took place in the NE-SW aligned horst-grabens where facies mosaic is influenced by tectonically induced slope resulting from hanging wall down tilting and foot­wall uplift

Authors have studied 28 wells along with seismic data of more then 1750 L.Km. and has conclusively established the process response model and assessed the potential of hydro­carbon generation. A new play for “deep basin gas” which is still unexplored along with def­inition of lithounits based on new tectono-sedimentation model is proposed for this hither­to moderately explored basin of Late Jurassic–Early Cretaceous age. This regionally perva­sive abnormally pressured gas accumulation is expected to be preserved in low permeabil­ity reservoir. The integrity of capillary pressure seals over a period of tectonic activity is analysed and discussed along with associated exploration strategy needed for exploration of this new play. This study will lead to substantial commercial accretion of hitherto unknown and accounted Hydrocarbon.