Abstract

Krishna-Godavari (K-G) basin is a continental passive marginperi-cratonic basin. It is located along the east coast of India. The basin got initiated through rift/syn-rift tectonics between Permo-Triassic to early Cretaceous periods. It consists of the deltaic plains of the Krishna and Godavari Rivers and the inter-deltaic regions. The areal extent of on land part is about 15,000 sq. km whereas the offshore area covers about 215000 sq. km up to 1,000 m isobath. The basin contains about 5 km thick sediments with several cycles of deposition, ranging in age from late Carboniferous to Pleistocene. The major geomorphologic units of the K-G basin are upland plains, coastal plains, Recent flood plain, and delta plain. Exploration for hydrocarbons in this basin was started in 1958 conducting geological mapping. Geophysical surveys using gravity and magnetic methods were started in 1964, and the seismic surveys were carried out from 1972 in the basin to identify the favourable sites of hydrocarbon accumulation. During the last four decades, 647 deep wells were drilled in different parts of the basin for exploration of oil and gas and their production activities of which 465 well are on landwhich include 85 development wells. More than 225 prospects were drilled out of which 83 are hydrocarbon bearing. 
 Cretaceous sediments having a thickness of about 6 km are known in the peri-cratonic K-G basin. Archaean basement consisting of khondalites, charnockites and some sedimentary rocks occur towards north and west of the basin. Lower Gondwana rocks overlie the basement and are exposed in a limited areas adjoining the Godavari Graben. There are several horsts and grabens in the basin. Many growth faults are also known here. The Pranhita Godavari Graben is a linear intra-cratonic rift that is in the south-central part of Peninsular India. The stratigraphic column of the basin includes older Talchir Formation of Permo-Carboniferous overlain by Barakar formations which in turn underlie the Chintalapudi sandstone of Permian age. The tectonic history of the K-G basin comprises of the Rift Stage, Syn-rift Stage, Drift Stage, and Late Drift Stage. A Petroleum System can be summarized as an independent stratigraphic compartment within which three primary requisites for hydrocarbon accumulation viz., the source, reservoir, and cap rocks occur. The basin has good hydrocarbon potential, and expletory efforts to locate oil and gas pools through seismic-stratigraphic analysis may enhance the discovery rate.

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