Understanding Reservoir Heterogeneity in Deep Water Settings Through Sequence Stratigraphic Approach: A Case Study from Krishna Godavari Basin, India
Kaushalendra B. Trivedi, Anil K. Srivastava, and Narendra K. Verma
INTEG, GEOPIC, Oil & Natural Gas Corporation Ltd, Dehradun, India
Krishna- Godavari basin situated on East coast of India is under exploration and development since early 70’s and a no. of wells are being drilled in shallow water and onland area of the basin. Six petroleum systems (!) are being established ranging in age from Cretaceous to Pliocene. With the advent of quest for search of hydrocarbon in deep water area the present acreage specific study is being carried out in the basin covering an area of 2000 Sq.Km. covered by 3-D data ranging in bathymetry from 700 to 2000m .The analysis of data and wells drilled in the area poses a grave concern for understanding the vertical and lateral extent of distribution of reservoir facies in the area as the connectivity of the reservoir facies with the source facies through conduits and pathway is major challenge to track in the area.
To understand the facies distribution and the likely locales of favorable juxtaposition is best understood by sequence stratigraphic analysis.
Two mega structural trend s are being mapped in the area making decollement' surface at Cretaceous and Mio-Pliocene surfaces. Seven Sequences of Second order are being identified and mapped in the area ranging in age from Early Cretaceous to Recent sediments. A major erosional surface is being mapped and supporting low stand basin floor fans during “forced regressional” setting is identified. A major subaquaous channel with meandering and splay features controlled by basin margin fault is also being mapped indicating prevailing sedimentary bypass system and providing a clue for paleoenvironment.
A comprehensive Sequence Stratigraphic model has helped in identifying the areas for future exploration and components of sequences specially TST , MFS and LST has guided the authors to firm up areas of better reservoir development in suitable setting to target charged reservoir.
Presentation GEO India Expo XXI, Noida, New Delhi, India 2008©AAPG Search and Discovery