Abstract

Cachar province is a part of Assam-Arakan Fold Belt and geographically situated in the North-Eastern part of India. This area of Surma valley got much importance because of oil and gas pools were discovered in Badarpur field by Burma Oil Company way back in 1915. The hydrocarbon findings in this basin are not commensurate with the exploration efforts made in this area over the long period of 90 years. Of the 64 wells drilled in the Cachar area only 8 wells are gas producers out of which three wells are in Adamtila field, four from Banskandi structure and one from Bhubandhar field. This discovery ratio suggest that sediment thickness over the basement need more understanding for true modeling of the sub surface and need more concreted efforts. The Cachar area is traversed by long narrow anticlines and broad synclines in an almost N-S trend that swings NorthEastward towards the Northern margin. Moreover, several tectonic movements gives rise to a number of thrust and folds that caused structural complexity in the area. Seismic exploration in this complex tectonic regime is a challenge to both acquisition and processing especially in the absence of proper geological model. The other factors affecting seismic exploration are rapid variation in near surface geology, poor receiver coupling in hard-rock surface, shot hole drilling difficulty and wave field scattering. Exploration in such areas often requires a re-look in the existing data with the help of new technology and wider experience. This needs generation of conceptual sub-surface model of the area. Moreover, poor seismic reflection data of both 2D and 3D limits the imaging upto 1 second that too in a patchy pattern. Due to the limitation of seismic imaging, there have been consorted efforts to extract as much information as possible from gravity and magnetic data. Hence, this study is taken up to obtain broad understanding of the basement configuration and provide information on the probable sub-surface structural configuration under the known exposed structure within the sediments based on gravity and magnetic data