Abstract

Initial exploration of hydrocarbons is limited to Anticlinal/High structures. But recent discoveries in the synclinal structures proved to be prospective hydrocarbon plays through strati-structural traps. In Tripura fold belt, Sundulbari structure lies in the northern plunge of Tichna anticline and is low structure. Relict pays have been identified through RMS attributes which are corroborated with elctrolog facies have been tested and yield enormous gas pools (1,60,000 m3/d gas) in Upper Bhuban formation of Miocene epoch, this accelerated the exploration activities. However, limited lateral extent, up dip pinch outs, and fault closures are throwing more uncertainty for its exploration. In view of the above complex reservoir configuration, exploitation of these gas plays is a challenging task, which needs an effective strategy for optimum completion & exploitation of this field. The objective of the present study is to understand the reservoirs in fold-belt Sundulbari syncline structures wholly for better exploration. Through this study it is concluded that, in relict gas pays, three major port (pore throat) systems/flow units are developed viz Megaport, Macroport & Mesoport. By comprehensive analysis of natural GR logs and XRD results, it is concluded that in the Upper Bhuban formation, matrix main frame work is quartz with occasional presence of feldspar and kaolinite & Chlorite are the main clay minerals. Integrated Structural and stratigraphic analysis of Resistivity image logs have yielded information about the paleo depositional environment that, it could be tidal bar/channel of tide dominated deltaic system. And also, could map the thrust/reverse faults on log scale along with many structural events. As a holistic approach, this study throws light on complete reservoir characterization and provides a strategy for future exploration and exploitation.