Some key exploration techniques for the subtle reservoirs and their application in Bohai water

Because a start has just been made in exploring for subtle reservoirs generally in Bohai water,it is difficult to depict subtle traps refinedly or to analyze accumulation conditions comprehensively due to less drilled wells,with an effective technique series absent.Therefore,four key techniques were created through tackling technical problems and making technical combination,including the main-line type of refined stratigraphic-sequence analysis under the dominated controls,the geological-seismic integrated prediction and description of reservoir guided by a geological model,the refined description of lithologic and stratigraphic traps and the comprehensive evaluation of migration and accumulation in subtle reservoirs.Their systematical applications have resulted in quite good exploration effects in Shijiutuo rise and its surrounding areas,Yallow River mouth and Liaodong bay,with the discovery of multiple subtle reservoirs been promoted,and a group of new favorable subtle prospects been identified.These key techniques may be good references to the subtle reservoir exploration in other rifted basins.