Fluxoturbidite development characteristics of northern area in Weigang oilfield,Nanyang sag

Subtle hydrocarbon reservoirs have become the key exploration target for Nanyang sag in Paleogene system.The sedimentary sub-facies of the main producing layers within paleogene Hetaoyuan formation in northern area of Weigang oilfield,Nanyang sag are delta front-prodelta.The analysis results show the slump turbidite body is the favorable exploration target.Constrained by coring,logging and seismic data,within the isochronous sequence stratigraphic framework,the research on sedimentary sub-facies of paleogene He-2 and He-3 members has been carried out.The research results indicate during the progradational process of low-stand and high-stand at the top and bottom of submembers of H22-H31,more fluxoturbidites of gravitational instability type have been developed.Meantime,duringthe retrogradtional process,turbidites of smaller scale have been developed due to the wave action.Ultimately according to seismic attributes,in combination with logging calibration,the favorable developed area of slump turbidite body for H22-H31 has been predicted and the deep lacustrine area has been considered to be the vision target for subtle hydrocarbon reservoirs of Nanyang sag.