Characteristics and main controlling factors of Permian heavy oil reservoirs in Lukeqin structure zone

The breakthrough on heavy oil reservoirs of Permian Wutonggou formation in Lukeqin structure zone confirmed that the area is an oil and gas enrichment zone with multiple series of layers.The exploration strata emphasis extended from Triassic kelamayi group to Permian,and the reservoir type traversed from structure to lithology-stratigraphic reservoirs.Research results indicate the heavy oil reservoirs from Wutonggou formation is a lithologic-stratigraphic reservoir,locally controlled by fault blocks.The main oilbearing layers areⅠ sand group and Ⅲ sand group.Hydrocarbon accumulation is under the control of low bulge and fan delta sedimentary system.The hydrocarbon migration is controlled by the indosinian ancient bump.The deep and bigfaults,which were cut into the deep source rocks,provide a good channel for hydrocarbon migration.The reservoir scale is controlled by the distribution range of fan delta depositional system.Around low bulge of Luxi and Kumu,the main exploration direction in the next step is to look for large fan delta sand bodies.