Hydrocarbon Accumulation Characteristics of Upper Wuerhe Formation in Well Block K82, Karamay Oilfield

The permian system upper Wuerhe formation of Zhongguai bulge is a large continuous conglomerate oil and gas reservoir group found after the triassic system Baikouquan formation., there are few studies on hydrocarbon accumulation characteristics in the northern part of the region, and the understanding of hydrocarbon accumulation patterns is unclear.Based on the data of core observation, cast thin section, well logging and log analysis, combined with the regional structural background and sedimentary environment, the characteristics of hydrocarbon accumulation in well block K82 north of Zhongguai bulge are comprehensively analyzed. Those studies have drawn the following conclusions: The well block K82 mainly develops fan-delta plain and shallow lakeside sedimentary subphase, with large area of divergent river channel sand and conglomerate, inter-channel and shallow lakeside fine gravel sediments forming a good reservoir-cover combination, the physical properties shown that the upper Wuerhe formation in the study area is a medium-low-hole and low-permeability conglomerate reservoir; Multiple sets of hydrocarbon source rocks, mainly from the permian Fengcheng formation, provide sufficient oil supply for the upper Wuerhe formation reservoir; Fractures and upper and lower stratigraphic unconformities formed in the Hercynian- Yanshanian period have become the oil and gas transportation system of the upper Wuerhe formation in the study area, and the oil reservoir is the source rock below, reservoir above and fault-lithology-type reservoir formation patterns.The conclusion provides scientific basis for further exploration and development of oil and gas in the upper Wuerhe formation of the Karamay oilfield.