Sedimentary Microfacies Of Chang-6_1 Reservoir In Houshi District,Ansai Oilfield

Houshi district is one of the important oil field in Ansai oil fields whose regional tectonics are westdipping monoclinal layers,and the Chang-6_1 oil reservoirs are the chief production zones.The analyses on core,grain size,thin section,shape of the log curves show that pre-delta deposition is the main sedimentary system of Chang6_1 in Honshi district,Ansai oilfield.The main sedimentary microfacies including submerged distributary channel,debouch bar,distal bar,front sand sheet and interdistributary deposits were divided.According to the core analysis and well-test results,the submerged distributary channel was believed to be the main reservoir microfacies,debouch bar was the poor reservoir,and front sand sheet was worse reservoir relatively in this area.