Reservoir characteristics and control factors of Tongbomiao formation in Hongqi sag

Hongqi sag is located in the north of Beiehur depression in Hailar Basin, which is a secondary structural unit in the peripheral depression of Hailar Basin, with great exploration potential. Based on SEM, conventional thin sheet, cast thin sheet, mercury pressure and physical property data, this paper discusses the reservoir characteristics, types and control factors of high quality reservoir in Tongbomiao formation, Hongqi sag, so as to provide a strong geological basis for the exploration of oil and gas in this area. The reservoir space of Hongqi sag is mainly composed of four types: primary intergranular pore, micro fracture, feldspar dissolution pore and debris dissolution pore. It is of the type of ultra low porosity and low permeability. Although Tongbomiao formation in Hongqi sag is of very low porosity and low permeability type, high quality reservoir is still developed, and its reason is mainly controlled by sedimentary environment, diagenesis and structural fracture.