Reservoir properties of Suderte buried hill and main controlling factors, Beir Depression, NE China

From drilling data, core, and thin section analysis, the sandbody of the Suderte buried hill is of low porosity and low permeability. After being reformed by late diagenesis, its reservoir conditions get better. Reservoirs around the Bei 2 well and the Beir town in the middle of the buried hill belong to the second level and have moderate storage capability. Reservoirs on its east and west sides are of the third level and have poor storage capability. Storage capability distribution relates closely to the degree of fracture development and the late reforming and less to primary porosity and permeability. The reservoir's effective spaces are mainly structural fractures, solution holes in cements, (dissolved) pores in particles, and fractures. Storage capability is affected by lithology, tectogenesis, and diagenesis. The region that has brittle rocks with many fractures and much tectogenesis is prone to accumulate oil gas, and strong compaction and cementation are important factors that destroy the storage capability.