Abstract:

Reservoir properties and gas-bearing properties vary significantly while sandstone is single-layer sand body or multilayer sand bodies assembled in different ways. Based on the fine evaluation of sandstone reservoir, sand body assemblages of Shan 2 and He 8 member in Ordos Basin are classified and evaluated. By analyzing well logging and core description, sand bodies can be divided into two categories and 16 different types of sand body assemblages. For different sand body assemblages, well logging and seismic response models are set up, and the reservoir characteristics and gas-bearing properties are evaluated. The results showthat thicker single sand body has better gas-bearing property than composite sand bodies, and that single sand body or composite sand bodies of distributary channel, underwater distributary channel and mouth bar have high porosity and gas-bearing property. Sedimentary system of braided river and braided delta is identified in He 8 member in Sulige area. The physical property of channel bar sand body is moderate-poor, and gets better downward to the delta plain and delta front. The single sand body of distributary channel in delta plain and superimposed sand bodies of distributary channel have the best properties. In Shan 2 member of Yulin area, single sand body and composite sand bodies of underwater distributary channel and mouth bar have the best physical properties. Single sand body of distributary channel and overlapping sand body have better properties. Through the sedimentary system, physical property becomes poor fromchannel center to channel flank.

Key words: sequence stratigraphy, sedimentary facies, favorable exploration belts, northern Bonaparte Basin