Buried Hill Reservoir Characteristics and Its Geophysical Identification Methods for Condensate Gas Field of Bozhong A

Bozhong A condensate gas field is a typical large Archean metamorphic buried hill gas field. Its reservoir lithology is mainly composed of gneiss, metamorphic monzogranite, metamorphic granodiorite and cataclastic monzogranite. The reservoir space is dominated by fracture⁃pore and pore⁃fracture combination types. Vertically, the buried hill is divided into semi⁃weathered zone and buried hill interior. The semi⁃weathered zone is generally developed with network fractures and intragranular dissolution pores, forming a massive reservoir with good reservoir guality. The buried hill interior is highly heterogeneous, and the reservoir guality is worse than that of the semi⁃weathered zone; Fracture system are both effective reservoir space and good seepage channel. The fracture is relatively rich near the major fracture. The reservoir space of porous reservoirs is mainly intergranular pores and dissolution pores, which are mainly developed at the top of the buried hill or near the fault inside the buried hill; The physical properties of the reservoir and the distribution of its dissolution pores in the semi⁃weathered zone are closely related to the faults; The density and opening of the fractures have an important impact on the open flow and production of the gas well.