Influence of sedimentary environment on the shale gas reservoir of Sahai formation in Fuxin Basin, northeast China

Fuxin Basin is a continental faulted lacustrine basin in northeast China with significant shale gas resources. The shale reservoir mainly developed in the sedimentary environment of the deep and semi-deep lake, swamp, and the interdistributary bay. Deep and semi-deep lake shale has considerable thickness, high clay content, dominant type II1 kerogen, and more pyrite framboid pores; swamp shale has the highest TOC content, type III kerogen, high clay content, and more organic pores; interdistributary bay shale shows high brittle mineral contents, type II2 kerogen, and more intergranular pores. The methane adsorption capacity is highest in swamp shale, followed by the deep and semi-deep lake and interdistributary bay.