关键词: 页岩气, 成藏要素, 页岩气的解吸, 裂缝, 四川盆地

Abstract: Gas-bearing shale is usually either as source rocks, but also can serve as reservoir and seal. As source rocks, its production is closely related to total organic content (TOC), thermal maturity (Ro) and total net thickness of shale sediments. As reservoir, shale possesses low porosity and permeability, so it can serve as seal. The gas in shale might be mainly stored as absorbed gas on kerogen and clay-particle surfaces, or free gas in natural fractures and intergranular pores. Based on the study of the coalbed methane (CBM) desorption mechanism, the adsorption mechanism of gas in shale and the detection of natural fractures in shale gas reservoir are demonstrated. Taking Sichuan basin for an example, the geochemical characteristics of source rock and occurrence of the gas in the basin are discussed

Key words: shale gas, accumulation factor, desorption of shale gas, fracture, Sichuan Basin