海陆过渡相页岩气储层含气性特征及其影响因素

Marine-terrigenous facies coal measures shale has the features of wide distribution, sedimentary interbed frequently, complex reservoir.The previous research and the actual data show that marine-terrigenous facies shale reservoirs are mainly shallow continental shelf, coastal tidal flat and barrier lagoon and delta front facies, with thickness between 20-290m and depth between 300~3000m; TOC is high, at average from 1.0% to 8.4%, and maturity is low to high mature stage (1.0%~2.5%) with type III type organic matter; Mineral composition is mainly clay and quartz, and brittleness coefficient between 30 and 50; Organic matter pore develop well in the part of area, and the mean of porosity is from 2.22% to 4.7%, specific surface area from 2.92% to 18.17m3/t, permeability 0.00076-0.895mD; Organic matter pore develop well in the part of area, and the mean of porosity is from 2.22% to 4.7%, specific surface area from 2.92% to 18.17m3/t, permeability 0.00076-0.895mD; The content of gas reservoir in South of China is higher than in North of China, with 2.0~6.9m3/t and 1.53~2.64m3/t respectively, among which is Longtan Formation> Dalong Formation > Taiyuan Formation > Shanxi Formation > Benxi Formation >Keluke Formation. The gas content of reservoir has a positive correlation with TOC, porosity and specific surface area. In addition, coal in coal measures has significant impact on gas bearing property.