| Based on outcrops, drilling cores and sample experimental data, the geological conditions of shale gas of the Upper Ordovician Wufeng Formation and the Lower Silurian Longmaxi Formation in Laifeng-Xianfeng block, Hubei Province, are systematically discussed from the aspects of thickness, organic carbon content, organic matter type, mineral composition and gas content of the high-quality shale section. Compared with Well Jiaoye 1 in Jiaoshiba shale gas field, one of the production areas in Sichuan Basin, the potential of shale gas in Laifeng-Xianfeng block is evaluated. The results show that: (1) The high quality shale section in the lower part of Wufeng Formation-Longmaxi Formation of Lianghekou Syncline in the study area is thick in the north and thin in the south, and most of the thickness is about 10 m. （2） Most of the organic carbon content of shale in the study area is more than 2.7%, which tends to increase towards the north; the organic matter type is Ⅱ1; the organic matter has a high degree of thermal evolution, mainly generating dry gas. (3) The shale in the study area contains more than 60% brittle minerals and a large number of organic pores and microfractures; the gas content of shale is higher in the north than in the south, and the gas content of Well Laidi 1 and Longtanping outcrop in the north is more than 3.0 m3/t. (4) Compared with Well Jiaoye 1 of Jiaoshiba shale gas field in Sichuan Basin, although the high-quality shale in Laifeng-Xianfeng block has a smaller thickness and a slightly lower organic carbon content, the brittle minerals and gas content of both are similar, which shows a certain shale gas resource potential in the study area, with the north of Lianghekou syncline as a favorable shale gas area. |
