鄂尔多斯盆地东南部长7段陆相页岩孔隙特征与吸附能力

为了深入研究鄂尔多斯盆地东南部延长组长7 段页岩孔隙特征与吸附能力，选取8 个岩心样品进行氩离子抛光—场发射扫描电镜、低温氮气吸附及等温吸附等实验。结果表明：该段页岩主要发育粒间孔、粒内孔、黄铁矿晶间孔、有机质孔及微裂缝等5 种微观孔隙类型；BET 比表面积为1.166～6.964 m2/g，孔体积为0.004 8～0.024 2 cm3/g，平均孔径为8.812～17.882 nm。等温吸附实验模拟了长7 段实际温压条件下的页岩吸附量，其最大吸附量为2.0～4.0 mg/g。长7 段页岩孔隙以中孔为主，大孔和微孔次之，纳米级孔隙发育，具有较好的吸附能力，可为进一步开展页岩气资源评价提供理论依据。

Pore characteristics and adsorption capacity of Chang 7 shale of Yanchang Formation in the southeastern Ordos Basin

In order to investigate the pore characteristics and methane adsorption capacity of Chang 7 shale of Yanchang Formation in the southeastern Ordos Basin, eight core samples were selected to carry out experiments, such as Arion milling field emission scanning electron microscope, low-temperature nitrogen adsorption and isothermal adsorption. The results show that five types of microcosmic pores are mainly developed,including intergranular pores, intragranular pores, intergranular pores in pyrite, organic pores and microfractures. The specific surface area ranges from 1.166 m2/g to 6.964 m2/g by BET equation, pore volume ranges from 0.004 8 m3/g to 0.024 2 m3/g by BJH equation, and the average pore diameter ranges from 8.812 nm to 17.882 nm. The methane adsorption capacity of Chang 7 shale under actual reservoir condition was simulated, and the maximum adsorption capacity is 2.0-4.0 mg/g. Mesopores are the main pores in Chang 7 shale, macropore and micropores come second, and nano scale pores are also developed, which indicates that the shale reservoir have good adsorption capacity. This study can provide theoretical basis for the further shale gas resource evaluation.