黔北地区下志留统龙马溪组页岩储层特征

为弄清黔北地区下志留统龙马溪组海相富有机质页岩储层特征,文中利用有机地球化学、低温氮气吸附、甲烷等温吸附和场发射扫描电镜等资料,分析讨论了龙马溪组页岩的矿物学、有机地球化学、页岩储集空间和吸附能力等特征.结果表明:研究区龙马溪组页岩有机质类型以Ⅰ型为主,有机质成熟度适中,总有机碳质量分数在0.39％～9.24％,平均为...

Shale reservoir characteristics of the lower Silurian Longmaxi Formation in northern Guizhou

In order to study the characteristics of marine organic-rich shale reservoirs of the Lower Silurian Longmaxi Formation in the northern Guizhou area,the data of organic geochemistry,low temperature nitrogen adsorption,methane isothermal adsorption,and field emission scanning electron microscopy were used to study the mineralogy,organic geochemistry,reservoir space and adsorption capacity of the Longmaxi Formation shale.The results are as follows.The organic matter type of Longmaxi Formation shale in the study area is mainly type I kerogen;the organic matter maturity is moderate,and the total organic carbon content is 0.39%-9.24%,with an average of 2.65%;the thermal evolution degree is high,and the average of Ro is 2.03%.The mineral components of shale are mainly quartz,with carbonate mineral content and clay mineral content of 21.5%and 21.4%respectively.The shale reservoir has a high degree of brittleness,which is conducive to later fracturing reconstruction.There are mainly five pore types such as organic-matter pores,intergranular pores,intercrystalline pores,dissolved pores and micro-fractures,which are differences in pore size,shape and development scale influenced by thermal evolution and diagenesis.The slit-shaped mesopores,which provide most of the specific surface area and pore volume,are the main storage space for shale gas.The adsorption capacity of Longmaxi Formation shale ranges from 1.596 to 2.127 cm^3/g.The organic matter,thermal evolution degree and brittle mineral content have a certain contribution to methane adsorption capacity.