鄂西来凤地区上奥陶统—下志留统龙马溪组富有机质页岩储层特征——以龙潭坪剖面为例

Characteristics of Organic-rich Shale Reservoir in the Upper Ordovician-Lower Silurian Longmaxi Formation of Laifeng Area in Western Hubei Province:Taking Longtanping Section as an Example

在野外观测的基础上,通过薄片鉴定、地球化学分析、X-衍射分析、物性测量、扫描电镜观察和等温吸附模拟等多种方法,对鄂西来凤地区龙潭坪剖面龙马溪组富有机质页岩储层特征进行研究。研究表明,龙潭坪龙马溪组富有机质页岩厚度较大,达51.8 m,有机碳含量高,介于0.80%~6.55%,平均值为2.70%,热演化程度高,处于高—过成熟阶段;脆性矿物含量丰富,平均值为59.0%;多种孔隙类型及裂缝发育;等温吸附实验表明吸附气量为1.83~3.54 m^3/t,平均值为2.68 m^3/t,气体吸附能力强。综合认为,鄂西来凤地区龙马溪组富有机质页岩储层条件好,具有良好的页岩气勘探前景。

Based on the field observation,thin section identification,geochemical analysis,X-diffraction analysis,physical property measurement,scanning electron microscope,the isothermal adsorption simulation and other methods are adopted,the characteristics of organic-rich shale in Longmaxi Formation of Laifeng Longtanping section in western Hubei are studied.Research shows that the Longmaxi Formation organic-rich shale has relatively high thickness,with an value of 51.8m,and the organic carbon content range from 0.8% to 6.55%,with an average value of 2.70%.The thermal evolution degree is in high-over mature stage.The brittle mineral content is abundant with an average value of 59%.Several types of pores and fissure are present in the shale.The adsorption isotherm experiments show that the adsorbed gas in shale range from 1.83 m^3/t to 3.54 m^3/t with an average value of 2.68 m^3/t,which means the gas has strong adsorption capacity.It is considered that shale reservoir conditions of Longmaxi Formation in this area are good,in which has a good exploration prospects.