构造变形对页岩孔隙结构及吸附性的影响

Effects of Structural Deformation on Shale Pore Structure and Adsorption

针对页岩构造变形作用对其孔隙结构和吸附性的影响,运用TOC、热解和低温氮气吸附法等实验方法,利用宏观尺度判别等手段,对川东北地区城口县修齐镇、龙田乡下寒武统鲁家坪组页岩样品的构造变形对孔隙结构控制机理进行研究。结果表明:川东北地区页岩构造变形形态主要表现为裂隙、褶皱、揉皱等;研究区页岩样品孔隙主要为纳米级,孔径大小主要分布在0.5~10.0 nm;页岩变形程度越高,纳米级孔隙越多,页岩比表面积越大,对页岩气的吸附性能越强。研究结果对认识泥页岩构造变形作用及其对页岩孔隙结构和储气能力的影响意义具有一定的指导意义,为四川盆地页岩气的勘探开发提供必要的依据。

TOC,pyrolysis,cryogenic nitrogen adsorption and other tests are used to analyze the effects of shale structure deformation on its pore structure and absorbability.Macro-scale discrimination and other means are adopted to study the action mechanism of structural deformation on pore structure based on the shale samples of the Lower Cambrian Lujiaping Formation in Xiuqi Town and Longtian Township of Chengkou County,Northeast Sichuan.Research indicates that the shale structure deformation forms in the northeast Sichuan mainly include fissure,fold,crumple,etc.The shale sample pores are dominated by nano-scale pore and the pore size is mainly ranged from 0.5 to 10.0 nm.The number of nano-scale pore increases with the increase of shale deformation level.The shale gas adsorption performance increases with the increase of shale specific surface area.This research could provide certain guidance for understanding the effect of shale structure deformation on shale pore structure and its gas storage capacity and could also provide certain reference for the shale gas exploration and development in Sichuan Basin.