泥页岩主要黏土矿物组分甲烷吸附实验

为了从深层次揭示控制黏土矿物天然气吸附能力的主要因素, 选择不同来源和成因的泥页岩中的常见黏土矿物进行了甲烷等温吸附实验.分析显示不同类型的黏土矿物气体吸附能力差异明显, 各种黏土矿物甲烷吸附容量次序为蒙脱石＞＞伊蒙混层＞高岭石＞绿泥石＞伊利石＞粉砂岩＞石英岩.黏土矿物结晶结构决定了矿物片层之间的层间孔隙和聚合体颗粒之间粒间孔隙的形态和大小, 从而决定着其表面积和气体吸附性能.黏土矿物甲烷吸附能力与电镜扫描所反映的微孔隙发育程度密切相关.研究表明, 黏土矿物的气体吸附能力不仅与黏土类型有关, 而且明显受成岩演化程度和岩石成因的影响.此外, 随粒度减小孔隙连通性和内表面积的不断增加, 黏土矿物气体吸附能力有所升高. 

Experiments on Methane Adsorption of Common Clay Minerals in Shale

In order to reveal the main control factors of natural gas adsorption capacity of clay minerals, the methane adsorption isotherm experiments of common clay minerals selected from different sources were performed. The analysis shows that differences of gas adsorption capacity are significant among different types of clay minerals, and the order of methane adsorption capacity of various clay minerals is smectite >> illite and smectite mixed-layers > kaolinite > chlorite > illite > siltstone > quartzite. The crystal structure of clay mineral determines the shape and size of pore spaces between polymer particles and interlayer spaces between crystal layers, and accordingly determines its surface area and gas adsorption capability. Methane adsorption capacities of clay minerals are highly consistent to the development degrees of micro-pores supplied by scanning electron microscopy. The study indicates that the gas adsorption capacity of clay minerals not only depends on the type of clay mineral, but also is significantly influenced by diagenesis and petrogenesis. In addition, the gas adsorption capacity of clay minerals slightly increases with the decrease of particle size due to the enlargement of pore connectivity and surface area.