页岩脱气实验下含气性变化特征研究

Research on Shale Gas Content in Degassing Experiment

为了解页岩内部气体变化特征与规律,采用电磁破碎、加热等脱气方法,分6个阶段对页岩中气体的含气性特征进行了精细的解析实验。通过对比不同分析方法下的实验结果,得出如下认识:多组分共生的页岩气藏中,每种气体的解吸/吸附能力各不相同,并存在竞争吸附关系;破碎阶段释出气体体积最大,烃类成分最多,指示页岩气藏主要开发潜力为封闭孔体系;在不同脱气阶段下,多元气体出现分馏效应,并可根据相互之间的关联性划分为不同吸附性能的两大类;实验显示成岩环境条件和页岩内部组织结构特征或是导致含气性差异的决定性因素。

In order to understand the characteristics and laws of gas evolution within shales, degassing methods such as electromagnetic crushing and heating were used to perform detailed analytical experiments on the gas- bearing characteristics of shales in six stages. By comparing the experimental results under different analytical methods, the following understanding was drawn： In a multi-component symbiotic shale gas reservoir, the desorption/adsorption capacity of each gas is different, and there is a competitive adsorption relationship; the volume of gas released during the crushing stage. The largest hydrocarbon component is the largest, indicating that the main development potential of shale gas reservoirs s a closed pore system; under different degassing stages, multicomponent gas effects fractionation, and can be divided into two major adsorption performances based on their correlations. Experiments show that the diagenetic environment conditions and shale internal organizational structure characteristics are decisive factors leading to differences in gas-bearing properties.