ABSTRACT

Soluble organic matter greatly affects shale pore structure and gas storage capacity. Based on elucidating the organic type, maturity, and content of shale of Qingshankou formation in Songliao Basin, this paper uses the mixed reagent of dichloromethane/methanol for cable extraction of shale and the change of shale pore structure before and after extraction of dissolved organic matter (DOM) was determined by low-temperature nitrogen adsorption method. The results show that DOM occupies a certain pore space and reduces pore connectivity. After extraction, the shale pore volume and specific surface area were increased, the specific surface area increased by 28.38%-221%, the total pore volume increased by 25.4%-73.2%, and the micropore grew by 48.89%. The effects of DOM on micropores are mainly occlusion and blocking, and mesoporous and macropores are mainly adsorbed and filled. The analysis of the effects of DOM on micropores provides a theoretical basis to examine shale pore structure with low maturity in the future.

摘要

可溶性有机质对页岩孔隙结构和储气能力有很大影响。本文在阐明松辽盆地青山口组页岩有机质类型、成熟度及含量的基础上，采用二氯甲烷/甲醇混合试剂对页岩进行电缆抽提及溶解有机质抽提前后页岩孔隙结构的变化。 (DOM) 采用低温氮气吸附法测定。结果表明，DOM 占据了一定的孔隙空间，降低了孔隙连通性。提取后页岩孔隙体积和比表面积增加，比表面积增加28.38%-221%，总孔隙体积增加25.4%-73.2%，微孔增加48.89%。DOM对微孔的作用主要是闭塞和阻塞，中孔和大孔主要是吸附和填充。DOM对微孔的影响分析为今后研究低成熟度页岩孔隙结构提供了理论依据。