川东南五峰–龙马溪组页岩储层孔隙结构特征及影响因素
Pore Structure Classification and Influence Factors of Shale Reservoir of Wufeng-Longmaxi Formation in Southeast Sichuan

微观孔隙结构特征及孔隙结构的影响因素研究对川东南地区页岩储层评价具有非常重要的意义。本文基于低温氮气吸附实验，针对研究区目的层段页岩储层的微观孔隙结构特征开展研究，并分析其差异性。研究结果表明：川东南五峰–龙马溪组页岩储层的孔隙结构主要以微孔和中孔为主，孔隙形态主要表现为细颈广体的墨水瓶孔、四周开放的平行板状孔和不透气的封闭性孔，且微孔和中孔是比表面积和孔体积的主要贡献者，是页岩气聚集的主要空间。基于孔体积和比表面积与TOC含量和矿物成分的关系图分析发现，TOC和矿物成分是影响储层微观孔隙结构特征的重要因素，其中比表面积和孔体积与TOC含量和脆性矿物呈正相关，与黏土矿物呈负相关。
The study of microporous structure characteristics and influencing factors of pore structure is of great significance for the evaluation of shale reservoirs in southeast Sichuan. Based on the low-temperature nitrogen adsorption experiment, the microscopic pore structure characteristics of shale reservoirs in the target strata section of the study area were studied and their differences were analyzed. The results show that the pore structure of the shale reservoir of Wufeng-Longmaxi Formation in southeast Sichuan is mainly microporous and medium pores, and the pore morphology is mainly manifested as ink bottle holes with fine necks and wide bodies, parallel plate pores and impermeable closed pores around them, and micropores and medium pores are the main contributors to the specific surface area and pore volume, and are the main space for shale gas aggregation. Based on the graph analysis of pore volume and specific surface area with TOC content and mineral composition, it is found that TOC and mineral composition are important factors affecting the microporous structure characteristics of reservoirs, of which specific surface area and pore volume are positively correlated with TOC content and brittle minerals, and negatively correlated with clay minerals.