黔南坳陷二叠纪玄武质火山活动对含煤泥页岩储层的影响

Influence of Permian basaltic volcanic activity on coal-bearing shale reservoirs, Southern Guizhou Depression

李欣诚 侯宇光 陈振宏 何生 梁雅琪 刘宇坤 宋颖睿 余锐

LI Xincheng HOU Yuguang CHEN Zhenhong HE Sheng LIANG Yaqi LIU Yukun SONG Yingrui YU Rui

中国地质大学(武汉) 构造与油气资源教育部重点实验室，武汉 430074 中国石油天然气集团有限公司 勘探开发研究院，北京 100083 湖北省地质实验测试中心，武汉 430034 中国科学院 地质与地球物理研究所，中国科学院 油气资源研究重点实验室，北京 100029

Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education, China University of Geosciences (Wuhan), Wuhan, Hubei 430074, China PetroChina Exploration and Development Research Institute, Beijing 100083, China Hubei Geological Research Laboratory, Wuhan, Hubei 430034, China Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China

为了研究火山活动对泥页岩储层的影响，以黔南坳陷二叠纪峨眉山玄武岩对龙潭组泥页岩储层的影响为例，通过总有机碳含量、XRD、镜质体反射率以及低温氮气及二氧化碳吸附等方法，研究了火山活动对含煤泥页岩生烃、矿物成分以及储层孔隙结构等方面的影响。研究表明：火山活动对含煤泥页岩的生烃、矿物组成和孔隙结构存在明显的影响；火山活动显著促进了泥页岩的有机质成熟演化，使其迅速进入到了过成熟阶段(Ro从2.0%增加到2.88%)，加快了烃源岩的生排烃效率；随着与岩浆岩距离的减小，石英和碳酸盐矿物含量增加，黏土矿物含量减小，伊利石和绿泥石含量呈现规律变化，指示了泥页岩成岩演化也受到了一定的影响；火山活动带来的热源对泥页岩储层孔隙的形成演化产生了重要的影响，随着距离岩浆岩越近，含煤泥页岩储层中的微孔占比逐渐增高，介孔和宏孔含量呈下降趋势，推测火山活动的热作用促进了有机质孔隙的生成，同时也影响了无机孔隙的发育。

To investigate the influences of volcanic activities on shale reservoirs, a case study was carried out on the Permian Mount Emei basalt and coal-bearing shale of Longtan Formation in the Southern Guizhou Depression. Based on the analytical results of total organic carbon content, XRD, vitrinite reflectance and cryogenic nitrogen and carbon dioxide adsorptions, the effects of volcanic activities on the hydrocarbon generation, mineral composition and reservoir microstructure of coal-bearing shale were discussed. The results showed that volcanic activities had obvious effects on the hydrocarbon generation, mineral composition and pore structure of coal-bearing shale. They significantly promoted the evolution and maturation of organic matters in shale, which quickly entered the over-mature stage (Ro% increased from 2.0% to 2.88%), and accelerated the hydrocarbon generation and expulsion efficiency. With the decrease of the distance to the basalt, the contents of clastic minerals and carbonate minerals increased, the content of clay minerals decreased, and the contents of illite and chlorite changed regularly, which indicated that the evolution of shale diagenesis had also been affected to a certain extent. The heat brought by volcanic activities had an important influence on the pores of reservoirs. As it got closer to basalt, the proportion of micropores increased while the content of mesopores and macropores decreased. It was speculated that the thermal effects of volcanic activities promoted the formation of organic pores and also affected the development of inorganic pores.

国家重点研发计划 2017YFE0106300;国家自然科学基金项目 41772143;中国地质调查局项目 DD20190561-1;国家科技重大专项子课题 2016ZX05034002-003

https://doi.org/10.11781/sysydz202104620