储层润湿性及孔隙水赋存对页岩储集空间的影响  

Effects of wettability and pore water occurrence of gas storage space of shale reservoirs

作　　者：范雨辰 陈磊[1] 刘可禹[1,2] 俞凌杰 刘建良 FAN Yuchen;CHEN Lei;LIU Keyu;YU Lingjie;LIU Jianliang(Key Laboratory for Deep Oil and Gas,China University of Petroleum(East China),Qingdao 266580,China;Qingdao National Laboratory for Marine Science and Technology,Qingdao 266237,China;Wuxi Research Institute of Petroleum Geology,SINOPEC,Wuxi 214126,China;State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Wuxi 214126,China)

机构地区：[1]中国石油大学(华东)深层油气重点实验室,山东青岛266580 [2]青岛海洋科学与技术试点国家实验室,山东青岛266237 [3]中国石油化工股份有限公司石油勘探开发研究院无锡石油地质研究所,江苏无锡214126 [4]页岩油气富集机理与有效开发国家重点实验室,江苏无锡214126

出　　处：《中南大学学报（自然科学版）》2022年第9期3575-3589,共15页Journal of Central South University:Science and Technology

基　　金：特提斯地球构造动力系统重大研究计划项目(92055204);中国石化油气成藏重点实验室开放基金资助项目(33550007-20-ZC0613-0041);山东省自然科学基金资助项目(ZR2021QD057)。

摘　　要：针对四川盆地陆相和海陆过渡相页岩气储层孔隙较为发育、含气量高但开发效果较差的问题,联合场发射扫描电镜、流体自发渗吸实验、水分平衡实验以及低压气体吸附实验研究储层孔隙润湿性和孔隙水赋存对页岩有效储集空间孔隙结构的影响。研究结果表明:海陆过渡相龙潭组页岩储层水润湿性较强,陆相大安寨段页岩储层更倾向于油润湿;2个层段中黏土质页岩孔隙的水润湿性最强,其次为混合质页岩和硅质页岩,钙质页岩孔隙的水润湿性最弱;孔隙水赋存使龙潭组和大安寨段页岩的有效储集空间平均下降60%~80%,微孔是孔隙水的主要赋存空间;孔隙水赋存对海陆过渡相龙潭组页岩孔隙总体积的影响程度大于对陆相大安寨段页岩的影响程度,对钙质页岩、硅质页岩、混合质页岩和黏土质页岩孔隙总体积的影响程度依次增大。高质量分数黏土矿物是导致孔隙水润湿性增强的主要因素,它使更多的水分赋存在孔隙中,进而显著影响页岩有效储集空间的孔隙结构。Aiming at the problems of relatively developed pores,high gas bearing content but poor development effect of continental and marine-continental transitional facies shale gas reservoirs in Sichuan Basin,the impact of reservoir pore wettability and pore water occurrence on the pore structure of effective reservoir space in shales were systematically studied,which was combined with field-emission scanning electron microscope observation,fluid spontaneous imbibition experiment,humidity equilibration and low-pressure gas adsorption experiments.The results show that the marine-continental transitional Longtan Formation shales have strong water wettability,while the continental Daanzhai shale reservoirs exhibit a strong oil wettability.In the two shale intervals,the pores of clayey shales show the strongest water wetting behavior,followed by the mixed shales and siliceous shales,while the calcareous shales are the least water wetting.The effective storage space of shale reservoirs in Longtan Formation and Daanzhai Member can decrease by 60%−80%on average in the presence of pore water,greatly influencing the storage capacity.Micropores appear to be the main storage space of pore water.The influence of pore water occurrence on the total pore volume of marine-continental transitional Longtan Formation shales is greater than that of the continental Daanzhai Member shales.The influence of pore water occurrence on the storage capacity of calcareous shales,siliceous shales,mixed shales and clayey shales increases progressively.High mass fraction of clay mineral is the main factor to enhance the water wettability of pores,which will lead to more water stored in the pores and affect the pore structure of shale effective storage space.

关 键 词：陆相页岩 海陆过渡相页岩 润湿性 孔隙水 孔隙结构 

分 类 号：TE122.2[石油与天然气工程—油气勘探]