四川盆地东部涪陵地区自流井组陆相页岩储层微裂缝发育特征及其对页岩气富集的意义  

Microfracture development at Ziliujing lacustrine shale reservoir and its significance for shale-gas enrichment at Fuling area in eastern Sichuan Basin

作　　者：王鹏威 张亚雄 刘忠宝 陈筱 李飞[3] 郝景宇[3] 王濡岳 WANG Pengwei;ZHANG Yaxiong;LIU Zhongbao;CHEN Xiao;LI Fei;HAO Jingyu;WANG Ruyue(Research Institute of Petroleum Exploration&Production,SINOPEC,Beijing 100083,China;CNOOC Research Institute,Beijing 100027,China;Southern Company of SINOPEC Exploration,Chengdu 610041,China)

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院,北京100083 [2]中海石油(中国)有限公司北京研究中心,北京100027 [3]中国石化勘探分公司,四川成都610041

出　　处：《天然气地球科学》2021年第11期1724-1734,共11页Natural Gas Geoscience

基　　金：中国石化科技部项目“川东北地区自流井组页岩气富集主控因素与有利目标”(编号:P19017-2)资助。

摘　　要：通过岩心观察、氩离子抛光扫描电镜观察、高压压汞等实验手段,开展了四川盆地东部涪陵地区自流井组陆相页岩储层裂缝的分类研究,取得以下成果:①明确了陆相页岩储层中裂缝类型及成因机制;②厘定了裂缝对陆相页岩储层储集空间的贡献。结果表明,川东北地区下侏罗统自流井组陆相页岩储层中微裂缝从成因角度可分为3类4种:与沉积作用相关的微裂缝(页理缝)、与成岩作用相关的微裂缝(黏土矿物收缩缝)和与生烃作用相关的微裂缝(有机质收缩缝和有机质裂解缝)。压汞曲线特征和面孔率估算结果证实,微裂缝是下侏罗统自流井组陆相页岩储层储集空间的重要组成部分,其对陆相页岩储层储集能力的贡献约为25%。Microfractures at the Ziliujing lacustrine shale at Fuling area in eastern Sichuan Basin were investigated via core observation, SEM image observation and high pressure mercury injection, and the contribution of microfracture development to reservoir capacity was quantitatively discussed. The following understanding is obtained:①Fracture types in lacustrine shale reservoir are defined;②The contribution of fractures to lacustrine shale reservoir is determined. Results show that the microfractures in the Lower Jurassic Ziliujing lacustrine shale reservoirs in eastern Sichuan Basin can be divided into three types with four groups: Microfractures related to sedimentation(bedding fractures), microfractures related to diagenesis(clay-mineral shrinkage fractures) and microfractures related to hydrocarbon generation(organic-matter shrinkage fractures and organic-matter-cracking fractures). High pressure mercury injection and plane porosity determination confirm that microfractures in lacustrine shale reservoirs have good reservoir performance, whose contribution to shale reservoir capacity is about 25%.

关 键 词：陆相页岩 微裂缝 发育特征 中下侏罗统 自流井组 涪陵地区 四川盆地东部 

分 类 号：TE122.1[石油与天然气工程—油气勘探]