复杂构造区大隆组页岩裂缝特征及对含气性的影响——以鄂西鹤峰地区为例  

Fracture characteristics and gas-bearing effects in Dalong Formationin complex tectonic zones:A case study of Hefeng area in western Hubei

作　　者：居字龙 万俊 李乐 温雅茹 张焱林 郝云飞 Ju Zilong;Wan Jun;Li Le;Wen Yaru;Zhang Yanlin;Hao Yunfei(Hubei Geological Survey,Wuhan,Hubei 430034;Hubei Institute of Geosciences,Wuhan,Hubei 430034;China University of Geosciences,Wuhan,Hubei 430074)

机构地区：[1]湖北省地质调查院,湖北武汉430034 [2]湖北省地质科学研究院,湖北武汉430034 [3]中国地质大学(武汉),湖北武汉430074

出　　处：《资源环境与工程》2024年第5期506-515,共10页Resources Environment & Engineering

基　　金：鄂西官店—走马地区构造综合调查及页岩气有利区优选(MCDZ202435)。

摘　　要：鄂西地区二叠系大隆组页岩气勘探潜力大,而复杂构造背景的裂缝发育特征对页岩气富集及保存具有重要影响。利用鹤峰地区已钻井的岩心及测井资料,系统对比各钻井大隆组页岩裂缝类型及特征参数的差异,探讨裂缝的发育特征、主控因素及其对页岩含气性的影响。结果表明,鹤峰地区大隆组页岩裂缝类型丰富,发育剪切缝、张裂缝、剪张复合缝和网状缝等类型,且不同构造位置的单井裂缝类型差异大;裂缝发育控制因素为构造和岩性,当构造相对平稳时,脆性矿物含量高时裂缝更为发育,而当断层发育时,裂缝发育程度与离断层距离呈反比关系;裂缝对于大隆组页岩气保存具有双重影响,构造不稳定区域的裂缝对页岩气保存起破坏作用,构造相对稳定区域的裂缝在物质基础较差时有一定的扩展储集空间的能力,而在物质基础较好时直接成为逸失通道。The exploration potential of shale gas in the Permian Dalong Formation in the western Hubei is great,while the characteristics of fractures under the complex structural background have an important impact on the enrichment and preservation of shale gas.Utilizing both of core data and logging data from existed wells in the Hefeng area of western Hubei,the differences in fracture types and characteristic parameters of Permian Dalong Formation shale were compared systematically,as well as the development characteristics,main controlling factors,and their impact on gas content of Dalong Formation shale fractures.The results show that the study area has a rich variety of fracture types,including shear fractures,tensile fractures,tension shear composite fractures,and network fractures,and the types of single well fractures at different structural locations vary greatly.The controlling factors for fracture development are structure and lithology.When the structure is relatively stable,the content of brittle minerals is high,and fractures are more developed.However,when faults develop,the degree of fracture development is inversely proportional to the distance from the structure.Fractures have a dual impact on the preservation of shale gas in the Dalong Formation.Fracture in structurally unstable areas have a destructive effect on shale gas preservation,while in structurally relatively stable areas,fracture have a certain ability to expand storage space when the material foundation is poor,and directly become escape channels when the material foundation is good.

关 键 词：裂缝 大隆组 页岩气 含气性 鄂西 

分 类 号：P618.13[天文地球—矿床学]