成都理工大学学报（自然科学版）2026，Vol.53Issue(2)：282-300,19.DOI:10.12474/cdlgzrkx.2024072801
川南长垣坝横跨叠加构造变形与古流体运移特征对页岩气保存条件分析
Analysis of shale gas preservation conditions based on tectonic deformation across superposition and paleo-fluid migration characteristics of Changyuanba in southern Sichuan
摘要
Abstract
The Changyuanba structural belt,located in the low fold belt in southern Sichuan,has undergone multiple tectonic movements and formed a typical superposition structure.The shale gas exploration conditions of the Wufeng-Longmaxi Formation in the Chishui block to the east of the belt are not good,which reflect that the complex structure in this area has an important influence on the preservation conditions of shale gas.To solve this problem,we carried out fine seismic structural interpretation and analyzed the fracture development characteristics of different formations in the Well TY1.Through the geochemical analysis of carbon,oxygen,and strontium isotopes,the controlling effect of complex structures on shale gas preservation has been clarified.The research results show that the Changyuanba structural belt mainly developed two groups of fold structures controlled by detachment layers in the north-south and east-west directions.Under the influence of strong tectonic compressive stress,closed anticlinal and a high steep reverse fault developed,which jointly controlled the development of bedding,and which produced a low-angle fault fracture at the bottom of the Wufeng-Longmaxi Formation and a middle-to high-angle fracture in the Maokou Formation.Isotope tests revealed three types of fluid sources,with 87Sr/86Sr enrichment in the Wufeng-Longmaxi Formation samples,while δ13C and δ18O in the vein body were found to be depleted relative to the surrounding rock,indicating that the formation was dominated by deep hydrothermal fluid,with cross-layer migration and poor sealing.The Permian Maokou Formation is rich in fluid sources:the lower part of the formation is dominated by carbonate fluid and the upper part is dominated by deep hydrothermal fluid;there is also cross-layer fluid activity,with negligible sealing between layers.The Triassic Feixianguan Formation was dominated by the fluid activity of isotopic carbonate rocks,including the participation of deep hydrothermal fluid,and its sealing property is poor.In summary,the Changyuangba tectonic belt contains strong tectonic deformation and developed thrust faults,and the three-dimensional network of fault fractures provides long-term escape channels for shale gas,resulting in relatively poor preservation conditions关键词
五峰组-龙马溪组/长垣坝构造带/构造保存/古流体/页岩气Key words
Wufeng-Longmaxi Formation/Changyuanba structural belt/structural preservation/paleo-fluid/shale gas分类
天文与地球科学引用本文复制引用
谢荣洁,李智武,李金玺,刘树根,叶玥豪,童馗,张毫生,魏力民,孟宪武..川南长垣坝横跨叠加构造变形与古流体运移特征对页岩气保存条件分析[J].成都理工大学学报（自然科学版）,2026,53(2):282-300,19.基金项目
新型油气勘探开发国家科技重大专项课题(2025ZD1400403) （2025ZD1400403）
国家自然科学基金项目(U2344209). （U2344209）
