地质力学学报2025，Vol.31Issue(4)：604-616,13.DOI:10.12090/j.issn.1006-6616.2025036
鄂西海槽下寒武统水井沱组沉积特征及其油气地质意义
Sedimentary characteristics of the Lower Cambrian Shuijingtuo Formation in the E'Xi trough and its petroleum geological significance
摘要
Abstract
[Objective]The organic-rich shales of the Lower Cambrian in South China are characterized by significant thickness and high thermal maturity.Recent explorations have yielded industrial gas flows from the Lower Cambrian shales in the Middle Yangtze region.To further investigate the shale gas resource potential of the Lower Cambrian in South China,this study focuses on the Lower Cambrian Shuijingtuo Formation in the Middle Yangtze region.[Methods]Through an integrated analysis of outcrop observations and drilling data,we analyzed its sedimentary characteristics and processes.A third-order stratigraphic sequence framework for the Lower Cambrian shale was established,and a sedimentary model of the Early Cambrian E'Xi Trough in the Middle Yangtze region was constructed,clarifying exploration targets.[Results]The Lower Cambrian Shuijingtuo Formation in the Middle Yangtze region primarily consists of shallow-water and deep-water shelf facies,with shallow carbonate deposits at both the bottom and top.The Lower Cambrian organic-rich shales can be divided into five third-order sequences,which are correlatable with those in the Upper Yangtze region.The Shuijingtuo Formation formed during the filling stage of the E'xi Trough,primarily consisting of argillaceous clastic sedimentary rocks.[Conclusion]Organic-rich shales are distributed in deep-water facies,with two identified subsags within the E'xi Trough(the Enshi and Yichang-Changyang depressions)serving as key exploration targets.The Lower Cambrian Shuijingtuo Formation,together with the underlying Sinian Dengying and Doushantuo Formations,forms a"sandwich-like"conventional hydrocarbon assemblage,which is a priority area for future conventional oil and gas exploration in Western Hubei.关键词
鄂西海槽/下寒武统/水井沱组/沉积特征/层序地层学Key words
E'Xi trough/lower Cambrian/Shuijingtuo Formation/sedimentary characteristics/sequence stratigraphy分类
天文与地球科学引用本文复制引用
陈科,王昱荦,卢妍欣,李飞..鄂西海槽下寒武统水井沱组沉积特征及其油气地质意义[J].地质力学学报,2025,31(4):604-616,13.基金项目
国家自然科学基金项目(U2344213) This research is financially supported by the National Natural Science Foundation of China(Grant No.U2344213). （U2344213）
