四川盆地西部坳陷中段二叠系栖霞组油气地质条件及勘探潜力

Petroleum geological conditions and exploration potential of the Permian Qixia Formation in the middle segment of Western Depression, Sichuan Basin

张庄 苏成鹏 宋晓波 石国山 汪仁富 李素华 董霞 胡永亮

ZHANG Zhuang SU Chengpeng SONG Xiaobo SHI Guoshan WANG Renfu LI Suhua DONG Xia HU Yongliang

中国石化 西南油气分公司 勘探开发研究院，成都 610041 中国石化 西南油气分公司 地质中心实验室，成都 610081

Research Institute of Exploration and Production, SINOPEC Southwest Oilfield Branch Company, Chengdu, Sichuan 610041, China Geological Center Laboratory, SINOPEC Southwest Oilfield Branch Company, Chengdu, Sichuan 610081, China

近年来，四川盆地西部坳陷北段双鱼石构造、南段平落坝构造二叠系栖霞组勘探取得重大突破，而西部坳陷中段栖霞组勘探尚未突破。为了加快栖霞组超深层海相油气勘探节奏，基于西部坳陷中段周边大量野外露头剖面，结合区内及邻区部分地震和钻井资料以及前人研究成果，系统梳理了栖霞组油气地质条件，综合分析西部坳陷中段的勘探潜力。结果表明，研究区栖霞组具有与西部坳陷北段和南段相同的沉积背景，具备台缘优势相带，具有形成优质储层的条件；同时，该区栖霞组通源断裂发育，能有效沟通寒武系筇竹寺组生烃中心，上覆二叠系致密灰岩和泥页岩以及三叠系膏岩层可作为良好盖层，源—储—盖组合较好，具有形成规模性油气藏的条件。

In recent years, great breakthroughs have been achieved for the exploration in the Permian Qixia Formation of the Shuangyushi structure in the north and the Pingluoba structure in the south of the Western Depression of the Sichuan Basin (Chuanxi Depression), while the exploration of the same formation in the middle segment of the Chuanxi Depression has not been carried out. In order to accelerate the ultra-deep marine natural gas exploration of the Qixia Formation, based on a large number of outcrops around the middle segment of the Chuanxi Depression, combined with seismic and drilling data and previous research results, this study systematically combed the oil and gas geological conditions of the Qixia Formation and comprehensively analyzed its exploration potential. Results show that the Qixia Formation in the study area has comparable sedimentary background as the north and south segments of the Chuanxi Depression, and is a platform margin sedimentary facies with superior reservoir conditions. Moreover, the Qixia Formation in the study area is connected with the hydrocarbon generation center of the Cambrian Qiongzhusi Formation by source faults. The tight limestone and shale of Permian and the gypsolyte of Triassic can be potential excellent cap rocks. Therefore, the source-reservoir-cap assemblage of the Qixia Formation in this area is preferential for large-scale hydrocarbon accumulation.

中国石化科技攻关项目 P20059-3;中国石化西南油气分公司科技攻关项目 KJ-633-2103

https://doi.org/10.11781/sysydz202206959