Abstract：

The Baima structure belt in the southern part of Fuling shale gas field has experienced many periods of structural movements since the Lower Paleozoic marine shale gasification, and the structural deformation is complicated and different, which has a controlling effect on the gas content of shale gas reservoirs, making the formation mode diverse and restricting the process of exploration and development. This paper analyzes the structural characteristics and evolution process of the Baima structure belt through 3D seismic interpretation, combined with a series of cores and drilling and logging data, and establishes three modes of shale gas enrichment and reservoir formation on the basis of these data. The study shows that: (1) the Baima structure belt mainly develops north-east oriented structures, and exhibits different deformation characteristics of vertical stratification and east-west stratification. Vertically, it is divided into four sets of upper, middle, lower, and Precambrian structural deformation layers by three sets of sliding layers, namely, the Cambrian Qinjiamiao Formation Salt Bed, the Silurian Longmaxi Formation Mud Shale Bed, and the Triassic Jialingjiang Formation Salt Bed. The plane from west to east can be divided into a fold deformation zone and a wide and slow oblique zone. (2) The late Yanshan period is an active period of structural deformation, and the Jiangnan-Xuefeng orogeny produces extrusion from the south-east to the north-west, forming the main north-east oriented tectonic structure of the Baima structure belt. Himalayan period for the structural transformation and finalization of the period, the Indo-European plate collision and the Tibetan Plateau to the east to escape the remote effect caused by the Sichuan Basin counterclockwise rotation, in the eastern part of the Sichuan region for the performance of the right-handed shear, the development of slip shear zones. The Baima structure belt is extruded in the east-west direction, and the first existing northeast structure is modified, and then it gradually turns into the north-south direction. (3) The Baima structure belt can be classified into three shale gas enrichment and storage modes: low-pressure crushed backslope type, normal-pressure wide and slow sloping type, and normal-pressure gentle sloping type. Among them, the shale gas enrichment and preservation conditions in the south slope of Baima are better, with high gas content in a single well. The core and the east wing of the Baima syncline are followed, and the gas content of a single well is higher. The north wing is poor, and the gas content of a single well is slightly lower. The Shimen-Jinping anticline belt is unfavorable for shale gas enrichment and preservation.

Key words：Baima structural belt; structural deformation; shale gas; accumulation model

Received： 2023-12-11

Corresponding Authors：luoliang1225@163.com

Cite this article：周杨帆, 罗良, 曾联波, 刘超, 刘世强, 犹钰玲, 莫娟. 涪陵页岩气田白马构造带变形特征及页岩气成藏模式. 石油科学通报, 2024, 02: 183-195 ZHOU Yangfan, LUO Liang, ZENG Lianbo, LIU Chao, LIU Shiqiang, YOU Yuling, MO Juan. Deformation characteristics and shale gas accumulation model of the Baima structural belt in the Fuling shale gas field. Petroleum Science Bulletin, 2024, 02: 183-195.

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