Beneficial development practice and countermeasures of Baima block in Fuling shale gas field, Sichuan Basin

Abstract

In recent years, while actively promoting the development and adjustment of high-pressure shale gas reservoirs such as Jiaoshiba shale gas reservoir, Fuling shale gas field has steadily expanded its development targets to Baima block and other complex structural blocks in order to ensure continuous and stable production capacity. Based on the strong structural deformation, complex geological conditions, low single-well productivity, and great development difficulty of Baima block, this paper deeply studies the tectonic deformation stages, stress field distribution characteristics, favorable targets, and development technical countermeasures of Baima block by means of fracture zone calcite U-Pb dating, three-dimensional stress field modeling, geoengineering integration evaluation and other technical methods, and has made positive progress: it is suggested that the thrust nappe force is the main controlling factor of the deformation difference of marine normal pressure shale gas reservoirs in Fuling area; the evaluation parameter system of "two categories, six items" for development area selection is established, and the south of Baima syncline core is identified as the most favorable target for beneficial development; a differentiated development technology policy based on the development characteristics of natural fractures has been formed; the engineering process countermeasures based on different geological characteristics such as gas well buried depth, stress property and crack are formed. On the basis of the above understanding, and in accordance with the idea of "overall deployment, evaluation-construction integration, and platform replacement", 30 development well locations were deployed and implemented in 2021-2022, the average ROP was increased by 38%, the fracturing rate was increased by 2-3 times, the single stage fracturing cost was reduced to 850 000 yuan, the daily gas output was stable at 800 000 square meters, and the annual gas output reached 224 million square meters in 2022, basically realizing beneficial development.

Keywords

• normal pressure
• shale gas
• beneficial development
• fuling shale gas field
• sichuan basin