Study on the deployment of differentiated well patterns for shale gas in southern Sichuan region
DOI:
https://doi.org/10.62813/see.2024.01.04Keywords:
Shale gas, Embedded discrete fractures, Fracturing simulation, Reservoir simulation, Well pattern optimizationAbstract
Shale gas blocks are of great geological differences in southern Sichuan, deploying differentiated well patterns accordingly is therefore significant. For two typical shale gas blocks in southern Sichuan, Dingshan normal pressure area and Yongchuan south area, a hydraulic fracturing interlayer law model based on the cohesive zone model and a fracture extension model based on rock damage theory were established. Hydraulic fracture height and length charts under different natural fracture density and operation parameters were drawn. Using these charts, fracture parameters in different areas were determined, and hydraulic and natural fracture models were established. By coupling an embedded discrete fracture model with geological models and fracture models, a complex fracture network simulation model was built to predict gas production. Horizontal well spacing, orientation, and length were optimized under different geological characteristics to maximize production and economic indicators, and a differentiated well pattern deployment strategy was proposed. Results show that, firstly, for Dingshan area, the fracture height range is 40-64 m with an average of 51 m, that of Yongchuan is 42-65 m with an average of 53 m. The fracture length range of Dingshan area is 215-350 m with an average of 300 m, whereas that of Yongchuan is 290-350 m with an average of 330 m. The optimal horizontal well spacing in Dingshan area is 300 m, the optimal well orientation is 60°-90°, and the optimal lateral length is 2000 m; and those of Yongchuan are 300 m, 90°, and 1680 m. Well pattern on-site can be adjusted according to the optimal parameters to achieve higher Estimated Ultimate Recovery (EUR) and Net Present Value (NPV).
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Copyright (c) 2024 Xianchao Chen, Hao Fan, Qin Li, Lijun Liu, Pengyu Jiang, Feng Qian, Taotao Lei
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