Geology-Engineering Integration Technology for High-Yield Well Cultivation of Deep Shale Gas in Wujiaping Formation

The Permian Wujiaping Formation in the eastern Sichuan Basin shows complex geological conditions including thin high-quality reservoir thickness, large burial depth, and vertically developed calcareous interlayers. To achieve large-scale and efficient production in such formation, based on the drilling and fracturing practices from pilot test platform wells in the DY1 well block, siliceous shale and mixed shale in Member 3 of the Wujiaping Formation were identified as the most favorable lithofacies combining geological modeling, numerical simulation, and field tests. On this basis, the reservoir reserve is characterized by “one thinness and four highs”. Three geological models (continuous, interlayered, and interbedded types) were built, forming a geology-engineering integration technology system for high-yield well cultivation of deep shale gas, with “refined deployment+dual sweet-spot target+high-intensity stimulation+scientific pressure-controlled production” as the core. Field application demonstrated that this technical system yielded remarkable results: 11 pilot test wells were completed 74.4 days ahead of schedule, with an average estimated ultimate recovery of 1.34×10⁸ m³. A commercial breakthrough in ultra-deep shale gas at 5 500 m was achieved. The research results could effectively support the large-scale efficient development of deep shale gas in the Wujiaping Formation, and provide a replicable and extendable technical paradigm for the economic production of similar deep, thin-bedded marine shale gas.