涪陵焦石坝地区页岩气水平井压裂改造实践与认识

水平井缝网压裂技术的应用大幅提高了涪陵焦石坝地区试验井组产量,促进了我国页岩气商业开发。在分析区块页岩储层构造及地质特征基础上,通过岩石力学参数测试和岩石矿物组分分析,评价了储层岩石脆性及其可压性。根据焦石坝地区五峰组-龙马溪组含气泥页岩段页岩有机质类型好、含气量高、脆性指数高的特点,以“复杂缝网+支撑主缝”为改造主体思路,增大页岩储层的改造体积为目标,优选了压裂材料,优化了压裂设计及配套工艺,确定了试验井组压裂改造工艺技术方法,形成了适用于涪陵焦石坝地区的页岩气水平井分段压裂改造技术。经过26口井的现场实施,效果显著,压裂井均获得了较高产能,平均单井无阻流量10.1×10⁴~155.8×10⁴ m³/d,证实了以“复杂缝网+支撑主缝”为改造主体的页岩气水平井分段压裂技术的有效性,为我国页岩气压裂改造积累了经验。

Practice and cognition of shale gas horizontal well fracturing stimulation in Jiaoshiba of Fuling area

The application of advanced fracturing technology greatly increased shale gas production of pilot well group in Jiaoshiba of Fuling area,and improved commercial development of shale gas in China.Based on the analysis of shale reservoir architecture and geological characteristics,the brittleness and fracturability of reservoir rock were evaluated through rock mechanics parameter testing and mineral composition analysis.Shale in Wufeng-Longmaxi Formations is characterized by good organic matter type,high gas content and high brittleness index.According to the idea of "complex fracture network+main supporting fracture",and aiming at enlarging the volume of fractured shale reservoir,we selected most suitable materials for fracturing fluids,optimized fracturing design and related technologies,and determined the technolo-gical methods for fracturing of the pilot well group.Finally,a set of optimal staged fracturing technologies were developed and applied to the horizontal wells in Jiaoshiba of Fuling area.A total of 26 wells were fractured and obtained high open flow of gas in the range of 10.1×10⁴~155.8×10⁴ m³/d,verifying the effectiveness of these fracturing technologies.