四川盆地页岩气水平井分段压裂技术系列国产化研究及应用

随着四川盆地页岩气勘探开发的持续深入,实施水平井分段压裂改造已成为页岩气这种非常规气藏有效开发的必要手段。针对四川长宁—威远国家级页岩气示范区水平井储层特点,结合套管固井完井方式,通过开展自主攻关与现场试验,在页岩气水平井压裂改造方面逐步形成了一套完整的技术系列,包括:新型复合桥塞分段工具、高效降阻滑溜水体系、优化分段设计技术、体积压裂工艺、连续油管钻磨技术、连续混配、连续供砂、连续作业技术、返排液重复利用技术等,从而实现了页岩气水平井储层改造的最优化体积和效果。应用结果表明:自主研发的页岩气水平井复合桥塞优化分段、滑溜水体积压裂工艺及工程配套技术,能够有效提高工程时效和增加井口产能,为页岩气水平井规模效益开发提供了技术保障,为下一步四川盆地页岩气工厂化压裂的实施提供了技术支撑。

Research about and application of autonomous staged fracturing technique series for horizontal well stimulation of shale gas reservoirs in the Sichuan Basin

With the further exploration and development of shale gas in the Sichuan Basin, the simulation with horizontal well multi staged fracturing is increasingly necessary for efficient development of unconventional shale gas reservoirs. According to the reservoir features of horizontal wells in the Changning Weiyuan National Shale Gas Demonstration Region in the Sichuan Basin, combined with the modes of casing cementing and completion, an integrated technology series was formed for the horizontal well stimulation of shale gas reservoirs in Sichuan oil and gas fields through independent research and field trials, including a new composite plug tool, an efficient slick water system, optimized multi stage design technology, SRV fracturing technology, coiled tubing drilling and milling technology, continuous fluid mixing, sand feeding and operating technology, flowback fluid recycling technology, etc., thus achieving the optimum volume and effect of the horizontal well simulation of shale gas reservoirs. The field application shows that the optimum staged fracturing of composite bridge plug, slick water SRV fracturing and the related supporting technologies can effectively improve engineering timeliness and increase well production, providing a technical support for the commercial development of shale gas horizontal wells as well as for the upcoming implementation of factory like fracturing treatment of shale gas reservoirs in the Sichuan Basin.