页岩气井用新型无限级全通径滑套压裂技术先导试验

Pilot test of new infinite stage and full-bore sliding sleeve fracturing technology in shale gas wells

水平井分段压裂工艺是页岩气开发的关键技术之一。随着中国页岩气开发向常压领域的不断拓展,压裂工艺的提速提效变得迫切,现有的泵送桥塞射孔联作工艺存在泵送时间长、工具易遇卡、固井投球滑套压裂段数有限、连油拖动封隔器压裂规模受限等各种局限。基于新型无限级全通径滑套压裂技术,阐述了滑套工具的结构原理与工艺技术特点,并在南川页岩气田开展了2井次16段滑套压裂先导试验。试验表明该技术通过预置滑套替代泵送射孔与连续油管钻塞,滑套开启成功率100%,压裂段数无限制且施工过程连续,单段压裂平均耗时3.5 h,完成了单日7段压裂施工,是一种快速、安全、高效的分段压裂技术,为我国页岩气井压裂作业提速提效提供了新的技术手段。

Staged fracturing for horizontal wells is one of the key technologies for shale gas development.As the shale gas development in China extends to normal pressure fields,it is urgent to enhance the speed and efficiency of fracturing technology.The existing plug and perf operation technology has many limitations,including long duration of pumping,easiness to stuck tools,limited number of fracturing stages for ball-actuated sliding sleeves,and limited fracturing scale for packers dragged by coiled tubing.For the new infinite stage and full-bore sliding sleeve fracturing technology,the structure principle of the sliding sleeve as well as its technological characteristics are explained,and a pilot test has been carried out in 16 fracturing stages of two wells in Nanchuan Shale Gas Field.This technology replaces perforation and coiled tubing drilling plugs by preset sliding sleeves.All the sliding sleeves are opened successfully.The number of fracturing stages is unlimited and the operation is continuous.The average time of single stage fracturing is 3.5 h and it can finish seven fracturing stages per day.As a fast,safe and efficient staged fracturing technology,it provides a new technical means for enhancing speed and efficiency of fracturing technology for shale gas wells in China.