直井全通径分层压裂关键技术及试验研究

苏里格气田采用的“K344型封隔器+喷砂滑套”分层压裂技术,由于整个管柱压后不能实现全通径,影响了后续排液采气、冲砂、测试、监测产液剖面,且无法进行二次改造作业。采用可溶金属材料,设计了直井全通径分层压裂工艺管柱。介绍了直井全通径分层压裂工艺管柱及关键工具。研制了新型喷砂滑套、滑套密封器和节流底阀。室内试验和现场试验结果表明,直井全通径分层压裂工艺管柱中关键工具的溶解时间可控,初始溶解时间大于72 h,压裂后工具内的可溶部分溶解时间小于7 d,不可溶部分脱离可溶部分的束缚下行掉落到井底,整个管柱全通径可达ø57 mm,能够满足一趟管柱分7层压裂施工及后续作业的要求。为直井分层压裂实现管柱全通径提供了新的技术手段。

Key Technology and Experimental Study on the Full Diameter Separate LayerFracturing in Vertical Wells

According to the "K344 Packer + sandblasting sliding sleeve" separate layer fracturing technology used in Sulige gas field, due to the full diameter cannot be achieved after the entire pipe string is compressed, subsequent liquid drainage and gas extraction, sand blasting, testing, and monitoring of the liquid production profile are affected, and secondary reconstruction operations cannot be performed. Through the introduction of soluble metal materials, the process string of the full diameter separate layer fracturing in vertical wells was designed, and a new type of sandblasting sliding sleeve, sliding sleeve sealer and throttle bottom valve were developed. The process string and key tools of the full diameter separate layer fracturing in vertical wells were introduced in detail. Indoor and field tests results show that the dissolution time of the process string and key tools of the full diameter separate layer fracturing in vertical wells can be controlled. The initial dissolution time is greater than 72 h. The soluble parts in the tools after fracturing have a dissolving time of less than 7 d. The insoluble parts are detached from the soluble parts and fall down to the bottom of the well. Finally, the full diameter of the entire pipe string can reach 57 mm, which can meet the requirements of a 7-layer fracturing construction and further operations. The successful implementation of this technology provides a new technical means for separate layer fracturing in vertical wells to realize the full diameter of the pipe string.