无骨架内衬扩张式封隔器的研制与现场试验

摘要

为解决常规钢丝帘线或重叠钢片式扩张封隔器胀封承压后残余变形大、易卡管柱的问题,通过设计无骨架内衬扩张式胶筒,研制了无骨架内衬扩张式封隔器.该封隔器采用两端嵌套弹簧的方式来提高胶筒多次坐封的可靠性,在工作压差2.5～5.0 MPa下,胶筒可以充分胀封并可靠密封.室内试验表明,无骨架内衬扩张式封隔器在150℃下可以反复坐封/解封50次,双向承压85 MPa,解封后胶筒残余变形率小于1.5％.该封隔器在延长油田2口老并重复复压裂施工中进行了试验,其坐封显示明显,且在井内工作50 h多后,顺利解封,封隔器胶筒完好,外径仅由108 mm扩大至109 mm.研究结果表明,无骨架内衬扩张式封隔器封隔能力强,能重复坐封、解封,比常规扩张封隔器胶筒残余变形小,更易于解封起出管柱.%In order to solve the problem of residual deformation and potential pipe sticking created by steel wire screen or steel skeleton packer after its setting with pressure-bearing,an non-lining inflatable packer was developed with springs embedded in both ends to support the rubber by designing the non-lining inflatable packer rubber to improve the re-setting reliability.The packer rubber can be fully expanded and sealed under differential pressure difference of 2.5-5.0 MPa.Indoor tests showed that the newly developed packer could be set and reset for 50 times with bi-directional pressure-bearing capacity of 85 MPa at working temperature of 150℃,and the packer rubber has residual deformation less than 1.5％ after releasing.Field tests have been conducted in refracturing of old wells in the Yanchang Oilfield.The packer is very easy to set,and smoothly releases after setting in the well more than 50 hours,with OD expanded from 108 mm to 109 mm only.Research results showed that the innovative inflatable packers have outstanding sealing capacities and can be reset and released repeatedly,with less deformation of rubber than that of conventional packers,easily pulling the pipe string out of the hole.