摘要
大型体积压裂施工已经成为油气田储层改造的重要手段,在带来大量油气资源的同时,也容易发生压裂后套管变形的现象,已经发生套变导致内通径缩小的井后续再进行储层改造难度很大。为此,设计了一种耐高温、承高压的套变井用封隔器:①采用具有雨伞骨架结构的护肩,可以在受压时阻止胶筒形变部分挤入油套环形空间而损坏;②三级活塞的设计可以使封隔器卡瓦、胶筒在坐封时可以分别独立运动,避免出现胶筒在弹性回弹力作用下留有余量导致坐封不严;③优化了AFLAS氟橡胶与氢化丁腈橡胶配比,使封隔器胶筒具有高强度和耐高温性能;④增加水力锚数量以及加装坐封锁环的设计,提高了封隔器坐封稳定性。应用结果表明:该高温高压套变井用封隔器在200℃的条件下,坐封、解封动作顺利,承压能力超过90 MPa,这个性能指标满足了大部分油气井对储层改造的施工要求,具有很大推广价值。
Massive volume fracturing,an important technique for reservoir stimulation,can help enhance oil and gas production,but lead to casing deformation.Especially,for one well with a smaller internal diameter,subsequent stimulation is very difficult owing to this casing deformation.So,a high temperature and high pressure(HTHP)packer was developed.It is advantageous for:(1)the configuration of an umbrella-shaped shoulder,which can prevent the deformed part of packer rubber from being squeezed into annulus between tubing and casing;(2)the design of three-stage piston,which enables the packer slip and rubber to move independently,thus avoiding loose setting due to the allowance left after the rubber moving back under the effect of elastic resilience;(3)the optimized ratio of AFLAS fluororubber to hydrogenated nitrile rubber,which makes the packer rubber adaptable for high strength and temperature;and(4)more hydraulic anchors and adding lock ring,which improve the setting stability of packer.Its application shows that the HTHP packer can pack and unpack successfully at 200℃,and work well at pressure over 90 MPa,allowing it workable for reservoir stimulation in most wells.The HTHP packer is worth extending.
作者
张毅
郭云鹏
李瑞祺
金显鹏
谭学
孙世强
黄晓亮
Zhang Yi;Guo Yunpeng;Li Ruiqi;Jin Xianpeng;Tan Xue;Sun Shiqiang;Huang Xiaoliang(CNPC Bohai Drilling Engineering Company Limited,Tianjin 300457,China;Center for Hydrogeology and Environmental Geology Survey,China Geological Survey,Baoding,Hebei 071051,China)
出处
《天然气勘探与开发》
2022年第2期49-55,共7页
Natural Gas Exploration and Development
关键词
高温高压
套变井
封隔器
伞状护肩
三级活塞
HPHT
Casing deformation well
Packer
Umbrella-shaped shoulder
Three-stage piston
