小直径管内水力切割器的研制与应用

Development and application of a small-diameter inside tube hydraulic cutter

为解决聚能和化学切割井下复杂遇卡管柱高破坏性、高危险性的难题,研制了小直径管内水力切割装置。该装置通过地面泵车打压使井下液压马达带动切割工具旋转,当工作液通过底部喷嘴时,喷嘴节流作用形成工作压差,使活塞向上运行压缩弹簧并与刀片根部相接触,锥体逐步推动刀片伸出并完全张开到切割位置,高速旋转的刀片从内部铣削油管直至将卡点以上油管割断。该装置应用不受井斜限制,配备液压驱动扶正器、水力机械锚,可在直井、斜井、水平井任意井深位置切割遇卡管柱。目前在胜利油田应用4井次,切割成功率100%。现场应用表明该装置操作简单方便,切割遇卡油管端面规则,并且工作效率高,可靠性强,在油水井作业管柱卡钻处理方面具有广阔的应用前景。

In order to solve the problem that cumulative and chemical cutting of stuck downhole string brings high risk of destructiveness, the small-diameter inside tube hydraulic cutter has been developed. The device works in such a principle where downhole hyaulic motor, after being pressurized by ground pumper drives the cutting tool to rotate; when the fluid runs through the bottom nozzle, its throttling action produces differential pressure, which drives the piston to move upward, compress spring and touch the blade root, while the cone pushes the blade extended and fully opened at the cutting position, before the high-speed rotating blade mills the oil tube from inside until cutting off the oil tube above the stuck-point. The device, which can be also applied in deviated wells, after equipped with a hydraulic centralizer and hydro-mechanical anchor, can be used to cut a stuck string at any well depth position in vertical, deviated and horizontal wells. Up to now, it has been applied in four wells in Shengli oilfield and the successful rate of cutting was 100%. Field applications show that the device is easy and convenient to operate, and it can efficiently and reliably cut the stuck oil tube leaving regular end face, so this device has a wide application prospect in aspect of dealing with the stuck string in oil-water well operation.