海上油田防砂完井注水井反洗工艺及配套工具

Backwash Technology and Matching Tool for Sand Control Completion Water Injection Well in Offshore Oilfield

目前海上油田防砂完井注水管柱不具有洗井功能,注水井长期注水会有污垢、有机沉积、腐蚀物质以及杂质等注入地层,使得注水压力上升、注水量降低,严重影响注水效果;长时间不洗井会出现管柱上提困难,造成大修作业,增加注水井作业成本。鉴于此,将注水管柱配套反洗插入密封工具、防返吐工作筒和配水器工具,可实现注水井不动管柱注水、反洗工艺技术切换,加强海上油田防砂完井井筒维护与管理,提高注水质量,降低注水井反洗成本,缩短施工周期,增强注水效果。现场应用情况表明,经过反洗的注水井注水压力降低,地层吸水指数提高,注水井分层配注量明显增加;井筒及近井地带得到了清洗,井筒内污垢、腐蚀物和杂质均被清除,解决了钢丝作业遇阻问题,改善了注入水质,增强了水驱开发效果。

Currently the sand control completion water injection string in offshore oilfields does not have the well-flushing function. Long-term injection in water injection wells will result in dirt, organic deposits, corrosion substances, impurity accumulation or injection into formation. This will raise the injection pressure, reduce injec- tion volume and seriously affect injection effects. Therefore the backwash insertion seal tool, anti-backflow working barrel and water distributing tool are installed in the injection string to achieve the technological switching between water injection and backwashing. The field application shows that after backwash the injection pressure of injection wells decreases, formation water absorption index rises and layered distributional injection volume of injection wells goes up remarkably. The shaft and the zone near the well have been washed. The dirt, corrosives and impurities within the shaft have been removed. The problem of the barrier in wire operation has been solved. The injected wa- ter quality has been improved and the water-drive effect has been enhanced.