海上油田同心多管分注洗井防溢流工艺管柱

Anti-overflow Tubing String for Offshore Separate layer Water Injection Well Washing Using Concentric Multi-tube

针对同心多管分注工艺存在管柱不具备洗井功能和不具有井控保护能力的缺点,研究开发了海上同心多管分注洗井防溢流工艺技术。该技术可实现地面直接调节各层注入量,精确控制各层注水量,有效解决大斜度井无法钢丝作业的分注问题;多通道精确注水,有效解决多介质注入问题;能实现不动井口条件下的管柱提升,建立洗井通道,有效解决海上油田注水井洗井不方便、反洗通道易堵塞、反洗排量小、反洗不彻底等技术难题,通过定期活动注水管柱,避免管柱遇卡,减少大修作业;同时可避免注水井停注时液体返出问题,有效地解决了井下安全控制问题。现场应用结果表明,进行该工艺后,绥中X24井分层配注效果良好,在地面实现精确控制各层流量的同时有效解决了因无法洗井管柱拔不动、注水压力上升等问题。

The concentric multi-tube separate layer injection tubing string is disadvantageous for no functions of well washing and well control. Accordingly, the anti-overflow tubing string for offshore separate layer injection well washing using concentric multi-tube is developed. The technology can precisely control the injection volume of each layer through surface regulation, thus achieving separate layer injection in highly-deviated well which could not be done by slickline operation. The multi-tube injection method turns out to be an effective solution for the multi-media injection, which coutd establish well washing channel and address the inconvenient well washing, easy-to-plug reverse washing channel, low reverse washing flow rate and poor reverse washing performance of off- shore water injection well. Through regular water injection string movement, string stick could be avoided and over- haul operations could be reduced. Meanwhile, backflow could be avoided when the injection stops, which effec- tively controls the downhole safety. Field application shows that the technology achieves precise control of injection rate of each layer and effectively addresses the difficult well sure with a great performance of separate layer injection. ling and rise of injection pres- multi-tube separate layer injection; well washing;