Long Term Downhole Wet-connector Technology for Separate Injection Well - A Case Study in Changqing Oil Field

Abstract

Drill pipe conveying wet-connector horizontal well logging technology is a more mature logging technology. It could be used in all kinds of well loggings, even in highly-deviated wells and horizontalwell, as its downhole joint is connected to the bottom of the drill, using cables to carry heavier and the joint under pump. The two joint complete electrical and mechanical connections, located in themud, cannot meet the need of field test, since it generally lasts less than 15 days. Therefore, longterm downhole Wet-connector technology for separate injection well is proposed, basing on wet-connector horizontal well test technology. This technology mainly consists of the lower docking and upper docking. Specifically, the lower joint is connected to the top of tool string after completion. The upper one joins up on the lower joint by cables from wellhead with help of gravity. Five flow holes of20mm diameter are assembly designed on the lower joint which unlocking mechanism stress is 1.2-2 t approximately. It achieves long-term stability, communications and power supply after docking and normal water injection consequently. Changqing oil field application results show that the wet-connector has several advantages such ashigh success rate, repeatable docking and maintenance. Its various technical indexes could meet the requirements of power, communication and wells backwashing. This proposed technique is an effective method of dynamical real-time monitor and downhole control for seperate injection well in low permeable oilfield.