井口完整性技术在鲁迈拉油田的应用

The Application of Wellhead Integrity Technologies Within Rumaila Oilfield

目前鲁迈拉油田大部分油水井存在不同程度的井口完整性问题,严重影响油田的安全生产运行。通过总结、管理与实践,建立完备的井口问题诊断、维护与维修的技术应用体系,对油水井的安全生产和管理具有重要指导意义。在分析鲁迈拉油田井口装置的结构特点和密封特性的基础上,探讨了井口阀门密封失效、油管悬挂器密封失效及套管悬挂器密封失效问题的诊断方法与处理手段,并研究了井口完整性问题处理过程中的井控技术、设备原理及应用条件,包括带压钻孔/阀技术、背压阀和环空丝堵技术、SIM油管桥塞技术及碳酸钙+酸溶水泥塞压井技术。并以Ru-032为典型井实例,根据现场井况选择了碳酸钙+酸溶水泥塞的井控工艺,压井过程中又应用了带压钻孔设备进行环空A圈闭压力释放,最终成功处理了该井的井口问题。结果表明,本文所给出的技术选项适用于处理井口完整性问题;通过分析实际井况,选择合适的井控工艺,从而保证井口维护或作业的安全与高效。

Currently most of the oil producers and water injectors within Rumaila Oilfield have wellhead integrity issues, which affects the performance of the wells in terms of safety, operation and management in the Oilfield. It is significant to establish a technology application system for the diagnosis and treatment for wellhead integrity issues through the methods of management and practice. On the basis of studying the wellhead structure and sealing properties within Rumaila Oilfield, this paper presented the wellhead integrity issues including the gate valves malfunction, tubing hanger seals failure, and casing hanger seals failure, and the maintenance philosophy how to fix them. The well control technologies during the well- head maintenance, such as hot tap/gate valve drilling, back pressure valve, Valve Removal Plug, calcium carbonate＋ acid soluble cement, were also presented and the mechanism of the equipment and its application were discussed. A case study of Ru-032 showed the whole process of dealing with complicated wellhead integrity issues. The decision of choosing calcium carbonate＋ acid soluble cement technology as the well control method was based upon the actual well condition. The trapped pressure in A Annulus was bled down using hot tap unit during well kill. It was a successful experience for wellhead integri- ty issues. It showed that the technology options given in this paper are suitable for dealing with wellhead integrity issues. It is recommended to choose the best option for well control based upon the actual well condition for wellhead maintenance in a safe and efficient manner.