从伊朗Arvand-1井溢流压井再谈置换法压井方法

Discussion on Displacement Well Killing Method for Well Arvand-1 Killing

为指导现场技术人员正确使用置换法压井,以伊朗Arvand-1井置换法压井为例,探讨了该井置换法压井作业中的问题,分析了该井采用置换法压井失败的原因。认为该井在关井套压52.5MPa情况下始终保持注入压力61.6MPa停泵,降至57.4MPa后再次开泵,套压保持在42.0MPa以上平衡地层压力的做法和采取的排气方法都存在一定问题,以致注入了2.55倍井眼容积的压井液却成效不大。指出若将井眼容积、注入量和施工压力结合起来进行分析,采取逐次降低注入套压和排气压力的方法,仅用置换法就可以压井成功。根据压井过程中始终保持井内压力平衡的原则和置换法压井原理,给出了正确的压井方法。

In order to enable technicians to use displacement well killing method in the right way, this paper discusses the problems occurred during well Arvand-1 killing and analyzes the failure causes in the killing. When the shut-in casing pressure is 52. 5 MPa, the measures taken to maintain the injection pressure 61.6 MPa then stop and reinjection when the pressure drops to 57.4 MPa, and to keep casing pressure more than 42.0 MPa to balance the pore pressure are considered improper. Although killing fluid 2.55 times borehole volume were injected, the killing was unsuccessful. If borehole volume,injection volume and treatment pressure were considered in whole, and injection pressure and exhaust pressure were reduced gradually,the well could have been successfully killed with displacement well killing method. This paper proposes the right killing method based on the principle of displacement well killing and pressure balance.