不丢手带压更换气井主控阀门技术改进与应用

Technical improvement and application of replacing main control valve of gas well under pressure without releasing

在气田开发的进程中,采气树主控阀门多由出砂冲刷、内部腐蚀严重等因素导致阀芯等控制部位泄漏。为解决常规压井换阀作业时间长、成本高以及可能对储层产生伤害等问题,现场开展不丢手带压更换主控阀门技术研究。通过对堵塞器封堵原理的改进,不丢手更换气井主控阀门技术的适用压力范围和座封成功率同时得到提升。同时,开展不丢手带压换阀的现场应用,累计更换井口主控阀门25只,证明不丢手主控阀门适用性强。通过以上技术研究及改进得出:(1)不丢手带压换阀施工周期短,成本较低,具有显著的经济效益;(2)不丢手带压换阀作业过程中无入井液、气体和压井液排放,有效避免储层污染和伤害;(3)通过技术升级改用活塞式暂堵器,适用压力范围扩大,降低了旧工艺风险。

In the process of gasfield development, the main control valve of the christmas tree often leaks from the valve core and other control parts which can due to sand scouring, severe internal corrosion and other factors. In order to solve the problems of conventional well killing and valve replacement for long time, high cost and potential damage to the reservoir,technical research on replacing the main control valve under pressure without letting go was carried out on site. Through the improvement of plugging principle of the plug, applicable pressure range of the technology on replacing the main control valve of the gas well without letting go and the success rate of sealing are developed at the same time. Meanwhile, the on-site application of valve replacement under pressure without releasing was carried out,and 25 wellhead master valves were replaced, which proved the applicability of the master valve without releasing was strong. Through the above technical research and improvement, it is concluded that,(1)valve replacement under pressure without releasing featured with short construction period, low cost and significant economic benefits.(2)The operation of valve replacement under pressure without releasing avoids charge of well entering fluid, gas and kill fluid, as well as the reservoir pollution and damage.(3)Through technical upgrading, the piston type temporary plug is used, which expands the a pplicable pressure range and reduces the risk of the old process.