酸性气田CO_(2)二级射流泵排水采气工艺模拟研究

Simulation Study of CO_(2) Two Stages Jet Pump Drainage Gas Recovery Technology

川渝地区酸性气田众多,由于气井腐蚀及油套不连通限制了部分工艺的应用。对于产水气井,射流泵是常用的排水采气工艺措施之一。采用射流泵排水采气具有排液周期短、施工工序少、井下无运动部件等优点。但是,一级射流泵吸入压力低,容易出现气蚀现象。设计了二级射流泵,通过模拟表明:二级射流泵能增大吸入压力,有利于降低气蚀的发生;考虑到水、天然气或氮气等常规“动力液”的不足,提出采用二氧化碳代替常规动力液。通过Fluent对一级射流泵和二级射流泵排液采气工艺进行数值模拟,对混合比、压力、速度参数进行分析,优化设计具有最佳参数的二级射流泵。为酸性气田排水采气提供了新的工艺方案。

There are many acidic gas fields in Sichuan and Chongqing,but the application of some processes is limited by the corrosion of gas wells and the packer between tubing and annulus.It is one of the important measures to use jet pump to solve the problem of gas well liquid loading in water-producing gas reservoir.The use of jet pump has the advantages of short discharge period,less construction process and no moving parts in the well,but the first stage jet pump has low suction pressure and is prone to cavitation.Therefore,the second stage jet pump was designed.At the same time,considering the shortcomings of conventional“power fluids”such as water,natural gas or nitrogen,it was proposed to replace conventional power fluids with carbon dioxide.Through Fluent,the first-stage jet pump and the second-stage jet pump were used to carry out numerical simulation experiments on the liquid and gas production process.The mixing ratio,pressure and speed parameters were analyzed,and the second-stage jet pump with the best parameters was optimized.It provides a new technology for the drainage and gas recovery of the sour gas field.