柱塞气举排水采气研究现状及展望

Research status and prospect of deliquification and gas recovery by plunger lift

气井积液是大部分天然气井在开发中后期存在的主要问题,排水采气工艺是排出井底积液并恢复和提高气井产量的关键技术之一。柱塞气举是一种可以高效排出井底积液的间歇生产工艺,该工艺具有结构简单、成本低等优点,适用于低产井和高气液比井,是目前我国最主要的排水采气技术之一。为此,系统地从柱塞类型及应用场景、柱塞气举速度模型、工作制度优化及故障诊断、新型柱塞气举工艺4个方面进行研究综述,分析了不同模型的优缺点,并总结了8种新型柱塞的特点和应用场景,进而针对目前气井生产效率低和井底积液难排出的情况,展望了柱塞气举工艺的技术发展方向。研究结果表明:(1)相比于国外,中国柱塞气举工艺应用广泛,发展较为成熟,新型柱塞气举工艺的发展进一步扩大了其应用范围。(2)速度模型可精确模拟柱塞在井筒中的运动状态;工作制度优化逐步向智能化发展。(3)目前仍存在柱塞气举工艺智能化程度低和无法适应复杂油气井生产的问题。结论认为,柱塞气举工艺下一步发展应聚焦4个方向:智能化技术的应用、适应复杂井条件下的技术开发、结合其他采气工艺的复合应用、基于气藏—井筒—地面一体化的井群制度优化。该研究成果对进一步推动国内柱塞气举相关研究与应用,具有较好的参考作用,并可以为柱塞气举未来发展方向提供指导。

Liquid loading in gas wells is a major problem encountered by most gas wells in the middle and late development stages,and the deliquification and gas recovery technology is one of the key technologies to discharge the liquid loaded at a bottom hole,and restore and improve the production of gas wells.Plunger lift is an intermittent production process that can efficiently discharge the liquid loaded at a bottom hole,with the advantages of simple structure,low cost and being suitable for low production wells and high gasliquid ratio wells,thus it is currently one of the most important deliquification and gas recovery technologies in China.In this paper,research is conducted systematically from four aspects,i.e.plunger types and application scenarios,plunger lift velocity model,work system optimization and fault diagnosis,and new plunger lift process.Besides,the advantages and disadvantages of different models are analyzed,and the characteristics and application scenarios of 8 new types of plungers are summarized.Considering the current situation of gas wells such as low production efficiency and difficult discharge of liquid loaded at the bottom hole,the technological development prospect of plunger lift process is proposed.The results show that the plunger lift process is more widely used and has developed more maturely in China than in other countries.The velocity model can accurately simulate the motion state of the plunger in the wellbore,the working system optimization is gradually developing towards intelligence,and the development of new plunger lift process has further expanded its application scope.The plunger lift process still has practical problems of having low intelligence and being unable to adapt to complex oil and gas well production.It is concluded that the development of plunger lift process in the next step should focus on four directions:the application of intelligent technology;the development of technologies adapting to complex well conditions;composite application together with other gas recovery technologies;and optimization of well cluster system based on gas reservoir-wellbore-surface integration.The research results have a good reference value of further promoting the research and application of plunger lift in China,and can provide guidance for the future development direction of plunger lift.