低压低产井泡排工艺应用技术界限研究

Study on Application Technology Limits of Foam Drainage Gas Recovery Technology in Low-pressure and Low-production Wells

泡沫排水采气工艺是川西中浅层气藏主要的低成本维护工艺,然而气井自身能量下降,不同泡排药剂维护效果差异较大,有效率逐年降低。通过不同药剂原理、性能指标对比分析,开展不同生产带液条件下气井携液临界流量计算研究。气井携液能力较自然生产情况下提升约40%,较常规泡排剂下提升约10%,根据气井自然生产、常规泡排药剂及低表面张力泡排剂下的携液临界流量,划分气井介入常规泡排、低表面张力泡排及自生气泡排时机;分类制定了间歇产水和连续产水气井泡排维护制度,降低了部分井泡排维护成本,实现了低压低产气井带液生产。现场应用后,泡排维护有效率由81.7%提升至93.7%,排液增产效果显著。

Foam drainage gas recovery technology is the main low-cost maintenance technology for middle-shallow gas reservoirs in western Sichuan.However,the energy of the gas well itself decreases,and the maintenance effects of different foaming agent for gas drainage vary greatly,and the effective rate decreases year by year.Through the comparative analysis of the principles and performance indicators of different agents,this paper carried out the calculation of the critical flow rate of liquid carrying in gas wells under different production conditions.The critical liquid-carrying capacity of gas wells is increased by about 40%compared with natural production conditions,and about 10%higher than that under conventional foaming agent for gas drainage.According to the critical liquid-carrying flow rate under natural gas well production,and conventional foaming agent for gas drainage and low surface tension foaming agent for gas drainage,the timing of intervention of conventional foam drainage,low surface tension foam drainage and self-generated foam drainage of gas wells was classified.And the foam drainage maintenance system of intermittent water production and continuous water production gas well was developed,which reduced the foam drainage maintenance cost of some wells,and achieved liquid-carrying production of low-pressure and low-production gas wells.After on-site application,the effective rate of foam drainage maintenance has been increased from 81.7%to 93.7%,and the production increasing effect of liquid drainage has been significantly increased.