停产凝析气井一体化治理工艺技术

INTEGRATED OVERHAUL TECHNOLOGY FOR SHUT-IN CONDENSATE GAS WELL

凝析气井进入开发中后期,受地层能量下降、反凝析、水锁污染的影响,井筒积液现象凸现,生产过程中气井压力、产量不断下降直至停喷,严重影响凝析油气采收率。凝析气井流体相态、井筒流态复杂,停喷影响因素多,主要有地层液锁、井筒积液、地面高回压等,各因素相互关联、相互作用,前期针对单一因素的治理措施效果不理想。文章系统分析了凝析气井从地层到井筒到井口的停产影响因素,针对性的开展了液锁解除剂技术、注氮气解水锁技术、井下涡流排液采气技术、井口降回压开采技术研究与试验,形成了停产凝析气井一体化治理工艺技术,现场应用效果良好。

In the middle-late development stage of condensate gas well,liquid loading in wellbore becomes more and more serious under the influence of the formation pressure decrease and the pollution of retrograde condensation and water lock.The pressure and production rate continuously will decline till flowing stops,the recovery rate of condensate oil and gas is seriously affected.Because the fluid phase state and flow pattern in the borehole is complex,the reasons for flowing stop is numerous,mainly including formation liquid-lock,the liquid loading in wellbore,the high back pressure at wellhead,they are interrelated and interactional.In the past the treatment was aimed at only single factor,not much effects observed.In order to achieve effective overhaul in shut-in condensate gas well,by analyzing all factors influencing condensate well flowing,from the formation to the wellbore to the wellhead,an integrated well treatment technology for shut-in condensate gas wells is formed after research on the liquid-lock relieving agent,injecting nitrogen to relieve liquid-lock,water drainage gas production by downhole vortex tools and reducing wellhead back pressure.The field application shows good results.