摘要
随着气井开发周期延长,井筒积液问题加剧,导致油田产量下降、采收率降低。为此,基于最小压降理论,针对深度为2400~4000 m的直井,采用Ф50.8 mm连续管与Ф60.3 mm油管2种管柱,建立以井口油压、水气比为变量的临界携液流量计算模型。研究表明:Ф50.8 mm连续管自主携液能力更强,积液程度更小,井底流压更低,日产气量更高;临界携液流量随水气比、井口油压、井深增加而增大,其中,水气比与井口油压对临界携液流量的影响程度显著高于井深的影响;当井筒流型转变为段塞流时,Ф50.8 mm连续管气相流量(7000 m^(3)/d)低于Ф60.3 mm油管(16000 m^(3)/d),后者生产时间比前者减少了70%以上。现场试验表明,相比Ф60.3 mm油管,Ф50.8 mm连续管完井效率更高,自然连续生产期延长了1.5 a,进一步验证了模型的准确性。该研究可为气井携液规律分析及排水采气措施优化提供理论依据,对提升低产气井开发效益具有重要指导意义。
As the development cycle of gas wells extends,wellbore liquid loading intensifies,leading to reduced field production and recovery.To address this issue,based on the minimum pressure drop theory,critical liquid-carrying flow rate calculation models with wellhead tubing pressure and water-gas ratio as variables were established for vertical wells with depths of 2400-4000 m,using two types of tubing strings:Φ50.8 mm coiled tubing andΦ60.3 mm tubing.The study shows thatΦ50.8 mm coiled tubing has stronger autonomous liquid-carrying capacity,less severe liquid loading,lower bottom-hole flowing pressure,and higher daily gas production;the critical liquid-carrying flow rate increases with water-gas ratio,wellhead tubing pressure,and well depth,among which the influence of water-gas ratio and wellhead tubing pressure on the critical flow rate is significantly higher than that of well depth;when the wellbore flow pattern transitions to slug flow,the gas flow rate forΦ50.8 mm coiled tubing(7000 m^(3)/d)is lower than that forΦ60.3 mm tubing(16000 m^(3)/d),and the production time of the latter is reduced by more than 70%compared to the former.Field tests show that compared toΦ60.3 mm tubing,Φ50.8 mm coiled tubing brings higher completion efficiency,extending the natural continuous production period by 1.5 years,further verifying the accuracy of the model.This research provides a theoretical basis for analyzing gas well liquid-carrying laws and optimizing liquid drainage gas production measures,and offers important guiding significance for improving the development efficiency of low-productivity gas wells.
作者
刘时春
贾友亮
白晓弘
杨旭东
卫亚明
赵彬彬
肖述琴
LIU Shichun;JIA Youliang;BAI Xiaohong;YANG Xudong;WEI Yaming;ZHAO Binbin;XIAO Shuqin(PetroChina Changqing Oilfield Company,Xi′an,Shaanxi 710018,China;National Engineering Laboratory for Exploration and Development of Low-Permeability Oil and Gas Fields,Xi′an,Shaanxi 710018,China)
出处
《特种油气藏》
北大核心
2025年第4期158-166,共9页
Special Oil & Gas Reservoirs
基金
中国石油科学研究与技术开发项目“致密气及页岩气井连续管带压完井与采气一体化技术现场试验”(2022ZS26)。
关键词
生产管柱
最小压降理论
临界携液
气液两相流动
井筒流型
production tubing
minimum pressure drop theory
critical liquid-carrying
gas-liquid two-phase flow
wellbore flow pattern
