不同井斜页岩气水平井流动特征的CFD模拟研究  

CFD simulation of flow characteristics of shale gas horizontal wells with different inclination

作　　者：邱小雪 钟光海 李贤胜 陈猛[3] 凌玮桐 QIU Xiaoxue;ZHONG Guanghai;LI Xiansheng;CHEN Meng;LING Weitong(Shale Gas Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China;Research Institute of Geological Exploration and Development,Chuanqing Drilling Company,PetroChina,Chengdu,Sichuan 610051,China;School of Geosciences and Technology,Southwest Petroleum University,Chengdu,Sichuan 610500,China)

机构地区：[1]中国石油西南油气田公司页岩气研究院,四川成都610051 [2]中国石油川庆钻探工程公司地质勘探开发研究院,四川成都610051 [3]西南石油大学地球科学与技术学院,四川成都610500

出　　处：《油气藏评价与开发》2023年第3期340-347,共8页Petroleum Reservoir Evaluation and Development

基　　金：油气藏地质及开发工程国家重点实验室开放基金“致密气藏孔隙尺度多因素耦合作用渗吸机理研究”(PLN201933)。

摘　　要：页岩气水平井流动特征的准确表征是定量评价生产动态及进一步指导开发方案优化设计的关键基础。为了探究页岩气水平井在不同井斜角下的气液两相流动规律,构建了管径为0.124 m,管长为10 m,井斜角依次为0°、5°、10°、15°、20°、30°、45°、-5°、-10°、-15°、-20°、-30°、-45°的三维立体仿真井筒模型,采用体积模型追踪气液界面,对井筒气液两相流动特征进行动态监测。模拟实验得到井下300 m3/d液量和500 m3/d气量在各井斜角下井筒的流型、平均流速和持率分布特征,深入分析井斜角对页岩气水平井气液两相流动特征的影响规律。结果表明:上倾管(井斜角大于0°)流型特征为段塞流,其流体平均速度随井斜角增加呈单峰式变化,在井斜角为15°时出现峰值,气液分界面处平均流速最低,且低井斜角较高井斜角时的底部持水率大,在井斜角为10°时达到最大值;下倾管(井斜角小于0°)流型特征为分层流,流体平均速度与井斜角呈线性递增关系,气液分界面处平均流速介于顶部和底部值之间,底部持水率随井斜角增加而减小。Accurate characterization of the flow characteristics of shale gas horizontal wells is the key basis for quantitative evaluation of production performance and further guidance of development program optimization design.In order to explore the gasliquid two-phase flow law of shale gas horizontal wells at different inclination angles,a three-dimensional simulation wellbore model with the pipe diameter of 0.124 m,pipe length of 10 m and inclination angles of 0°,5°,10°,15°,20°,30°,45°,-5°,-10°,-15°,-20°,-30°,-45°respectively is constructed.The volume model is used to track the gas-liquid interface.The characteristics of gas-liquid two-phase flow in wellbore are dynamically monitored.The flow pattern,velocity and holdup distribution characteristics of wellbore with 300 m3/d liquid volume and 500 m3/d gas volume are obtained by simulation experiments under various well inclination angles,and the influence law of well inclination angle on gas-liquid two-phase flow characteristics of shale gas horizontal wells is deeply analyzed.The results show that the flow pattern of up-dip pipe(well angle is larger than 0°)is characterized by slug flow,and the average fluid velocity changes in a single-peak form with the increase of well angle,and the peak appears when the well angle is 15°.The flow velocity at the gas-liquid interface is the lowest,and the bottom water holdup is larger with lower well angle is than that with higher well angle,and reaches the maximum value when the well angle is 10°.The flow pattern of down-dip pipe(well angle is less than 0°)is characterized by stratified flow,and the average fluid velocity is linearly increasing with well inclination angle.The flow velocity at gas-liquid interface is between the top and bottom value,and the bottom water holdup decreases with the increase of well inclination angle.

关 键 词：页岩气 水平井 井斜角 体积模型 流型 平均流速 

分 类 号：TE319[石油与天然气工程—油气田开发工程]