页岩气水平井全井段临界携液流量计算模型  

A calculation model for critical liquid-carrying flow rate of shale gas horizontal well section

作　　者：胡之牮 金子一 张小涛 孔凡伟 王佳鑫 罗雨阳 HU Zhijian;JIN Ziyi;ZHANG Xiaotao;KONG Fanwei;WANG Jiaxin;LUO Yuyang(Sichuan Shale Gas Exploration and Development Company Limited,Chengdu,Sichuan 610051,China;Chongqing Dazu Gas Company Limited,Dazu,Chongqing 400999,China)

机构地区：[1]四川页岩气勘探开发有限责任公司,四川成都610051 [2]重庆大足燃气有限责任公司,重庆大足400999

出　　处：《天然气勘探与开发》2024年第6期18-24,共7页Natural Gas Exploration and Development

基　　金：中国石油西南油气田公司科研计划项目(编号:20210304-013)。

摘　　要：全生命周期气液同产是页岩气井重要的生产特征,井筒积液是影响气井中后期正常生产的重要因素。传统临界携液流量计算模型未全面考虑气芯中液滴、液膜流速、返排液量动态变化和页岩气水平井复杂井身结构。为此,基于井筒内两相环雾流理论,运用液膜模型,考虑气芯中液滴、液膜流速以及液膜厚度不均匀分布,建立了页岩气水平井全井段临界携液流量计算模型,运用牛顿—拉夫森迭代法求得临界携液流量数值解,并分析了临界携液流量的影响因素。研究结果表明:(1)相较于传统临界携液流量计算模型,新模型井筒积液的预测符合率最高,达到88.2%。(2)临界携液流量随井斜角的增加先升高后降低,36°达到最大值。(3)临界携液流量随油管内径的增加而升高,随温度的增加而降低,随压力的增加而升高,随产液量的增加而降低。研究模型为页岩气水平井的井筒积液预测提供了指导。Full lifecycle gas-liquid co-production is an important feature in shale gas well production,and wellbore liquid loading is a key factor affecting well production in the middle and later stages.The traditional calculation model for critical liquid-carrying flow rate does not fully consider the liquid droplets,liquid film flow velocity,and the dynamic changes of backflow fluid in gas core,as well as the complex wellbore configuration of shale gas horizontal well.In this context,based on the two-phase annular mist flow theory in wellbore,a critical liquid-carrying flow rate calculation model considering the liquid droplets,liquid film flow velocity,and the uneven thickness of liquid film in gas core for the entire section of shale gas horizontal well was established by using the liquid film model.The numerical solution of critical liquid-carrying flow rate was obtained by the Newton-Raphson Method,and the factors influencing the flow rate were analyzed.The results show that,(i)compared with the traditional calculation model,the new one yields the highest coincidence rate of prediction for wellbore liquid loading,with an accuracy up to 88.2%;(ii)the critical liquid-carrying flow rate increases and then decreases with the increase of wellbore inclination angle,reaching its maximum value at 36°;and(iii)the critical liquid-carrying flow rate increases with the increase of tubing inner diameter,decreases with the temperature increase,increases with the pressure increase,and decreases with the increase of liquid production.The established model provides guidance for predicting wellbore liquid loading in shale gas horizontal wells.

关 键 词：页岩气 水平井 井筒积液 临界携液流量 液膜模型 

分 类 号：TE37[石油与天然气工程—油气田开发工程]