摘要
东海气田水驱气藏普遍发育,部分气井带水生产,产水井呈现高水气比特征。利用传统两相流井筒压力计算方法进行井筒压力分布预测时,发现目前常用模型存在预测精度较低,影响气井积液状态的诊断及排采措施的选择。为此,通过分析不同井径、不同倾角、不同水气比条件下的气液两相流态,基于Kaya流型判别模型修正得到了适用于高水气比井的流型判别新方法,并对Mukherjee-Brill持液率计算公式相关经验系数进行修正,引入表征水气比的无量纲参数和角度修正系数,建立适用于高水气比气藏的新压降模型。研究表明:新的持液率计算模型对不同管径在不同倾角下的持液率计算误差平均小于15%,新的井筒压降计算方法在东海见水气井井筒压力预测中的精度可提升50%以上,与实测值误差不超过8%。新的井筒压降计算方法对于高水气比气井井筒两相流压力分布预测具有较好的推广应用价值,对水驱气藏开发中后期工作制度优化和排水采气工艺选择具有重要的指导意义。
Gas reservoirs in the East China Sea gas fields,which operated by water flooding,are commonly developed.Some gas wells produced along with water,the water/gas ratio of which are high.The traditional two-phase flow wellbore pressure calculation methods were employed to predict wellbore pressure distribution.However,it was found that the current models suffer from low prediction accuracy,which affects the diagnosis of liquid loading conditions in gas wells and the selection of drainage and production measures.To address this issue,gas-liquid two-phase flow patterns under different well diameters,inclinations,and water/gas ratios were analgzel and,a new flow pattern discrimination method suitable for high water/gas ratios was derived based on the discrimination model by corrected Kaya flow pattern.Additionally,the empirical coefficients related to the Mukherjee-Brill liquid holdup calculation formula were revised.Introducing dimensionless parameters characterizing the water/gas ratio and angular correction factors.On this basis,a new pressure drop model applicable to high water/gas ratio gas reservoirs was established.The research shows that the new liquid holdup calculation model achieves an average calculation error of less than 15%for liquid holdup under different pipe diameters and inclinations.The new wellbore pressure drop calculation method improves the prediction accuracy of wellbore pressure in water-injected gas wells in the East China Sea by over 50%,with an error not exceeding 8%compared to measured values.The new method has significant application value for predicting the pressure distribution of two-phase flow in high water/gas ratio gas wells and is of great guiding significance for optimizing operational systems and selecting drainage and gas production processes in the middle and later stages of water-drive gas reservoir development.
作者
伍锐东
李元生
马恋
路颖
石美雪
廖锐全
程阳
Wu Ruidong;Li Yuansheng;Ma Lian;Lu Ying;Shi Meixue;Liao Ruiquan;Cheng Yang(CNOOC(China)Limited Shanghai Branch,Shanghai 200335,China;Yangtze University,Wuhan,Hubei 430100,China)
出处
《特种油气藏》
CAS
CSCD
北大核心
2024年第5期95-101,共7页
Special Oil & Gas Reservoirs
基金
中海石油(中国)有限公司综合科研项目“东海上产560万吨关键技术研究”(CNOOC-KJ 135 ZDXM39SH03)。
关键词
气井
高水气比
倾角
流型
持液率
压力分布
gas well
high water/gas ratio
inclination
flow pattern
liquid holdup
pressure distribution
