低渗透气藏产水气井两相产能方程研究  

Research on Two-phase Productivity Equation for Water-producing Gas Well in Low-permeability Gas Reservoir

作　　者：李元生[1] 李相方[1] 藤赛男 廖源[3] 徐大融[1] 

机构地区：[1]石油工程教育部重点实验室中国石油大学,北京102249 [2]上海海洋油气分公司,上海200120 [3]中石化河南油田分公司,河南南阳473400

出　　处：《特种油气藏》2014年第4期97-100,155,共4页Special Oil & Gas Reservoirs

基　　金：国家重点基础研究发展计划("973"计划)项目"低渗透碎屑岩天然气藏有效储层分布与渗流规律"(2007CB209506);国家科技重大专项课题子课题"西非深水油田注采参数优化及单井产能预测研究"(2011ZX05030-005-04)

摘　　要：基于低渗透气藏渗流理论和质量守恒原理,建立考虑拟启动压力降和气水高速非达西效应的低渗透气藏气水两相产能方程。该方程提出了拟启动压降的概念,可分析不同气水比下储层流动含水饱和度、平均含水饱和度以及储层中相对渗透率的分布和含水饱和度对拟启动压降的影响,从而得到低渗透气藏气水两相流稳定流入动态曲线和不同气水比下的气井产能变化规律。实例研究发现,气井产能随着水气质量比的增大而减小,满足近似的对数关系。当水气质量比与井底流压不变时,储层流动含水饱和度和拟启动压降随着与井眼距离的增大而增大。并且气井水气质量比越大,储层平均流动含水饱和度越大而拟启动压降越小。该研究为低渗透气藏气水两相流的产能及动态分析提供了理论基础。Based on filtration theory for low- permeability reservoir and law of conservation of mass,a two- phase( water /gas)productivity equation for low- permeability gas reservoir is established which considers quasi- kickoff pressure drop and water /gas high- speed non- Darcy effect. With this equation,the distribution of flow water saturation,average water saturation and relative permeability in reservoir are analyzed under different gas /water ratio,and the influence of water saturation on quasi- kickoff pressure drop is also identified. Accordingly,steady IPR curve of gas and water flow in low- permeability reservoir and the changes of gas productivity under different gas /water ratio are obtained. Case study indicates that the productivity of gas well declines with the increase of water /gas ratio,which corresponds approximately to a logarithmic relationship. When water /gas ratio and downhole flow pressure remain constant,the flow water saturation and quasi- kickoff pressure drop increase with the increase of distance to the wellbore. Furthermore,the larger the water /gas ratio is,the larger the average flow water saturation is and the smaller the quasi-kickoff pressure is. The research results can serve as a theoretical basis for the analysis on productivity and performance of gas /water flow in low- permeability gas reservoir.

关 键 词：气水两相 拟启动压降 产能 低渗透气藏 产水气井 

分 类 号：TE312[石油与天然气工程—油气田开发工程] TE348