考虑闪蒸的凝析气井动态产能计算  

Dynamic productivity calculation of condensate gas wells considering flash evaporation

作　　者：卢德唐[1] 何鹏[1] 牛聪[1] 张龙军[1] 

机构地区：[1]中国科学技术大学近代力学系

出　　处：《天然气工业》2014年第10期47-53,共7页Natural Gas Industry

基　　金："十二五"国家科技重大专项"新一代油藏数值模拟软件"(编号:2011ZX05009-006);中国科学院战略性先导科技专项"页岩气勘探开发基础理论与关键技术"(编号:XDB10030402);国家重点基础研究发展计划(973计划)"二氧化碳减排;储存和资源化利用的基础研究"(编号:2011CB707305)

摘　　要：凝析气井在生产中常会出现反凝析现象,会对其产能预测产生影响,特别是在凝析油含量较高的气藏中影响尤为明显。为此,提出了使用关井压力恢复试井结果,计算凝析气井瞬态产能的方法。从油、气两相渗流方程出发,利用相渗曲线定义拟压力,得到线性化后的油气两相渗流方程。结合状态方程及多组分闪蒸计算,准确描述了凝析气藏在开发过程中相态的变化,得到准确的地层压力和油相饱和度关系,实现了压力与拟压力的转化。利用线性化的拟压力方程可计算试井分析图版,并通过试井分析得到地层渗透率等参数。使用这些地层参数,通过拟压力方程计算得到凝析气井的IPR曲线,最终可对凝析气井的产能进行准确计算和预测。将模型的计算结果与实际井例的生产测试数据进行对比,结果表明其计算合理准确,与已有的井产量数据基本吻合,可在凝析气井中推广使用,以获得准确的产能预测数据。Retrograde condensation frequently occurs in condensate gas wells during the production,exerting a significant impact on production forecast,especially for the reservoirs with higher condensate oil contents.To deal with this,we proposed a method to use shut in pressure build-up test results to calculate the transient production of a condensate gas well.Specifically,we employed elative permeability curves to define pseudo-pressure,thereby to work out the linearized oil/gas permeability equations,then accurately described the phase transition of a gas condensate reservoir during production according to state equation and multi component flash calculations,and finally determined the accurate relationship between formation pressure and oil phase saturation,realizing the conversion between pressure and pseudo pressure.Additionally,we applied the linearized pseudo-pressure equation to figure out the test well analysis charts,thus to obtain the permeability and other parameters of the strata,with which we got IPR curves of a conden sate gas well by calculating the pseudo-pressure equation; in this way,we could accurately calculate and predict the production of the condensate gas well.As a result,the calculated results fit well with the in-situ data,which means the proposed method is applicable and accurate for forecasting the productivity of a condensate gas well.

关 键 词：凝析气井 闪蒸计算 拟压力 生产能力 反凝析 相变 数学模型 

分 类 号：TE328[石油与天然气工程—油气田开发工程]