凝析气井流入动态分析方法研究

【作者】 胡伟岩；

【导师】 孙雷； 黄全华；

【作者基本信息】 西南石油学院 ， 油气田开发工程， 2003， 硕士

【摘要】 在凝析气田的开发过程中，由于凝析气的逆行凝析，随地层压力降到露点压力以下后，气相中重烃会发生相间传质、相态变化，凝析出凝析油并大量凝聚在从气井井周到储层远处的储层多孔介质中，形成井周和储层内部的压降漏斗、渗透率漏斗、饱和度漏斗以及不易流动的圈闭凝析油，从而影响凝析气藏的开发效果。另外，凝析油气体系相态变化和渗流过程发生在地下多孔体质中，孔隙介质壁面几乎挨着流体所有分子，流休与储层介质间会发生相互作用。由于储层颗粒细、孔隙小，使储层介质具有巨大的比面积，并对流体在储层孔隙介质中的分布、渗流发生巨大的影响，引起流体存在于多孔介质中所特有的效应。而解决这些难题的基点之一，正是如何从微观和宏观上正确认识和评价凝析油气在储层多孔介质中的相态变化和渗流规律。 为此，本文在前人的研究基础上，针对多孔介质中凝析油气体系相平衡、渗流规律的研究现状，研究了考虑吸附和毛管压力的凝析气井的流入动态，并将实例计算的结果与单井数值模拟方法计算的结果进行对比： 1、给出了考虑吸附和毛管压力的凝析气井油气两相径向渗流数学模型，并通过引入拟压力函数的方法简化和求解模型，来描述考虑和不考虑多孔介质的气井周围产能、压力、含油饱和度和相对渗透率分布剖面。 2、在单井数值模拟中引入相态等效的方法来研究考虑吸附和毛管压力的凝析气井井周的产能、压力、含油饱和度和相对渗透率分布剖面。 3、对比两种方法的计算结果，得出结论即本文采用的单井数值模拟的方法是合理的。 4、利用单井数值模拟的方法进行凝析气井动态预测，并对计算结果进行分析，得出结论即考虑吸附和毛管压力的凝析气井的流体参数场分布规律与常规气井差异明显，考虑吸附和毛管压力的凝析气井的产能和气相相对渗透率偏低，并且地层反凝析油饱和度比常规气井要高一些。更多还原

【Abstract】 During the course of development of gas condensate fields, for the converse condensation of gas condensate, when the layer pressure is below the saturation pressure, the heavy compositions in gas phase will change and separate out a lot of oil condensate which gather in from the ^well bottom to far porous medium to form pressure filler, permeability filler, saturation filler and oil condensate filler, and this will affect the development effect of the gas condensate reservoir, In addition, the phase change and seepage processing of oil-gas condensate system happen in the porous medium underground, the porosity medium almost gets close to the liquid molecule, therefore, transactions between liquid and porous medium will happen Grains thin and holes small, the porous mediums have great comparing area which arose the special domino effect in the porous medium To resolve all these problems, most of important is how to know and estimate the phase change and seepage theory of oil-gas condensate in porous medium every aspect Therefore, on the base of the formers, aiming at the research actuality of oil-gas condensate phase equilibrium and seepage theory of porous medium, the paper researches the influx performance of gas condensate well considering absorption and capillary pressure, and compares the result of example with single well simulation During the courses, I did the following works:Firstly, giving the oil-gas two phase radial seepage maths models of the gas condensate well with regard of absorption and capillary pressure, and simplifying and getting the solution of the equations by using of psedu-pressure function to describe the distributing the product, pressure, oil saturation and relative permeability.Secondly, introduce equivalent phase state to research thedistributing of produce, pressure, oil saturation and relative permeability near the well bore with regard of absorption and capillary pressure during the course of single well numerical simulation.Thirdly, comparing the calculation result of the two ways and get the conclusion that the way of single well simulation is reasonable.Finally, Use the way of single well numerical simulation to carry through the oil-gas condensate well performance prediction and analyse the calculation result to draw the conclusion.Finally, comparing the calculation result of the general gas well with the result of the gas condensate well with regard of the interface absorption and capillary pressure to draw the conclusion.更多还原