特殊类型气井凝析气井井筒动态分析新方法

随着天然气勘探开发向地层深部的发展,一些特殊的如异常高温、高压富含气态凝析水、元素硫的气藏、凝析气藏不断涌现,并且所占的比例越来越大。对富含凝析水、元素硫的特殊类型气藏、凝析气藏,当温度较高时,地层束缚水、边底水和可动隙间水与烃类流体的互溶能力就较强,烃类流体中含水量就会增加,且随开采过程温度及压力的降低,元素硫会从烃类流体中析出,再用常规的烃类流体相态研究方法去指导开发这些特殊的气藏、凝析气藏,就致使该类气藏在开发方式、油气藏工程设计和动态分析方面产生一定的误差。在总结常规方法的基础上,综合利用垂直管流公式,结合气-液-液-固四相相平衡闪蒸计算,运用状态方程模拟,对其中的偏差因子、黏度等相关参数进行修正,建立了更为完善的气井井筒动态预测新方法;最后结合地层流入、井筒携液、携固模型,建立了更为综合、全面的气井生产动态分析新方法,该方法更适用于异常高温、高压富含凝析水、元素硫的特殊气井、凝析气井。根据文中建立的气井生产动态预测模型在数值求解的基础上,编制了相应的计算程序,可准确预测不同时期气井生产动态,改善数值模拟一体化动态分析效果,进行最优化生产。

Wellbore Performance Analysis of Special Gas Well

When the formation temperature is high,bound water,edge water and active interstitial water will coexist with condensate gas in vapor.With the reduction of pressure and tem-perature,the elemental sulfur dissolved in gas reservoirs or con-densate gas reservoirs will separate out.If using conventional phase research ways develop the special gas reservoirs or conden-sate gas reservoirs,it will result in some errors in producing meth-od,engineering design and performance analysis.Combining the gas-liquid-liquid-solid 4-phase flash calculation model,the particulate energetics theories and state equation simulation,the correlation parameters of deviation facil,viscosity etc.in reser-voirs were corrected and a new wellbore dynamic prediction meth-od of gas well was established.In combination with the formation inflow model,wellbore outflow model,and drafting system analysis curve,the gas well production performance can be predicted more directly and allsidedly.The method was suitable for special gas well with HPHT,high pressure condensate water and elemental sulfur.Based on established the forecast model of gas well produc-tion performance,the corresponding computation was pro-grammed,it could accurately predict the production performance of gas well in different times,and improved the analysis result of numerical simulation.