一种新的凝析气藏无因次产能评价方程

凝析气藏在衰竭开发过程中存在复杂的相态变化，凝析油的析出使得地层呈现出油气两相混合渗流状态.针对目前凝析气藏无因次产能评价方程的研究较少的现状，在凝析气藏拟稳态流入动态方程的基础上，利用泰勒级数展开、多项式回归等一系列解析方法建立了一种新的凝析气藏无因次产能评价方程.首先对拟稳态流入动态方程中的拟压力函数定积分进行泰勒级数展开，然后利用稳态定理和多项式回归方法求解出泰勒展开式的各项系数，最后通过解析方法得到了凝析气藏的无因次产能评价方程.应用实例表明，该无因次产能方程与实际系统试井数据基本吻合，能够较好地描述凝析气藏的油气两相流入动态；无因次产能评价法所得到无阻流量比常规干气法低，且考虑高速效应的无因次产能评价法所得到的无阻流量要大于忽略高速流动的无因次产能评价法所得到的结果. 

A New Dimensionless Deliverability Equation of Gas Condensate Reservoir

Complicated phase changes occur during the depletion exploitation of gas condensate reservoirs, which causes the precipitation of condensate oil and the mixed flow of gas phase and oil phase. Due to few research reports done so far, a new dimensionless deliverability equation of gas condensate reservoir is established by means of Taylor series expansion and polynomial regression on the basis of the inflow performance equation of gas condensate reservoir in pseudo-steady state in this study. Firstly, the definite integration of pseudo-pressure function in the equation is developed by Taylor series based on the inflow performance equation of gas condensate reservoir in pseudo-steady state; secondly, the coefficients of Taylor series are calculated by steady-state theory and polynomial regression method; finally, the dimensionless deliverability equation of gas condensate reservoir is established by analytic method. Its application shows that the inflow performance curve calculated by the dimensionless deliverability equation coincides with actual data of system well testing, which indicates that this equation can describe the two-phase inflow performance of gas condensate reservoir more accurately. Moreover, the open flow potential obtained by dimensionless deliverability equation is smaller than that by conventional dry gas conversion method; the open flow potential calculated by dimensionless deliverability equation which considers high velocity flow effect is much higher than the one that ignores the high velocity flow effect.