对凝析气藏物质平衡方程的研讨

A STUDY ON MATERIAL BALANCE EQUATION FOR GAS CONDENSATE RESERVOIR

凝析气藏是一种不同于普通气藏的油气藏。因为气藏压力低于露点之后流体中出现了反凝析液相物，所以凝析气藏的物质平衡方程应和普通气藏的有较大不同，要求建立的方程既可以表示气藏弹性能释放的过程，又可以描述气藏反凝析现象。由凝析气藏开发的基本原理出发，建立了物质平衡方程，为解决凝析气藏开发的地质问题提供了一种手段。经过实际资料验证，该方程适合各种类型的凝析气藏。

Applving material balance principle to study recovery behavior of oil and gas reservoirs has a long history, which could beused to resolve geology problem based on behavior data. Condensate gas reservoir is a peculiar reservoir, which is differentfrom normal gas reservoir, because retrograde condensate liquid phase comes into existence after gas reservoir pressure belowdew point pressure, thus material balance equation of condensate gas reservoir differs greatly from that of normal gasreservoir. The equation is required not only to denote release of elastic energy but also reflect the fact of existence ofretrograde condensate phenomenon.In this paper, material balance equation including gas iIljection has been discussed andestablished based on basic principle of condensate gas reservoir development, and its rationality and applicability are proved bycomputation results of practical data from gas reservoir development.