注气混相及非混相驱替物质平衡方程式

常规物质平衡方程在油田已广泛应用，然而对油田注气物质平衡方程的研究较少。注入气与油藏油接触时，油气体系间会发生相传质和传热，由于气体溶解于油中引起油的体积膨胀，所以注气过程中物质平衡方程与以前传统的没有考虑相间传质作用的物质平衡方程不同。从物质平衡原理和膨胀理论出发，建立起了注气混相及非混相驱替和气水交替注入过程物质平衡方程式。该物质平衡方程考虑了油气体系相间传质作用和油中溶解气体后的体积膨胀，为注气开发油藏的开发动态分析及预测提供了一种有效的手段。

Material Balance Equation of Miscible and Immiscible Flooding During Gas Injection

The general material balance equation was applied widely in the field, but few studies about material balance equation of gas injection flooding has been conducted. When the injected gas comes into contact with the oil in place, there will be diffusion and dispersion between oil and gas system. And the volume of oil in place will expand due to the dissolved gas. As a result, the material balance equation of gas injection is different from that without regard to diffusion and dispersion between phases. According to the mechanism of gas injection, this paper classified the reservoir floods into three zones-free gas, free oil and transitional zone. Using slim tube experiment to study the relation between the transitional zone and the pressure and quantity of injected gas. And we erect the material balance equation of gas injection flooding and WAG injection flooding according to the principle of material balance and expansion. This equation has taken diffusion and dispersion between oil and gas system and the expansibility of oil into consideration, and provides an effective way for gas injection reservoir.