注气过程相态变化特征

注气混相驱和非混相驱已成为国内外提高原油采收率的重大方法之一。注气将改变原有油藏体系的组分、组成等热力学条件,使原油的一系列物理、化学性质发生改变。注气过程中流体相态研究是最基础的油藏工程研究内容,其结果为注气过程油藏开发设计、动态分析等提供基础依据。研究结果表明,对黑油油藏注天然气,油藏饱和压力将大幅度地提高,在温度—压力图上表现为泡点线变化大、而露点线变化小。

PHASE BEHAVIOR VARIATION FOR AN OIL SYSTEM IN THE PROCESS OF GAS INJECTION

Miscible flooding and non-miscible flooding for gas injection has been one of the major methods of enhancing oil recover throughout the world. Gas injection will change physical and chemical properties of a system caused by thermodynamic condition variation in the process of gas injection. The research on the phase behavior for the system of gas injection is a main subject of reservoir engineering, which can offer a basis of development design and performance analysis for a reservoir injected by gas. Results show that saturation pressures will greatly enhanced, the bubble lines will be changed considerably and the dew point lines be varied slightly in the process of gas injection for a black oil reservoir.