注二氧化碳试井三区复合渗流模型研究

Research on three-region well testing model for CO_2 injection well

试井方法分析是油气田开发过程中了解地层特性的一种被广泛使用的技术.本文建立了考虑储集效应和表皮的CO_2驱的三区复合试井模型,并通过解析方法建立了驱替过程中无因次渗流方程组,进而通过拉普拉斯变换方法求解方程组,获得CO_2试井井底压力的表达式.通过对井底压力及其导数的特征形态进行分析可以得出,注CO_2试井的三区复合模型,其双对数曲线可以分为7个部分,分别对应CO_2驱替过程中的不同流动阶段.

Investigating formation characters by well testing technology has been widely ap‐plied in field developing experience .In this paper ,considering wellbore storage and skin effect ,a new three‐region well testing model for CO2 injection wells is established and solved by Laplace transformation ,and then wellbore pressure calculation method is reached . Through the analysis of type curves′characters of wellbore pressure ,seven consecutive sta‐ges during CO2 injection process can be recognized ,w hich corresponds to the w hole process of CO2 injection .The well testing model established here is expected to provide theoretical basis for further research on CO2‐EOR field .