黑59区块回注气驱CO_2浓度优选

Optimization of the CO_2 concentration for gas reinjection flooding in HEI-59 oil-field

国内部分油田进入了三次采油期.采用CO2驱油提高采收率,具有低碳环保、经济高效等优势,已经得到了推广应用.回注气驱油技术作为CO2驱替技术的一个延伸,其组分的确定对矿场提高采收率具有十分重要的意义.本文针对松辽盆地的油藏特征,进行了细管实验分析和数值模拟研究,分析了回注气组成对最小混相压力的影响以及不同CO2纯度下的驱油效率特征.同时,应用油藏工程方法,确定了回注气提高采收率的工程技术指标,为矿场回注气的高效开发提供技术参考.实验分析和数值模拟结果均表明,黑59区块回注气CO2浓度比例不低于93%时,驱油效果最佳.

Some of domestic oil fields are in the tertiary EOR phase.Carbon dioxide drive is an environmental friendly,low carbon emission and high economic efficiency EOR method.The technique of gas reinjection,as extension of Carbon dioxide drive tech,the determination of the components is of great significance to the field oil recovery′s improvement.According to Song Liao Basin′s reservoir characteristics,methods of experimental analysis and theoretical studies were combined.Phase behavior of reinjection gas was studied.Reinjection gas composition′s impact on the minimum miscibility pressure（MMP）was analyzed.Oil displacement efficiency characteristics under different CO2 purity were researched.Technical indicators of gas injection EOR were determined through combination of reservoir engineering and numerical simulation methods.The result shows that when the concentration ratio of CO2 in reinjection gas is greater than 93%,HEI-59 reaches an optimal displacement characteristics.