CO_2混相驱最小混相压力确定方法研究

Determination of minimum miscible phase pressure for CO_2 miscible drive

CO2混相驱是低渗透油藏提高采收率的三次采油技术,而CO2混相驱最小混相压力是研究的关键。文章从经验公式计算、室内实验和数值模拟三个方面进行了研究,分析论证了确定CO2混相驱最小混相压力的方法;通过岩心驱替实验研究证明了混相驱可以大幅度提高油藏采收率,混相驱应用于低渗透油藏开发是可行性的;在确定了最小混相压力的基础上,把CO2混相驱应用于东营凹陷樊124块的油藏开发取得了良好的效果。

The CO_2 miscible drive is the third production technique to enhance oil recovery for the low permeability reservoir. The minimum miscible phase pressure of the CO_2 miscible drive is the key of the study. In this paper, three respects are studied, including empirical equation, lab test and numerical model. The method to calculate the minimum miscible phase pressure of the CO_2 miscible drive is analyzed. The core driving test demonstrates that the miscible drive can greatly increase oil recovery efficiency. It is feasible that the miscible drive is used for the low permeability reservoir development. Based on the calculation of the minimum miscible phase pressure, the result to apply the CO_2 miscible drive to reservoir development for Fan-124 in the Dongying sag is very good.