非均质油藏混相调驱技术渗流特性研究

Study on Seepage Characteristics of Miscible Profile Control and Flooding Technology in Heterogeneous Reservoirs

针对气液两相在油藏中具有较复杂的渗流机理和驱油特性,通过岩心驱替实验在0.5mL·min-1,温度60℃条件下,通过室内实验研究气液两相在不同渗透率岩心中的注入性和在驱油性能,通过双管并联驱替实验模拟气液两相在气液比1∶5和2∶5时,在岩心渗透率极差8,10,15,20,30下,研究混相驱体系在地层中的注入性,并且在岩心渗透率极差8,15,30时,对混相调驱体系在层级地层中的驱油效果进行评价。实验结果表明:混相体系能够有效封堵高渗层,具有良好的封堵性能,并且发生液流转向,有效的驱替出低渗层中的原油,在极差为30时,能提高驱油效率36.24%,分析混相驱过程的渗流特征和其在油藏中的适应性,对混相驱驱油参数进行优化,为混相驱油在现场取得良好增油效果提供一定的指导意义。

In view of the complex percolation mechanism and oil displacement characteristics of gas-liquid two-phase in the reservoir,the injectivity and oil displacement performance of gas-liquid two-phase in different permeability cores under the condition of 0.5 mL·min-1 and 60℃were studied,and the permeability of the core was simulated when the gas-liquid ratio was 1∶5 and 2∶5 through the double pipe parallel displacement experiment under the core permeability contrast of 8,10,15,20 and 30,the injectivity of miscible flooding system in the formation was studied under the core permeability contrast of 8,15 and 30,the displacement effect of miscible flooding system in the hierarchical formation was evaluated.The experimental results showed that,miscible system could effectively seal high-permeability layer,had good plugging performance,and effectively displaced the crude oil in low-permeability layer.When the permeability contrast was 30,the oil displacement efficiency was increased by 36.24%.The seepage characteristics and adaptability of miscible flooding process in the reservoir were analyzed,and the miscible displacement parameters were optimized for miscible displacement,which could provide some guidance for increasing oil production by miscible displacement in the field.