考虑传质的CO_(2)非混相驱流动模式及其提采机理  

Flow pattern and enhanced oil recovery mechanism of CO_(2)immiscible flooding by considering mass transfer

作　　者：和龙 任少坤 张宏 HE Long;REN Shao-kun;ZHANG Hong(College of Mechanical and Electrical Engineering,Shaanxi University of Science&Technology,Xi′an 710021,China)

机构地区：[1]陕西科技大学机电工程学院,陕西西安710021

出　　处：《陕西科技大学学报》2023年第1期96-102,共7页Journal of Shaanxi University of Science & Technology

基　　金：国家自然科学基金项目(52106204);陕西省西安市科协青年人才托举计划项目(095920221332)。

摘　　要：CO_(2)非混相驱过程中CO_(2)与原油间存在复杂相互作用,流动不稳定性较大,驱替前沿形成指进,导致驱油效率显著降低.目前对CO_(2)的提采机理往往局限于对原油粘度、界面张力等物性的影响,但是缺乏传质对指进特性及驱替效率的作用机理认识.利用COMSOL建立了多孔介质模型,采用相场法描述两相界面变化,模拟CO_(2)非混相驱过程,研究CO_(2)传质对流动模式、原油粘度及驱替压力的影响.结果发现,在不同的粘度比M和毛细数Ca下,存在三种流动模式:稳定驱替、毛细指进、粘性指进.M较高时会出现稳定驱替;M较低时,随着Ca的增大,粘性指进转变为毛细指进.CO_(2)传质会显著降低油粘度,促进毛细指进,同时能够显著降低驱替压力,且随着毛细数增加,驱替压力降低的幅度更高.During CO_(2)immiscible flooding process,due to complex interactions between CO_(2)and crude oil,fingers forms in the displacement interface when flow instability is large,resulting in the significant reduction of oil recovery efficiency.At present,the enhanced oil recovery mechanism of CO_(2)flooding is always revealed as the influence on physical properties such as crude oil viscosity and interfacial tension,but the knowledge of CO_(2)mass transfer on fingering and displacement efficiency is still missing.A porous media model was established by COMSOL,and phase-field method was used to track the change of two-phase interface.CO_(2)immiscible flooding process was conducted to study the effect of CO_(2)mass transfer on the flow pattern,oil viscosity and displacement pressure.Three flow patterns were presented under different viscosity ratios(M)and capillary numbers(Ca):stable displacement,capillary fingering and viscous fingering.Stable displacement occurred when M was high.Viscous fingering was changed to capillary fingering as Ca increased when M was low.The CO_(2)mass transfer significantly reduce the oil viscosity,promote capillary fingering,and significantly reduce the displacement pressure.With the increase of the Ca,the decrease of displacement pressure was higher.

关 键 词：CO_(2)非混相驱 指进 CO_(2)传质 提采 

分 类 号：TE31[石油与天然气工程—油气田开发工程]