孔隙介质中CO_2非混相驱替的渗流特性

Flowing characteristic of CO_2 immiscible flooding in pore media

为解决目前CO2-地层原油的非混相作用过程及体系在孔隙介质中的渗流特征仍较为模糊这一问题,利用CO2试验区的地层原油进行非混相体系的驱替实验,研究渗流特征及流体组分的变化规律。根据CO2在水、油介质中的溶解性质,对系统压力轻微降低的现象进行分析。实验监测记录了流体组成含量的变化过程,规律显示:CO2向原油中的溶解及两相间的作用过程是缓慢的;在分离气相中,CO2比重逐渐增大;液相中轻质组分含量降低,而重质组分含量逐渐增加,验证了CO2的抽提作用。非混相状态CO2在实验条件下的性质与常规状态表现出很大不同,非混相驱替方法可取得较好开发效果。

At present,it is still unclear that the immiscible process of CO2-Oil and the flowing characteristic of the mixture system in pore media.Using oil that come from CO2 pilot area to do the immiscible system flooding experiment,the flowing characteristic and fluid compose content are analyzed.According to CO2 solubility in water/oil,it is analyzed that the pressure decreased in a slight scope.The changing process of fluid compose content was monitored.The results list as follow: the process of CO2 dissolve in oil and the action between CO2 and oil are very slow.The CO2 content in gas increases step by step.The lightweight compose content decreases in fluid,on the contrary,the heavyweight compose content increases.This confirmed that CO2 can do a pumping way.In experimental condition,immiscible CO2 is different with the general state.The immiscible CO2 flooding way can get a better production.