溶解作用对低渗油藏CO_2驱两相相渗的影响  

IEFLUENCES OF THE DISSOLUTION ON THE RELATIVE PERMEABILITIES FOR CO_2 FLOODED LOW-PERMEABILITY OIL RESERVOIRS

作　　者：赵淑霞[1,2] 王锐[1,2] 吕成远[1,2] 伦增珉[1,2] 周宇[1,2] 

机构地区：[1]中国石油化工集团公司海相油气藏开发重点实验室,北京100083 [2]中国石化石油勘探开发研究院采收率所,北京100083

出　　处：《大庆石油地质与开发》2016年第3期126-129,共4页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家(863)项目"二氧化碳提高石油采收率与封存关键技术研究"(2009AA063402);国家自然科学基金青年基金"核磁共振技术研究裂缝性油藏二氧化碳驱油机理"(51504283)

摘　　要：运用PVT分析仪分别测定了不同压力条件下CO_2在油水中的溶解度,并测定了溶解CO_2后油水性质的变化。采用非稳态相渗实验方法,分别进行了饱和CO_2前后的油水、油气、气水相对渗透率测定实验,明确了CO_2溶解作用对相对渗透率的影响规律。结果表明:油藏条件下,CO_2在原油中的溶解度约为地层水中的7倍。CO_2溶解作用使得原油黏度急剧降低,水相黏度略微增大,原油体积膨胀系数显著增大,而水相体积膨胀系数基本不变。溶解CO_2后,油水性质的变化,使得油水相渗曲线向右偏移,油相相渗提高;CO_2溶解于原油后,使得油气相渗曲线与水相相渗均有不同程度的提升;地层水溶解CO_2后气水相渗曲线变化不大。The solubility of CO_2 and the property changes of the crude oil and water are measured through PVT analyzing device.And moreover,the relative permeabilities of oil/water,oil/gas and gas/brine before and after the CO_2 dissolution are determined through the unsteady-state relative permeability testing method,finally the influencing laws of the dissolution on the permeabilities are made clear.The results show that the solubility of CO_2 in the crude oil is 7 times comparing with that in the formation water.The dissolution sharply decreases the viscosity of the oil while the viscosity of the water is increased slightly;the swell/expansion factor of the oil volume increases remarkably.In contrast,that of the brine increases hardly.After the solution,the changes of the oil and water properties make the relative permeability curves shift right and the permeability of the oil phase rise a bit;when CO_2 dissolved in the oil,contrasting with the water relative permeability,both oil and gas phase permeabilities increasesomewhat;on the contrary,dissolved in the formation water,the gas and water relative permeability curves change slightly.

关 键 词：溶解作用 油水相渗 油气相渗 气水相渗 

分 类 号：TE357.7[石油与天然气工程—油气田开发工程]