Laboratory Study on Carbon Dioxide and Surfactant Assisted with Steam Flooding in Qi 40

Abstract

The natural oil sand from Qi 40 block formation is made into 5 teams total 10 high temperature and pressure long double tube reservoir nonhomogeneity models .The experimental oil is simulation oil which is made by mixing the wellhead crude oil with diesel. On the base that steam soaking and steamdriving recovery reach to the current oilfield average level, we do 1 group double tube steam +CO2 .The natural oil sand from Qi 40 block formation is made into 5 teams total 10 high temperature and pressure long double tube reservoir nonhomogeneity models .The experimental oil is simulation oil which is made by mixing the wellhead crude oil with diesel. On the base that steam soaking and steamdriving recovery reach to the current oilfield average level, we do 1 group double tube steam +CO2 composite displacement experiment and 4 group double tube surfactant adjustable profile + steam +CO2 composite displacement experiment. And record after steamflooding steam drive with carbon dioxide and surfactant improvement value. The results show that in the steam composite flooding, enhanced oil recovery rate increases as the number of composite plug PV growing. Carbon dioxide and steam are injecter by 1:1 alternately and composite plug is 0.3PV, in which enhanced oil recovery rate can reach 19% and cost of oil displacement agent is 38.77 Yuan/ton of oil. Carbon dioxide and II thermostability discharge aiding agent are injecter by 1:1 alternately and thebest composite slug is 0.3PV, in which enhanced oil recovery rate can reach 23.7% and cost of oil displacement agent is 289.66 Yuan/ton of oil. When the plug PV number is same(0.3), surfactant + CO2 composite plug can improve more 4.7% than steam +CO2. Hence, thermostability discharge aiding agent have some effects on improving recovery.