In Binnan Tract of Shengli Oilfield, there is sufficient CO2 in the reservoirs and there are much reserves suitable to take the measure of soaking and discharging CO2 to enhance production. In this paper, laboratory experiments and field tests have been conducted pertaining to this technology, and the results indicate that under the pressure of 25MPa, CO2 can mix with oil well. Then, the recovery efficiency of residual oil by water drive can increase 10%. The results of numerical simulation show that optimized effect can be reached through regulating the volume of CO2, duration of soaking, injecting and discharging velocity, while the production will decrease in the second stage compared to the first one. The processes of reverse injection, corrosion and expansion prevention, were taken in the field test, which input-output ratio was as high as 1:4.22, proving that this technology is viable in small lower-permeability reservoirs.

You can access this article if you purchase or spend a download.