IMPROVEMENT IN OIL RECOVERY BY WATER DRIVEN MISCIBLE CO_2 SLUG FLOODING

摘要

Oil displacement experiments with water driven miscible CO_2 slug flooding were conducted using core flood apparatus. The objectives of the research were to determine the CO_2 slug sizes which correspond to the maximum oil recovery if used for continuous CO_2 displacement processes and to study the effect of CO_2 slug size variation on oil recovery. The reservoir core model used was a 43 cm length of 5.12 cm diameter cylindrical artificial core with 30% porosity and 1237 mD permeability. The displacement processes were done under a miscible condition for DS-01 oil sample at 2500 psi displacement pressure and 167 OF temperature with 10%, 20%, 30% PV CO_2 slug sizes driven by formation water and finally 100% PV or continuous CO_2 flooding. The displacement was done horizontally at the rate of displacement in porous media of 3.24 cm/hour and injection continued up to 1.2 PV cumulative fluid injected. Based on the experiment results, we observe that oil recovery at horizontal core displacement for the corresponding CO_2 slug sizes are 75.12%, 82.28%, 84.68% and 87.10% of initial oil in place. The optimum CO_2 slug size for DS-01 oil sample is 32% PV.