Experimental Study and Simulation of Different EOR Techniques in a Non-Fractured Carbonate Core from an Iranian Offshore Oil Reservoir

In this research the experimental and theoretical studies on different Enhanced Oil Recovery (EOR) techniques, i.e. Water Flooding (WF), Gas Injection (GI) and Water Alternating Gas process (WAG) were performed on specimens taken from an Iranian carbonate offshore reservoir at the reservoir condition. The experimental results for each specified techniques were compared with the corresponding results obtained from a simulation model. In the case of WF and GI, the injection rates were set to be 0.1, 0.2 and 0.5 cc/min while for the WAG experiments, with two WAG ratios 1 and 2 and with 7, 7, and 10 cycles, the injection rates were 0.1, 0.2 and 0.5 cc/min. The results obtained from the experiments revealed that in all cases the amount of recovered oil is increased. Furthermore, the results showed that increase in the recovery of oil is significant in the case of the WAG injection with optimum rate of injection fluids comparing to those of the WF and GI scenarios. It was also pronounced that the recovery of oil with WAG ratio 2 is more than that with ratio 1. It should be mentioned that samples for sea water and pure methane were considered to be as injection fluids. It was also shown that the experimental results can be accurately correlated with a black oil numerical simulator, Eclipse100.