Effect Of Heterogeneity Variation On The Oil Recovery Performance In Co2-Wag Process

The main objective of this study is to investigate the effect of the heterogeneity on the oil recovery with various WAG ratios using a probabilistic manner in a CO2-WAG process. For the probabilistic scheme, 100 cases of different permeability distributions were generated for each heterogeneity index and used as parameters for different compositional simulations. In generating the fields, the correlation lengths and directions were considered for various permeability fields within the same heterogeneity index. Oil recovery factors according to the WAG ratio were obtained from 2D areal and vertical models. As a result, the heterogeneity has a significant effect on determining the WAG ratio and performance. Especially, it was revealed that the direction of permeability has an effect on the determination of the WAG ratio. The optimum WAG ratio differs depending on the permeability direction of the reservoir. When the direction of permeability is consistent with the extension line between the injector and the producer, the proportion of water should be increased to obtain favourable oil recovery performance.