Analysis on the Design Parameters and Evaluation of the Oil Recovery in CO2-WAG Process

Abstract

In applying CO2-WAG, the optimization of design parameters is a main concern to obtain favorable oil recovery. In this study, a parametric study was implemented to investigate the effect of injection rate, WAG ratio and CO2 slug size on oil recovery. A 1-D model was developed to confirm the oil recovery factor for different design parameters. As a result, the optimum parameters for CO2-WAG were WAG ratio of 1:2, slug size of 0.04 PV and total slug size of 0.5 PV. Based on the analysis, reservoir simulations were carried out to investigate the effect of enhanced oil recovery. It was confirmed that CO2-WAG results in incremental 20% and 7% oil recovery compared to the primary recovery and water flooding, respectively. As oil recovery was increased to 8% with the increased oil of 21 MMbbl during injection period of CO2-WAG, the application of CO2-WAG process is economically feasible.