CO2 Enhanced Oil Recovery in Reservoirs with Advanced Wells; Simulations and Sensitivity Analysis

Abstract

The global climate challenge from CO2 emission leading to adverse climate conditions requires action to reduce its emission into the world. The process of CO2 enhanced oil recovery is one of the actions that can contribute to reduced carbon footprints from the oil production industry. The objectives of this master’s thesis are to perform a literature review on the water alternating gas (WAG), simulate a model of the miscible CO2 injection for WAG process on computer modeling group software (CMG) and evaluate the performance of the autonomous inflow control valve (AICV) developed by InflowControl AS including sensitivity analysis of the parameters affecting the CO2 EOR process.

The minimum miscible pressure (MMP) was determined using the CMG’s-WinProp tool. The simulations were on experimental data of PVT analyses on the oil compositions and the CO2. The CMG’s-WinProp result showed that the MMP for the miscible CO2 injection equals 15284kPa. The results from the CMG-simulations indicate that well completion with AICV can maintain good oil production while the production of water is decreased from 3e+06m3 to 9.8e+04m3 which corresponds to 30 times reduction in water production from the AICV completion. This is beneficial as the possibility of corrosive mixture production is avoided. In addition, the simulations of the WAG showed an increase in the oil production from 2.4e+06m3 to 2.7e+06m3 which is around 12.5% increase than only water injection. Furthermore, sensitive parameters such as permeability show only a small increase in the effect on oil production, while the water production is reduced with 50%. Both well perforation and the spacing show an increase in productivity of oil with increasing well distances. The simulation results also show that the vertical miscible CO2 injection contributes to increased oil recovery compared to the horizontal miscible CO2 injection.