Investigation of the effects of carbon dioxide injection on the rock and fluid intraction in high permeable sandstone reserviors

Abstract

The injected fluid can chemically react with reservoir rocks and fluids, which changes the properties of petroleum and rocks. Consequently, oil recovery rates are subject to change during the EOR process. Therefore, the study of chemical reactions during EOR process is important . During the CO2 injection, the deposition of asphaltene, and the change of minerals, dissolution and deposition can occur at the same time. Dissolution of rock minerals can increase permeability and effective porosity, but precipitation of asphalt and deposition of these minerals can have the opposite effect. This study investigates the CO2 flooding process in heavy oil reservoirs containing highly permeable sandstone and assesses the effect of orientation on oil recovery and rock-fluid interactions. The results show that due to the gravitational stability in the vertical configuration, there is more oil recovery, mineral solution, and asphaltene sedimentation in the vertical configuration compared to the horizontal configuration. The percentage of asphaltene in the sandpacket model was 1.92 weight percent vertically and 1.18 weight percent horizontally. The increase in porosity for vertical was 2.6% and 1.1% for horizontal infusion. From this it can be concluded that the dissolution of minerals is higher with vertical injection than with horizontal injection.