A Comprehensive Study on the Process of Greenhouse Gas Sequestration Based on a Microporous Media Model

Abstract

Carbon dioxide geological sequestration is an effective method to reduce the content of greenhouse gases in the atmosphere of our planet. This process can also be used to improve the production of oil reservoirs by mixing carbon dioxide and crude oil. In the present study, a differential separation experiment (DL) based on actual crude oil components is used to simulate such a process. The results show that after mixing, the viscosity and density of reservoir fluid decrease and the volume coefficient increase, indicating that the pre buried gas induces fluid expansion and an improvement of the fluid rheological properties. These effects are interpreted using a pore scale model based on real scanning electron microscopy (SEM). The results show that increasing the pressure and reducing the viscosity are beneficial to increasing the micro oil displacement efficiency. Moreover, these effects can improve the production in the target area and slow down the decline of the formation pressure. Furthermore, in the case of fracture development in the reservoir (due to CO2 injection before exploitation), the risk of gas channelling, induced by the displacement pressure difference between injection and production wells, is avoided.