Simultaneous water and CO2 injection has been performed on a sandstone core to evaluate oil recovery under the secondary and tertiary near-miscible injection modes. It is demonstrated that secondary SWACO2 injection as well as tertiary flood is an effective method for the oil/residual oil recovery from oil saturated/water-flooded porous media. In the secondary SWACO2 injection, the ultimate oil recovery increases by increasing SWAG ratio from 0.2 to 0.4 but due to some limits, e.g. topological effects, prohibiting contacting of injected gas with residual oil in pores, altering SWAG ratio from 0.4 to 0.6 showed no effect on ultimate oil recovery. Secondary SWACO2 injection can recover higher fraction of the oil than tertiary SWACO2 injection. Higher oil recovery results from the oil being more accessible by the injected gas due to less water-shielding effect. The results of this work can be helpful to better recognition and selection of gas-based oil recovery methods to be implemented in depleted reservoirs.
|Number of pages
|Published - Jun 2014
|76th EAGE Conference and Exhibition 2014 - Amsterdam, Netherlands
Duration: 16 Jun 2014 → 19 Jun 2014
|76th EAGE Conference and Exhibition 2014
|16/06/14 → 19/06/14