Carbon dioxide-based enhanced oil recovery methods to evaluate tight oil reservoirs productivity: A laboratory perspective coupled with geo-sequestration feature

In this paper, three different scenarios were experimentally investigated to compare carbon dioxide based enhanced oil recovery methods. These methods are continuous carbon dioxide (immiscible injection), water alternating gas, and cyclic carbon dioxide injection were investigated. In scenario A, the maximum oil recovery factor for water flooding is about 19% when there is no oil production. The maximum oil recovery at miscibility stage is about 46%. The reason for this low value of oil recovery factor might correspond to the sufficient interaction time between oil and dissolved gas. In scenario B, the total oil recovery factor is about 60% when the water alternating gas injection was performed in the system. In scenario C, after cyclic carbon dioxide injection, final oil recovery factor reached to 62%. The maximum oil recovery after miscibility stage is about 78%. In scenario B and C, regarding the more oil volume production, there are more void spaces that can be a good place for carbon dioxide storage. However, for scenario B, as the injection pattern has been changed alternatively, the void spaced had been occupied by water and this is why the carbon storage capacity was being decreased for this scenario rather than other two scenarios.