Ionic liquid enhanced oil recovery in sand-pack columns

Studies on the ionic liquids (ILs) for Chemical Enhanced Oil Recovery (CEOR) processes are limited. This work aims at fulfilling a gap in the research on IL-based CEOR processes (hereby designated by IL-EOR), showing the possibility to use the ILs as an alternative to the conventional chemicals widely studied for this purpose. Results application of ionic liquids are here reported, for the first time, on IL-EOR at Lab scale using a sand-pack column model. A 2 wt% aqueous solution of 1-ethyl-3-methylimidazolium tosylate ([C2mim][OTs]) was used to recover an aromatic oil. The results show that a flooding processes using only 4 pore volumes (PV) could recover 65.7% (±1.0) of the oil in place, almost the double of what was recovered with a brine solution (NaCl, 2 wt%). These preliminary results, requiring further optimization of the IL characteristics and concentration, and other process parameters, suggest that water-flooding with aqueous solutions of ILs can contribute to enhance the oil recovery in mature reservoirs.