Alkaline‐ionic liquid slug injection for improved heavy oil recovery

Abstract

AbstractChemical flooding has a great potential for improving the recovery factor of heavy oil, especially for reservoirs in which thermal techniques are not applicable. In this novel study, chemical flooding experiments of alkali and alkali + ionic liquid (AIL) mixtures were performed using unconsolidated sand packs. The aim was to investigate the effect on the recovery factor (RF) of combining an alkali, Na2CO3, and four different imidazolium‐based ionic liquids (1‐ethyl‐3‐methylimidazolium acetate [EMIM][Ac], 1‐ethyl‐3‐methyl imidazolium chloride [EMIM][Cl], 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulphonyl)imide [BMIM][Tf2N], and 1‐dodecyl‐3‐methylimidazolium chloride [DMIM][Cl]). The obtained data show that as the ionic liquid concentration and slug size increase, the recovery factor (RF) was found to increase. The study also demonstrates that ionic liquids (ILs) are better in improving heavy oil than recovery than a well‐known surfactant, sodium dodecyl sulphate (SDS). IFT measurements were performed for the Pelican oil used with brine and with [DMIM][Cl], and [EMIM][Ac]. The surface tension (SFT) and zeta potential (ZP) were also measured and correlated to the improvement in the RF. The study shows that in the presence of Na2CO3, the ionic liquid type, concentration, and slug size are important parameters in enhancing heavy oil recovery.