Arabian Journal of Chemistry (Dec 2019)
Molecular modeling, synthesis and characterization of branched geminal zwitterionic liquids for enhanced oil recovery
Abstract
A Sulfobetaine-based Branched Geminal Zwitterionic Liquid (SBGZL) and another one based on hydroxysultaine (HBGZL), were synthesized and their performance was evaluated in the enhancement of the oil recovery (EOR) when they are injected through flooding water into carbonate reservoirs. SBGZL obtained 39.4% and 215.5% more recovery factor for light- and heavy-oil, respectively, than obtained by a synthetic brine used as a reference; conversely, HBGZL obtained 37.5% and 44.7%, respectively. Density-Functional-Theory calculations of interaction energies reveal that both the SBGZL and HBGZL molecules adsorb on the carbonate surfaces stronger than an asphaltene molecule, implying that the good EOR performance of the zwitterionic liquids is due to the induced wettability change of the firstly-oil-wet carbonate surfaces. Keywords: Enhanced oil recovery, Density Functional Theory, Sulfobetaine-based zwitterionic geminal liquid, Supramolecular chemistry