Interfacial Properties, Wettability Alteration and Emulsification Properties of an Organic Alkali–Surface Active Ionic Liquid System: Implications for Enhanced Oil Recovery

Abstract

Combinatory flooding techniques evolved over the years to mitigate various limitations associated with unitary flooding techniques and to enhance their performance as well. This study investigates the potential of a combination of 1-hexadecyl-3-methyl imidazolium bromide (C16mimBr) and monoethanolamine (ETA) as an alkali–surfactant (AS) formulation for enhanced oil recovery. The study is conducted comparative to a conventional combination of cetyltrimethylammonium bromide (CTAB) and sodium metaborate (NaBO2). The study confirmed that C16mimBr and CTAB have similar aggregation behaviors and surface activities. The ETA–C16mimBr system proved to be compatible with brine containing an appreciable concentration of divalent cations. Studies on interfacial properties showed that the ETA–C16mimBr system exhibited an improved IFT reduction capability better than the NaBO2–CTAB system, attaining an ultra-low IFT of 7.6 × 10−3 mN/m. The IFT reduction performance of the ETA–C16mimBr system was improved in the presence of salt, attaining an ultra-low IFT of 2.3 × 10−3 mN/m. The system also maintained an ultra-low IFT even in high salinity conditions of 15 wt% NaCl concentration. Synergism was evident for the ETA–C16mimBr system also in altering the carbonate rock surface, while the wetting power of CTAB was not improved by the addition of NaBO2. Both the ETA–C16mimBr and NaBO2–CTAB systems proved to form stable emulsions even at elevated temperatures. This study, therefore, reveals that a combination of surface-active ionic liquid and organic alkali has excellent potential in enhancing the oil recovery in carbonate reservoirs at high salinity, high-temperature conditions in carbonate formations.

Evaluation of the Oil Recovery Potential and Cost Implication Analysis of Alternative ASP Formulations for Sandstone and Carbonate Reservoirs

“…Results of Core Flooding for the ASP Formulations in Carbonate Cores is consistent with previously observed results in prior studies 48. Figures 11 and 12 depict the dynamic curves obtained from the various displacement experiments.…”

“…Our previous studies have validated that combinations of alkalis and surfactants yield synergistic performance in enhancing oil recovery. 47,48 All optimized AS formulations displayed improved interfacial properties and wetting capabilities. The inclusion of alkali has been found to mitigate anionic surfactant adsorption while enhancing cationic surfactant adsorption.…”

Alkane-Strengthened Viscoelasticity in Micellar Solutions of Surface-Active Ionic Liquids and Their Potential Application in Enhanced Oil Recovery

“…Additionally, the advantageous physicochemical characteristics of ILs, such as low vapor pressure, excellent chemical and thermal stability, nonflammability, strong solvating abilities, and liquid state over a wide temperature range, contribute to the high safety profile of SAILs . Many reports have documented the utilization of SAILs as agents for enhanced oil recovery (EOR), supported by experimental studies that highlight their remarkable efficacy in enhancing oil recovery efficiency. − …”

“…Moreover, as oil-displacing agents, the high toxicity and corrosiveness drawbacks of common nitrogenous heterocyclic long alkyl chain ionic liquids were avoided by BD-OA. 37,38 Therefore, long-chain fatty acid SAILs hold substantial promise in EOR.…”

“…It could be seen that BD-OA WLMs have excellent resistance to alkanes and offer the potential to effectively address the issue of viscoelasticity decline sharply when conventional surfactant micelle solutions touch with alkanes. Moreover, as oil-displacing agents, the high toxicity and corrosiveness drawbacks of common nitrogenous heterocyclic long alkyl chain ionic liquids were avoided by BD-OA. , Therefore, long-chain fatty acid SAILs hold substantial promise in EOR.…”