Date of Defense
14-4-2026 12:00 PM
Location
Room 1043, F1 Building
Document Type
Thesis Defense
Degree Name
Master of Science in Petroleum Engineering (MSPE)
College
College of Engineering
Department
Chemical and Petroleum Engineering
First Advisor
Prof. Basim Abu Jdayil
Keywords
Ionic liquids, Enhanced oil recovery (EOR), Carbonate reservoirs, IFT reduction, Wettability alteration, Spontaneous imbibition, Core flooding.
Abstract
Despite advancements in renewable energy, oil and gas still dominate global energy supply, while a substantial portion of original oil in place (OOIP) remains unrecovered through conventional recovery methods. One of the most effective approaches used to mobilize residual oil is chemical enhanced oil recovery (CEOR) through mechanisms such as reduction of interfacial tension (IFT), alteration of wettability, emulsification, and improved displacement efficiency. Recently, ionic liquids (ILs) have gained interest as alternative CEOR agents due to their tunable structure and superior stability under harsh reservoir conditions. This thesis experimentally investigates the potential of low-cost and commercially available ILs for enhanced oil recovery (EOR) in carbonate reservoirs under realistic reservoir conditions. Both ammonium and phosphonium based ILs were systematically evaluated through IFT measurements, contact angle measurements for wettability alteration assessment, microemulsion phase behavior, spontaneous imbibition, and core flooding studies. The impact of the IL structure, particularly cation-anion combinations and alkyl chain length, on EOR performance under high salinity and temperature was a central focus. Among phosphonium based ILs (PILs), Cyphos IL 104 ([P6,6,6,14][(iC8H17)2PO2]) was found to be superior to Cyphos IL 101 ([P6,6,6,14][Cl]) in surface activity. It resulted in a lower critical micelle concentration (CMC) and up to 96% IFT reduction. Moreover, Cyphos IL 104 induced a strong wettability shift toward water-wet state and produced stable Winsor III microemulsions with fine droplets under high-salinity and high-temperature conditions. Core flooding experiments confirmed an additional oil recovery (AOR) of 23.57% of OOIP, which highlights its robustness for carbonate reservoirs. Ammonium based IL also exhibited exceptional interfacial activity with ultra-low IFT values reaching the 10-3 mN/m range. Furthermore, it formed Winsor III microemulsions and reached a maximum oil recovery of 92.65% of OOIP during displacement tests. These findings indicated strong emulsification capability and enhanced viscous forces that resulted in effective oil mobilization. Overall, this study demonstrates that both ammonium and phosphonium based ILs are promising CEOR agents for carbonate reservoirs, as they offer high efficiency, salinity tolerance and temperature stability. The presented systematic screening methodology offers a viable framework for choosing cost-effective ILs tailored to specific reservoir conditions, supporting their potential use in field-scale EOR applications.
Included in
UTILIZATION OF COMMERCIAL PHOSPHONIUM AND AMMONIUM IONIC LIQUIDS IN ENHANCED OIL RECOVERY OF CARBONATE RESERVOIRS
Room 1043, F1 Building
Despite advancements in renewable energy, oil and gas still dominate global energy supply, while a substantial portion of original oil in place (OOIP) remains unrecovered through conventional recovery methods. One of the most effective approaches used to mobilize residual oil is chemical enhanced oil recovery (CEOR) through mechanisms such as reduction of interfacial tension (IFT), alteration of wettability, emulsification, and improved displacement efficiency. Recently, ionic liquids (ILs) have gained interest as alternative CEOR agents due to their tunable structure and superior stability under harsh reservoir conditions. This thesis experimentally investigates the potential of low-cost and commercially available ILs for enhanced oil recovery (EOR) in carbonate reservoirs under realistic reservoir conditions. Both ammonium and phosphonium based ILs were systematically evaluated through IFT measurements, contact angle measurements for wettability alteration assessment, microemulsion phase behavior, spontaneous imbibition, and core flooding studies. The impact of the IL structure, particularly cation-anion combinations and alkyl chain length, on EOR performance under high salinity and temperature was a central focus. Among phosphonium based ILs (PILs), Cyphos IL 104 ([P6,6,6,14][(iC8H17)2PO2]) was found to be superior to Cyphos IL 101 ([P6,6,6,14][Cl]) in surface activity. It resulted in a lower critical micelle concentration (CMC) and up to 96% IFT reduction. Moreover, Cyphos IL 104 induced a strong wettability shift toward water-wet state and produced stable Winsor III microemulsions with fine droplets under high-salinity and high-temperature conditions. Core flooding experiments confirmed an additional oil recovery (AOR) of 23.57% of OOIP, which highlights its robustness for carbonate reservoirs. Ammonium based IL also exhibited exceptional interfacial activity with ultra-low IFT values reaching the 10-3 mN/m range. Furthermore, it formed Winsor III microemulsions and reached a maximum oil recovery of 92.65% of OOIP during displacement tests. These findings indicated strong emulsification capability and enhanced viscous forces that resulted in effective oil mobilization. Overall, this study demonstrates that both ammonium and phosphonium based ILs are promising CEOR agents for carbonate reservoirs, as they offer high efficiency, salinity tolerance and temperature stability. The presented systematic screening methodology offers a viable framework for choosing cost-effective ILs tailored to specific reservoir conditions, supporting their potential use in field-scale EOR applications.