Jitendra Sangwai

Matured reservoirs are being targeted for enhanced oil recovery (EOR) operations in the hope to recover the residual oil that remains trapped within the porous media. Chemical enhanced oil recovery is one of the successful oil recovery methods which is being employed for the recovery of the residual oil. Many of the conventional chemicals fail to perform under high temperature and high saline reservoir conditions. These situations lead to the search for alternate flooding techniques which could efficiently produce the crude oil to the surface. The present work investigates a possible solution for the recovery of trapped crude oil using lactam and imidazolium based ionic liquids (ILs) specifically targeted towards recovery in high saline environment. Initially, the interfacial tension of the crude oil-water system has been investigated using various chemical agents, such as sodium dodecyl sulfate (SDS), and six different ILs at varying high saline concentrations as a function of temperature (283.15–353.15 K). Subsequently, flooding experiments with only polymer, only SDS, only IL, SDS + polymer and IL + polymer at zero and high saline conditions were performed. It was observed that the IL + polymer flood performed very well in both zero and high salinity conditions as compared to all other flooding systems. The present investigation also portrays an intuition on the evaluation of ILs based on their alkyl chain length.

The purpose of the present work is to evaluate applicability of ionanofluids for enhanced oil recovery (EOR) applications. Two different ionanofluids have been prepared for this study by adding silica nanoparticles into two different ionic liquids (tripropyl ammonium sulphate and triethyl ammonium sulphate) solutions. The effects of nanoparticle and ionic liquid on the interfacial tension of crude oil-nanofluid and their enhanced oil recovery performances have been evaluated. Ionanofluids are found to have the ability to reduce the interfacial tension to a significantly low value. The results of this study also indicate that ionanofluids has much higher enhanced oil recovery efficiencies in comparison to nanofluid and ionic liquid alone. Therefore, ionanofluids have the potential to be used as an excellent future EOR agent.

The need for development of better surface active agents for upstream oil and gas industry which can survive harsh condition of salinity are in great demand, particularly for the applications related to improved/enhanced oil recovery, flow assurance and oil and gas production operations keeping in mind the environmental constraints. The technical difficulties which need to be considered are those involving the surface forces such as surface tension (SFT) and interfacial tension (IFT) acting between the formation water and the low waxy crude oil. In this study, we have employed the use of eight aliphatic ionic liquids (ILs), based on di- and tri-alkyl ammonium as cations and with various anions such as [CH3COO]-, [BF4]-, [H2PO4]- and [HSO4]- for the investigation of the surface phenomenon of crude oil-water system. The synergistic effect of NaCl along with the ILs is investigated in detail. It is observed that there is a significant reduction in the surface tension of water and the interfacial tension of crude oil-water system in the presence of salt, particularly at higher concentration of NaCl (200,000ppm). Effect of temperature, time, alkyl chain length of the cationic part of the ILs, nature of anions of ILs and the concentration of ILs is also discussed. The trend in the electrical conductivity of aqueous IL solutions with various concentrations at three different temperatures 298.15-318.15K is also presented along with critical aggregation concentration. The study on the effect of ILs on the SFT/IFT of water and low waxy crude oil-water system reveal that the ILs are successful in minimizing the effect of the surface forces in the presence of salt and thereby, could pave the way for efficient enhanced oil recovery operations.