Effect of Alkyl Ammonium Ionic Liquids on the Interfacial Tension of the Crude Oil-Water System and Their Use for the Enhanced Oil Recovery Using Ionic Liquid-Polymer Flooding

摘要

Crude oil recovery from matured reservoir still pose challenges due to the low efficiency of the existing enhanced oil recovery (EOR) methods. The chemical enhanced oil recovery technique is one of the potential EOR technique being used to produce trapped oil from mature reservoirs. One of the key challenge for chemical-EOR process is that the conventional surfactants does not show efficacy toward reduction in interfacial tension and oil recovery under high saline and high temperature conditions. Ionic liquids (ILs) can be one of the potential alternative for possible application in chemical-EOR due to their enhanced stability under high saline and thermal conditions. In this investigation, six different alkyl ammonium ILs and sodium dodecyl sulfate (SDS) have been investigated for their effect on the interfacial tension (IFT) of low waxy crude oil water system (with and without salt) as a function of temperature (283.15-353.15 K) and for EOR-flooding process. Water-soluble polymer (polyacrylamide) was used as a polymer flood after SDS/ILs flood in EOR study. This combined flood is referred to as SDS/IL + polymer EOR flooding process. Several EOR flooding experiments such as, only polymer, only SDS, only IL, and SDS/ILS + polymer have been carried out. Also, the evaluation of ILs and SDS for EOR has been investigated under zero and high salinity (100 000 ppm) reservoir conditions and compared. The study also provides an insight into the effects of different cations and anions (alkyl chain length) of the ILs on the IFT of crude oil water system and for the enhanced oil recovery operation.