(334d) Foam Stabilization at High Temperature and High Salinity Conditions Using in-House Synthesized Ionic Liquids

Enhanced Oil Recovery (EOR) is a set of advanced techniques used to extract additional oil from reservoirs after primary and secondary recovery methods have been exhausted. It significantly increases the efficiency of oil production, helping to maximize resource utilization and extend the life of existing oil fields. One way to help get the remaining oil is by using CO₂ gas and carbonated water. CO₂ flooding can suffer from issues like poor sweep efficiency due to gas channeling and high mobility. To address this, foam is used to improve conformance by reducing CO₂ mobility, but challenges include foam stability under reservoir conditions and the complexity of designing effective foaming formulations. In this study, we used in-house synthesized Ionic Liquid (FIL-11) as a foaming agent. The ionic liquid was designed to tolerate high temperatures and high salinity conditions. Thermal stability data shows that it was stable at 90 ^oC for at least two weeks. We tested FIL-11 in five different concentrations, from 500 to 2500 ppm, and used CO₂ gas for injection. All tests were done in different temperature and pressure conditions. We measured several important parameters from the foam that was formed, such as: how long the foam could last (half-life time based on bubble count and foam height), how the foam height changed over time, how the number of bubbles changed over time, and how the size of the bubbles changed too. The results showed that the higher the concentration of FIL-11, the more stable the foam became and the longer it could last. Foam with concentrations above 1500 ppm gave the best results. This foam can slow down the movement of CO₂ gas and help spread the gas across the whole rock, so more oil can be recovered.