Investigation of Alpha Olefin Sulfonates Microemulsion Performance without Addition of Cosurfactant under Different Types of Salinity and Temperature

Surfactant is one of the chemical widely used in enhanced oil recovery (EOR) process to reduce the interfacial tension (IFT) between oil and water to ultralow, thus improve the displacement efficiency. It was also known for its ability to change the wettability of a rock from oil-wet to water-wet, depending on the type of surfactant used. Despite all of its beneficial use, the stability and economic of a surfactant flooding is a major issue in its application. A good understanding of the microemulsion phase is important in implying the project. Microemulsion phase, which consists of oil, water, surfactant and co- surfactant plays an important role in the performance of surfactant flooding. Addition of cosurfactant is frequently added to enhance the microemulsion performance. Several factors such as brine salinity, surfactant type and concentration as well as the temperature within the system also affects the performance of microemulsion. Understanding the behavior of microemulsion phase is an important step in designing surfactant flooding processes. The project evaluates the feasibility of anionic surfactant namely alpha olefin sulfonate (AOS), which is frequently used in surfactant flooding due to its economical friendly price and good stability under high temperature. The AOS microemulsion were tested under different range of salinity, concentration and temperature without the addition of alcohol or any cosurfactant. In this project, the behavior of AOS cosurfactant-free microemulsion and the feasibility on an EOR project had been evaluated