(19g) Investigation of the Foaming Characteristics of Newly Developed Surfactants Under Harsh Reservoir Conditions

Surfactants face challenges in reservoir conditions due to the complex interplay of factors such as high temperatures, pressure, and salinity. Maintaining surfactant stability and effectiveness amidst these conditions requires precise formulation and understanding of their behavior under such extreme environments. Additionally, surfactants must overcome challenges related to adsorption onto reservoir surfaces and interaction with reservoir fluids, impacting their ability to generate and sustain foams for applications like Enhanced Oil Recovery and CO2 sequestration. This study investigates the foaming behavior of newly synthesized zwitterionic surfactants in diverse reservoir conditions, including varying seawater concentrations, pH levels, pressures, and temperatures, particularly in conjunction with oil presence, with a focus on foam structure and bubble coalescence. These surfactants were developed by tuning molecular structures in a way to works under harsh reservoir conditions. Its worth mentioning here that most of the commercial surfactants precipitate or degrade at high reservoir temperatures (>100 °C) and high salinity (> 200,000 ppm). Utilizing ambient and high-pressure high-temperature dynamic foam analyzers, we evaluated the foam properties, introducing varying seawater concentrations (0.01 to 0.2 wt.%) and pH levels (1 to 12), especially in the presence of different oil concentrations (0-50 wt.%), while employing a high-speed camera to analyze foam morphology. Results indicate remarkable foamability and stability of the synthetic zwitterionic surfactants across diverse conditions, suggesting their suitability for upstream oil & gas applications. Furthermore, in the presence of oil, foam stability is maintained up to a certain concentration but deteriorates at a critical oil saturation level. These findings enhance our understanding of the potential of synthetic zwitterionic surfactants in generating stable foams under extreme reservoir conditions, making them viable for EOR and CO2 sequestration in depleted oil reservoirs.