Investigation of the Stability Mechanism of Stimulus-Responsive Wormlike Micelle-CO2 Foams in the Oil Phase

Foam flooding is an important tool for reservoir development. This study aims to further investigate the interaction between stimulus-responsive wormlike micelle (WLM)-CO₂ foams and crude oil. We performed micromorphology experiments as our major studies and used molecular dynamics simulations as an auxiliary tool for interfacial analysis. We utilized foam generation, liquid separation, and defoaming as the entry points of experimental research and energy as the quantitative assessment index to investigate the dynamic process of the action of different oil contents and oil phase types in a DOAPA@NaSal-H⁺ foam system. We also examined the role of NaSal in the generation and development of the foam system. Results indicated that the law of crude oil’s effect on foam could be summarized as “low contents are beneficial and high contents are harmful.” In addition, although the DOAPA@NaSal-H⁺ foam system has high compatibility for saturated and aromatic hydrocarbons, it is highly suitable for application in reservoir environments with relatively high asphaltene and resin contents. Through combined experimental and simulation approaches, we clarified the law governing the stability of the DOAPA@NaSal-H⁺ foam system in different oil-containing environments, identified the key role of NaSal, and provided a reference for the targeted application of the DOAPA@NaSal-H⁺ foam system in different oil reservoirs.