Interfacially Active Components in Heavy Oil: Structure, Interfacial Behaviors, and Regulation Strategies

Natural interfacially active substances in heavy oil induce phenomena such as emulsification, deposition, hyperviscosity, and clogging through interfacial behaviors including adsorption, aggregation, and self-assembly, significantly impacting extraction and transportation processes in the petroleum industry. Although the macroscopic behaviors have been extensively studied, molecular-level mechanisms remain in debate, limiting the ability to control interfacial phenomena effectively. This review examines the active structures and molecular mechanisms of these substances in heavy oil, elucidating the unique behaviors of molecules such as asphaltenes and colloids in the oil phase and at phase interfaces. The study reveals how molecular structures, hydrogen bonding, π-π stacking, and external conditions affect their interfacial properties and summarizes strategies for regulating interfacial behaviors by adjusting molecular interactions. By providing new perspectives on the molecular behavior of interfacially active substances, this review establishes a scientific foundation for developing more efficient interfacial regulation strategies. These insights address specific issues in heavy oil extraction and processing while promoting broader advancements in molecular interface science, potentially guiding technological innovations in the energy and petrochemical industries.