According to the energy institute statistical review of world energy compiled by British Petroleum, global crude oil production surpassed 96 million barrels per day in 2023, while consumption exceeded 100 million barrels per day for the first time in history [1]. This widening demand–supply gap underscores the increasing urgency for the oil and gas industry to improve recovery efficiency beyond primary and secondary methods, which primarily rely on natural reservoir energy and external water flooding. A significant proportion of crude oil remains inaccessible due to capillary entrapment and unfavorable interfacial conditions in the reservoir matrix. Under such constraints, enhanced oil recovery (EOR) technologies have emerged as indispensable for altering phase behavior, interfacial dynamics, and fluid properties to increase displacement efficiency and maximize hydrocarbon recovery [2].

Among the suite of EOR techniques, gas-assisted approaches are of growing importance, particularly those involving CO2 injection [[3], [4], [5], [6]]. Owing to its favorable solubility, interfacial tension reduction capabilities, and ability to modify fluid rheology, CO2 demonstrates excellent performance in both miscible and immiscible displacement regimes [7]. In addition to its efficacy in enhancing oil recovery, CO2-based EOR also presents the dual advantage of long-term carbon sequestration, thereby aligning with environmental imperatives. From the moment of their formation in the aqueous phase to their interactions with oil droplets or rock surfaces, bubbles induce localized pressure, modify interfacial curvature, and disturb the surrounding flow field [8,9]. Each of these effects contributes to the reconfiguration of fluid interfaces, which can promote the mobilisation and redirection of otherwise trapped oil. Accordingly, understanding the generation, evolution, and deformation of gas bubbles in confined fluid systems forms a critical basis for interpreting their macroscopic effects in oil recovery contexts.

Recent reviews have provided valuable insights into gas-related interfacial phenomena and that relevant to CO2-assisted oil recovery [[10], [11], [12], [13]]. For example, Peng et al. [14] examined bio-based materials such as surfactants, polymers, and nanoparticles for regulating interfacial properties, offering a materials-centric view. Elkhatib et al. [15] focused on wettability and surface forces across rock minerals, emphasizing AFM and SFA studies and their implications for oil recovery and storage. Quainoo et al. [16] reviewed asphaltene precipitation and deposition kinetics under CO2, addressing chemistry and flow assurance aspects. While these reviews are valuable, they remain largely materials-focused or focus on fundamental colloid science, without explicitly bridging interfacial mechanisms to CO2-EOR practice [10]. In contrast, this work develops a bubble lifecycle framework, examining how nucleation, growth, thin-film drainage and rupture, detachment, coalescence, and foam stability govern oil–water–CO2 interactions. By linking these processes to the observed performance of carbonated water injection (CWI), water-alternating-gas (WAG), and foam-assisted CO2 flooding, this review consolidates dispersed findings into a mechanistic framework for interpreting CO2-EOR, with geological carbon storage treated as a secondary implication.

In light of these considerations, this review provides a structured overview of gas-bubble dynamics within immiscible oil–water–CO2 systems, emphasizing their mechanistic relevance to displacement. Beginning with bubble formation and growth, we examine deformation and thin-film drainage/rupture at oil–water interfaces, three-phase contact line behavior, and the roles of interfacial forces and mobility. We then relate these mechanisms to the observed features of CO2-EOR strategies—carbonated water injection (CWI), water-alternating-gas (WAG), and foam flooding. The novelty of this review lies in consolidating bubble-lifecycle processes into a multiscale perspective that explicitly couples interfacial physics with CO2-EOR practice. Geological carbon storage is noted as a related benefit, but the primary focus is on understanding and interpreting CO₂-EOR performance.