A Review of High‐Temperature Foam for Improving Steam Flooding Effect: Mechanism and Application of Foam

Abstract

With the exploitation of light oil approaching saturation, the exploitation of heavy oil is of particular importance. Thermal recovery technology is typically used in heavy oil recovery, such as steam flooding (SF), steam‐assisted gravity drainage, and cyclic steam stimulation. However, SF technology brings problems such as gravity overlap, viscous fingering, and channeling, reducing the sweep efficiency and oil recovery efficiency. Some studies have proposed that foam and steam should be injected into the reservoir together to plug, turn, and reduce viscosity. Heavy oil production occurs mostly under high‐temperature conditions, which require that the foaming agents have good foaming ability in this environment. The generated foam should have good stability. Meanwhile, the mechanism of steam foam enhancing oil recovery (EOR) also changes. Therefore, the research on the mechanism and application of steam foam technology is discussed. First, the basic theory of foam is introduced, and the research on the mechanism of steam foam EOR is discussed. Second, the application of steam foam in the laboratory and the field is summarized. Finally, the full text is summarized and some prospects are made, to provide some help for future research.

Investigation of Foam Flooding Assisted by Non-Newtonian and Novel Newtonian Viscosifying Agents for Enhanced Oil Recovery

“…The reason for pre-flushing the core with surfactant solution is to compensate for rock surface adsorption, while it also speeds up the foam generation since the surfactant is already in the system when gas is injected. As the core is saturated with the surfactant solution, gas injection into the core causes the process of “leave-behind”, where films are formed in the pore throats as gas comes into the pore from different directions . This process only occurs when drainage is present (increasing gas fraction).…”

“…As the core is saturated with the surfactant solution, gas injection into the core causes the process of “leave-behind”, where films are formed in the pore throats as gas comes into the pore from different directions. 9 This process only occurs when drainage is present (increasing gas fraction).…”

“…During foam generation in a porous medium, gas injection into the core plug causes the process of “leave-behind”, where films are formed in the pore throats as gas comes into the pore from different directions. This process only occurs when drainage is present (increasing gas fraction). , Phase separation of foam occurs as the liquid fraction of foam enters small pores in the low-permeable sections of the core as it does not require the same high-pressure gradient as the gas phase does. The gas phase invades the high-permeable regions. , …”

“…This process only occurs when drainage is present (increasing gas fraction). 8 , 9 Phase separation of foam occurs as the liquid fraction of foam enters small pores in the low-permeable sections of the core as it does not require the same high-pressure gradient as the gas phase does. The gas phase invades the high-permeable regions.…”

Foam stability of temperature-resistant hydrophobic silica particles in porous media

“…Therefore, the key factor that affects the foam-plugging steam during SFCF is the stability of the foam in the geological formation. The foam system must be highly stable to plug geological formations ( Chen et al, 2021 ), and must exhibit surface activity for washing oil after the foam fracture ( Petkova et al, 2021 ), to maximize the synergy of the foam and steam over the course of flooding ( Zhao et al, 2022 ).…”