Foam EOR as an Optimization Technique for Gas EOR: A Comprehensive Review of Laboratory and Field Implementations

Abstract

Foam-enhanced oil recovery (EOR) is poised to become one of the most promising tertiary recovery techniques to keep up with the continuously increasing global energy demands. Due to their low sensitivity to gravity and permeability heterogeneities that improve sweep efficiency, foams are the preferred injection fluids over water or gas. Although foam injection has been used in the field to improve oil recovery and control gas mobility, its success is still hindered by several conceptual and operational challenges with regard to its stability and foamability under reservoir conditions. This can be attributed to the insufficient attention given to the mechanisms underlying foam generation and stability at the microscopic level in many studies. For a deeper understanding, this study reviews the most pertinent published works on foam-EOR. The major objective is to provide a broad basis for subsequent laboratory and field applications of foam-EOR. In this work, we highlighted foam classification and characterization, as well as the crucial factors impacting foam formation, stability, and oil recovery. Additionally, the principal mechanisms of foam generation are thoroughly explained. Finally, the most recent developments in foam generation and stability improvement are discussed. Foam-EOR is comprehensively reviewed in this work, with an emphasis on both theoretical and practical applications.

Coreflood Testing of Gas-Blocking Agents: Selectivity in High-Heterogeneity Reservoirs and Efficiency in Low-Temperature Conditions

“…Foams are used to control the mobility of gas flow in porous media to improve sweep efficiency of gas flooding, , improve gas-driven processes efficiency with in situ foam generation, and for gas blocking purposes. , Foam sweep efficiency increases with an increase in the heterogeneity of the formation in terms of permeability, – which is one of the main advantages of foam as a colloid system. In contrast to cross-linking agents, foams show better efficiency at low temperatures due to an increase in viscosity .…”

Ecofriendly Natural Surfactants in the Oil and Gas Industry: A Comprehensive Review

“…Surfactants reduce surface tension at the gas–water interface, allowing stable foams to develop. The capacity of the foam to move through the reservoir and displace the trapped oil is determined by foam stability, which is critical for effective EOR applications …”

“…Surfactant–crude oil compatibility is a pivotal consideration in enhanced oil recovery and other oilfield applications . For optimal performance, surfactants need to be soluble within the crude oil phase, enabling them to significantly reduce the interfacial tension.…”

Nanoparticle and Surfactant Stabilized Carbonated Water Induced In-Situ CO2 Foam: An Improved Oil Recovery Approach

“…The foam lamella acts as a physical barrier that hinders the movement of gas, allowing for a more efficient oil displacement. 42,43 This restriction of gas mobility helps to ensure that the injected gas reaches a more significant portion of the reservoir, enhancing oil recovery. 26,37,44 One of the significant challenges associated with surfactantstabilized foams is their inherent instability due to the abrupt disintegration of the thin liquid layers present at the interface or boundary between gas and liquid phases.…”

“…Foam lamella formation can restrict gas mobility in the reservoir, leading to improved conformance control. The foam lamella acts as a physical barrier that hinders the movement of gas, allowing for a more efficient oil displacement. , This restriction of gas mobility helps to ensure that the injected gas reaches a more significant portion of the reservoir, enhancing oil recovery. ,, …”