Unsteady-state CO2 foam injection for increasing enhanced oil recovery and carbon storage potential

Abstract

The efficiency of CO 2 injection for enhanced oil recovery and carbon storage is limited by severe viscosity and density differences between CO 2 and reservoir fluids and reservoir heterogeneity. In-situ generation of CO 2 foam can improve the mobility ratio to increase oil displacement and CO 2 storage capacity in geological formations. The aim of this work was to investigate the ability of CO 2 foam to increase oil production and associated CO 2 storage potential, compared to other CO 2 injection methods, in experiments that deploy field-scale injection strategies. Additionally, the effect of oil on CO 2 foam generation and stability was investigated. Three different injection strategies were implemented in the CO 2 enhanced oil recovery and associated CO 2 storage experiments: pure CO 2 injection, water-alternating-gas and surfactant-alternating-gas. Foam generation during surfactantalternating-gas experiments showed reduced CO 2 mobility compared to water-alternatinggas and pure CO 2 injections indicated by the increase in apparent viscosity. CO 2 foam increased oil recovery by 50% compared to pure CO 2 injection and 25% compared to water-alternating-gas. In addition, CO 2 storage capacity increased from 12% during pure CO 2 injection up to 70% during surfactant-alternating-gas injections. Experiments performed at high oil saturations revealed a delay in foam generation until a critical oil saturation of 30% was reached. Oil/water emulsions in addition to CO 2 foam generation contributed to CO 2 mobility reduction resulting in increased CO 2 storage capacity with foam.

Surfactant–Nanoparticle Foam to Increase CO2 Storage in High-Salinity Carbonate Reservoirs

“…A foam of CO 2 and surfactant solution can be injected to increase CO 2 storage by decreasing CO 2 mobility, blocking high permeability zones, and diverting fluid to lower permeability zones. − Of course, the injected foam lasts for only a few days after injection stops, but it helps increase the sweep of the foam during injection. To be effective, the foam must be strong and stable during flow.…”

Hybrid EOR Performance Optimization through Flue Gas–Water Alternating Gas (WAG) Injection: Investigating the Synergistic Effects of Water Salinity and Flue Gas Incorporation

“…These methods, tailored to specific conditions, offer distinct advantages and limitations. To optimize results, EOR must be implemented under specific circumstances. − In an effort to enhance oil reservoir production, novel EOR methods and combinations have been proposed. − Gas injection, a widely used recovery method, effectively boosts oil production by elevating reservoir pressure and displacing oil toward production wells. However, challenges like reservoir heterogeneity, mobility control, gas miscibility, operational hurdles, and wellbore damage need to be effectively managed for successful gas injection projects. − …”

Effect of Gas Composition on Surfactant Injectivity in a Surfactant-Alternating-Gas Foam Process

“…Foam presents unique rheological properties as it flows through porous media, in particular reduced gas mobility. For this reason, in a variety of applications, foam is injected into geological formations, such as aquifer (or soil) remediation [ 3 , 4 ], CO 2 sequestration [ 5 , 6 ], and enhanced oil recovery [ 7 , 8 ].…”