CO₂ Foam for Enhanced Oil Recovery Applications

Abstract

CO 2 -foam yields improved sweep efficiency in enhanced oil recovery (EOR) applications over that of polymers to avoid potential polymer-induced formation damage. In addition to carbon sequestration in underground formations, CO 2 foam has low water content, which also reduces formation damage in water-sensitive formations and allows for fast cleanup. However, foam stability diminishes in harsh environments such as those with high salinity and temperature and when in contact with crude oil. This chapter highlights the different foam-generation mechanisms and the deterioration effect of crude oil on CO 2 -foam stability. More specifically, this chapter investigates using nanoparticles and viscosifiers to improve foam stability. Further, the effects of different nanoparticles, including aluminum oxide, copper oxide, and low-cost nanoparticles such as silicon dioxide, will be demonstrated. Field applications of viscoelastic surfactants and polymers in foam systems are also reviewed. The controlling factor for these different systems is the foam stability and improved oil recovery.

Perspectives of Foam Generation Techniques and Future Directions of Nanoparticle-Stabilized CO2 Foam for Enhanced Oil Recovery

“…121,169 The ability of NPs to absorb at the gas−liquid interface and reduce the contact area between the two phases is what causes this action; this allows it to create a robust barrier that stops bubbles from coalescing. 10,166 There is potential for using CO 2 foam to improve oil recovery during EOR. However, the surfactantbased foam is unreliable, and the sweeping efficiency is poor.…”

“…The capillary pressure rises to its critical value as a bubble is displaced through the pores. , Thus, a number of lamellae inside the foam rupture at once, leading to a coarsening of the foam and a reduction in capillary pressure. When the coarse foam is being displaced, the capillary pressure once again rises. , When a foam lamella that is relatively larger than the pore body reaches a “branch point” and is separated into two or more bubbles, lamella division occurs, as illustrated in Figure . The lamella will break into two bubbles or lamellae if it is at a branch point with more than one direction that requires identical pressure for the lamella to flow.…”

“…The bubble that passes by the base of the compression shatters the bubble that passes through the crest, and then shatters the bubble that passes through the base. This figure was reproduced with permission from ref . Copyright 2019 IntechOpen.…”

“…The results demonstrate that the inputs of polymers have no impact on the surface tension at high temperatures, and the viscosity of a surfactant may be significantly increased by mixing it with NPs. Additionally, it was discovered that optimal quantities of NPs and polymers can improve the stability of CO 2 foam. , The ability of NPs to absorb at the gas–liquid interface and reduce the contact area between the two phases is what causes this action; this allows it to create a robust barrier that stops bubbles from coalescing. , There is potential for using CO 2 foam to improve oil recovery during EOR. However, the surfactant-based foam is unreliable, and the sweeping efficiency is poor.…”

“…However, the surfactant-based foam is unreliable, and the sweeping efficiency is poor. Therefore, NPs or viscosifiers should be utilized to enhance the stability of the foam for EOR …”