An Integrated Property–Performance Analysis for CO₂-Philic Foam-Assisted CO₂-Enhanced Oil Recovery

Abstract

Foam is used in CO2-enhanced oil recovery due to its potential high benefits in mitigating all three causes of CO2 poor sweep efficiency, as it provides a means to lower the effect of permeability heterogeneity, overcome viscous instability, and minimize the occurrence of gravity override. The conventional foaming surfactants are not suitable in contact with oil due to premature lamellae rupture, need for copious amounts of water to generate foam, surfactant loss due to adsorption on the rock or partitioning between water and oil, and less tolerance against salinity, pressure, and temperature. The surfactant blending and addition of CO2-philic functionalities in surfactant structure are suggested to mitigate the above problems, enhance foam stability, improve mobility control, and accelerate foam propagation. However, there is a lack of general guidelines on the evaluation of CO2-philic surfactant properties and applications and the surfactant structure–performance analysis. In the present work, tailor-made laboratory tests and simulation analysis were conducted on CO2-philic surfactants with different structures and chain lengths in conditions close to a Malaysian reservoir case and in the presence of oil. The results from experiments combined with analytical analysis of foam flow parameters are used to provide a comprehensive simulation model of a CO2-philic surfactant alternating gas process. A meaningful correlation between the CO2-philic surfactant structure and the sensitivity of foam model to different parameters was observed. On the basis of sensitivity analysis results, optimization of CO2-philic surfactant activity at gas–water and oil–water interfaces can improve the system recovery through macroscopic and microscopic displacement.

CO2-Philic Surfactants Structural Morphology Prerequests for CO2 Philicity for Foam Durability for EOR Applications

“…They need the Isopropyl acetate molecule as a sample. In the picture below, the red colour imitate oxygen, black represents carbon and white is used for atoms of hydrogen [7,[30][31][32][33][34].…”

“…A series of trials was conducted by Matthew B. Miller* by the mixing of different solvents with various extents of carbon dioxide to measure the compatibility for both mixture components having bubble point as basis. It is observed that species with low MM (molar mass) having minimum one atom of O 2 in ether, acetate groups/or carbonyl would have most favourable interaction with carbon dioxide through Lewis base/Lewis acid interactions [7].…”

Numerical Assessments of Key Aspects Influencing Supercritical CO2 Foam Performances when Using CO2-Soluble Surfactants

“…Moreover, Ren et al , and Zeng et al demonstrated that gravity segregation between phases in a homogenous reservoir could be better mitigated by novel foams. Experimentally, a correlation was derived by Talebian et al , to indicate the variation of foam model parameters with CO 2 -philic surfactant chain lengths during the EOR process.…”

Quantum Chemical Study of the Carbon Dioxide-Philicity of Surfactants: Effects of Tail Functionalization

“…Supercritical carbon dioxide (scCO 2 ) has attracted tremendous attention in organic synthesis, extraction, oil industry, and other fields − due to its intrinsic properties (e.g., low cost, nontoxicity, stability, and abundance). − However, the CO 2 molecule can only be dissolved in nonpolar substances due to its linear configuration. In contrast, scCO 2 has extremely low solubility in polar substances such as biomolecules, polymers, ions, and water, greatly limiting the development and application of scCO 2 .…”