Measurement and estimation of CO2–brine interfacial tension and rock wettability under CO2 sub- and super-critical conditions

Abstract

Saline aquifer storage is considered to be a promising method of carbon dioxide (CO) mitigation. The CO-brine interfacial tension (IFT) and the caprock wettability under reservoir temperature and pressure conditions are essential for storage capacity estimation. In this study, the CO-brine (NaCl + KCl) IFTs were obtained by using the pendant drop method under 298-373 K temperature, 3-15 MPa pressure, and 1.0-4.9 mol·kg salinity. A detailed analysis of the relationship of IFT with temperature, pressure, and salinity was conducted. In addition, an empirical equation was developed to estimate the CO-brine IFTs in a wide range of temperatures, pressures, and salt molality. The contact angles (CAs) of brine on quartz, Berea Sandstone, and limestone surfaces in the presence of supercritical, liquid, and gaseous CO were measured by using the sessile drop method, and the wettability alteration of the rock surfaces in the presence of supercritical CO was systematically investigated. According to the results, the CO-brine IFTs increased with salinity and temperature and decreased with pressure until reaching a plateau. For a CO-mixed brine system, a linear relationship between the IFT increase (Δγ) and molality was observed. The CAs of the different rock samples varied with temperature and pressure. However, all the three rock samples became less water-wet when the CO phase state changed from subcritical to supercritical.

CO2-Fluid-Rock Interactions and the Coupled Geomechanical Response during CCUS Processes in Unconventional Reservoirs

“…In contrast, in the supercritical zone, IFT reaches a platform. (2) IFT usually decreases with the increase of temperature, but it reacts to more temperature dependence when CO 2 is near the critical point [79]. (3) IFT increases linearly with salt concentration [74].…”

Link Between CO2‐Induced Wettability and Pore Architecture Alteration

“…and pore geometry (r) (Arif et al, 2016;Iglauer, 2017;Mutailipu et al, 2019). In porous media, the capillary pressure (P c ) can be calculated by the Young-Laplace equation:…”

“…In addition, the buoyant CO 2 migrates upward and can be sealed permanently by a low permeability caprock, where high capillary entry pressure stalls CO 2 upward migration. Capillary forces influence the efficiency of residual and structural trapping, through CO 2 ‐brine‐rock interactions, that is, CO 2 ‐brine interfacial tension ( γ wc ) and contact angle (CA) ( θ ), and pore geometry ( r ) (Arif et al, 2016; Iglauer, 2017; Mutailipu et al, 2019). In porous media, the capillary pressure ( P c ) can be calculated by the Young‐Laplace equation: …”

“…Research has focused on convective‐dominant regimes by continuously injecting CO 2 ‐enriched brine, typically causing uniform dissolution as the porous media are surface reaction controlled. Insights into effects of these reactions on pore networks, brine chemistry (salinity and ion type), and reservoir pressure and temperature on CA (Al‐Yaseri et al, 2017; Arif et al, 2016; Botto et al, 2017; Chen et al, 2017; Iglauer, 2017; Jung & Wan, 2012; Mutailipu et al, 2019; S. Wang et al, 2012; Zhang et al, 2016) and rock porosity and permeability (Luquot & Gouze, 2009; Nogues et al, 2013; Soong et al, 2018) have been studied under convective‐dominant conditions extensively. However, few studies have focused on diffusion‐dominant transport and their impact on changes in wettability and the subsequent influence on capillary pressure and relative permeability curves.…”

The density characteristics of CO2 and alkane mixtures using PC‐SAFT EoS

“…As the consumption of fossil fuels continues to increase rapidly, the resulting enormous and continuous emissions of CO 2 are leading to global warming 1–7 . As a promising carbon capture, utilization, and storage (CCUS) technique, CO 2 ‐enhanced oil recovery (CO 2 ‐EOR) is expected to play an important role in mitigating global warming 7–12 . To develop a comprehensive understanding of the CO 2 ‐EOR process, knowledge of the phase behavior and transport regularity of CO 2 ‐containing fluids is essential 13 .…”