Effect of CO2 phase on contact angle in oil-wet and water-wet pores. (May 2015)

• Record Type: Journal Article
• Authors: Li, Xingxun; Fan, Xianfeng
• Is Part Of: International journal of greenhouse gas control. Volume 36(2015:May)
• Page Start: 106
• Page End: 113
• Publication Date: 2015-05
• Subjects: Carbon Storage -- CO2 phase -- Contact angle -- Oil/Water-wet pore -- Pore wetting; Greenhouse gases -- Environmental aspects -- Periodicals; Air -- Purification -- Technological innovations -- Periodicals; Gaz à effet de serre -- Périodiques; Gaz à effet de serre -- Réduction -- Périodiques; Air -- Purification -- Technological innovations; Greenhouse gases -- Environmental aspects; Periodicals; 363.73874605
• DOI: 10.1016/j.ijggc.2015.02.017
• Languages: English
• ISSNs: 1750-5836

Abstract

Graphical abstract: Highlights: We developed a technique to experimentally measure CO2 –fluid wetting in a small pore. CO2 phase affects CO2 –fluid contact angle significantly in an oil-wet pore. The effect of CO2 phase is not pronounced on contact angle in a water-wet pore. Salinity has a significant effect on the CO2 –water/brine–glass pore contact angle. Abstract: Pore wetting is a principal factor in CO2 storage, enhanced oil recovery and fuel cells. However, few measurements were directly carried in a small pore. In this study, we measured the contact angles of CO2 –fluids systems in single capillaries, by considering effect of CO2 phase. The liquids used are deionized water, n-decane and brine. FEP (Fluorinated Ethylene Propylene) and glass capillaries were used to represent oil-wet pores and water-wet pores, respectively. In an oil-wet pore (FEP), CO2 –fluids contact angles vary significantly with CO2 phase: θ gas CO 2 < θ supercritical CO 2 < θ liquid CO 2 . The contact angles mainly changes at CO2 phase transition boundary. The contact angles of CO2 –water and CO2 –brine systems increase from 120° to 155°, and CO2 –decane contact angles increase from 28° to 38°, when CO2 phase changes from gas to liquid or supercritical. CO2 –brine contact angles are close to CO2 –water contact angles: θ brine ≈ θ water . Comparatively, in a water-wet pore (glass), the CO2 –fluid contact angles in a glass pore do not significantly vary with CO2 phase: θ gas CO 2 ≈ θ supercritical CO 2 ≈ θ liquid CO 2 . The contact angles of CO2 –water, CO2 –brine and CO2 –decane systems stay approximately around 30°, 40° and 26°, respectively. Moreover, the salinity does affect the CO2 –water/brine–glass pore contact angle; θ brine > θ water in a glass pore.