Interfacial Tension between CO₂, Freshwater, and Brine in the Range of Pressure from (2 to 27) MPa, Temperature from (20 to 125) °C, and Water Salinity from (0 to 334 000) mg·L⁻¹

Abstract

An extensive laboratory program was conducted for the measurement of the interfacial tension between CO 2 and water or brine covering the ranges of (2 to 27) MPa pressure, (20 to 125) °C temperature, and (0 to 334 010) mg • L -1 water salinity. The laboratory experiments were conducted using the pendant drop method combined with the solution of the Laplace equation for capillarity for the profile of the brine drop in the CO 2 -brine equilibrium environment. The analysis of the resulting set of 378 IFT measurements reveals that: (1) under conditions of constant temperature and water salinity, IFT steeply decreases with increasing pressure in the range P < P c and mildly decreases for P > P c with an asymptotic trend toward a constant value at higher pressures; (2) under the same conditions of constant pressure and temperature, IFT increases with increasing water salinity, reflecting decreasing CO 2 solubility in brine as salinity increases;(3) the dependence of IFT on temperature is more complex than that on either pressure or salinity, depending on the CO 2 phase. For T < T c , IFT increases with increasing temperature, and around the critical point (T ≈ T c ), IFT significantly decreases (believed to be associated with the fact that at T c the IFT between CO 2 liquid and vapor phases tends to zero) and then increases again with increasing temperature for T > T c with an asymptotic trend toward a constant value for high temperatures. The dependence of IFT on pressure, temperature, and water salinity for CO 2 and water/brine systems can be well approximated by a power function of pressure whose coefficient and exponent depend on temperature and water salinity. These results indicate that, in the case of CO 2 storage in deep saline aquifers as a climate-change mitigation strategy, the formation water displacement by injected CO 2 during the injection (drainage) phase of CO 2 storage and the possible subsequent CO 2 displacement by invading brine during the CO 2 migration (imbibition) phase depend on in situ conditions of pressure, temperature, and water salinity through the effects that these primary variables have on the IFT between CO 2 and aquifer brine.

Heat transport and pressure buildup during carbon dioxide injection into depleted gas reservoirs

“…Bachu & Bennion (2008a) observed a set of k rg0 values for the same sandstone core, ranging from 0.298 to 0.526, for CO 2 -brine mixtures, with IFT ranging from 56.2 to 19.8 mN m −1 , respectively (IFT was varied by increasing the fluid pressure from 1.378 to 20 MPa). At 40 • C and 1 MPa of pressure, the IFT for CO 2 -water and CH 4 -water mixtures are around 90.95 mN m −1 (Bachu & Bennion 2008b) and 69.06 mN m −1 (Ren et al 2000), respectively. Therefore, the relative permeabilities for CO 2 -brine and CH 4 -brine mixtures can be expected to be quite different.…”

Supercritical CO2 flow through a layered silica sand/calcite sand system: Experiment and modified maximal inscribed spheres analysis

“…A comparison between Figure 4(a) and Figure 4(b) suggests that the gas phase is better connected for contact angle of 60  than for zero contact angle, whereas the curvature of disconnected gas bubbles is smaller. N/m, see [Bachu and Bennion, 2008;Kim et al, 2012]. The simulation shows that fluid distribution is sensitive to the contact angle.…”

“…To mitigate the effects of increasing greenhouse gas concentrations in the atmosphere, injection of anthropogenic CO 2 into porous subsurface strata having a confining caprock is being strongly considered and tested in laboratory studies, field pilot studies, and using numerical simulation [Bachu et al, 1994;Bachu, 2000;Bachu and Adams, 2003;Bachu and Bennion, 2008;Benson et al, 2006;Gunter et al, 1993;Gunter et al, 1997;Holloway and Savage, 1993;Holloway and Straaten, 1995;Holloway, 1996;Holloway, 2001;Holloway, 2007;Juanes et al, 2006;Kharaka et al, 2009;Kneafsey and Pruess, 2010;Oldenburg et al, 2001;Perrin and Benson, 2010;Pini et al, 2012]. Reservoir rock wettability is of critical importance in predicting flow characteristics of nonaqueous fluids such as gas, oil, organic solvents, and supercritical carbon dioxide (scCO 2 ) through subsurface media [e.g.…”

Development and Application of Micromodel for Visualization of Supercritical CO₂ Migration in Pore-scale

“…이러한 상호 작용에는 계면장력, 습윤성, 모세관 현 상, 계면 물질 전달 등이 있는데, 이 중 습윤성 (wettability)은 모세관압, 상대투과도, 상분배 등 공극 내 유체 거동과 분포에 절대적인 영향을 미칠 수 있는 인자 이다 (Yang et al, 2008;Krevor et al, 2011). (Massoudi and King, 1975;Bachu and Bennion, 2008;Jung and Wan, 2012;Chalbaud et al, 2009;Li et al, 2012), 특히, 계면장력 측정에 더하여 실제 공극 구조 내에서 일어나는 scCO 2 의 거동과 습윤성 변화를 시각적으로 관찰하기 위 한 연구에서는 투명한 재질로 제작된 '마이크로모델'이 활 용되었다. 마이크로모델은 연구의 목적에 따라 다양하게 제작되는데, 주로 실리콘 웨이퍼 (Kim et al, 2012;Wang et al, 2013)나 유리판 (Er et al, 2010;Riazi et al, 2011 • 강화 유리판(10 cm × 3 cm × 0.5 cm) 위에 1 mm 두께 의 아크릴 테 2개를 좌우로 고정하여 긴 육각형 형태 의 공간을 생성한다 (Fig.…”