Determination of effective air‐water interfacial area in partially saturated porous media using surfactant adsorption

Abstract

Abstract. The effective specific air-water interfacial area (•i) in a sand-packed column was measured at several water saturations (Sw) using a surface-reactive tracer (sodium dodecylbenzene sulfonate (SDBS)) and a nonreactive tracer (bromide). Miscible displacement experiments were conducted under steady water flow conditions to quantify the retardation of SDBS resulting from its adsorption onto the air-water interface in a sand-packed column. A consistent trend of increased retardation of SDBS compared with the nonreactive tracer, bromide, was observed with decreasing S w. The data for air-water surface tension measured at various SDBS concentrations were interpreted using the Gibbs model to estimate the required adsorption parameters. The retardation factors (Rt) for SDBS breakthrough curves were then used in combination with the estimated SDBS adsorption coefficient to calculate the •i values at different Sw. For the range of experimental conditions employed in this study, the retardation factor for SDBS ranged from R t = 1.07 at Sw = 1.00 (R t > 1 due to SDBS sorption on sand) to R t = 3.44 at Sw = 0.29 (which corresponds to •i = 46 cm2/cm3). These values are in agreement with theoretical predictions and recently published data. Improvements needed to overcome the experimental limitations of the presented method are also discussed.

Insights into the Relationships Among Capillary Pressure, Saturation, Interfacial Area and Relative Permeability Using Pore-Network Modeling

“…These techniques are mostly categorized under two main groups; tracers or imaging techniques. Aqueous tracers have been used by Karkare and Fort (1996), Brusseau et al (1997), Kim et al (1997), Saripalli et al (1998), Anwar (2000), Schaefer et al (2000), and Chen and Kibbey (2006), and gas tracers have been used in some other studies such as Kim et al (1999), Costanza-Robinson and Brusseau (2002), and Brusseau et al (2006). Imaging techniques have been used by Montemagno and Gray (1995), Wildenschild et al (2002), Cheng et al (2004), Culligan et al (2004), Al-Raoush and Willson (2005a,b), and Brusseau (2005, 2006).…”

Fundamentals of Reservoir Surface Energy as Related to Surface Properties, Wettability, Capillary Action, and Oil Recovery From Fractured Reservoirs by Spontaneous Imbibition

“…Bradford and Lei (1997) makes theoretical predictions for the changes in interfacial areas during imbibition and drainage whereas Jain et al (2003) and Gladkikh et al (2003) rely on the tracer technique to estimate the same quantities In our research, actual core samples from outcrops are used for analysis. This involves a greater of degree of complication as compared to the work done by other researchers (Morrow, 1970, Kim et al, 1997, Gladkikh et al, 2003, Bradford and Lei, 1997, Scheafer et al, 2000aand 2000b who worked with unconsolidated media (either bead pack or soil). Preliminary analysis will be done for Berea sandstone and a limestone sample.…”

“…Epoxy resins of two different colors were used to simulate the wetting and the non-wetting phase. Indirect method of using interfacial tracer to determine the interfacial areas have been tried by a few researchers Kim et al, 1997;Gladkikh et al, 2003). Bradford and Lei (1997) discuss theoretical ways of predicting changes in surface energy in soil samples.…”

Assessment of the Use of Partitioning and Interfacial Tracers To Determine the Content and Mass Removal Rates of Nonaqueous Phase Liquids

“…The retardation of these tracers gives information on the NAPL-water (or air-water) interfacial area. Interfacial tracers have also been applied in both laboratory (4,11,12) and field experiments (3). Verification of the relation between tracer retardation and interfacial area is complicated since the interfacial area is difficult to determine independently.…”

“…Surfactants such as linear alkylbenzenesulfonate (LAS, also known as sodium dodecyl benzenesulfonate, SDBS) tend to partition between the water-air or water-NAPL interface and bulk water and can thus be used as interfacial tracers (3,4,11,12). The retardation of these tracers gives information on the NAPL-water (or air-water) interfacial area.…”