High Temperature CO₂-in-Water Foams Stabilized with Cationic Quaternary Ammonium Surfactants

Abstract

The design of surfactants for stabilizing CO 2 -in-water (brine) (C/W) foams at high temperature is challenging given the low density (solvent strength) of CO 2 , limited surfactant solubility in brine, and a lack of knowledge of the interfacial and rheological properties. Herein, the tail length of trimethylammonium cationic surfactants was optimized to provide the desired phase behavior and interfacial properties for formation and stabilization of the C/W foams. The headgroup was properly balanced with a C 12−14 hydrocarbon tail to achieve aqueous solubility in 22% total dissolved solids (TDS) brine up to 393 K (120°C) along with high surfactant adsorption (area/surfactant molecule of 154 Å 2 ) at the CO 2 − water (C−W) interface which reduced the interfacial tension from ∼40 mN/m to ∼6 mN/m. For C 12−14 N(CH 3 ) 3 Cl, these properties enabled stabilization of a C/W foam with an apparent viscosity of 14 mPa·s at 393 K in both a crushed calcium carbonate packed bed (75 μm 2 or 76 Darcy) and a capillary tube downstream of the bed. In addition, the partition coefficient of the surfactant between oil and 22% TDS (255 kg/m 3 ) brine was less than 0.15, which would be beneficial for minimizing the loss of the surfactant to an oil phase in applications including enhanced oil recovery and hydraulic fracturing.

Empirical Modeling of the Viscosity of Supercritical Carbon Dioxide Foam Fracturing Fluid under Different Downhole Conditions

“…This is due to thermal thinning of the foam film with a temperature increase, which quickly drains away foam lamella and drops the foam viscosity resulting in weak foam [40,47]. Structural changes that include lamella rupture and bubble coalescence occur more rapidly in foam bubbles as the foam film becomes thin due to the increment in temperature [5,[40][41][42]. The effect of temperature on foam viscosity was more prominent at low shear rates.…”

“…Energies 2018, 11, x FOR PEER REVIEW 6 of 15 lamella rupture and bubble coalescence occur more rapidly in foam bubbles as the foam film becomes thin due to the increment in temperature [5,[40][41][42]. The effect of temperature on foam viscosity was more prominent at low shear rates.…”

“…Due to temperature increases, thermal thinning and foam film thickening occur, which quickly drains liquid in the lamellas [40]. At elevated temperatures, foam lamella drainage and bubble coalescence are fast, which causes a significant drop in foam viscosity [5,[40][41][42]. Besides this, high fluctuations in temperature cause holes in the lamella because the foam undergoes high lamella rupture and bubble coalescence occurs [42].…”

“…At elevated temperatures, foam lamella drainage and bubble coalescence are fast, which causes a significant drop in foam viscosity [5,[40][41][42]. Besides this, high fluctuations in temperature cause holes in the lamella because the foam undergoes high lamella rupture and bubble coalescence occurs [42]. Therefore, the apparent viscosity of sCO 2 foam is expected to decrease with rising temperature [5,33].…”

Predicting and Controlling the Effect of Solubilized Flavor Oil on Foam Properties of Surfactant through Study of the Adsorption Activity and Configuration

“…Aqueous foam stabilized by surfactants has been widely used in many fields (Langevin, 2008) such as detergents, personal care products, food production, and enhanced oil recovery (Burapatana et al, 2005;Chen et al, 2016;Farajzadeh et al, 2009;Kokini and Aken, 2006;Kunimune and Shellhammer, 2008;Li et al, 2017;Pang et al, 2015;Patino et al, 2008). To meet different demands of those applications, foam properties must be adjusted to the ideal level (Fraga et al, 2014;Garrett, 2015;Hadjiiski et al, 2001;Lin et al, 2018;Miller, 2008;Pugh, 1996;Wang et al, 2016a).…”