Effect of Electrolytes on Interfacial Tensions of Alkyl Ether Carboxylate Solutions

Abstract

Alkyl ether carboxylate is one type of surfactant that can produce ultralow interfacial tension (IFT) under high-salinity and high-temperature conditions. In this paper, the influence of counterions on dynamic IFTs of fatty alcohol polyoxyethylene carboxylate (C12EO3C) against alkanes has been studied. The effect of the temperature on the IFT has been investigated. On the basis of our experimental results, one can find that the NaCl concentration has little effect on the IFT, while divalent ions can reduce the IFT to an ultralow value. With the increasing CaCl2 or MgCl2 concentration, dynamic IFT passes through a minimum at a particular salt concentration (“V” shape). Moreover, the stable value of IFT achieves an ultralow value and also passes through a minimum at the same salt concentration. MgCl2 has a stronger tendency to achieve ultralow IFT than that of CaCl2, while the addition of CaCl2 has a stronger tendency to partition surfactant molecules to the oil phase. Ultralow IFT could also be achieved by improving the temperature because of the enhancement of oil solubility of the surfactant. An interfacial model combining two mechanisms, partitioning the surfactant into the oil phase and decreasing the charge repulsive force between interfacial surfactant molecules, responsible for the effect of the electrolyte on dynamic IFT has been provided. All experimental results above can be explained well. Our studies are of great significance in designing ultralow IFT formulation for the reservoir in a high temperature and with high-salinity formation water.

Interfacial Tensions of Ethoxylated Fatty Acid Methyl Ester Solutions Against Crude Oil

“…The video board can ''capture'' the droplet image immediately for analysis. The process of analysis always includes the measurement of the drop width and length [35].…”

“…The oils used in this study were heavy crude oil Chen 11-23 with a density of 0.9692 g/mL, from the Shengli Oilfield (Dongying, China), a series of n-alkanes with chain lengths from C 6 to C 14 (99? mol% purity) [35] and kerosene from Beijing Chemical Co. Ltd with a stable IFT value of 40 mN/m against pure water [36]. All inorganic reagents used were analytical-grade.…”

Synthesis, Surface and Interfacial Properties of Dodecyl Diphenyl Oxide Disulfonate with Different Counterions

“…), and small amounts of which have significantly effect on the IFT. Usually, for traditional surfactants such as for petroleum sulfonates and SDBS, the presence of CaCl 2 or MgCl 2 leads to drastic increase in IFT [17,18]. Figure 4 shows the calcium chloride concentrations had no significantly effect on equilibrium IFT between crude oil and surfactants (C 12 MADS-Na, C 12 MADS-Mg and C 12-MADS-Ca) aqueous solution.…”

Effects of Divalent Salts on the Interfacial Activity of the Mixed Surfactants at the Water/Model Oil Interface

“…Many reports focused on the effects of salts on the interfacial activity of surfactants (Anachkov et al, 2015;Cao et al, 2012;Gandomkar and Rahimpour, 2017;Johnson et al, 2017;Lashkarbolooki et al, 2016;Lashkarbolooki and Ayatollahi, 2018;Liu et al, 2013Liu et al, , 2014Robertson et al, 2013;Sharma and Sangwai, 2015;Tichelkamp et al, 2014Tichelkamp et al, , 2015Tummons et al, 2017). The addition of salts can affect surfactants in the following ways (Cayias et al, 1976;Eftekhardadkhah and ye, 2013): First, the electrostatic attraction between the counterions and the charged heads of ionic surfactants compresses the occupied area of surfactant head groups at the interface and increases their effective concentrations.…”

“…The salinity is one of the vital factors for the interfacial activity of surfactants (Gandomkar and Rahimpour, 2017;Robertson et al, 2013;Sharma and Sangwai, 2015;Tummons et al, 2017). The salt type (Na + , Ca 2+ , and Mg 2+ ), the salt concentration, and even the ratio of different cations may dominate the salinity effects on the IFT (Anachkov et al, 2015;Cao et al, 2012;Johnson et al, 2017;Lashkarbolooki et al, 2016;Lashkarbolooki and Ayatollahi, 2018;Liu et al, 2013Liu et al, , 2014Tichelkamp et al, 2014Tichelkamp et al, , 2015. Tichelkamp et al investigated the synergistic effects between low-salinity (NaCl) solutions and surfactants, which improved the IFT reduction (Tichelkamp et al, 2014).…”