Poly(Oxyethylene)-Amidoamine Based Gemini Cationic Surfactants for Oilfield Applications: Effect of Hydrophilicity of Spacer Group

Abstract

Thermal stability, salt tolerance, and solubility in normal and high salinity brine are the major requirements for any surfactant designed for oilfield applications because the surfactant stays in a non-ambient environment inside the reservoir for a long period of time. Herein, a series of new gemini cationic surfactants (GSs) with varying spacer hydrophilicity were synthesized and elucidated using MALDI-ToF-MS, NMR (1H, 13C), as well as FTIR spectroscopy. GSs found to be soluble in normal as well as high salinity brine and aqueous stability tests revealed that GSs possess the ability to retain their structural integrity at high salinity and high temperature conditions because no suspension formation or precipitation was detected in the oven aged sample of GSs at 90 °C for 30 days. Thermal gravimetric analysis displayed a higher decomposition temperature than the real reservoir temperature and the GS with a secondary amine spacer exhibited high heat stability. The significant reduction in surface tension and critical micelle concentration was observed using 1 M NaCl solution in place of deionized water. The difference in surface tension and critical micelle concentration was insignificant when the 1 M NaCl solution was replaced with seawater. The synthesized surfactants can be utilized for oilfield applications in a challenging high temperature high salinity environment.

Synthesis and evaluation of new cationic polymeric surfactant based on N-phthalimidomethyl methacrylate

“…The maximum surface excess concentration (max) is defined as the effectiveness of adsorption at interface. max was calculated from the slope of the straight line in the surface tension plot (  / log c) below CMC, using the appropriate form of Gibbs adsorption equation [52,53].…”

“…The average minimum surface area (Amin; in square angstrom) occupied by each molecule adsorbed at the interface is given by: Amin = 10 16 / NA .max (3) Where NA is the Avogadro's number (NA = 6.02214076×10 23 mol −1 ) and max (mol m -2 ) is the maximum surface excess of adsorbed surfactant molecules at the interface [53,54].…”

Adsorption Study of Novel Gemini Cationic Surfactant in Carbonate Reservoir Cores—Influence of Critical Parameters

“…This includes nonionic, cationic, anionic, and zwitterionic surfactants. More recently, the use of natural, viscoelastic, polymeric, and gemini surfactants has received prodigious attention [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ].…”

Impact of Spacer Nature and Counter Ions on Rheological Behavior of Novel Polymer-Cationic Gemini Surfactant Systems at High Temperature

“…Mainly, three kinds of interactions exist between surfactant and polymer: (1) attractive forces among molecules of surfactant are very low in comparison with repulsive forces between surfactant and polymer, (2) attractive forces between surfactant and polymer are lower than attractive forces among molecules of surfactant, (3) attractive forces between surfactant and polymer are greater than forces among surfactant molecules [31]. Gemini surfactants are a unique class of surfactants with more water-soluble hydrophilic head and oil-soluble hydrophobic tail units [32][33][34][35]. Both groups are connected by a spacer at or near to the head groups.…”