Analysis of the interaction between polymer and surfactant in aqueous solutions for chemical-enhanced oil recovery

Abstract

Most petroleum reservoirs are subjected to Improved and Enhanced Oil Recovery (IOR and EOR) processes following secondary recovery. EOR involves the application of external forces and substances to improve the chemical and physical interactions in hydrocarbon reservoirs in order to improve preferable recovery conditions. The process of chemical flooding with solutions of polymers and surfactants can be used for developing oil exploitation. Studying the interaction between surfactants and polymers is indispensable for successful oil recovery. The interaction between non-ionic & anionic surfactants and polymers in ternary mixtures was examined at different concentrations and temperatures by dynamic light scattering and gel permeation chromatography. The hydrodynamic size of surfactant-polymer composites was higher than the particle size of individual components indicating a formation of associates. The size of associates increased by increasing the concentration of the surfactants and the temperature. It could be supposed that the polymer formed a mixed micelle with the surfactants. Gel permeation chromatography has confirmed the increase in molecular weight of the associate formed by surfactants and polymers.

Characterization of Hydrophobically Modified Polyacrylamide in Mixed Polymer-Gemini Surfactant Systems for Enhanced Oil Recovery Application

“…It is observed that viscosity of copolymer solutions increases with increasing concentration. This suggests the formation of interchain and intrachain aggregates caused by entanglement of HMPA hydrophobe chains. , However, in gemini surfactant + copolymer-based systems, surfactant micelles associate with polymer chains described as a “string of beads model” owing to the improved hydrophobic interaction effect . In the presence of 14-6-14 GS, cationic head groups enhanced the electrostatic forces existing among the polymer-surfactant molecule.…”

“…25 Kothencz et al and others and Al-Sabagh et al also studied the interaction between polymer chains and surfactant micelles/molecules and optimized fluid compositions to control their relative effects on mixed polymer-surfactant systems. 26,27 Surfactant-polymer systems are functional in situations wherein high tolerance to salt is necessary. The synergistic interactions between the polymer and surfactant play a pivotal role in understanding mechanistic interactions, as well as devising/optimizing novel chemical displacing fluids.…”

Cationic/Nonionic Mixed Surfactants as Enhanced Oil Recovery Fluids: Influence of Mixed Micellization and Polymer Association on Interfacial, Rheological, and Rock-Wetting Characteristics

“…In EOR processes, surfactant fluids recover residual oil molecules by interfacial tension (IFT) reduction. − Previous studies reported that the IFT between oil and displacing fluid must decrease to ultralow magnitudes for displacement of in situ oil from pore spaces (otherwise trapped by capillary forces) of hydrocarbon-bearing reservoir rocks. , Surfactant monomers are adsorbed onto the oil/aqueous interfaces, with the hydrophobic tail groups orienting toward the oil phase and hydrophilic heads pointing toward the aqueous phase. This results in micelle/aggregate formation, which is an important transport conduit for crude oil movement. , Mixed surfactant fluids improve the oil micellization ability of constituent surfactants by forming mixed micelles in dynamic flow systems. − Incorporation of ionic + nonionic surfactants into aqueous fluids reduce the repulsive interactions among charged polar head groups and favors improved adsorption efficiencies, which in turn is responsible for improved oil extraction. Earlier studies showed that binary surfactant mixtures exhibit lower critical micelle concentration (CMC) values in comparison to single surfactants alone. − The neutral head groups in nonionic surfactant molecules impart a blanketing effect on the ionic surfactant head groups, thereby leading to the formation of condensed/denser micellar structures with greater stability .…”

Effect of microscopic aggregation behavior on polymer shear resistance

“…The average hydrodynamic radii ( D h ) were measured using the dynamic light scattering. Polymer solution was dedusted and filtered using a disposable 0.8‐μm filter purchased from Millipore corporation . In the measuring process, a 532 nm laser wavelength was used.…”