Intermolecular Interaction between Heavy Crude Oils and Surfactants during Surfactant-Steam Flooding Process

Abstract

The objective of this study is to investigate the intermolecular interactions between the surfactants and the fractions of heavy crude oils. Two possible interactions were considered; polar and ionic interactions for two heavy crude oil–surfactant systems, and 20 surfactant-steam flooding tests were conducted on these crudes by testing nine surfactants (three anionic, three cationic, and three nonionic) with different tail lengths and charged head groups. The performance differences observed in each core flood were discussed through the additional analyses. To explain polar interactions, the pseudo blends of crude oil fractions (fractionation of saturates, aromatics, resins, and asphaltenes) were exposed to the surfactant solutions under vapor and liquid water conditions and their mutual interactions were visualized under an optical microscope. To explain ionic interactions, the charges on asphaltene surfaces were analyzed by zeta potential measurements before and after core flood tests on both the produced and the residual oil asphaltenes. The addition of surfactants improved the oil recovery when compared to steam injection alone. However, different oil recoveries were obtained with different surfactants. Further analyses showed that asphaltenes are key and the interaction of asphaltenes with other crude oil fractions or surfactants determines the success of surfactant-steam processes. The polar interactions favor the emulsion formation more; hence, if the polar interactions are more dominant than the ion interactions in the overall crude oil–surfactant system, the surfactant flooding process into heavy oil reservoir became more successful.

Effect of Amphiphilic CaCO3 Nanoparticles on the Plant Surfactant Saponin Solution on the Oil–Water Interface: A Feasibility Research of Enhanced Oil Recovery

“…27,28 However, the emulsion system is very unstable owing to the imbalance of the interaction force between the surfactant and the oil−water phase, and the emulsion is extremely easy to be destroyed under the influence of gravity and temperature, resulting in the separation of oil and water. 29 to ensure emulsion stability is the most important problem in surfactant flooding.…”

“…In chemical flooding, surfactant flooding is a kind of chemical flooding method which has wide fitness for purpose and development potential. − Surfactants can reduce the oil–water interface tension to increase the efficiency of oil washing. − Meanwhile, the molecule structure of surfactants has lipophilic groups and hydrophilic groups, which can emulsify oil and water into the single-phase emulsion. , If the emulsion is the O/W emulsion, it can reduce the viscosity of crude oil, improve the water–oil mobility ratio, and expand the sweep volume. , Conversely, if the emulsion belongs the W/O emulsion, it can form a stable front to expand the sweep volume . In addition, the emulsion can plug large pores owing to the “Jamin effect”, resulting in the subsequent fluid divert into the low permeability zones to enhance oil recovery. , However, the emulsion system is very unstable owing to the imbalance of the interaction force between the surfactant and the oil–water phase, and the emulsion is extremely easy to be destroyed under the influence of gravity and temperature, resulting in the separation of oil and water . Therefore, how to ensure emulsion stability is the most important problem in surfactant flooding.…”

Influence of Anionic and Amphoteric Surfactants on Heavy Oil Upgrading Performance with Nickel Tallate under Steam Injection Processes

“…Most of the above-mentioned studies have not considered the influence of surfactants between polar and nonpolar components of heavy oil. − It is well known that asphaltenes and resins are polar components, whereas saturates and aromatics are nonpolar fractions. Very little is known about the behavior of surfactants between such polar and nonpolar components of heavy crude oils under the steam injection process.…”

Demulsification of Crude Oil Emulsions Using Versatile and Eco-Friendly Demulsifiers Based on Cellulose Decorated with Imidazolium-Bearing Triazole Moiety

“…2 The stability of the emulsion is related to the presence of natural surfaceactive agents such as asphaltene, fine solid, resin, and naphthenic acid. 3,4 These compounds form a stable W/O emulsion by creating a rigid film around the water droplets. 5,6 The W/O emulsion causes several problems in the handling and processing stages, including fouling in pipelines, corrosion, and poisoning of catalysts in the refinery processes.…”

“…More than 80% of the crude oil produced worldwide is obtained in the emulsified form . The stability of the emulsion is related to the presence of natural surface-active agents such as asphaltene, fine solid, resin, and naphthenic acid. , These compounds form a stable W/O emulsion by creating a rigid film around the water droplets. , The W/O emulsion causes several problems in the handling and processing stages, including fouling in pipelines, corrosion, and poisoning of catalysts in the refinery processes. , Therefore, separation of the aqueous phase from the extracted crude oil is very necessary due to economic and operational reasons . Various methods are used to separate the aqueous phase from the oil phase, such as electrical, mechanical, thermal, and chemical methods. − Chemical demulsifiers are usually used along with mechanical and electrical methods to speed up the emulsion breaking .…”