Surfactant flooding is an important technique used in enhanced oil recovery to reduce the amount of oil in pore space of matrix rock. Surfactants are injected to mobilize residual oil by lowering the interfacial tension between oil and water and/or by the wettability alteration from oil-wet to water-wet. A large number of cationic, anionic, non-ionic, and amphoteric surfactants have been investigated on a laboratory scale under different conditions of temperature and salinity. Selection of the appropriate surfactant is a challenging task, and surfactants have to be evaluated by a series of screening techniques. Different types of surfactants along with their limitations are reviewed with particular emphasis on the phase behavior, adsorption, interfacial tension, and structure–property relationship. Factors affecting the phase behavior, interfacial tension, and wettability alteration are also discussed. Field applications of surfactants for chemical enhanced oil recovery in carbonate and sandstone reservoi...

Review on Surfactant Flooding: Phase Behavior, Retention, IFT, and Field Applications

Polymer flooding is one of the most promising techniques for the recovery of remaining oil from light oil reservoirs. Water soluble polymers are used to enhance the viscosity of displacing fluid and to improve the sweep efficiency. In this paper, water soluble polymers used for chemical enhanced oil recovery are reviewed. Conventional and novel modified polymers are discussed along with their limitations. The review covers thermal stability, rheology, and adsorption behavior of various polymer systems in sandstone and carbonate reservoirs. Field and laboratory core flooding data of several polymers are covered. The review describes the polymer systems that are successfully applied in low-temperature and low-salinity reservoirs. Comprehensive review of current research activities aiming at extending polymer flooding to high-temperature and high-salinity reservoirs is performed. The review has identified current and future challenges of polymer flooding.

Review on Polymer Flooding: Rheology, Adsorption, Stability, and Field Applications of Various Polymer Systems

Antimicrobial polymeric nanoparticles

This work aims to improve the rheological properties of partially hydrolyzed polyacrylamide (HPAM) for enhanced oil recovery by using silica (or silicon dioxide, SiO2) nanoparticles (NPs). Novel aqueous HPAM-based SiO2 nanocomposites were formulated, and their rheological properties were investigated under different salinities, temperatures, and aging times. The results show that the inclusion of silica NPs significantly improved the viscosity and viscoelastic properties of HPAM especially under high temperature and high salinities. The NP/HPAM hybrid showed an impressive thermal stability at T = 80 °C after 12 days, and the viscosity reached ∼5 times that of HPAM at 0.8 wt % NP loading. The Fourier transform infrared spectral data confirmed that the formation of a hydrogen bond between the carbonyl groups in HPAM and the silanol functionalities on the surface of silica NPs contributed to the improved performance. The oscillation test indicated that seeding SiO2 remarkably facilitated the cross-links amon...

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Rheological Properties of Partially Hydrolyzed Polyacrylamide Seeded by Nanoparticles

Chemically enhanced oil recovery methods are utilized to increase the oil recovery by improving the mobility ratio, altering the wettability, and/or lowering the interfacial tension between water and oil. Surfactants and polymers have been used for this purpose for the last few decades. Recently, nanoparticles have attracted the attention due to their unique properties. A large number of nanoparticles have been investigated for enhanced oil recovery applications either alone or in combination with surfactants and/or polymers. This review discusses the various types of nanoparticles that have been utilized in enhanced oil recovery. The review highlights the impact of nanoparticles on wettability alteration, interfacial tension, and rheology. The review also covers the factors affecting the oil recovery using nanoparticles and current challenges in field implementation.

https://downloads.hindawi.com/journals/jnm/2017/2473175.pdf

Recent Advances in Nanoparticles Enhanced Oil Recovery: Rheology, Interfacial Tension, Oil Recovery, and Wettability Alteration

Water-soluble polymers are known to be used in chemically enhanced oil recovery (EOR) processes, but their applications are limited in high-temperature and high-salinity oil reservoirs because of their inherent poor salt tolerance and weak thermal stability. Hydrophobic association of partially hydrolyzed polyacryamide (HAHPAM) complexed with silica nanoparticles to prepare nano-hybrids is reported in this work. The rheological and enhanced oil recovery (EOR) properties of such hybrids were studied in comparison with HAHPAM under simulated high-temperature and high-salinity oil reservoir conditions (T: 85 °C; total dissolved solids: 32,868 mg∙L−1; [Ca2+] + [Mg2+]: 873 mg∙L−1). It was found that the apparent viscosity and elastic modulus of HAHPAM solutions increased with addition of silica nanoparticles, and HAHPAM/silica hybrids exhibit better shear resistance and long-term thermal stability than HAHPAM in synthetic brine. Moreover, core flooding tests show that HAHPAM/silica hybrid has a higher oil recovery factor than HAHPAM solution.

https://www.mdpi.com/1996-1073/7/6/3858/pdf

Aqueous Hybrids of Silica Nanoparticles and Hydrophobically Associating Hydrolyzed Polyacrylamide Used for EOR in High-Temperature and High-Salinity Reservoirs

A novel thermoviscosifying water-soluble polymer was synthesized by direct free radical copolymer- ization of acrylamide with a newly-prepared macromono- mer, and its aqueous solution viscosity behavior at different temperatures was preliminarily examined in both pure water and KCl brine in comparison with its homopo- lyacrylamide counterpart. Thermoviscosifying ability of the copolymer was clearly evidenced in both aqueous media, and the thermoassociative temperature of the copolymer decreased upon increasing KCl content in poly- mer solution. Under the same conditions, homopolyacryl- amide shows only thermothinning behavior and viscosity loss in both pure water and KCl solution. V C 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 3516-3524, 2010

A novel thermoviscosifying water‐soluble polymer: Synthesis and aqueous solution properties

A new cationic gemini surfmer (polymerizable surfactant or surface-active monomer) with an acrylic reactive group in its spacer group was synthesized and characterized, and its surface activity properties were examined in comparison with its intermediate surfactant 12-3OH-12·2Cl−, a previously-reported gemini surfmer 12′-2-12′·2Br−, as well as monomeric surfactant dodecyl trimethylammonium bromide. It was found that neither the incorporation of a double bond onto the gemini surfactant nor the change of location of the double bond will affect surface activities of the gemini surfactant.

A New Cationic Gemini Surfmer: Synthesis and Surface Activities

Preparation of antibacterial poly(sulfobetaine methacrylate) grafted on poly(vinyl alcohol)-formaldehyde sponges and their properties

Subendothelial macrophage internalization of modified lipids and foam cell formation are hallmarks of atherosclerosis. Deubiquitinating enzymes (DUBs) are involved in various cellular activities; however, their role in foam cell formation is not fully understood. Here, using a loss-of-function lipid accumulation screening, we identified ubiquitin-specific peptidase 9 X-linked (USP9X) as a factor that suppressed lipid uptake in macrophages. We found that USP9X expression in lesional macrophages was reduced during atherosclerosis development in both humans and rodents. Atherosclerotic lesions from macrophage USP9X-deficient mice showed increased macrophage infiltration, lipid deposition, and necrotic core content than control apolipoprotein E–KO (Apoe–/–) mice. Additionally, loss-of-function USP9X exacerbated lipid uptake, foam cell formation, and inflammatory responses in macrophages. Mechanistically, the class A1 scavenger receptor (SR-A1) was identified as a USP9X substrate that removed the K63 polyubiquitin chain at the K27 site. Genetic or pharmacological inhibition of USP9X increased SR-A1 cell surface internalization after binding of oxidized LDL (ox-LDL). The K27R mutation of SR-A1 dramatically attenuated basal and USP9X knockdown–induced ox-LDL uptake. Moreover, blocking binding of USP9X to SR-A1 with a cell-penetrating peptide exacerbated foam cell formation and atherosclerosis. In this study, we identified macrophage USP9X as a beneficial regulator of atherosclerosis and revealed the specific mechanisms for the development of potential therapeutic strategies for atherosclerosis.

http://www.jci.org/articles/view/154217/files/pdf

Biqing Wang

Papers

Aqueous Hybrids of Silica Nanoparticles and Hydrophobically Associating Hydrolyzed Polyacrylamide Used for EOR in High-Temperature and High-Salinity Reservoirs

A novel thermoviscosifying water‐soluble polymer: Synthesis and aqueous solution properties

A New Cationic Gemini Surfmer: Synthesis and Surface Activities

Preparation of antibacterial poly(sulfobetaine methacrylate) grafted on poly(vinyl alcohol)-formaldehyde sponges and their properties

Disruption of USP9X in macrophages promotes foam cell formation and atherosclerosis