Nanofluid Enhanced Oil Recovery Using Hydrophobically Associative Zwitterionic Polymer-Coated Silica Nanoparticles

Abstract

Intense interest has been shown in the development of “smart nanofluids” because they can dramatically change their flow properties in complex fluid systems. We introduce a robust and straightforward approach to develop a smart nanofluid system, in which associative silica nanoparticles (ASNPs) were incorporated to regulate their flow properties in rock pores. ASNPs were synthesized by covalently coating a hydrophobically associative hygroscopic zwitterionic poly­[2-methacryloyloxyethyl phosphorylcholine (MPC)-co-divinylbenzene (DVB)] shell layer on 20 nm sized silica nanoparticles (NPs) by surface-mediated living radical polymerization. The essence of our approach is to copolymerize DVB, which endows the polymer shell of ASNPs with a weak long-range hydrophobic attraction. This leads to the favorable formation of a wedge film as a result of structural disjoining pressure. This wedge film made the oil adsorbed on the rock surface more dewettable, thus enhancing the efficiency of oil recovery. As a result of this unique behavior, the ASNP nanofluid developed in this study remarkably improved the fluidity of complex oil fluids; ∼5 vol % oil recovery enhancement and ∼0.3 psi pressure reduction were also achieved in comparison to neat nanofluid controls.

Polymer-functionalized silica nanoparticles for improving water flood sweep efficiency in Berea sandstones

“…The authors reported an incremental oil recovery up to 5.2% of OOIP after water flood. Like Choi, et al [30], they reported pressure decrease with NPs injection. The oil recovery was attributed to the interfacial tension reduction and wettability alteration to more waterwet condition.…”

“…Behzadi and Mohammadi [29] reported that polymer-coated silica NPs can modulate oil and water IFT and change the wettability of the oil-wet glass micromodel to more waterwet, resulting in higher EOR than unmodified silica nanoparticles. Experiments conducted by Choi, et al [30] found that, when injecting polymer-coated silica NPs into water-wet sandstones, 74.1% oil was recovered, which was comparable to water flood (68.9%) and 72.7% of OOIP from unmodified NPs. The authors argued that modified silica NPs increased oil recovery by lowering the injection pressure relative to unmodified ones, which was associated to the ordering of NPs in the wedge film between oil and rock surface, rendering more hydrophilic surface.…”

Interfacial and Colloidal Forces Governing Oil Droplet Displacement: Implications for Enhanced Oil Recovery

“…The effect of nanoparticles is lessened at surfactant concentrations greater than the CMC. The use of surfactant blends and composite particles (polymer-coated particles) to enhance oil film displacement have also been considered but such mechanisms are considered outside the scope of this paper [74,75]. Recent studies, which have considered composite fluids (particles), have been summarized in Table A3.…”

Nano-fluid viscosity screening and study of in situ foam pressure buildup at high-temperature high-pressure conditions

“…For decades, polymers are known as viscosity enhancer and have shown promising results, but present various challenges in oil field such as thermal instability, adsorption, gelation, high cost and environmental concern (Rellegadla et al 2017;Speight 2016). However, recent EOR studies focus on nanoparticles (NPs) utilization to improve important properties such as interfacial tension, wettability alteration and viscosity due to their thermophysical properties (Koca et al 2017;Adenutsi et al 2018;Zallaghi et al 2018;Sharma and Sangwai 2017;Choi et al 2017;Kean Chuan et al 2016;Cheraghian et al 2015;Pozhar 2000;Hendraningrat et al 2013). Worthen et al (2013) describe the advantage of NPs in surfactant blends for their ability to be irreversibly adsorbed at interface and provide potential benefits to surfactant's properties.…”