applied sciences Review A State-of-the-Art Review of Nanoparticles Application in Petroleum with a Focus on Enhanced Oil Recovery Madhan Nur Agista 1,2, Kun Guo 1,3,* ID and Zhixin Yu 1,* ID 1 Department of Energy and Petroleum Engineering, University of Stavanger, 4036 Stavanger, Norway; [email protected] 2 Auroris Energy, Jakarta 12950, Indonesia 3 The National IOR Centre of Norway, University of Stavanger, 4036 Stavanger, Norway * Correspondence: [email protected] (K.G.); [email protected] (Z.Y.); Tel.: +47-5183-2198 (K.G.); +47-5183-2238 (Z.Y.) Received: 21 April 2018; Accepted: 15 May 2018; Published: 25 May 2018 Abstract: Research on nanotechnology application in the oil and gas industry has been growing rapidly in the past decade, as evidenced by the number of scientific articles published in the field. With oil and gas reserves harder to find, access, and produce, the pursuit of more game-changing technologies that can address the challenges of the industry has stimulated this growth. Nanotechnology has the potential to revolutionize the petroleum industry both upstream and downstream, including exploration, drilling, production, and enhanced oil recovery (EOR), as well as refinery processes. It provides a wide range of alternatives for technologies and materials to be utilized in the petroleum industry. Nanoscale materials in various forms such as solid composites, complex fluids, and functional nanoparticle-fluid combinations are key to the new technological advances. This paper aims to provide a state-of-the-art review on the application of nanoparticles and technology in the petroleum industry, and focuses on enhanced oil recovery. We briefly summarize nanotechnology application in exploration and reservoir characterization, drilling and completion, production and stimulation, and refinery. Thereafter, this paper focuses on the application of nanoparticles in EOR. The different types of nanomaterials, e.g., silica, aluminum oxides, iron oxide, nickel oxide, titanium oxide, zinc oxide, zirconium oxide, polymers, and carbon nanotubes that have been studied in EOR are discussed with respect to their properties, their performance, advantages, and disadvantages. We then elaborate upon the parameters that will affect the performance of nanoparticles in EOR, and guidelines for promising recovery factors are emphasized. The mechanisms of the nanoparticles in the EOR processes are then underlined, such as wettability alteration, interfacial tension reduction, disjoining pressure, and viscosity control. The objective of this review is to present a wide range of knowledge and expertise related to the nanotechnology application in the petroleum industry in general, and the EOR process in particular. The challenges and future research directions for nano-EOR are pinpointed. Keywords: nanotechnology; nanoparticle; petroleum; enhanced oil recovery; recovery mechanism; wettability alteration; interfacial tension reduction 1. Introduction Hydrocarbon is a major energy source for human civilization, and it is predicted to remain the primary source of energy in the coming decades. However, most oil fields have already reached or will soon reach the declining stage of production, even though a large fraction of the original oil in Appl. Sci. 2018, 8, 871; doi:10.3390/app8060871 www.mdpi.com/journal/applsci Appl. Sci. 2018, 8, 871 2 of 29 place (OOIP) has not yet been recovered. Based on the U.S. Department of Energy (DoE, Washington, DC, USA) data, 67% of the total oil in the U.S. will remain in the reservoirs because of the limitations of the technology used to extract residual hydrocarbon [1]. As cheap and reliable renewable energy sources are not yet available, fundamental studies on enhanced oil recovery (EOR) are critical to develop technologies enabling a high recovery factor from oil reservoirs. Various EOR technologies have been applied and proven to significantly increase hydrocarbon recovery. These include thermal, miscible, and chemical methods, as well as some new technologies (microbial, low salinity flooding). More recently, nanoparticles and nanotechnology have been proposed as a promising EOR method since nanoparticlesAppl. Sci. 2018, can8, x penetrate the pore throat and change the reservoir properties2considerably of 28 to increase oilDC, recovery USA) data, [1 67%–6]. of the total oil in the U.S. will remain in the reservoirs because of the limitations Over theof the past technology years, used numerous to extract studies residual have hydrocar shownbon [1]. promising As cheap and results reliable of renewable nanomaterials energy application sources are not yet available, fundamental studies on enhanced oil recovery (EOR) are critical to for improving hydrocarbon recovery. Laboratory studies have shown that surface-coated silica develop technologies enabling a high recovery factor from oil reservoirs. Various EOR technologies nanoparticleshave been can applied stabilize and proven emulsions to significantly and improveincrease hydrocarbon mobility recovery. control These in include the EOR thermal, process [7,8]. Nanoparticlesmiscible, (NPs) and chemical have also methods, been as reported well as some to ne alterw technologies rock wettability (microbial, and low salinity reduce flooding). interfacial tension when usedMore as EOR recently, agents nanoparticles [3,9,10 ].and Different nanotechnology parameters have been of proposed nanoparticles as a promising such EOR as size, method concentration, since nanoparticles can penetrate the pore throat and change the reservoir properties considerably to ionic composition,increase oiland recovery type [1–6]. have been studied in relation to their effect on EOR [11,12]. This paperOver presents the past ayears, comprehensive numerous studies review have ofshown the recentpromising applications results of nanomaterials of nanoparticles and nanotechnologyapplication in for the improving petroleum hydrocarbon industry recovery. in general Laboratory and studies EOR have in shown particular, that surface-coated and aims to provide silica nanoparticles can stabilize emulsions and improve mobility control in the EOR process [7,8]. insights for researchers to work in the nano-EOR field. Some earlier reviews on nanomaterials on Nanoparticles (NPs) have also been reported to alter rock wettability and reduce interfacial tension EOR havewhen been used published as EOR agents elsewhere, [3,9,10]. Different whichare parameters mainly of from nanopa eitherrticles such a mechanistic as size, concentration, or an experimental perspectiveionic [13 composition,–15]. This and review type have is based been studied on a material in relation approach to their effect for on nano-EOREOR [11,12]. and will focus on the effect of NP typeThis and paper parameters presents a comprehensive on EOR. Furthermore, review of the the recent nanoparticle applications applicationof nanoparticles in and different fields nanotechnology in the petroleum industry in general and EOR in particular, and aims to provide such as exploration,insights for researchers drilling, production,to work in the andnano-EOR refining field. is Some briefly earlier summarized reviews on nanomaterials at the start on of the review. ExperimentalEOR studieshave been thatpublished have elsewhere, been done which with are mainly different from typeseither a ofmechanistic nanoparticles or an experimental are discussed along with theirperspective proposed [13–15]. mechanisms This review and is based driving on a parameters.material approach for nano-EOR and will focus on the effect of NP type and parameters on EOR. Furthermore, the nanoparticle application in different 2. Applicationsfields such of Nanotechnologyas exploration, drilling, in production, the Petroleum and refining Industry is briefly summarized at the start of the review. Experimental studies that have been done with different types of nanoparticles are discussed Nanotechnologyalong with their hasproposed the mech potentialanisms and to driving revolutionize parameters. the petroleum industry both upstream and downstream,2. Applications including of Nanotechnology exploration, in the Petroleum drilling, Industry production, and EOR, as well as refinery processes [1,16–18]. It provides a wide range of alternatives for technologies and materials to be Nanotechnology has the potential to revolutionize the petroleum industry both upstream and utilized indownstream, the petroleum including industry. exploration, Nanoscale drilling, production, materials and in variousEOR, as well forms as refinery such asprocesses solid composites, complex fluids,[1,16–18]. and It provides functional a wide NP-fluid range of alternatives combinations for technologies are key toand the materials new technologicalto be utilized in the advances [19]. The numberpetroleum of studies industry. on Nanoscale nanotechnology materials in various related forms to such the as petroleum solid composites, industry complex has fluids, been growing and functional NP-fluid combinations are key to the new technological advances [19]. 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