Sustainable Materials for Oil and Gas Applications - Chapter 4: Nanoparticles for enhanced oil recovery

Due to their large surface-area-to-volume ratio and enhanced chemical reactivity, nanoparticles have attracted increasing interest among researchers in the upstream petroleum industry for enhanced oil recovery (EOR) applications which target the recovery of oil left behind by primary and secondary recoveries, by pressure depletion and waterflooding, respectively. In EOR applications, fluids not originally present in the reservoir, such as polymer, surfactant, carbon dioxide or steam, are injected into the reservoir to either increase the sweep efficiency or to mobilize remaining oil so as to reduce the residual oil saturation. In these applications, EOR agents are used to either reduce the mobility of the injected fluid relative to that of oil or to increase the ratio of viscous to interfacial forces, that is, capillary number. In this chapter, we begin with a discussion of the potential use of nanoparticles in the upstream oil industry. This will be followed by a discussion of the unique physics and chemistry of nanoparticles. Then a detailed discussion on how nanoparticles can be used to improve the mobility control and capillary number will be given. It is shown that nanoparticles hold promise in either augmenting existing EOR agents (e.g., surfactant and polymer) or may even replace them to become EOR agents in their own right, although many technical challenges still exist and research is in its early stage. Next the HSE aspects of nanoparticles both in laboratory investigation and field applications will be discussed. We will then conclude with suggestions for future research. With ever increasing advances of nanoparticle technology in many fields of science and engineering, we believe translation of this knowledge to EOR will yield tangible fruits in the not too distant future. However, concerted multidisciplinary efforts will be needed to realize this goal.