Use of nanoparticles in enhanced oil recovery; an evaluation

Abstract

Nanotechnology is now becoming an emerging area of research in many industries; oil industry too, is not an exception. Many research works has been done and in progress to use nanotechnology from exploration to drilling, to production and enhancing the recovery. The current secondary and tertiary recovery mechanisms have their own limitations. The idea to overcome these limitations in assistance of nanoparticles in current EOR techniques and introducing a new Enhanced Oil Recovery method, nanotechnology has got much attention in this regard. The nano sized particles, owing different (from its bulk sate) and enhanced physical and physiochemical properties may be injected in to an oil reservoir's micro pore system to interact with the reservoir rock and fluids in such a way to mobilize ~rapped oil. This mobilization can be done by modifying wettability of the reservoir rock, reducing interfacial tension, reducing viscosity and maintaining a favorable mobility ratio. In this review paper, the research works carried in the use of nanoparticles (particularly silica nanoparticles) to enhance the oil recovery up to date is reviewed briefly. The main areas reviewed are nanoparticles' dispersion stability, transport through porous media and its effect on rock and fluid characteristics. Oil recovery enhancement through the use of nanoparticles in different recovery mechanisms is discussed. Experimentally and theoretically it is shown that introducing functionalized (different coatings) silica nanoparticles can modify rock wettability, maintain a favorable mobility ratio and reduce interfacial tension between oil and water in the reservoir rock so that the trapped oil could be mobilized. Further, the synergy between oil and surfactant has shown good impacts in improving surfactants functioning in reducing interfacial tension between oil and water. Foams and emulsions stabilized by nanoparticles are also reviewed in this paper. Working conditions and environment like effect of different particles' sizes, concentration, different coatings, properties of rock (mineralogical and petrophysical), temperature, pH and salinities range for any specific nanoparticles are evaluated. This review paper may provide some basic information based on near past and current research works through experimental, theoretical models and field application on the use of nanoparticle in enhanced oil recovery.