Nanoparticles for Enhancing Heavy Oil Recovery: Recent Progress, Challenges, and Future Perspectives

Heavy oil is estimated to account for about 70% of the remaining oil reserves and considered as the most promising and readily available oil resource to meet energy demands in the coming decades. However, traditional enhanced oil recovery (EOR) methods for heavy oil face significant challenges, such as high mobility of injected fluids, polymer degradation, surfactant adsorption, significant chemical consumption, considerable energy and water consumption, significant greenhouse gas emissions, high operation costs, and the need for robust facilities. Recently, nanoparticle technology has been launched as a promising alternative technology for heavy oil recovery enhancement due to their unique characteristics of ultrasmall size, large surface area to volume ratio, low costs, and environmental friendliness. This paper presents a comprehensive discussion of the most recent studies about nanoparticle applications for heavy oil recovery and helps researchers gain insights into EOR mechanisms underlying these various applications. Nanoparticle applications for enhancing heavy oil recovery can be summarized into two major categories: nanofluid flooding (i.e., the use of nanoparticles alone) and its hybrids of traditional EOR methods. First, various applications of nanofluid flooding are summarized in terms of incremental oil recovery performance and EOR mechanisms. Second, recent research progress on the hybrids of nanoparticles and traditional EOR methods including thermal, chemical, and gas injection technologies is highlighted. Finally, the challenges and future perspectives for development and applications of nanoparticles for enhancing heavy oil recovery are identified.