Nanofluid flooding technology has demonstrated enormous potential in enhancing the recovery efficiency of unconventional oil and gas resources. However, due to the complex physicochemical properties of nanofluids and their intricate interaction mechanisms in different reservoir environments, the research and application of nanofluids still face numerous challenges. Although existing review articles have systematically covered various aspects of nanofluid flooding technology and its enhanced oil recovery (EOR) mechanisms, they have not comprehensively addressed all facets of nanofluid-based EOR. In particular, they lack detailed introductions to the field applications of nanofluid flooding technology in reservoirs with different geological structural characteristics, the preparation of bio-based nano-oil displacement materials, the technology of forming nanofluids through in situ self-assembly of silica nanoparticles by reservoir microorganisms, and nanomaterial-mediated carbon dioxide flooding and microbial flooding technologies. This paper aims to identify the existing deficiencies in current nanofluid EOR technologies, especially focusing on the green and low-carbon microbial composite nanofluid flooding technology based on the utilization of reservoir microbial resources. Furthermore, targeted future development directions are proposed, with the goal of providing a more comprehensive, in-depth, and forward-looking reference for the theoretical research and industrial application of nanofluid EOR technologies, thereby further promoting the advancement of EOR technologies for low-permeability and tight oil reservoirs.
Wang et al. (2026) studied this question.