Abstract: With the increasing domestic demand for reservoir resources and the advancement of development technologies, the production and development of low-permeability, high-salinity, and heavy oil reservoirs have gained increasing attention. Primary and secondary oil recovery methods can only produce a limited amount of crude oil. Therefore, the characteristics of small particle size, low interfacial tension, and strong solubilization capacity make microemulsions effective in enhancing oil production and efficiency in reservoirs.This paper introduces the basic composition, formation theory, preparation methods, and research progress of microemulsions both domestically and internationally. It analyzes the mechanisms of microemulsion flooding, in-situ microemulsion flooding, and microscopic mechanism of microemulsion flooding for enhanced oil recovery. The application of microemulsification chemical flooding technology in reservoir resources is introduced briefly. The aim is to pave new pathways for reservoir exploitation and ultimately form a supporting system to continuously improve crude oil recovery rates.

Key words: inaccessible reservoirs, recovery rate, tertiary recovery, microemulsion