Document Type : Review Article
Department of Petroleum Engineering Islamic Azad University, Omidiyeh, Iran,
The importance of hydrocarbons in the production of various materials, as well as the supply of most part of the world's energy in the last century and the inability to replace renewable energy due to the rapid growth of global energy demand, on the other hand, has led to the extraction of hydrocarbon reserves should not be out of the focus of researchers and experts in this industry. One of the most important methods of Enhanced Oil Recovery (EOR), especially in carbonate reservoirs, is wettability alteration of the rock using chemical flooding, which has recently been considered by many researchers and research centers. Since most of the world's reservoirs, as well as our beloved country, are made of carbonates, changing the wettability of reservoir rock from oil to water wet have a significant effect on increasing the final recovery factor of the reservoir. The present study is an overview of the latest achievements of EOR through chemical flooding in carbonate reservoirs aimed at changing the wettability towards hydrophilicity. Despite extensive research on the mechanism of chemical flooding, not all aspects of it have been clarified so far. Obviously, without a comprehensive and accurate knowledge of the mechanism of this process, it will not be possible to control and improve it.in the work at hand mechanism of chemical flooding using low salinity, surfactants, polymers, nanoparticles or Nano fluids has been reviewed and an attempt is made to investigate the interactions of surface rock minerals, ions in the injection fluid, crude oil and formation brine be reviewed.