Abstract: Low salinity water injection technique employs modified injection brine chemistry to reach the favorable conditions for crude oil/brine/rock interactions which allows the oil to be moved easily in the porous media and obtain higher oil recovery. This work is aimed to investigate the efficiency of low salinity water injection with laboratory experimental approach. A case study includes three different core samples from different wells of Brazilian Pre-Salt carbonate reservoir to examine oil recovery factor variation during sea water injection followed by sea water with the addition of copper ion. The
recovery factor by seawater reached values up to around 25% of the OOIP. Additional oil recovery was observed during the injection of seawater with the addition of copper chloride. During this process, the recovery increased around 6 to 29% of the OOIP for different core samples which shows the application potential of low salinity water injection process and effectiveness of mechanism of desorbtion of the acidic oil from the rock surface by forming acid-copper complexes Ver menos