ELECTRODIALYSIS REVERSAL FOR OIL & GAS APPLICATION: PRODUCED WATER DESALINATION
To guarantee a responsible use of water resource which is necessary for the oil production, TotalEnergies is trying to both minimize surface water use and production water disposal. Offshore sea water offtake and disposal at sea of produced water is still widely used while in onshore facilities, produced water full reinjection and minimal disposal are a paradigm. In Enhanced Oil Recovery (EOR) mechanisms, low salinity water injection has proven its effectiveness in many aspects: Its potential of improving oil production has been proved through laboratory experiments, low-salinity water flooding can change the wettability of the reservoir rock to increase oil recovery. It is a simple injection, low cost, and low capital investment EOR method. Use of low salinity water in Polymer flooding projects is also advantageous as it is well known that the required dose of polymer powder to obtain a targeted viscosity will decrease by reducing the salinity of the inlet water. When the water salinity is low enough, desalination of water for reducing the required polymer concentration brings effective cost savings. A lower concentration of polymer leads to significant reductions of CAPEX (storage tank, pump size, polymer preparation unit) and OPEX (polymer cost, transport, and handling). But there are also indirect advantages of produced water desalination and reinjection: lower consumption of anticorrosion or desemulfier chemicals and lower investment in water treatment facilities.