Patent attributes
We provide an evaporation based zero-liquid discharge method for generation of steam for enhanced oil recovery (EOR) processes utilizing once-through steam generators (OTSGs). The method includes feeding the OTSG(s) with produced water, vaporizing a fraction of this water for steam injection and blowing down the balance of the water. This water, referred to as OTSG blowdown, can be flashed to produce a vapor stream and a liquid that is fed to a mechanical vapor compression (MVC) evaporative process. The latent energy contained in the vapor stream generated by the upstream flash is beneficially recycled to substantially reduce or eliminate the energy consumption of the MVC process. The evaporative process can be used to reduce the liquid waste for disposal or eliminate the need for liquid disposal by achieving zero liquid discharge.
