An oil recovery process is provided where an oil-water mixture is recovered from an oil-bearing formation. Oil is separated from the oil-water mixture to yield produced water. The produced water is typically subjected to a pre-treatment process. After pre-treatment, the produced water is directed to an evaporator that evaporates at least some of the produced water and produces steam and an evaporator blowdown. The evaporator blowdown is directed to a dual stage crystallizer that concentrates the evaporator blowdown.