Patent ID: 8899326

Claim:
A method of recovering oil and producing steam for injection into an injection well to assist in the recovery of oil, the method comprising: recovering an oil-water mixture from an oil bearing formation; separating oil from the oil-water mixture to produce an oil product and produced water where the produced water includes suspended solids and dissolved solids; directing the produced water having the suspended and dissolved solids to a treatment system; treating the produced water by removing suspended solids and dissolved solids from the produced water and producing treated water; directing the treated water to a forced circulation steam generator comprising a furnace having a burner, at least one water cooled wall and an evaporator unit; pumping a first portion of the treated water through at least one water cooled wall and pumping a second portion of the treated water through the evaporator unit in the furnace; heating the water passing through the water cooled wall to form a first water-steam mixture comprising approximately 10% to approximately 30% quality steam; heating the water passing through the evaporator unit to produce a second water-steam mixture comprising approximately 10% to approximately 30% quality steam; directing the first and second water-steam mixtures to a steam separator and separating steam from the first and second water-steam mixtures to form injection steam comprising 95% or more quality steam; and directing the injection steam into the injection well to facilitate the recovery of the oil-water mixture from the oil bearing formation.