Abstract: The present invention entails dual centrifuges configured to remove suspended solids, silica, and other precipitants from evaporator brine prior to the brine being disposed of via deep well injection. First, the evaporator brine is directed through a highly efficient first centrifuge configured to remove essentially all suspended solids, including very small suspended solids that typically cannot be retained in a filter or other dewatering devices. The centrate from the first centrifuge, depleted in suspended solids, silica and other precipitants, can be disposed of via deep well injection. The first centrifuge also produces a slurry that is directed to a separate centrifuge that produces a second centrate and waste wet cake. The second centrate is recycled and mixed with the evaporator brine and the mixture is directed to the first centrifuge.

Abstract: The present invention relates to a process for removing dissolved silica from a high pH brine produced by an evaporator employed in treating a waste stream. The high pH brine is directed to a crystallizer reactor and an acid or CO2 is mixed therewith to reduce the pH of the brine, causing the silica in the brine to precipitate. The brine is then directed to a first solids-liquid separator which produces a slurry containing the precipitated silica. The slurry is split into first and second streams with one stream recycled to the crystallizer reactor while the other slurry stream is directed to a second solids-liquid separator which produces a wet cake containing the silica solids.

Abstract: An oil recovery process includes recovering an oil-water mixture from an oil-bearing formation and separating the produced water from the oil-water mixture. The produced water includes dissolved gases and the method includes heating and pressurizing the produced water. After the produced water is heated and pressurized, it is flash vaporized through a lesser pressure which produces a vapor and residual produced water. The flash vaporization of the produced water evaporates dissolved gases and the dissolved gases are vented away with the vapor.

Abstract: The present invention relates to a process for treating evaporator concentrate. The process includes generating or producing a vent stream that includes carbon dioxide and mixing the carbon dioxide with the evaporator blowdown to reduce the pH of the evaporator blowdown. In cases where the evaporator blowdown includes a significant concentration of silica, lowering the pH will precipitate silica from the evaporator blowdown.

Abstract: The present invention relates to a process for treating evaporator concentrate. The process includes generating or producing a vent stream that includes carbon dioxide and mixing the carbon dioxide with the evaporator blowdown to reduce the pH of the evaporator blowdown. In cases where the evaporator blowdown includes a significant concentration of silica, lowering the pH will precipitate silica from the evaporator blowdown.

Abstract: An oil recovery process includes recovering an oil-water mixture from an oil-bearing formation and separating the produced water from the oil-water mixture. The produced water includes dissolved gases and the method includes heating and pressurizing the produced water. After the produced water is heated and pressurized, it is flash vaporized through a lesser pressure which produces a vapor and residual produced water. The flash vaporization of the produced water evaporates dissolved gases and the dissolved gases are vented away with the vapor.

Abstract: An evaporation based method for generation of high pressure steam from produced water in the heavy oil production industry. De-oiled produced water is processed through a high pH/high pressure evaporator driven by a commercial watertube boiler. The vapor produced by the evaporator is suitable for the steam assisted gravity drainage (SAGD) method being utilized by heavy oil recovery installations, without the use of once through steam generators that require extensive chemical treatment, and without requiring atmospheric distillation, which requires high power consuming compressors. Evaporator blowdown may be further treated in a crystallizing evaporator to provide a zero liquid discharge (ZLD) system and, with most produced waters, at least 98% of the incoming produced water stream can be recovered in the form of high pressure steam.

Abstract: A method for recovering oil includes recovering an oil-water mixture from a well and separating oil from the oil-water mixture to produce an oil product and produced water. The produced water is directed to an evaporator which produces steam that is condensed to form a distillate. Thereafter the distillate is directed to a steam generator and is heated to form steam and water. At least a portion of the water is recirculated through the steam generator. Another portion of the water is mixed with the steam to form a steam-water mixture that is injected into an injection well.

Abstract: A method for recovering oil includes recovering an oil-water mixture from a well and separating oil from the oil-water mixture to produce an oil product and produced water. The produced water is directed to an evaporator which produces steam that is condensed to form a distillate. Thereafter the distillate is directed to a steam generator and is heated to form steam and water. At least a portion of the water is recirculated through the steam generator. Another portion of the water is mixed with the steam to form a steam-water mixture that is injected into an injection well.

Abstract: An evaporation based method for generation of high pressure steam from produced water in the heavy oil production industry. De-oiled produced water is processed through a high pH/high pressure evaporator driven by a commercial watertube boiler. The vapor produced by the evaporator is suitable for the steam assisted gravity drainage (SAGD) method being utilized by heavy oil recovery installations, without the use of once through steam generators that require extensive chemical treatment, and without requiring atmospheric distillation, which requires high power consuming compressors. Evaporator blowdown may be further treated in a crystallizing evaporator to provide a zero liquid discharge (ZLD) system and, with most produced waters, at least 98% of the incoming produced water stream can be recovered in the form of high pressure steam.