Brine based indirect steam boiler

Abstract

Systems and methods generate steam in hydrocarbon recovery operations and may further enable emulsion separation and product upgrading. The methods rely on indirect boiling of water by contact with a thermal transfer liquid heated to a temperature sufficient to vaporize the water. Examples of the liquid include oils, recovered hydrocarbons, liquid metals and brine. Heating of the liquid may utilize circulation of the liquid across or through a furnace, heat exchangers, or a gas-liquid contactor supplied with hot gas. Further, a solvent for bitumen introduced into the water may also vaporize upon contact with the thermal transfer liquid.

1 . A method of generating steam in a hydrocarbon recovery operation, comprising:
 introducing water produced in the hydrocarbon recovery operation into a vessel;   heating a brine within the vessel to above a boiling point of the water;   contacting the water with the brine for vaporization of the water into steam at a first pressure within the vessel;   separating the steam in an overhead of the vessel from the liquid for injection in the hydrocarbon recovery operation; and   removing impurities within the brine that buildup from the water by purging a portion of the brine from the vessel and flashing the portion at a second pressure lower than the first pressure to generate an aqueous waste stream and a vapor stream for reuse.   
     
     
         2 . The method according to  claim 1 , further comprising thermal oxidizing the aqueous waste stream to destroy organics and render inorganic matter into solids. 
     
     
         3 . The method according to  claim 1 , further comprising pumping the portion of the brine purged to above the first pressure before heating and then flashing at least at the first pressure to generate additional steam prior to the flashing at the second pressure. 
     
     
         4 . The method according to  claim 1 , wherein the brine is heated by heating coils disposed in the brine within the vessel. 
     
     
         5 . The method according to  claim 1 , wherein the brine is heated by molten sodium circulated through heating coils disposed in the brine within the vessel. 
     
     
         6 . The method according to  claim 1 , wherein the brine is heated in a circulation loop from the vessel by a furnace before being returned to the vessel. 
     
     
         7 . The method according to  claim 1 , wherein the first pressure exceeds 10,000 kilopascals. 
     
     
         8 . The method according to  claim 1 , further comprising preheating the water prior to being introduced into the vessel as droplets. 
     
     
         9 . The method according to  claim 1 , further comprising adding a solvent to the water prior for vaporization of the solvent with the water. 
     
     
         10 . The method according to  claim 1 , further comprising removing solids entrained in the steam prior to the injection. 
     
     
         11 . The method according to  claim 1 , further comprising separating condensable hydrocarbons from the steam prior to the injection. 
     
     
         12 . The method according to  claim 1 , wherein heat is recovered from the vapor stream prior to being recycled back into the vessel for vaporization at the first pressure. 
     
     
         13 . The method according to  claim 1 , wherein the brine contains at least 50 grams of salt per liter of water. 
     
     
         14 . A system for generating steam in a hydrocarbon recovery operation, comprising:
 a vessel coupled to a production well for receiving water produced in the hydrocarbon recovery operation;   a feed pump to supply the water into the vessel at a first pressure;   a brine disposed within the vessel in contact with the water and heated to above a boiling point of the water for vaporization of the water into steam within the vessel;   an injection well in fluid communication with the steam separated in an overhead of the vessel from the brine and for conveying the steam into the formation to facilitate additional hydrocarbon recovery;   a flash drum in fluid communication with a purge of the brine from the vessel for flashing a portion of the brine at a second pressure lower than the first pressure to generate an aqueous waste stream and a vapor stream for reuse.   
     
     
         15 . The system according to  claim 14 , further comprising a thermal oxidizer coupled to receive the aqueous waste stream for destroying organics and rendering inorganic matter into disposable solids. 
     
     
         16 . The system according to  claim 14 , further comprising:
 a booster pump to pressurize the portion of the brine purged to above the first pressure;   a heater coupled to increase temperature of a pressurized output from the booster pump; and   an auxiliary steam generator to flash fluid output from the heater to generate additional steam at least at the first pressure prior to the flashing at the second pressure.   
     
     
         17 . The system according to  claim 14 , further comprising a nozzle to introduce the water as droplets into the vessel. 
     
     
         18 . The system according to  claim 14 , further comprising heating coils disposed in the brine within the vessel for transfer of heat to the brine. 
     
     
         19 . The system according to  claim 14 , further comprising heating coils disposed in the brine within the vessel for transfer of heat to the brine from molten sodium circulated within the coils. 
     
     
         20 . The system according to  claim 14 , further comprising a circulation loop from the vessel for heating the brine by a furnace before being returned to the vessel.