Bitumen 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 separating and upgrading liquid hydrocarbons, comprising:
 introducing into a vessel a mixture recovered from an underground formation and including the hydrocarbons and produced water;   heating the hydrocarbons in a bottom of the vessel such that the produced water introduced into the vessel is vaporized by contact with the hydrocarbons that are heated and rises to an overhead of the vessel for removal; and   withdrawing from the vessel a sales portion of the hydrocarbons that have been upgraded by visbreaking resulting from the heating.   
     
     
         2 . The method according to  claim 1 , further comprising desalting the hydrocarbons withdrawn from the vessel. 
     
     
         3 . The method according to  claim 1 , wherein the heating of the hydrocarbons occurs in a circulation loop from the vessel. 
     
     
         4 . The method according to  claim 1 , wherein the mixture is introduced into the vessel through a nozzle as droplets. 
     
     
         5 . The method according to  claim 1 , further comprising preheating the mixture prior to being introduced into the vessel. 
     
     
         6 . The method according to  claim 1 , further comprising preheating the mixture by heat exchange with the sales portion of the hydrocarbons prior to the mixture being introduced into the vessel. 
     
     
         7 . The method according to  claim 1 , further comprising injecting steam removed from the overhead of the vessel into the formation for additional hydrocarbon recovery. 
     
     
         8 . The method according to  claim 1 , further comprising removing solids entrained in the steam. 
     
     
         9 . The method according to  claim 1 , further comprising separating the steam from condensable hydrocarbon gases. 
     
     
         10 . The method according to  claim 1 , further comprising separating the steam from condensable hydrocarbon gases that are mixed back with the sales portion of the hydrocarbons. 
     
     
         11 . The method according to  claim 1 , wherein the hydrocarbons are heated to at least 385° C. with residence soak time in the vessel of between 5 minutes and 60 minutes for the visbreaking 
     
     
         12 . The method according to  claim 1 , wherein the mixture is an emulsion from a steam assisted gravity drainage operation. 
     
     
         13 . A system for separating and upgrading liquid hydrocarbons, comprising:
 a production well for recovering a mixture of produced water and the hydrocarbons from an underground formation;   a vessel coupled to the production well for receiving the mixture;   a heater to increase temperature of the hydrocarbons in a bottom of the vessel to above a boiling point of the water and a thermal cracking point of the hydrocarbons;   an overhead conduit coupled to a top of the vessel for withdrawing steam from vaporization of the water by contact with the hydrocarbons; and   a liquids conduit coupled to the bottom of the vessel for withdrawing a sales portion of the hydrocarbons upgraded by visbreaking   
     
     
         14 . The system according to  claim 13 , further comprising a desalter disposed along the liquids conduit for desalting the hydrocarbons withdrawn from the vessel. 
     
     
         15 . The system according to  claim 13 , further comprising a circulation loop from the vessel for heating the hydrocarbons by the heater before being returned to the vessel. 
     
     
         16 . The system according to  claim 13 , further comprising a nozzle to introduce the mixture as droplets into the vessel. 
     
     
         17 . The system according to  claim 13 , further comprising a heat exchanger to transfer heat from the sales portion of the hydrocarbons to the mixture prior to the mixture being introduced into the vessel. 
     
     
         18 . The system according to  claim 13 , further comprising an injection well coupled to the overhead conduit for conveying the steam into the formation. 
     
     
         19 . The system according to  claim 13 , further comprising a separator to remove solids entrained in the steam. 
     
     
         20 . The system according to  claim 13 , further comprising a separator to remove condensable hydrocarbons from the steam.