Zero emission steam generation process

Abstract

This invention provides a new process to generate steam directly from untreated water produced simultaneously with thermally recovered crude oil, and to inject the steam and combustion products into a hydrocarbon reservoir to recover hydrocarbons and to sequester a portion of the carbon dioxide produced during the creation of steam. The invention removes the ongoing additional water requirements for thermal oil recovery and the need for surface treating of produced water for re-use, yielding improved process efficiencies, reduced environmental impact, and improved economic value.

1 . A steam processing system comprising:
 a) an oxy-fuel steam generator having an inlet for fluids, said generator adding heat directly to inlet fluids by intimately combining the combustion fuels, oxygen and water feed in a reaction chamber in sufficient proportions, for a substantially complete combustion; this system providing a steam mixture with carbon dioxide and traces of impurities in the outlet; and   b) a steam separator, utilizing advanced inert metallurgy, controlling the quality of the steam mixture; wherein the resulting steam mixture is used as an injectant in a thermal oil process.   
     
     
         2 . A method of using the steam processing system of  claim 1 , said method comprising:
 a) Injecting fuel and oxygen together into a reaction chamber   b) Igniting the mixture,   c) Passing feed water through the combustion gases;   d) Adding additional water downstream of the flame until a desired carbon dioxide and steam mixture is attained;   e) Removing entrained impurities downstream, prior to the injection of a 100% quality steam and carbon dioxide mixture.   
     
     
         3 . The method of  claim 2 , wherein the feed water comprises untreated subterranean water which may contain unlimited suspended solids (greater than 5,000 ppm) hardness and any other components, that is co-produced with oil production. 
     
     
         4 . The method of  claim 2 , wherein the mixture generated for injection consists largely of steam and carbon dioxide for use as an injectant in a thermal oil process such as, but not limited to, Steam Assisted Gravity Drainage (SAGD), Cyclic Steam Stimulation (CSS), Steam Flooding, or other thermal recovery processes that starts with steam injection e.g. in situ combustion;
 the mixture being generated by:
 a) injecting fuel and oxygen together into a reaction chamber at a pressures between 690 and 17,800 kPa; 
 b) igniting the mixture; 
 c) passing produced water through the combustion gases; 
 d) adding additional produced water downstream of the flame until a desired carbon dioxide, vapour steam and liquid water mixture is attained; 
 e) removing any liquid salt water or brine downstream, prior to the injection of a substantially pure quality steam and carbon dioxide mixture. 
   
     
     
         5 . The method of  claim 2  wherein lower quality steam (<100% saturation) and carbon dioxide is generated by steam processing system. 
     
     
         6 . The method of  claim 2  wherein the fuel is selected from: methane, oil, heavy oil, bitumen, emulsions, or mixtures thereof or similar fluid materials that undergo combustion with oxygen. 
     
     
         7 . The method of  claim 2  further comprising production of water condensed from injected steam and associated oil from the thermal recovery process through the injection well, an adjacent well, or both. 
     
     
         8 . The method of  claim 2  further comprising the use of some liquid blowdown water from a steam separator as process feed water, and disposing of the balance of liquid blowdown water. 
     
     
         9 . The method of  claim 8  further comprising the removal of solids from liquid blowdown prior to sequestration or re-use as feed water. 
     
     
         10 . The method of  claim 2 , further comprising varying the fraction of carbon dioxide from 1 to 50 volume percent of the injectant stream through the use of other fuels and/or carbon dioxide recirculation. 
     
     
         11 . The method of  claim 10 , further comprising altering carbon dioxide in the injectant stream used to increase thermal oil recovery from a reservoir where the carbon dioxide is ramped up from 1 to 50 volume percent as the recovery process evolves or ramped down from 50 to 1 volume percent as the recovery process evolves. 
     
     
         12 . The method of  claim 2 , further comprising operating the reservoir and surface facilities to capture the majority of produced carbon dioxide to re-inject the carbon dioxide back into the reservoir. 
     
     
         13 . The method of  claim 2 , further comprising locating steam processing systems remotely at well sites, as opposed to the standard practice of building a central plant. 
     
     
         14 . The method of  claim 2 , further comprising adding light hydrocarbons or other substances to the mixture of steam and carbon dioxide downstream of the steam separator to act as a further solvent. 
     
     
         15 . The method of  claim 14  where the preferred solvent is propane, butane, pentane, hexane, natural gas condensates, diluent, naphtha and combinations. 
     
     
         16 . The method of  claim 2 , wherein partial combustion is taking place to produce a synthesis gas that is delivered to a thermal oil well for injection in a thermal oil recovery process. This is accomplished through the partial oxidation of the fuel which, which together with pyrolysis and aquathermolysis, can produce a synthesis gas (consists of water, hydrogen, carbon dioxide, and carbon monoxide) which can be injected into the oil formation to enable oil recovery and partial upgrading if the injected gas is at sufficient temperatures to enable in situ gasification of the oil (typically above about 300° C.). 
     
     
         17 . A steam processing system comprising:
 an oxy-fuel steam generator having an inlet for fluids including combustion fuels, oxygen and water including a percentage of dirty returned process water having substantially over 4,000 ppm suspended solids, said generator adding heat directly to inlet fluids by intimately combining the combustion fuels, oxygen and water feed in a reaction chamber in sufficient proportions at a pressure substantially
 a) generally between 690 and 17,800 kPa, 
 b) for SAGD between 500 to 5000 kPa and preferably between 1000 and 3000 kPa. 
 c) for CSS at or above the fracture pressure of the reservoir 
   for a substantially complete combustion; this system providing a steam mixture with carbon dioxide and traces of impurities in the outlet; and   a steam separator, constructed utilizing advanced inert metallurgy, and controlling the quality of the steam mixture; wherein the resulting steam mixture is used as an injectant in a thermal oil process.   
     
     
         18 . A method of using the steam processing system of  claim 17 , said method comprising:
 a) Injecting fuel and oxygen together into a reaction chamber   b) Igniting the mixture,   c) Passing feed water through the combustion gases;   d) Adding additional water downstream of the flame until a desired carbon dioxide and steam mixture is attained;   e) Removing entrained impurities downstream, prior to the injection of a substantially pure quality steam and carbon dioxide mixture.   
     
     
         19 . The method of  claim 18 , wherein the feed water comprises untreated subterranean water which may contain unlimited suspended solids (greater than 5,000 ppm) hardness and any other components, that is co-produced with oil production. 
     
     
         20 . The method of  claim 19 , wherein the mixture generated for injection consists largely of steam and carbon dioxide for use as an injectant in a thermal oil process such as, but not limited to, Steam Assisted Gravity Drainage (SAGD), Cyclic Steam Stimulation (CSS), Steam Flooding, or other thermal recovery processes that starts with steam injection such as in situ combustion;
 the mixture being generated by:
 a) injecting fuel and oxygen together into a reaction chamber and igniting the mixture; 
 b) passing produced water through the combustion gases; 
 c) adding additional produced water downstream of the flame until a desired carbon dioxide, vapour steam and liquid water mixture is attained; 
 d) removing any liquid salt water or brine downstream, prior to the injection of a substantially pure quality steam and carbon dioxide mixture. 
   
     
     
         21 . The method of  claim 18  wherein lower quality steam (<100% saturation) and carbon dioxide is generated by said steam processing system. 
     
     
         22 . The method of  claim 18  wherein the fuel is selected from: methane, oil, heavy oil, bitumen, emulsions, or mixtures thereof or similar fluid materials that undergo combustion with oxygen. 
     
     
         23 . The method of  claim 18  further comprising production of water condensed from injected steam and associated oil from the thermal recovery process through the injection well, an adjacent well, or both. 
     
     
         24 . The method of  claim 18  further comprising the use of some liquid blowdown water from the steam separator as process feed water, and disposing of any balance of liquid blowdown water. 
     
     
         25 . The method of  claim 24  further comprising the removal of solids from liquid blowdown prior to sequestration or re-use as feed water. 
     
     
         26 . The method of  claim 18 , further comprising varying the fraction of carbon dioxide from 1 to 50 volume percent of the injectant stream through the use of other fuels and/or carbon dioxide recirculation. 
     
     
         27 . The method of  claim 26 , further comprising altering carbon dioxide in the injectant stream used to increase thermal oil recovery from a reservoir where the carbon dioxide is ramped up from 1 to 50 volume percent as the recovery process evolves or ramped down from 50 to 1 volume percent as the recovery process evolves. 
     
     
         28 . The method of  claim 18 , further comprising operating reservoir and surface facilities to capture the majority of produced carbon dioxide to re-inject the carbon dioxide back into the reservoir. 
     
     
         29 . The method of  claim 18 , further comprising a modular transportable steam processing system and locating said system remotely at well sites, as opposed to the standard practice of building a central plant. 
     
     
         30 . The method of  claim 18 , further comprising adding light hydrocarbons or other substances to the mixture of steam and carbon dioxide downstream of the steam separator to act as a further solvent. 
     
     
         31 . The method of  claim 30  where the preferred solvent is selected from propane, butane, pentane, hexane, natural gas condensates, diluents, naphtha and combinations thereof. 
     
     
         32 . The method of  claim 18 , wherein partial combustion is taking place to produce a synthesis gas that is delivered to a thermal oil well for injection in a thermal oil recovery process accomplished through the partial oxidation of the fuel which, together with pyrolysis and aquathermolysis, can produce a synthesis gas consisting of mixtures of water, hydrogen, carbon dioxide, and carbon monoxide injected into the oil formation to enable oil recovery and partial upgrading if the injected gas is at sufficient temperatures to enable in situ gasification of the oil (typically above about 300° C.).