Subsurface heating device

Abstract

In one aspect, the present invention provides a subsurface heating device comprising: (a) a combustion conduit casing defining a combustion conduit; (b) at least two combustors disposed within the combustion conduit casing; (c) at least one fuel supply conduit; d) at least one oxygen supply conduit configured to supply oxygen to at least one combustor; and (e) a combustion product gas outlet. The at least two combustors are characterized by an inter-combustor distance of at least one thousand feet and a combustion power of at least 3.41 million BTU per hour. The at least one fuel supply conduit is configured to supply a combustible fuel to at least one combustor. Also provided in another aspect of the present invention, is a method for heating a subsurface zone.

1 . A subsurface heating device comprising:
 (a) a combustion conduit casing defining a combustion conduit;   (b) at least two combustors disposed within the combustion conduit casing and characterized by an inter-combustor distance of at least one thousand feet and a combustion power of at least 3.14 million BTU per hour;   (c) at least one fuel supply conduit configured to supply a combustible fuel to at least one combustor;   (d) at least one oxygen supply conduit configured to supply oxygen to at least one combustor; and   (e) a combustion product gas outlet.   
     
     
         2 . The subsurface heating device according to  claim 1 , wherein the combustion conduit serves as the oxygen supply conduit. 
     
     
         3 . The subsurface heating device according to  claim 2 , wherein the oxygen supply conduit is configured to receive the output of a compressor. 
     
     
         4 . The subsurface heating device according to  claim 1 , wherein the combustors are independently moveable with respect to the combustion conduit casing. 
     
     
         5 . The subsurface heating device according to  claim 4 , wherein the combustors are attached to a rail attached to an interior surface of the combustion conduit casing. 
     
     
         6 . The subsurface heating device according to  claim 1 , further comprising at least one sensor configured to provide data to a remote controller. 
     
     
         7 . The subsurface heating device according to  claim 1 , wherein the combustors are independently controllable. 
     
     
         8 . The subsurface heating device according to  claim 1 , wherein the combustion conduit casing is comprised of at least one material selected from the group consisting of steel pipe, stainless steel, inconel, and corrosion resistant alloys. 
     
     
         9 . The subsurface heating device according to  claim 1 , wherein the combustion product gas outlet is configured to deliver samples of combustion product gases to a gas analyzer. 
     
     
         10 . The subsurface heating device according to  claim 1 , wherein the combustion product gas outlet is configured to deliver combustion product gases to a gas treatment unit. 
     
     
         11 . The subsurface heating device according to  claim 1 , wherein the combustion product gas outlet is configured to return at least a portion of the combustion product gases in a direction parallel to the combustion conduit casing. 
     
     
         12 . A method for heating a subsurface zone comprising:
 (i) creating an accommodation cavity for a subsurface heating device; said subsurface heating device comprising (a) a combustion conduit casing defining a combustion conduit; (b) at least two combustors disposed within the combustion conduit casing and characterized by an inter-combustor distance of at least one thousand feet and a combustion power of at least 3.41 million BTU per hour; (c) at least one fuel supply conduit configured to supply a combustible fuel to at least one combustor; (d) at least one oxygen supply conduit configured to supply oxygen to at least one combustor; and (e) a combustion product gas outlet;   (ii) installing the subsurface heating device within the accommodation cavity; and   (iii) operating the subsurface heating device.   
     
     
         13 . The method according to  claim 12 , wherein the accommodation cavity is created in a hydrocarbon reservoir. 
     
     
         14 . The method according to  claim 12 , wherein the accommodation cavity is created in a shale oil reservoir. 
     
     
         15 . The method according to  claim 12 , wherein the accommodation cavity is created in a tar sands reservoir. 
     
     
         16 . The method according to  claim 12 , wherein the fuel supply conduit provides liquid fuel to at least one combustor. 
     
     
         17 . The method according to  claim 12 , wherein the fuel supply conduit provides natural gas to at least one combustor. 
     
     
         18 . The method according to  claim 12 , wherein the fuel supply conduit provides heating oil to at least one combustor. 
     
     
         19 . The method according to  claim 12 , wherein the combustion conduit serves as the oxygen supply conduit and provides compressed air to the combustors. 
     
     
         20 . The method according to  claim 12 , wherein the thermal output of a first combustor is about 1.5 to about 2.5 times that of the thermal output of a following combustor. 
     
     
         21 . A method for shale oil recovery comprising:
 (i) creating an accommodation cavity for a subsurface heating device; said subsurface heating device comprising (a) a combustion conduit casing defining a combustion conduit, (b) at least two combustors disposed within the combustion conduit casing and characterized by an inter-combustor distance of about 1000 feet, and wherein the thermal output of a first combustor is 1.5-2.5 times that of the thermal output of a following combustor spaced at the inter-combustor distance of about 1000 feet, (c) at least one fuel supply conduit configured to supply a combustible liquid fuel to at least one combustor, (d) at least one oxygen supply conduit configured to supply oxygen to at least one combustor, and (e) a combustion product gas outlet;   (ii) installing the subsurface heating device within the accommodation cavity; and   (iii) operating the subsurface heating device.