Treating hydrocarbon formations using hybrid in situ heat treatment and steam methods

Abstract

A method for treating a tar sands formation includes providing heated fluid to a first section of the hydrocarbon layer while providing heat to a second section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The second section is vertically displaced from the first section. Heat is allowed to transfer from the heaters and heated water to at least a portion of the formation. Fluids are allowed to gravity drain to a third section of the hydrocarbon formation. Fluids are produced from the formation through at least one production well that is located in the third section of the formation.

What is claimed is: 
     
         1 . A method for treating a tar sands formation, comprising:
 providing heated fluid to a first section of the hydrocarbon layer while providing heat to a second section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation, wherein the second section is vertically displaced from the first section;   allowing the heat to transfer from the heaters and heated water to at least a portion of the formation;   allowing fluids to gravity drain to a third section of the hydrocarbon formation; and   producing fluids from the formation through at least one production well that is located in the third section of the formation.   
     
     
         2 . The method of  claim 1 , wherein the heat and heated fluid are provided simultaneously. 
     
     
         3 . The method of  claim 1 , wherein the heated fluid is provided to a highly permeable fracture in the second section. 
     
     
         4 . The method of  claim 1 , wherein the heated fluid comprises water. 
     
     
         5 . The method of  claim 1 , wherein the second section is vertically displaced substantially above the first section. 
     
     
         6 . The method of  claim 1 , wherein the third section is vertically displaced substantially below the second section. 
     
     
         7 . The method of  claim 1 , further comprising heating such that an average pressure in the two sections is within about 20% of each other. 
     
     
         8 . The method of  claim 1 , further comprising heating such that an average viscosity in the two sections is within about 20% of each other. 
     
     
         9 . The method of  claim 1 , wherein the at least one production well allows fluid communication between the bottom section and the second section. 
     
     
         10 . The method of  claim 1 , wherein the heated fluid comprises water and heating the fluid in the first section heats the water sufficiently to form steam. 
     
     
         11 . The method of  claim 1 , wherein a temperature of the heated fluid is greater than 100° C. 
     
     
         12 . The method of  claim 1 , further comprising controlling an average pressure in the formation such that the average pressure remains below a selected pressure. 
     
     
         13 . The method of  claim 12 , wherein the selected pressure is the fracture pressure of the formation. 
     
     
         14 . The method of  claim 12 , wherein the selected pressure is between about 1000 kPa and about 15000 kPa. 
     
     
         15 . The method of  claim 12 , wherein the selected pressure is a pressure below which substantial hydrocarbon coking in the formation occurs when the average temperature in the formation is less than 300° C. 
     
     
         16 . The method of  claim 15 , wherein the selected pressure is between about 100 kPa and about 1000 kPa. 
     
     
         17 . The method of  claim 1 , wherein the plurality of heaters comprise:
 piping positioned in at least two wellbores in the first section;   a fluid circulation system coupled to the piping; and   a heat supply configured to heat a liquid heat transfer fluid circulated by the circulation system through the piping to heat the temperature of the formation to temperatures that allow for mobilization of hydrocarbons in the formation.   
     
     
         18 . The method of  claim 17 , wherein the heat transfer fluid comprises one or more metals. 
     
     
         19 . The method of  claim 17 , wherein the heat transfer fluid comprises one or more molten salts. 
     
     
         20 . The method of  claim 17 , wherein the heat transfer fluid comprises hydrocarbons. 
     
     
         21 . The method of  claim 1 , wherein at least one of the heaters of the plurality of heaters comprises one or more insulated electrical conductors. 
     
     
         22 . The method of  claim 1 , wherein the second section has a permeability of greater than about 1 Darcy. 
     
     
         23 . The method of  claim 1 , wherein the hydrocarbon layer comprise fractures. 
     
     
         24 . The method of  claim 1 , wherein the hydrocarbon layer comprises fractures and wherein a fracture spacing is at least about 20 m. 
     
     
         25 . The method of  claim 1 , wherein the heated fluid is provided in an injection well and wherein the injection well is at least 50 m from the production well. 
     
     
         26 . The method of  claim 1 , wherein the first and second sections comprise hydrocarbon having a viscosity of at least 10 Pa·s. 
     
     
         27 . The method of  claim 1 , wherein the heated fluid is provided to a substantially vertical injection well. 
     
     
         28 . The method of  claim 1 , wherein at least one of the heaters is substantially horizontal or inclined in the first section. 
     
     
         29 . A method for treating a tar sands formation, comprising:
 providing heat to a hydrocarbon layer in the formation from heated fluid injected in a first section of the formation and from a plurality of heaters located in a second section the formation;   producing fluids from the second section of the formation;   turning off or down heaters in the second section; and   producing fluids from the formation from a third section of the formation, wherein the produced fluids comprise visbroken hydrocarbons from the first section.   
     
     
         30 . A method for treating a tar sands formation, comprising:
 providing heated fluid to a first section of the hydrocarbon layer while providing heat to a second section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation;   allowing the heat to transfer from the heaters and heated fluid to at least a portion of the formation;   allowing fluids to gravity drain to a third section of the hydrocarbon formation; and   producing fluids from the formation through at least one production well that is located in at least the second section and third section in the formation, wherein the third section comprises bitumen and the second section comprises upgraded hydrocarbons, and wherein the second section is between the first and third sections.   
     
     
         31 . The method of  claim 30 , wherein the upgraded hydrocarbons have an API gravity of greater than about 25. 
     
     
         32 . The method of  claim 30 , wherein the bitumen is produced from the third section prior to producing the upgraded hydrocarbons from the second section. 
     
     
         33 . The method of  claim 30 , wherein the production well comprises a heater, and wherein heat from the heater upgrades at least a portion of the bitumen. 
     
     
         34 . The method of  claim 30 , wherein the upgraded hydrocarbons are produced from the second section prior to producing the bitumen from the third section. 
     
     
         35 . The method of  claim 30 , further comprising removing water from the formation prior to producing fluids. 
     
     
         36 . A method for treating a formation, comprising:
 providing heat to a first section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation while providing heated fluid to a second section of the hydrocarbon layer, wherein the first portion of the layer comprises an impermeable barrier;   allowing the heat to transfer from the heaters and heated fluid to one or more portions of the formation, wherein at least a portion of the heat is sufficient to create permeability in the barrier;   mobilizing hydrocarbon fluids in the formation; and   producing hydrocarbon fluids from the formation.   
     
     
         37 . The method of  claim 36 , wherein the barrier comprises carbonate. 
     
     
         38 . The method of  claim 36 , wherein the barrier comprises dolomite. 
     
     
         39 . A method for treating a tar sands formation, comprising:
 providing heat to first section of a hydrocarbon containing layer from a heater positioned in a wellbore, wherein the wellbore extends through the first section and a second section of the hydrocarbon containing formation;   producing at least some fluids from the formation;   generating steam in the first section of the hydrocarbon formation;   providing at least a portion of the steam to a portion of the wellbore in the second section;   providing heat to the second section from the steam;   mobilizing hydrocarbons in the second section; and   producing additional fluids from the formation.   
     
     
         40 . The method of  claim 39 , wherein generating steam comprises injecting water into the first section of the hydrocarbon formation. 
     
     
         41 . The method of  claim 39 , wherein generating steam comprises injecting water into the first section of the hydrocarbon formation, wherein the water comprises nonpotable water. 
     
     
         42 . The method of  claim 39 , wherein generating steam comprises injecting water into the first section of the hydrocarbon formation, wherein the water comprises water produced from a hydrocarbon containing formation. 
     
     
         43 . The method of  claim 39 , wherein the heater is removed from the wellbore prior to generating steam. 
     
     
         44 . The method of  claim 39 , wherein the additional fluids comprise bitumen and water.