Abstract: Systems for coupling ends of elongated heaters and methods of using such systems to treat a subsurface formation are described herein. A system may include two elongated heaters with an end portion of one heater abutted or near to an end portion of the other heater and a core coupling material. The core coupling material may extend between the two elongated heaters. The elongated heaters may include cores and at least one conductor substantially concentrically surrounds the cores. The cores may have a lower melting point than the conductors. At least one end portion of the conductor may have a beveled edge. The gap formed by the beveled edge may be filled with a coupling material for coupling the one or more conductors. One end portion of at least one core may have a recessed opening and the core coupling material may be partially inside the recessed opening.

Abstract: A heater system may include an alternating current supply and an electrical conductor. An alternating current may be applied to one or more electrical conductors at a voltage above about 200 volts. The electrical conductors may be located in a formation. The electrical conductors may provide an electrically resistive heat output upon application of the alternating electrical current. At least one of the electrical conductors may include an electrically resistive ferromagnetic material. An electrical conductor may provide a reduced amount of heat above or near a selected temperature. Heat may be allowed to transfer from an electrical conductor to a part of the formation.

Abstract: Systems and methods are described for heating a subsurface formation. Alternating electrical current may be applied to one or more electrical conductors. The electrical conductors may be located in a subsurface formation. The electrical conductors may provide an electrically resistive heat output upon application of the alternating electrical current. At least one of the electrical conductors may include an electrically resistive ferromagnetic material. The electrical conductor may provide a reduced amount of heat above or near a selected temperature. Heat may be allowed to transfer from the electrical conductor to a part of the subsurface formation.

Abstract: Systems for coupling ends of elongated heaters and methods of using such systems to treat a subsurface formation are described herein. A system may include two elongated heaters with an end portion of one heater abutted or near to an end portion of the other heater and a core coupling material. The core coupling material may extend between the two elongated heaters. The elongated heaters may include cores and at least one conductor substantially concentrically surrounds the cores. The cores may have a lower melting point than the conductors. At least one end portion of the conductor may have a beveled edge. The gap formed by the beveled edge may be filled with a coupling material for coupling the one or more conductors. One end portion of at least one core may have a recessed opening and the core coupling material may be partially inside the recessed opening.

Abstract: An oil shale formation may be treated using an in situ thermal process. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. Heat input into the formation may be controlled to raise the temperature of portion at a selected rate during pyrolysis of hydrocarbons within the formation. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. The mixture may be separated into condensable hydrocarbons and non-condensable hydrocarbons. The condensable hydrocarbons removed from the formation may be a high quality oil that has a relatively low olefin content and a relatively high API gravity.

Abstract: Systems for coupling end portions of two elongated heater portions and methods of using such systems to treat a subsurface formation are described herein. A system may include a holding system configured to hold end portions of the two elongated heater portions so that the end portions are abutted together or located near each other; a shield for enclosing the end portions, and one or more inert gas inlets configured to provide at least one inert gas to flush the system with inert gas during welding of the end portions. The shield may be configured to inhibit oxidation during welding that joins the end portions together. The shield may include a hinged door that, when closed, is configured to at least partially isolate the interior of the shield from the atmosphere. The hinged door, when open, is configured to allow access to the interior of the shield.

Abstract: An oil shale formation may be treated using an in situ thermal process. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. Heat input into the formation may be controlled to raise the temperature of portion at a selected rate during pyrolysis of hydrocarbons within the formation. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. The mixture may be separated into condensable hydrocarbons and non-condensable hydrocarbons. The condensable hydrocarbons removed from the formation may be a high quality oil that has a relatively low olefin content and a relatively high API gravity.

Abstract: In an embodiment, a system may be used to heat a hydrocarbon containing formation. The system may include a heater placed in an opening in the formation. The system may allow heat to transfer from the heater to a part of the formation. The transferred heat may pyrolyze at least some hydrocarbons in the formation. The heater may be removable from the opening in the formation and redeployable in at least one alternative opening in the formation.

Abstract: An oil shale formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. Heat may be supplied to the formation by reacting an oxidant with hydrocarbons adjacent to wellbores to generate heat. Generated heat may be transferred to the portion substantially by conduction to pyrolyze at least a portion of hydrocarbon material within the portion.

Abstract: An oil shale formation may be treated using an in situ thermal process. Hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation from one or more heat sources to raise a temperature of a portion of the formation to a desired temperature. Some of the heat sources may be conductors placed within conduits. The conductors may be resistively heated so that the conductors radiantly heat the conduits. The generated heat may transfer to the formation.

Abstract: A hydrocarbon containing formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. Heat may be supplied to the formation by reacting an oxidant with hydrocarbons adjacent to heater wellbores to generate heat. Generated heat may be transferred to the portion substantially by conduction to pyrolyze at least a portion of hydrocarbon material within the portion.

Abstract: In an embodiment, a system may be used to heat a hydrocarbon containing formation. The system may include a heater placed in an opening in the formation. The system may allow heat to transfer from the heater to a part of the formation. The transferred heat may pyrolyze at least some hydrocarbons in the formation. The heater may be removable from the opening in the formation and redeployable in at least one alternative opening in the formation.

Abstract: An oil shale formation may be treated using an in situ thermal process. Hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation from one or more heat sources to raise a temperature of a portion of the formation to a desired temperature. Some of the heat sources may be conductors placed within conduits. The conductors may be resistively heated so that the conductors radiantly heat the conduits. The generated heat may transfer to the formation.

Abstract: A hydrocarbon containing formation may be treated using an in situ thermal process. Hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation from heat sources to raise a temperature of a portion of the formation to a desired temperature. Some of the heat sources may be conductors placed within conduits. The conductors may be resistively heated so that the conductors radiantly heat the conduits. The conduits may transfer heat to the formation.

Abstract: Systems and methods are described for heating a subsurface formation. Alternating electrical current may be applied to one or more electrical conductors. The electrical conductors may be located in a subsurface formation. The electrical conductors may provide an electrically resistive heat output upon application of the alternating electrical current. At least one of the electrical conductors may include an electrically resistive ferromagnetic material. The electrical conductor may provide a reduced amount of heat above or near a selected temperature. Heat may be allowed to transfer from the electrical conductor to a part of the subsurface formation.

Abstract: A coal formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. Heat may be supplied to the formation by reacting an oxidant with hydrocarbons adjacent to heater wellbores to generate heat. Generated heat may be transferred to the portion substantially by conduction to pyrolyze at least a portion of the hydrocarbons within the portion.

Abstract: An oil shale formation may be treated using an in situ thermal process. Heat may be applied to the formation from one or more heat sources to raise a temperature of a portion of the formation to a desired temperature. Hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Some or all of the sources may be removable from the formation during and/or after use.

Abstract: An oil shale formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. A reducing environment may be maintained within a portion of the formation.

Abstract: A coal formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. Heat may be supplied to the formation by reacting an oxidant with hydrocarbons adjacent to heater wellbores to generate heat. Generated heat may be transferred to the portion substantially by conduction to pyrolyze at least a portion of the hydrocarbons within the portion.

Abstract: A hydrocarbon containing formation may be treated using an in situ thermal process. A mixture of hydrocarbons, H2, and/or other formation fluids may be produced from the formation. Heat may be applied to the formation to raise a temperature of a portion of the formation to a pyrolysis temperature. Heat may be supplied to the formation by reacting an oxidant with hydrocarbons adjacent to heater wellbores to generate heat. Generated heat may be transferred to the portion substantially by conduction to pyrolyze at least a portion of hydrocarbon material within the portion.