Abstract: Methods for assessing a temperature in an opening in a subsurface formation are described herein. A method may include assessing one or more dielectric properties along a length of an insulated conductor located in the opening and assessing one or more temperatures along the length of the insulated conductor based on the one or more assessed dielectric properties.

Abstract: A fitting for coupling ends of cores of three insulated conductors includes an end termination placed over end portions of the three insulated conductors. The end termination includes three separate openings that pass through the end termination longitudinally. Each of the insulated conductors passes through one of the openings with end portions of the insulated conductors protruding from one side of the end termination. Exposed cores of the end portions of the insulated conductors protrude from the end termination. A cylinder is coupled to the side of the end termination from which the end portions of the insulated conductors protrude. An electrical bus is coupled to the exposed portion of the cores. Electrically insulating material fills the cylinder such that the cores are substantially enclosed in the electrically insulating material. An end cap is coupled to the cylinder to seal off the interior of the cylinder.

Abstract: A system for treating a subsurface hydrocarbon containing formation includes one or more shafts. At least two substantially horizontal or inclined tunnels extend from one or more of the shafts. A plurality of heat sources are located in at least one heat source wellbore extending between at least two of the substantially horizontal tunnels. Electrical connections for the heat sources are located in at least one of the substantially horizontal tunnels.

Abstract: A method for coupling a lead-in cable to an insulated conductor includes exposing an end portion of a core of the insulated conductor by removing at least a portion of a jacket and an electrical insulator surrounding the end portion of the core. A recess is formed in the electrical insulator at the end of the electrical insulator surrounding the end portion of the core. An end portion of a conductor of the lead-in cable is exposed by removing at least a portion of a sheath and insulation surrounding the end portion of the conductor. The end portion of the core is coupled to the end portion of the conductor. The end portion of the core and the end portion of the conductor are placed in a body filled with electrically insulating material.

Abstract: A system for treating a subsurface hydrocarbon containing formation includes one or more shafts. A first substantially horizontal or inclined tunnel extends from one or more of the shafts. A second substantially horizontal or inclined tunnel extends from one or more of the shafts. Two or more heat source wellbores extend from the first tunnel to the second tunnel. The heat source wellbores are configured to allow electrical current to flow between the heat source wellbores.

Abstract: A system for treating a subsurface hydrocarbon containing formation includes one or more tunnels having an average diameter of at least 1 m. At least one tunnel is connected to the surface. Two or more wellbores extend from at least one of the tunnels into at least a portion of the subsurface hydrocarbon containing formation. At least two of the wellbores contain elongated heat sources configured to heat at least a portion of the subsurface hydrocarbon containing formation such that at least some hydrocarbons are mobilized.

Abstract: Methods for assessing a temperature in an opening in a subsurface formation are described herein. A method may include assessing one or more dielectric properties along a length of an insulated conductor located in the opening and assessing one or more temperatures along the length of the insulated conductor based on the one or more assessed dielectric properties.

Abstract: A heater includes a conduit and three insulated electrical conductors located in the conduit. At least one of the three insulated conductors includes an electrical conductor at least partially surrounded by an insulation layer and an electrically conductive sheath at least partially surrounding the insulation layer. One or more layers of electrical insulation at least partially surround the three insulated electrical conductors in the conduit. The one or more layers of electrical insulation electrically isolate the insulated electrical conductors from the conduit.

Abstract: A system for treating a subsurface hydrocarbon containing formation includes one or more substantially horizontal or inclined tunnels extending from at least one shaft. One or more heater sources are located in one or more heater wellbores coupled to at least one of the substantially horizontal or inclined tunnels.

Abstract: A system for treating a subsurface hydrocarbon containing formation includes one or more substantially horizontal or inclined tunnels extending from one or more shafts. A production system is located in at least one of the tunnels. The production system is configured to produce fluids from the formation that collect in the tunnel.

Abstract: A system for treating a subsurface hydrocarbon containing formation includes one or more shafts. At least two substantially horizontal or inclined tunnels extend from one or more of the shafts. A plurality of heat sources are located in at least one heat source wellbore extending between at least two of the substantially horizontal tunnels. Electrical connections for the heat sources are located in at least one of the substantially horizontal tunnels.

Abstract: A system for treating a subsurface hydrocarbon containing formation includes one or more shafts. A first substantially horizontal or inclined tunnel extends from one or more of the shafts. A second substantially horizontal or inclined tunnel extends from one or more of the shafts. Two or more heat source wellbores extend from the first tunnel to the second tunnel. The heat source wellbores are configured to allow electrical current to flow between the heat source wellbores.

Abstract: A system for treating a subsurface hydrocarbon containing formation includes one or more shafts. A first substantially horizontal or inclined tunnel extends from one or more of the shafts. A second substantially horizontal or inclined tunnel extends from one or more of the shafts. Two or more heat source wellbores extend from the first tunnel to the second tunnel. The heat source wellbores are configured to allow heated fluid to flow through the wellbores from the first tunnel to the second tunnel.

Abstract: A system for treating a subsurface hydrocarbon containing formation includes one or more tunnels having an average diameter of at least 1 m. At least one tunnel is connected to the surface. Two or more wellbores extend from at least one of the tunnels into at least a portion of the subsurface hydrocarbon containing formation. At least two of the wellbores contain elongated heat sources configured to heat at least a portion of the subsurface hydrocarbon containing formation such that at least some hydrocarbons are mobilized.

Abstract: A system for treating a subsurface hydrocarbon containing formation includes one or more substantially horizontal or inclined tunnels extending from at least one shaft. One or more heater sources are located in one or more heater wellbores coupled to at least one of the substantially horizontal or inclined tunnels.

Abstract: A system for treating a subsurface hydrocarbon containing formation includes one or more substantially horizontal or inclined tunnels extending from one or more shafts. A production system is located in at least one of the tunnels. The production system is configured to produce fluids from the formation that collect in the tunnel.