Abstract: A system for assessing one or more temperatures along an insulated conductor in an opening in a subsurface formation includes an insulated conductor with a length comprising at least two sections of insulation with different capacitances. The sections with the different capacitances include different takeoff temperatures for at least one dielectric property of the insulation.

Abstract: A method for installing two or more heaters in a subsurface formation includes providing a spool having a substantially helical configuration of two or more heaters that have been spooled on the spool. The helical configuration of heaters is unspooled from the spool and the helical configuration of heaters is installed into an opening in a subsurface formation.

Abstract: An insulated conductor heater may include an electrical conductor that produces heat when an electrical current is provided to the electrical conductor. An electrical insulator at least partially surrounds the electrical conductor. The electrical insulator comprises a resistivity that remains substantially constant, or increases, over time when the electrical conductor produces heat. An outer electrical conductor at least partially surrounds the electrical insulator.

Abstract: An insulated conductor heater may include an electrical conductor that produces heat when an electrical current is provided to the electrical conductor. An electrical insulator at least partially surrounds the electrical conductor. The electrical insulator comprises a resistivity that remains substantially constant, or increases, over time when the electrical conductor produces heat. An outer electrical conductor at least partially surrounds the electrical insulator.

Abstract: An insulated conductor heater may include an electrical conductor that produces heat when an electrical current is provided to the electrical conductor. An electrical insulator at least partially surrounds the electrical conductor. The electrical insulator comprises a resistivity that remains substantially constant, or increases, over time when the electrical conductor produces heat. An outer electrical conductor at least partially surrounds the electrical insulator.

Abstract: A system used to heat a subsurface formation includes an elongated heater at least partially located in an opening in a hydrocarbon containing layer of the formation. The opening extends from the surface of the formation through an overburden section of the formation and into the hydrocarbon containing layer of the formation. The elongated heater includes an electrical conductor, an insulation layer at least partially surrounding the electrical conductor, and an electrically conductive sheath at least partially surrounding the insulation layer. The elongated heater tapers from a larger thickness at a first end of the heater to a smaller thickness at a second end of the heater. The first end is at or near the junction between the overburden section and the hydrocarbon containing layer and the second end is further into the hydrocarbon containing layer.

Abstract: A system for heating a subsurface formation includes a heater wellbore located in a subsurface formation. A single conducting heater element includes a heated portion located in a part of the subsurface formation configured to be heated and a lead-in portion located in an overburden of the subsurface formation. The heated part is located below the overburden. A heater casing is located substantially in an overburden portion of the heater wellbore. The heater casing includes an electrically non-conducting portion and an electrically conducting portion. The non-conducting portion begins at the surface of the formation. The conducting portion is located between the non-conducting portion and the heated portion of the heater. The non-conducting portion extends to a depth that is at least about 30 m above the heated portion of the heater.

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 down-hole tool provided with a transmitter system for inducing a transient electromagnetic field in an earth formation has an induction coil with a number of windings to generate essentially a magnetic dipole field. The number of windings is divided into two or more groups of windings arranged to cooperatively generate the essentially magnetic dipole field when energized. Switching means are arranged to essentially simultaneously terminate the energizing of the groups of windings. The groups of windings are electrically isolated from each other or connected in parallel to each other, at least when the energizing is terminated. A transient electromagnetic field may thus be induced in an earth formation by essentially simultaneously terminating energizing each group of windings by operating the switching means. A transient electromagnetic response signal may be recorded, and used in a method of producing a mineral hydrocarbon fluid.

Abstract: A method for heating a subsurface formation includes applying heat from a plurality of heaters to at least a portion of the subsurface formation. A portion of one or more of the heaters are allowed to move relative to the heaters respective wellhead using sliding seals to accommodate thermal expansion of the heaters.

Abstract: A system used to heat a subsurface formation includes an elongated heater at least partially located in an opening in a hydrocarbon containing layer of the formation. The opening extends from the surface of the formation through an overburden section of the formation and into the hydrocarbon containing layer of the formation. The elongated heater includes an electrical conductor, an insulation layer at least partially surrounding the electrical conductor, and an electrically conductive sheath at least partially surrounding the insulation layer. The elongated heater tapers from a larger thickness at a first end of the heater to a smaller thickness at a second end of the heater. The first end is at or near the junction between the overburden section and the hydrocarbon containing layer and the second end is further into the hydrocarbon containing layer.

Abstract: A method for installing two or more heaters in a subsurface formation includes providing a spool having a substantially helical configuration of two or more heaters that have been spooled on the spool. The helical configuration of heaters is unspooled from the spool and the helical configuration of heaters is installed into an opening in a subsurface formation.

Abstract: An insulated conductor heater may include an electrical conductor that produces heat when an electrical current is provided to the electrical conductor. An electrical insulator at least partially surrounds the electrical conductor. The electrical insulator comprises a resistivity that remains substantially constant, or increases, over time when the electrical conductor produces heat. An outer electrical conductor at least partially surrounds the electrical insulator.

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 down-hole tool provided with a transmitter system for inducing a transient electromagnetic field in an earth formation has an induction coil with a number of windings to generate essentially a magnetic dipole field. The number of windings is divided into two or more groups of windings arranged to cooperatively generate the essentially magnetic dipole field when energized. Switching means are arranged to essentially simultaneously terminate the energizing of the groups of windings. The groups of windings are electrically isolated from each other or connected in parallel to each other, at least when the energizing is terminated. A transient electromagnetic field may thus be induced in an earth formation by essentially simultaneously terminating energizing each group of windings by operating the switching means. A transient electromagnetic response signal may be recorded, and used in a method of producing a mineral hydrocarbon fluid.

Abstract: A system for heating a subsurface formation is described. The system includes a first elongated heater in a first opening in the formation. The first elongated heater includes an exposed metal section in a portion of the first opening. The portion is below a layer of the formation to be heated. The exposed metal section is exposed to the formation. A second elongated heater is in a second opening in the formation. The second opening connects to the first opening at or near the portion of the first opening below the layer to be heated. At least a portion of an exposed metal section of the second elongated heater is electrically coupled to at least a portion of the exposed metal section of the first elongated heater in the portion of the first opening below the layer to be heated.

Abstract: A system for heating a subsurface formation includes a heater wellbore located in a subsurface formation. A single conducting heater element includes a heated portion located in a part of the subsurface formation configured to be heated and a lead-in portion located in an overburden of the subsurface formation. The heated part is located below the overburden. A heater casing is located substantially in an overburden portion of the heater wellbore. The heater casing includes an electrically non-conducting portion and an electrically conducting portion. The non-conducting portion begins at the surface of the formation. The conducting portion is located between the non-conducting portion and the heated portion of the heater. The non-conducting portion extends to a depth that is at least about 30 m above the heated portion of the heater.

Abstract: A method for heating a subsurface formation includes applying heat from a plurality of heaters to at least a portion of the subsurface formation. A portion of one or more of the heaters are allowed to move relative to the heaters respective wellhead using sliding seals to accommodate thermal expansion of the heaters.

Abstract: An in situ process for treating a hydrocarbon containing formation is provided. The process may include providing heat from one or more heaters to at least a portion of the formation. The heat may be allowed to transfer from the one or more heaters to a part of the formation such that heat from the one or more heat sources pyrolyzes at least some hydrocarbons within the part. Hydrocarbons may be produced from the formation.

Abstract: An apparatus and method for operating an electrically powered device in a packer using the piping structure of the well as an electrical conductor for providing power and/or communications. The electrically powered device may comprise an electrically controllable valve, a communications and control module, a modem, a sensor, and/or a tracer injection module.