Abstract:
An insulated electrical conductor (MI cable) may include an inner electrical conductor, an electrical insulator at least partially surrounding the electrical conductor, and an outer electrical conductor at least partially surrounding the electrical insulator. The insulated electrical conductor may have a substantially continuous length of at least about 100 m. The insulated electrical conductor may have an initial breakdown voltage, over a substantially continuous length of at least about 100 m, of at least about 60 volts per mil of the electrical insulator thickness (about 2400 volts per mm of the electrical insulator thickness) at about 1300° F. (about 700° C.) and about 60 Hz. The insulated electrical conductor may be capable of being coiled around a radius of about 100 times a diameter of the insulated electrical conductor. The outer electrical conductor may have a yield strength based on a 0.2% offset of about 100 kpsi.
Abstract:
A method for forming an insulated conductor heater includes placing an insulation layer over at least part of an elongated, cylindrical inner electrical conductor, placing an elongated, cylindrical outer electrical conductor over at least part of the insulation layer to form the insulated conductor heater; and performing one or more cold working/heat treating steps on the insulated conductor heater, reducing the cross-sectional area of the insulated conductor heater by at most about 20% to a final cross-sectional area. The cold working/heat treating steps include cold working the insulated conductor heater to reduce a cross-sectional area of the insulated conductor heater; and heat treating the insulated conductor heater at a temperature of at least about 870° C. The insulation layer includes one or more blocks of insulation.
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 method for forming an insulated conductor heater includes placing an insulation layer over at least part of an elongated, cylindrical inner electrical conductor. An elongated, cylindrical outer electrical conductor is placed over at least part of the insulation layer to form the insulated conductor heater. One or more cold working/heat treating steps are performed on the insulated conductor heater. The cold working/heat treating steps include: cold working the insulated conductor heater to reduce a cross-sectional area of the insulated conductor heater by at least about 30% and heat treating the insulated conductor heater at a temperature of at least about 870° C. The cross-sectional area of the insulated conductor heater is then reduced by an amount ranging between about 5% and about 20% to a final cross-sectional area.
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 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 method for forming an insulated conductor heater with a final cross-sectional area includes reducing a cross-sectional area of an insulated conductor assembly to form an insulated conductor heater with a final cross-sectional area. The insulated conductor assembly may have been previously treated with at least one combination of a cold working step and a heat treating step. Reducing the cross-sectional area of the insulated conductor assembly to form the insulated conductor heater with the final cross-sectional area may include cold working the insulated conductor assembly to further reduce the cross-sectional area of the insulated conductor assembly by at most about 20% of the cross-sectional area of the insulated conductor assembly after the at least one combination of the cold working step and the heat treating step has been completed.
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.