Abstract: A system for assessing one or more temperatures in an opening in a subsurface formation includes an electrical conductor and electrical insulation at least partially surrounding the electrical conductor. The electrical insulation includes magnesium oxide and a ferroelectric material. An electrically conductive sheath at least partially surrounds the electrical insulation. A profile of one or more dielectric properties of the electrical insulation along a length of the electrical insulation is assessed during use to assess a temperature profile with spatial resolution along the length of the electrical insulation.

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 fiber optic cable includes an outer tube, a ceramic fiber sleeve within the outer tube, and an optical fiber having a metal plating within the ceramic fiber sleeve. A method of forming a fiber optic cable includes placing a metal plated optical fiber in a ceramic fiber sleeve, and placing the ceramic fiber sleeve in an outer tube.

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 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 system for assessing one or more temperatures in an opening in a subsurface formation includes an electrical conductor and electrical insulation at least partially surrounding the electrical conductor. The electrical insulation includes magnesium oxide and a ferroelectric material. An electrically conductive sheath at least partially surrounds the electrical insulation. A profile of one or more dielectric properties of the electrical insulation along a length of the electrical insulation is assessed during use to assess a temperature profile with spatial resolution along the length of the electrical insulation.

Abstract: A fitting for coupling an end of a first insulated conductor to an end of a second insulated conductor is described. The fitting includes a first splice housing placed over the end of the first insulated conductor and coupled to the first insulated conductor. The fitting also includes a second splice housing placed over the end of the second insulated conductor and coupled to the second insulated conductor. A sleeve is located over the end of the second insulated conductor and adjacent to the second splice housing. An interior volume of the fitting is substantially filled with electrically insulating material. The interior volume of the fitting is reduced such that the electrically insulating material substantially filling the interior volume is compacted.

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: 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 an end of a first insulated conductor to an end of a second insulated conductor is described. The fitting includes a first splice housing placed over the end of the first insulated conductor and coupled to the first insulated conductor. The fitting also includes a second splice housing placed over the end of the second insulated conductor and coupled to the second insulated conductor. A sleeve is located over the end of the second insulated conductor and adjacent to the second splice housing. An interior volume of the fitting is substantially filled with electrically insulating material. The interior volume of the fitting is reduced such that the electrically insulating material substantially filling the interior volume is compacted.