Abstract: A skin effect heat tracing system including a heat tube and a heater cable with a core conductor and an electrical insulation layer surrounding the core conductor. The heater cable is sized to lie within the heat tube so that a gas-filled space is defined between an outer surface of the electrical insulation layer and an inner surface of the heat tube. During operation of the skin effect heat tracing system, the gas-filled space may be pressurized, by a gas source, above an external pressure outside the heat tube.

Abstract: A skin effect heating cable used to form a heat tracing circuit for heating a production pipe carrying process media. The skin effect heating cable includes a heating tube which includes a conductor, an insulating layer wrapped around the conductor and a dielectric fluid disposed between the insulating layer and the inner wall of the heating tube. The dielectric fluid increases the heat transfer characteristic from the conductor to the heating tube while providing mechanical load relief to the cable.

Abstract: Embodiments of the invention provide systems and methods for heating a wellbore environment. One or more electric heating cables are attached to an elongated support member, such as a wire rope, so that the support member receives and relieves the heating cables of a mechanical load. The attachment may be with two-piece clamps spaced at regular intervals along the support member. The heating cables and support member may be disposed in coiled tubing within the wellbore. The coiled tubing can be pressure-sealed and filled with a dielectric fluid. The heating cables and support member can be attached to a cable hang-off having a plurality of wedge-shaped slips that cooperate with a bowl to form a pinching member that grips the support member and suspends the support member and heating cables in the wellbore. The methods include methods for manufacturing and installing the heating apparatus.

Abstract: A skin-effect heater cable has inorganic ceramic insulation. The heater cable has at lease one core conductor wire within a sheath. Electricity is directed through the core conductor in an outward path and returns along a surface “skin” of the sheath in a return path for generating heat.

Abstract: Embodiments of the invention provide systems and methods for heating a wellbore environment. One or more electric heating cables are attached to an elongated support member, such as a wire rope, so that the support member receives and relieves the heating cables of a mechanical load. The attachment may be with two-piece clamps spaced at regular intervals along the support member. The heating cables and support member may be disposed in coiled tubing within the wellbore. The coiled tubing can be pressure-sealed and filled with a dielectric fluid. The heating cables and support member can be attached to a cable hang-off having a plurality of wedge-shaped slips that cooperate with a bowl to form a pinching member that grips the support member and suspends the support member and heating cables in the wellbore. The methods include methods for manufacturing and installing the heating apparatus.

Abstract: A skin-effect heater cable has inorganic ceramic insulation. The heater cable has at least one core conductor wire within a sheath. Electricity is directed through the core conductor in an outward path and returns along a surface “skin” of the sheath in a return path for generating heat.

Abstract: A skin effect heating cable used to form a heat tracing circuit for heating a production pipe carrying process media. The skin effect heating cable includes a heating tube which includes a conductor, an insulating layer wrapped around the conductor and a dielectric fluid disposed between the insulating layer and the inner wall of the heating tube. The dielectric fluid increases the heat transfer characteristic from the conductor to the heating tube while providing mechanical load relief to the cable.

Abstract: An improved power cable for a heating system that utilizes the skin effect of alternating current, and a method and apparatus for joining lengths of the improved cable. In one embodiment, the cable includes a stranded copper conductor (20) surrounded by a semiconductive layer (22) formed by carbonized tetrafluoroethylene (TFE) tape which is surrounded by a primary insulation layer (24) formed by pressure extruded, perfluoroalkoxy resin (PFA), the thickness of which is determined by an equation that considers the eccentric positioning of the power cable in a heat tube (14). In a second embodiment, the cable comprises a central conductor (30) surrounded by a semiconductive layer (32), followed by a primary insulation layer (34) formed by pressure extruded PFA. A shield layer (36) formed by a layer of semiconductor material (38) and several helically wrapped drain wires (40) surrounds the primary insulation layer. A protective PFA jacket (42) is pressure extruded over the shield layer.

Abstract: An improved power cable for a heating system that utilizes the skin effect of alternating current, and a method and apparatus for joining lengths of the improved cable. In one embodiment, the cable includes a stranded copper conductor (20) surrounded by a semiconductive layer (22) formed by carbonized tetrafluoroethylene (TFE) tape which is surrounded by a primary insulation layer (24) formed by pressure extruded, perfluoroalkoxy resin (PFA), the thickness of which is determined by an equation that considers the eccentric positioning the power cable in a heat tube (14). In a second embodiment, the cable comprises a central conductor (30) surrounded by a semiconductive layer (32), followed by a primary insulation layer (34) formed by pressure extruded PFA. A shield layer (36) formed by a layer of semiconductor material (38) and several helically wrapped drain wires (40) surrounds the primary insulation layer. A protective PFA jacket (42) is pressure extruded over the shield layer.

Abstract: An improved power cable for a heating system that utilizes the skin effect of alternating current, and a method and apparatus for joining lengths of the improved cable. Lengths of the improved cable are joined by first removing predetermined portions of the insulating and semiconductor layers from a terminal end (50) and a feed end (52) of respective cable lengths. The exposed conductors (30') are mechanically joined and covered by a spirally wrapped carbonized TFE tape (60). An insulating layer (62) is formed over the junction by spirally wrapping uncured, nonadhesive tetrafluoroethylene tape with a 50% overlap and then heat fusing the layer. Shield extensions (66), (68) are formed by spirally wrapped, carbonized TFE tape that extend into noncommunicating, isolated overlapped relationship from the respective shield layers (38) of each cable end. The entire splice is covered with a layer of insulation (73) formed by uncured, nonadhesive TFE tape which is subsequently heat fused.