Press-fit coupling joint for joining insulated conductors
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 sleeve placed over the end of the first insulated conductor and the end of the second insulated conductor and a core coupling located inside the sleeve. The core coupling fits around an end of a core of the first insulated conductor and an end of a core of the second insulated conductor. An interior volume of the sleeve is at least partially filled with electrically insulating material. The electrically insulating material is compressed with an end portion of an electrical insulator in the first insulated conductor and an end portion of an electrical insulator in the second insulated conductor when the fitting is coupled to the insulated conductors.
1. A fitting for coupling an end portion of a first insulated conductor to an end portion of a second insulated conductor, comprising:
a sleeve configured to be placed over the end portion of the first insulated conductor and the end portion of the second insulated conductor; and
an electrically conductive core coupling located inside the sleeve, the core coupling being configured to fit around an end portion of an electrically conductive core of the first insulated conductor and an end portion of an electrically conductive core of the second insulated conductor and the core coupling electrically couples the core of the first insulated conductor to the core of the second insulated conductor when the end portions of the insulated conductors are inserted into the fitting;
wherein an interior volume of the sleeve around the core coupling is substantially filled with electrically insulating material, and the electrically insulating material is configured to be compressed between an end portion of an electrical insulator in the first insulated conductor and an end portion of an electrical insulator in the second insulated conductor when the end portions of the insulated conductors are inserted into the fitting.
2. The fitting of claim 1 , wherein the sleeve comprises one or more grooves to inhibit electrically insulating material from moving out of the sleeve.
3. The fitting of claim 1 , wherein at least one of the insulated conductors comprises electrical insulation that tapers at an angle from a jacket of the insulated conductor to a core of the insulated conductor inside the fitting.
4. The fitting of claim 1 , wherein the core coupling comprises a tapered inside diameter with a smaller diameter at the center of the coupling to enhance contact with the cores of the insulated conductors.
5. The fitting of claim 1 , wherein the core coupling comprises one or more grooves on the inside diameter of the coupling to enhance contact with the cores of the insulated conductors.
6. The fitting of claim 1 , wherein the electrically insulating material is configured to be compacted by a pressure of at least 25,000 pounds per square inch.
7. The fitting of claim 1 , wherein the electrically insulating material is configured to be compacted by application of vibration along with reduction of an interior volume of the fitting.
8. The fitting of claim 1 , wherein the fitting is configured to be centered between the end portions of the insulated conductors.
9. The fitting of claim 1 , wherein an interior volume of the fitting is configured to be reduced by applying hydraulic pressure.
10. The fitting of claim 1 , wherein an interior volume of the fitting is configured to be reduced using a swaging method.
11. The fitting of claim 1 , wherein the electrically insulating material comprises material substantially similar to electrical insulation in at least one of the two insulated conductors.
12. The fitting of claim 1 , wherein at least one of the insulated conductors is configured to be used to heat a subsurface formation.
13. The fitting of claim 1 , wherein the core coupling is configured to tightly fit around the end portion of the core of the first insulated conductor and the end portion of the core of the second insulated conductor.
14. The fitting of claim 1 , wherein the interior volume of the sleeve around the core coupling is substantially filled with electrically insulating material such that there are substantially no macroscopic voids in the interior volume.
15. The fitting of claim 1 , wherein the first insulated conductor and the second insulated conductor each comprise the electrically conductive core surrounded by electrical insulation with an electrically conductive jacket surrounding the electrical insulation.
16. The fitting of claim 1 , wherein the electrically insulating material comprises a mixture of magnesium oxide and/or boron nitride.
17. The fitting of claim 1 , wherein the electrically insulating material is configured to be compressed between the end portion of an electrical insulator in the first insulated conductor and the end portion of an electrical insulator in the second insulated conductor when the end portions of the insulated conductors are moved towards the center of the fitting.
18. The fitting of claim 1 , wherein the first insulated conductor and the second insulated conductor each comprise an electrically conductive jacket, and wherein the sleeve is configured to be welded or brazed to the jackets of the insulated conductors.
19. The fitting of claim 1 , wherein the core coupling is positioned at or near the center of the fitting.