초록 ▼

A heater cable is strapped alongside tubing in a well to heat the production fluids flowing through the tubing. The heater cable has three copper conductors surrounded by a thin electrical insulation layer. An extrusion of lead forms a protective layer over the insulation layers. The lead sheaths ha

A heater cable is strapped alongside tubing in a well to heat the production fluids flowing through the tubing. The heater cable has three copper conductors surrounded by a thin electrical insulation layer. An extrusion of lead forms a protective layer over the insulation layers. The lead sheaths have flat sides which abut each other to increase heat transfer. A metal armor is wrapped around the lead sheaths of the three conductors in metal-to-metal contact. Three phase power is supplied to the conductors, causing heat to be generated which transmits through the lead sheaths and armor to the tubing.

대표청구항 ▼

[ We claim:] [1.] An electrical heater cable for heating a string of tubing located within a well, comprising:a plurality of heater wires, each heater wire having a conductor of metal having high electrical conductivity, an electrical insulation layer surrounding the conductor, and a metal sheath su

[ We claim:] [1.] An electrical heater cable for heating a string of tubing located within a well, comprising:a plurality of heater wires, each heater wire having a conductor of metal having high electrical conductivity, an electrical insulation layer surrounding the conductor, and a metal sheath surrounding the insulation layer, wherein the insulation layer comprises a polymer extrusion and has a thickness which is substantially no greater than 0.025 inch;the heater wires being located adjacent to each other with their metal sheaths contacting each other, defining a subassembly;an outer armor of metal tape wrapped around the subassembly with the sheaths in metal-to-metal contact with the outer armor; andwherein a lower end of each of the conductors may be connected together and current supplied to an upper end of the conductors to generate heat which transmits through the metal sheaths and the armor to the tubing.