An invention for supplying power to a well. In one embodiment power heats a tubing from adjacent the surface to a selected level to prevent the formation of solids. The tubing is heated by passing an electric current therethrough. In one form the tubing is insulated from the wellhead and the casing down to a selected level where an electrical connection is made between the tubing and casing. Current is applied to the tubing at a point below an insulating tubing collar. In another form an insulated conduit is run into the well to a selected depth and connected to the tubing. Electrical power is connected to the tubing and to the insulated conduit.
In another form a sucker rod is electrically insulated from the tubing down to a selected depth. The sucker rod includes a non-conducting section such as a fiberglas sucker rod. A conduit is run through the fiberglas rod and connected to the steel sucker rod therebelow.
Also disclosed is a system for preventing formation of solids in a petroleum well by suspending a loop of wire in a well and passing a controlled amount of power along said loop of wire to heat the wire in which the loop of wire has sections of different resistance to apply different amounts of heat at different depths of the well. Further, there is disclosed an electromagnet for use as a contact between a wire and a well tubing and/or as an anchor.