Coupling a conduit to a conductor inside the conduit so they have opposite current flow, giving zero potential at the conduit outer surface

摘要

Disclosed is a method of heating a subsurface hydrocarbon containing formation. The method comprise the steps of: providing a system with a ferromagnetic conduit (218) and an electrical conductor (226) within the conduit; applying current to the system; and allowing the conduit to generate heat. The conductor is coupled to the conduit in series so that current flows in the conductor in an opposite direction to current flow in the conduit during the application of current to the system. The current is applied so the flow of electrons is confined to the inside of the conduit by the filed generated from flow in the conductor, making the outside surface of the conduit have zero potential at 25 degree C.