Systems, methods, and processes for use in treating subsurface formations

摘要

A system for heating a hydrocarbon containing formation comprises a conduit located in an opening in the formation and an electrical conductor positioned inside the conduit, and electrically coupled to the conduit at or near an end portion of the conduit so that the electrical conductor and the conduit are electrically coupled in series and electrical current flows in the electrical conductor in a substantially opposite direction to electrical current flow in the conduit during application of electrical current to the system. The conduit comprises ferromagnetic material. During application of electrical current to the system, the flow of electrons is substantially confined to the inside of the conduit by the electromagnetic field generated from electrical current flow in the electrical conductor so that the outside surface of the conduit is at or near substantially zero potential at 25 °C. The conduit is configured to generate a majority of the heat output of the system to heat the formation during application of electrical current to the system and to allow a fluid to flow through the conduit to recover heat from the system; and the opening has a first end portion at a first location on the surface of the formation and a second end portion at a second location on the surface of the formation.