Temperature limited heaters having substantially conduit is electrically isolated from the layer

摘要

System for heating a hydrocarbon containing formation comprises a conduit arranged in the hole in the layer. Electrical conductors are provided in the conduit. Electrical conductor forms a heater, the heater since it is electrically isolated from the layer is reduced electrical losses to the layer and electrically connected to the conduit at or near the end portion at the end of the conduit an electrical conductor and conduit is to be are electrically connected in series. While current is flowing through the system, the current is a current flow in conduit flowing in an electric conductor in substantially opposite directions. Since the electromagnetic field generated by the current flow in the electrical conductor the flow of electrons is substantially confined to the inside of the conduit, the outer surface of the conduit is substantially zero potential at 25 ° C.. Conduit is configured to heat during a layer generates heat to flow a current to the system.