TEMPERATURE LIMITED HEATERS FOR HEATING SUBSURFACE FORMATIONS OR WELLBORES

摘要

A method described includes applying an alternating electrical current to one or more electrical conductors (112). The electrical conductors may be located in a subsurface or a subsurface wellbore. The electrical conductors may provide an electrically resistive heat output upon application of the alternating electrical current. At least one of the electrical conductors may include an electrically resistive ferromagnetic material. The electrically resistive ferromagnetic material may provide a reduced amount of heat above or near a selected temperature. Heat may be allowed to transfer from the electrically resistive ferromagnetic material to a part of the subsurface or the subsurface wellbore.