Patent ID: 8265468

Claim:
A fluid heater comprising: an elongated hollow body having a longitudinal passage therethrough, said hollow body connected to a tube adapted for positioning said hollow body to function as a heater at a desired location in a fluid; a plurality of heater elements carried on an exterior surface of said hollow body to contact the fluid; an electrical conductor having a proximal end at an electrical power supply source and having a distal end in an inert space in said hollow body where such electrical conductor is connected to each of the plurality of heater elements; and, a control circuit for sensing and generating a signal responsive to measured conditions adjacent the plurality of heater elements; whereby the control circuit senses conditions adjacent the heater elements and modifies the electrical power supply to said heater elements; and, a pass-through packer connected between an upper portion of the tube on which the fluid heater is connected providing a seal between an interior wall of a well bore casing and through which a valve can be selectively operated to permit fluid to enter from the annular space between the well bore casing and the tubing into the annular space immediately adjacent the fluid heater, whereby upon release of such fluid a flash of steam is generated within the well bore.