Patent ID: 8572966

Claim:
A heat engine apparatus, the apparatus comprising: (a) a first heat exchanger assembly adapted to be inserted in a borehole such that the first heat exchanger assembly is in fluid communication with a proximal segment of the borehole; (b) a second heat exchanger assembly adapted to be inserted in the borehole such that the second heat exchanger assembly is in fluid communication with a distal segment of the borehole; (c) a circulation barrier adapted to provide a seal between the apparatus and the borehole in order to isolate the proximal segment of the borehole and the distal segment of the borehole from each other; and (d) a heat engine adapted to be inserted in the borehole such that the heat engine is associated with the first heat exchanger assembly and the second heat exchanger assembly, wherein the heat engine is a gas phase closed cycle thermodynamic heat engine.