Patent ID: 8201409

Claim:
A closed loop, hot dry rock heat recovery system for heat recovery from one or more heat recovery locations in a geological formation at a depth of 9,000 to 12,000 meters and having a temperature greater than or equal to 250 degrees Centigrade comprising: (a) a hydrocarbon heat recovery fluid, consisting of water or hydrocarbon components having from four to eight carbon atoms, vaporized at a first state between 110 to 160 degrees Centigrade and between 30 to 35 bars deliverable to said geological location in a liquid state by way of one or more formation conduits; (b) one or more heat recovery units, each comprising a formation conduit extending from a surface location to a terminal heat exchanger at a heat recovery location; (c) each of the formation conduits comprising an axial downflow conduit and an upflow conduit annular to the downflow conduit; (d) each terminal heat exchanger receiving a liquid stream of the heat recovery fluid at a second state through its downflow conduit from a surface pressurizing means and returning the heat transfer fluid from the terminal heat exchanger to the surface at the first state by the upflow conduit; (e) a turbine receiving a vaporized portion of the heat recovery fluid from the upflow conduits for electrical power generation, and (f) condensing an exhaust stream of the heat recovery fluid from said turbine for condensation and delivery to the pressurizing means.