NOVELTY - The system has a terminal heat exchanger (12) for receiving a liquid stream (19) of heat recovery fluid at a first state through a downflow conduit (11) from a surface pressurizing unit and for returning the heat transfer fluid from the terminal heat exchanger to a surface at a second state by a upflow conduit (13). A turbine (15) receives a vaporized portion (22) of the heat recovery fluid from the upflow conduit for electrical power generation, where an exhaust stream of the fluid from the turbine condenses for condensation. The condensed exhaust stream (16) is delivered to the unit.    USE - Closed loop, hot dry rock heat recovery system for heat recovery from heat recovery locations in a geological formation at a depth of 9,000 to 12,000 meters for production of electrical energy for use in a power plant and an oil industry.    ADVANTAGE - The system maintains degree of vaporization of the heat transfer fluid for separation of the vapor and remaining liquid when the upflow conduit bears a dual-phase fluid in a sloping upward direction. The vapor phase stream can be used directly in a turbine, or separated liquid and vapor phases can indirectly transfer heat to a water or light hydrocarbon liquid, vaporizing as a working fluid for driving a turbine for electrical power production. The system can select the heat recovery fluid so as to minimize cost per unit length of installed conduits and installed heat transfer surface required at a terminal end heat exchanger to obtain objects of economic heat recovery from a geological formation, where energy required for returning condensed and cooled heat recovery fluid from electrical energy production to the terminal end heat exchanger is achieved by the downflow conduit, so that heat capacity and thermal properties of the heat transfer fluid are maintained to calculate the amount of heat removed by operation of each formation conduit and terminal heat exchanger at high degree of precision.    DETAILED DESCRIPTION - The heat recovery fluid is an iso-paraffin hydrocarbon containing components with six to eight carbon atoms.    DESCRIPTION OF DRAWING(S) - The drawing shows a flow diagram illustrating operations of a closed loop, hot dry rock heat recovery system.    Downflow conduit (11)    Terminal heat exchanger (12)    Upflow conduit (13)    Turbine (15)    Condensed exhaust stream (16)    Liquid stream (19)    Vaporized portion (22)