A direct transfer of heat is done with the dry hot rock or rock of any other kind working with a thermal fluid in a closed circuit. By means of sounding pipes (1) provided with internal fluid conducting pipes (3) or graduated lengths introduced in perforations made in the rock, the thermal exchange zones between two specific pipes are sequentially selected, leaving the remaining zones recovering heat from the geothermal deposit. Changing to other zones of the exploitation by means of the combina...

A method of precipitating metals from a spent geothermal brine containing the same comprises admixing the geothermal brine with a condensate of steam, derived from the brine, in a volume ratio of brine to condensate of 1:2 to 1:10. The invention is particularly applicable to geothermal brine processes for the production of electric power, such as are practiced at the Salton Sea.

An apparatus comprising a geothermal cell and recovery system comprising a heat exchange zone located in the earth and separated from the earth by an impermeable barrier. A housing containing a fluid pump and compressor is submersed in heat exchange zone and a fluid conduit return assembly is positioned in the bottom section of the heat exchange zone. A fluid discharge assembly receives fluid from the pump and is positioned in the top section of the heat exchange zone. An underground heat pipe e...

Method and apparatus for recovering and utilizing thermal energy from subterranean hot rock by means of a self-powered closed system which transfers heat from the hot rock to a relatively cool liquid, e.g. water, flowing in a heat-conducting pipe that extends in a loop descending from the earth's surface to and through the hot rock to a depth, e.g., in the range of 5,000 to 50,000 feet, and connects to the bottom of a heat-insulated riser in which the heated liquid flow ascends to the surface. T...

A helical screw expander for deriving energy from geothermally heated water. The expander includes a pair of helical rotors with helical structures fitted in an expansion chamber. The geothermally heated water is introduced into said chamber through a throttle port located at an end face of the expansion chamber, whereby precipitation which occurs as a consequence of reduction of pressure and temperature is formed in the expansion chamber where the helical rotors dispose of it. The throttle is p...

Apparatus and method for recovering resources from subterranean rock formations, particularly heat energy, and more particularly geothermal energy. A heat-drill, which has means associated therewith for removing some rock from the earth and forming other rock into shafts, drills into the earth and forms two shafts at the same time. Both shafts communicate with each other and with the surface and are used to circulate a drilling mud which passes through the drill body and carries off the rock bei...

A geothermal power generation system having an input well extending from the surface into a hot rock strata and an output well spaced away from the input well extending from the surface into the hot rock strata. The input and output wells extend into the hot rock strata. A horizontal bore connects the two wells together. The bore is located in the hot rock strata and consists of a casing alone or a casing and a backfill between the casing and the hole, in order to prevent the water and steam flo...

As geothermal steam containing contaminants such as boron, arsenic, and mercury is passed through a turbine-condenser system, the contaminants preferentially collect in the initial condensate produced from the steam. Collecting this initially-produced condensate and segregating it from the remainder of the steam being condensed ensures that condensate produced from the remainder of the steam is contaminants-lean, preferably containing the contaminants in concentrations allowing for discharge of ...

As geothermal steam containing contaminants such as boron, arsenic, and mercury is passed through a turbine-condenser system, the contaminants preferentially collect in the initial condensate produced from the steam. Collecting this initially-produced condensate and segregating it from the remainder of the steam being condensed ensures that condensate produced from the remainder of the steam is contaminants-lean, preferably containing the contaminants in concentrations allowing for discharge of ...

A plant for exploiting geothermal energy by circulating water through a geological formation (1) at a substantial depth below the earth surface (2), comprises at least one supply hole (3) leading from the surface (2) down to said formation (1) and at least one return hole (4) for transporting heated water from the formation to the surface. The supply and return holes (3, 4) are interconnected by a plurality of heat absorbing holes (5) which are spaced more than 50 m apart. The heat absorbing hol...