GB1496075A - Extraction of subterranean geothermal energy - Google Patents

Abstract

1496075 Utilizing geothermal energy ERDA ENERGY SYSTEMS Inc and A T VAN HUISEN 13 May 1975 20156/75 Heading F4U [Also in Division E1] An installation for transferring geothermal energy from a subterranean zone 18 to the surface comprises a reservoir 14 connected to a group of downwardly diverging wells 10, which have their lower ends located in the zone 18 and which conduct hot fluid to the reservoir 14. As shown, each well has a servo-controlled valve 26 connected to a time sequencer controller 28, and the reservoir 14 is connected to a power plant 48 through a separator 45. In a second embodiment, Fig. 3 (not shown), water from the surface is injected through further wells into the zone 18, which may be a dry, porous geothermal zone, to form a body of pressurized, heated hydrothermal fluid which passes up the wells 10 to the reservoir. In a modification, Fig. 4 (not shown), the water injection pipes are located within the wells 10. In a further embodiment, Fig. 5, the end 16 of each well 16 is closed by a plug 74 to form a heat exchanger 76 to which water from the surface is passed through a pipe 78 within the well 10, heated vapour then passing from the heat exchanger 76 to the reservoir 14 through the annular space 82 within the well 10. The well 10 may comprise a metal casing cased within a layer of concrete 81.