UNDERGROUND GEOTHERMAL ENERGY EXTRACTION SYSTEM Russian patent published in 2020 - IPC E21B33/127 E21B43/26 F24T10/20 

FIELD: mining.

SUBSTANCE: invention relates to an underground system for extracting geothermal energy for extracting heat from a subterranean formation. System comprises injection well containing first well tubular metal structure, located in the first wellbore to form the first annular space between them, extending from the surface into the subterranean formation and configured to inject the working fluid medium through the first injection opening into the production area defined in the subterranean formation, and thereby obtaining heated working fluid medium; and a first production well comprising a second well tubular metal structure disposed in a second wellbore to form a second annular space therebetween, extending from the surface into said subterranean formation, into said production area, and providing extraction of heated working fluid medium through first production hole. First well tubular metal structure of injection well comprises first annular barrier and a second annular barrier, configured to be opened in the first annular space with abutment to the wall of the first wellbore to isolate the production zone in said production area. Each annular barrier comprises a tubular metal part installed as part of the first well tubular metal structure and having a first opening for release and an outer surface, an expanding metal coupling, surrounding the tubular metal part and having an inner surface facing said tubular metal portion and an outer surface facing the wellbore wall. Each end of expanding metal coupling is connected to tubular metal part, and annular space between inner surface of expanding metal coupling and tubular metal part, wherein expanding metal coupling is opened so that it adjoins the wall of the first wellbore as a result of introduction of fluid medium under pressure into annular space through first opening for unfolding. First pressure hole is located in first well tubular metal structure between first annular barrier and second annular barrier, and the first production zone is located between the first well tubular metal structure and the second well tubular metal structure so that the heated working fluid can be extracted into the second well tubular metal structure through the first production opening. Present invention also relates to a method for underground extraction of geothermal energy for extracting heat from a subterranean formation using an underground system for extracting geothermal energy in accordance with the present invention.

EFFECT: technical result consists in reducing or eliminating seismic activity and reducing formation damage.

19 cl, 10 dwg