The present invention relates to a geothermal heat exchange system and a method of constructing a geothermal heat exchange system, and more specifically, to a geothermal heat exchange system which is to be installed in a borehole in the ground, the borehole being divided into a ground surface section and a shallow geothermal source section, the shallow geothermal source section of the borehole, which is hardly influenced by the atmospheric or ground surface temperatures, is filled with conventional heat conductive grouting material with high thermal conductivity, and the ground surface section of the borehole is filled with thermal insulation grouting material or thermal insulation cartridges to prevent the heat transferring medium in the geothermal heat exchange system, which has the geothermal heat obtained from the shallow geothermal source, from losing heat in the winter time or obtaining heat in the summer time when it passes through the ground surface section which is much influenced by the atmospheric or ground surface temperatures, thereby a geothermal heat exchange system that can increase the acquisition rate of geothermal energy, and a method of constructing the geothermal heat exchange system.

Disclosed are various approaches for using controlled fractures in geothermal systems. In some examples, a method includes drilling at least one injection well bore. The method can also include cutting at least a first slot at an angle to the injection well bore, where the first slot has a first end connected to the injection well bore and a distal end. The method can include cutting at least a second slot at an angle to the injection well bore, where the second slot has a first end connected to the distal end of the first slot and a distal end. The method can also include drilling at least one production well bore, where the production well bore is connected to the distal end of the second slot.

A geothermal power generation system comprising a geothermal water lift and a geothermal power generator is shown. The geothermal water lift comprises a well bore extending from the surface downwardly into the earth, a casing affixed inside to well bore, and a tubing extending downwardly through the casing creating an annulus area in the well bore between the casing and the tubing. Fluid is introduced into the annulus area from the surface and flows downwardly, gaining temperature due the temperature gradient with the surrounding earth, until it reaches an open end of the tubing down hole. The fluid reverses direction into the tubing and begins rising upward toward the surface. The pressure decreases on the fluid as it rises until it reaches critical vapor pressure and begins to boil increasing velocity of the stream. Power is generated at the surface through turbines operably connected to a power generator including through a fluid turbine that utilizes the momentum of the fluid/gas stream.

The present disclosure provides a hydrothermal geothermal development method of multilateral well closed circulation, comprises the steps of: dividing a geothermal reservoir into single layers according to geothermal reservoir geological conditions, wherein an upper single layer with a lower water temperature and a higher permeability is taken as a recharge layer, and a lower single layer with a higher water temperature is taken as a production layer; tripping a production casing, and injecting cement for well cementation; performing casing lateral windowing in a vertical hole corresponding to the recharge layer, and drilling several branch radial horizontal holes into the recharge layer; performing casing lateral windowing in the vertical hole corresponding to the production layer, and drilling several branch radial horizontal holes into the production layer; tripping a guiding pipe into the production casing of the vertical hole, with a depth thereof reaching a well section between the recharge layer and the production layer; tripping a packer at a guiding shoe to isolate the guiding pipe and an annulus of the casing from each other, so as to prevent geothermal fluid of the recharge layer and the production layer from being communicated with each other in the vertical hole.

Thermal energy is extracted from geological formations using a heat harvester. In some embodiments, the heat harvester is a once-through, closed loop, underground heat harvester created by directionally drilling through hot rock. The extracted thermal energy can be converted or transformed to other forms of energy.

A method to establish a well using a nested drill/completion string. The nested drill/completion string includes an inner pipe nested in an outer pipe, a flow crossover disposed at an end of the nested drill string and a drill bit disposed to one side of the flow crossover. Drilling fluid is pumped into the well through a first annular space between the inner pipe and the outer pipe, and drill cuttings created by the drill bit are returned to surface through in inner pipe. For the completion of the well, either (i) fluid in the annular space is displaced with a lower conductivity fluid or (ii) the annular space; is evacuated. Fluid to be heated is pumped through a second annular space between the well and the exterior of the nested drill string and geothermally heated fluid is moved from the subsurface to the surface through the inner pipe.

A method of producing a geothermal well includes obtaining site information including at least a site volume; obtaining drilling parameters; determining lengths and orientations of planned wellbores based at least partially on the site information and the drilling parameters.

A radiator (RAD) enhanced geothermal system (EGS) may comprise a radiator vane heat exchanger (RVHE). The RVHE may be configured to be located in a plane defined by an injector well and a production well that is defined by a principal stress direction (S.sub.1) of a plurality of principal stress directions and a maximum horizontal stress component (SH.sub.max). The RVHE may include one or more stacked laterals oriented along SH.sub.max. Each stacked lateral, of the one or more stacked laterals, may include one or more vertical branches oriented along S.sub.1. The RVHE may be configured to extract energy from a non-hydrothermal source of energy.

In various aspects of the invention, the following are provided: a process of creating a geothermal well in high-temperature, impermeable rock is provided; a geothermal well in high-temperature, impermeable rock; a process of operating a geothermal well; a packer; and a process for creating a seal in an annulus between a cylinder and a borehole located in a target zone in high-temperature, impermeable rock.

Wellbore synthesis techniques are disclosed suitable for use in geothermal applications. Embodiments are provided where open hole drilled wellbores are sealed while drilling to form an impervious layer at the wellbore/formation interface. The techniques may be chemical, thermal, mechanical, biological and are fully intended to irreversibly damage the formation in terms of the permeability thereof. With the permeability negated, the wellbore may be used to create a closed loop surface to surface geothermal well operable in the absence of well casing for maximizing thermal transfer to a circulating working fluid. Formulations for the working and drilling fluids are disclosed.