A heat pump system and a method for implementing efficient evaporation by using a geothermal well are provided. The system includes a stepped underground evaporator, a compressor, a condenser, a liquid storage tank, and a throttle. The underground evaporator includes an inner pipe and an outer pipe. The inner pipe is designed into a multi-section structure. Each section includes a gas guiding pipeline, a baffle plate, and a seepage hole. Under the action of the structure, a liquid working medium flowing into the underground evaporator flows downwards along an inner wall of the outer pipe, and absorbs heat from an underground rock mass and gasifies into a gas working medium; and the gas working medium flows upwards to ground. Compared with the prior art, neither gas-liquid re-entrainment nor a liquid accumulation effect can occur in the underground evaporator designed according to the system and method.

A geothermal system includes: at least two geothermal holes (1) formed in the ground; a return water circulation tube (10) for returning underground water of the geothermal holes; a water collection and supply well (20) for collecting and then supplying the underground water returned by the return water circulation tube; at least one heat pump (30) for generating heat for cooling and heating, by using, as a heat source, the heat of the underground water supplied by the water collection and supply well; and a supply tube (40) which is an underground water supply means for supplying, to the geothermal holes, the underground water that supplied heat to the heat pump.

Geothermal energy is increasingly recognized as a useful energy source for both industrial and residential purposes. Disclosed herein are units for subterranean heat exchange comprising a polymer block with ‘mini-channels’ adapted and/or sized for highly efficient heat exchange. In some embodiments such units can, as needed, be manufactured off site, spooled for transport, and conveniently installed in boreholes. Other arrangements are also described for conduits located within a borehole for heat exchange, without a polymer block. Also disclosed are geothermal heat exchange systems including those that employ such units, for example with direct expansion of a two-phase heat-exchange fluid such as carbon dioxide.

A well completion to convert a hydrocarbon production well into a geothermal well includes flow tubes to transport a working fluid through the well and a heat exchanger at a downhole location coupled to the flow tubes to exchange heat of the formation at the downhole location with the working fluid. A heat exchange fluid surrounds the heat exchanger at the downhole location to be heated by the formation at the downhole location. The heat exchanger heats the working fluid to a state in which the working fluid rises to the surface. At the surface, a power plant uses the heated working fluid to generate work. The working fluid is then cooled and returned to the downhole location to repeat the work generation cycle.

A method of generating electricity from geothermal energy utilizing an in situ closed loop heat exchanger deep within the earth using a recirculating heat transfer fluid to power an in situ modular turbine and generator system within a vertical, large bore, deep, tunnel shaft. The shaft length and diameter are dependent on the shaft temperature and sustaining heat flux. The method further includes methods of deep shaft boring and excavating, liner placement and sealing, shaft transport systems, shaft Heating, Ventilation, and Air Conditioning, and operations and maintenance provisions. The method has few global location restrictions, maximizes thermal efficiency as to make power generation practical, has a small site surface footprint, does not interact with the environment, is sustainable, uses renewable energy, and is a zero release carbon and hazardous substance emitter.

A method for recompleting a well is applied to a well such that the recompleted well can thermally transfer geothermal energy to surface. The recompleting method can comprise steps to enhance the thermal conductivity of a wellbore of a hydrocarbon well, by inserting a thermal material into the wellbore that displaces a reservoir fluid having a lower thermal conductivity than the thermal material. The recompleting method can also comprise steps to enhance the thermal conductivity of a reservoir in which the wellbore is located by inserting a thermal material into the reservoir that displaces a reservoir fluid having a lower thermal conductivity than the thermal material, or in which the reservoir is fractured, and a thermal material is inserted into created fractures.

Systems and methods for producing energy from a geothermal formation. A heat exchanger can be disposed within a well to absorb heat from a geothermal formation. The heat exchanger can be supported within the well using a high thermal conductivity material. The heat exchanger is connected to an organic Rankine cycle engine including a secondary heat exchanger and a turbine. The primary and secondary heat transfer fluids are chosen to maximize efficiency of the organic Rankine cycle.

A borehole is bored to a borehole target depth in a site and a geothermal heat exchanger is inserted into and then secured in the borehole at the desired depth. Once the heat exchanger has been secured in the borehole, the heat exchanger has a closed distal end and an open proximal end and has at least one fluid path between the closed distal end and the open proximal end, with installation fluid disposed in the fluid path(s). After securing the heat exchanger in the borehole and before excavation of a portion of the site immediately surrounding the borehole, the heat exchanger is temporarily sealed by installing, through the open proximal end, at least one respective internal seal in each fluid path. For each fluid path, the internal seal(s) will be disposed below a respective notional subgrade depth and excavation of the site immediately surrounding the borehole can proceed.

A geoexchange system is provided which includes a ground source heat exchanger positioned in the ground and a distribution system coupled to the ground source heat exchanger to circulate water through the ground source heat exchanger during operation. The distribution system may include a supply line, a return line and a circulation pump to circulate water through the internal fluid cavity of the ground source heat exchanger via the supply and return lines. The distribution system may further include a purge valve to release gas from the distribution system and a fill circuit that is configured to automatically replenish the internal fluid cavity of the ground source heat exchanger with water upon leakage of water from the ground source heat exchanger or conversion of water from the ground source heat exchanger to gas. Other geoexchange systems and related methods are also provided.

Method for installing a geothermal system, comprising: arranging a drilling equipment, including a support structure and a terminal module, mounted on the support structure; by means of the drilling equipment, drilling the soil in succession along a substantially vertical first tract, a substantially horizontal second tract and a substantially vertical third tract, the first, second and third tracts forming a substantially U-shaped well, the first tract having a surface inlet, where the drilling is started, the third tract having a surface outlet, where the drilling is finished, the well crossing a geothermal zone; arranging a casing in the well, so that the casing extends between the inlet of the first tract and the outlet of the third tract; arranging a heat utilization system, associated with an axial end of the casing; arranging a hydraulic system configured to cause a heat transfer fluid to circulate in the casing, so that the heat transfer fluid will absorb heat from the geothermal formation and will release it at the heat utilization system.