Geothermal heat transfer system
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-05
- Publication Date
- 2026-08-13
Smart Images
Figure GB2026050155_13082026_PF_FP_ABST
Abstract
Description
[0001] Geothermal System
[0002] Geothermal Heat Transfer System
[0003] Field
[0004] The present disclosure is directed towards accessing Energy from Thermal Heat producing sources below the Earth's surface.
[0005] Background
[0006] At present, high temperature energy is obtained from the Earth’s hot crystalline heat reservoir formations (which are referred to as ‘reservoirs’ for brevity in this disclosure) by drilling singular or multiple wells to enable a fluid (e.g. water) to ingress the reservoirs as a liquid and egress as high temperature liquid or gas (e.g. steam), often requiring extensive fracking to create fluid heat source reservoirs.
[0007] Likewise, obtaining heat may be obtained from a hot Aquifer, by drilling and pumping water to the source then returning same to the surface.
[0008] Current and conventional geothermal heat transfer can be inefficient and relies on pumped water with the potential of ingress contamination of the water table, and problems with fracking between wells. This results in a reduction in thermal recovery.
[0009] In particular, the conventional way of obtaining energy from HDR. (Hot Dry Rock) is a three well operation, two injecting, one producing. There is a lateral flow path of 400 feet between the two injecting wells, joining of which is shaped charged to connect the two. Water is then pumped down the injecting wells, and along the lateral flow path, where it takes heat from the surrounding hot dry rock. It is then transferred to the producing well and reaches the surface as steam. The steam then powers the turbines of the generator, which is then recycled back into the injection wells.
[0010] There have been attempts to solve this problem. In particular, CN 109539610 discloses a heat utilization system and method based on solid thermal conduction
[0011] A system in accordance with this disclosure differs from these and other similar applications in that a single borehole is drilled, and heat is transferred not by water to the surface, but by thermal dissipation through solid aluminium oxide, graphite, granulated graphite, graphene and / or as a mixture of heat conducting solids, for stable heat transfer from a subterranean heat sourceGeothermal System
[0012] through the single bore hole, in a unique sealed cartridge configuration, connected by multiple heat transfer subs, which are designed to be easily replaced as necessary.
[0013] This disclosure is configured to provide a means that allows a way of drilling a single bore hole to the heat source reservoir, sealing the hole wall with cemented conventional casing, and working as a self-contained sealed system, maximising heat transfer and preventing any water table contamination.
[0014] Summary of the Invention
[0015] The present disclosure is directed towards a system for extracting geothermal energy from a heat source comprising: a heat transfer column comprising a plurality of heat conductive units containing thermal heat dissipating materials cojoined by heat transfer subs containing thermal heat dissipation plugs thereby in use transferring energy from source along a single hole drilled into a heat source formation to the surface avoiding without interaction with any subterranean water course.
[0016] Preferably, a surface heat exchanger extracts energy from the heat transfer column for the generation of electricity with a turbine. More preferably, the surface heat exchanger comprises a return pipe to provide an enclosed circulation loop.
[0017] Preferably, a length of thermally conductive material from the heat transfer column is located within the surface heat exchanger. More preferably, the length is adjustable.
[0018] Preferably, the heat exchanger is mounted on a support collar, and the length is adjusted by varying the thickness of the support collar.
[0019] Preferably, the heat dissipation plug is configured to provide a thermal connection between the heat conductive units. More preferably, the length of the heat dissipation plug is shorter than the distance between the heat conductive units it is configured to thermally connect prior to use, whereby in use the heat dissipation plug expands due to heat to thermally connect the heat conductive units.
[0020] Preferably, a heat conductive units comprises a thermally conductive core. Preferably, the thermally conductive core is aluminium rod, and / or aluminium oxide with graphite. Preferably, the thermally conductive core is provided with a wrap of a graphene pipe or graphene foil.
[0021] Optionally, the system comprises a second heat exchange unit.
[0022] Preferably, the heat conductive units are 79 cm, 31 inches, in length.Geothermal System
[0023] Preferably, the heat transfer subs configured to provide a connection having a smooth outer profile for the heat conductive units.
[0024] Preferably the heat transfer column is configured to operate in temperature of greater than 250 °C or 300 °C.
[0025] Preferably, the heat exchanger comprises a heating chamber for converting a liquid to a gas and a return chamber for receiving liquid from a turbine. Preferably, the heating chamber comprises baffle plates to accelerate heat exchange. Preferably the heating chamber comprises helical or corrugated structured baffle plate located between the ingress and egress of the heating chamber.
[0026] Brief Description of the Drawings
[0027] The invention will be more clearly understood from the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawings, in which:- Figure 1 shows a plan view of a system in accordance with the present disclosure;
[0028] Figure 2 shows a sectional view of a heat exchange unit engaged with a heat transfer unit; Figure 3 shows a sectional view of a heat transfer unit; and
[0029] Figure 4 shows a top view of a system in accordance with the present disclosure comprising a second heat exchange unit.
[0030] Detailed Description of the Drawings
[0031] Figure 1 shows the configuration of a production well. The production may comprise a drilling rig E. The drilling rig E is preferably removed after completion of the drilling phase. The surface equipment of the production well preferably includes a heat exchange unit C. The heat exchange unit is connected to a turbine D. The turbine is in turn connected to a generator B. Power is then provided from the generator B to a power distribution network A.
[0032] Figure 1 further shows the layout of the sub surface aspects of a system in accordance with the present disclosure. In particular, the system comprises a solid-state heat transfer column comprising a plurality of heat conductive units J. The heat conductive units J may be preformed cartridges. The heat conductive units J have a thermally conductive core F. The heat transfer column is enclosed by casing. The casing preferably comprises a surface casing G and an intermediate casing H. The thermally conductive core F preferably comprise a thermally conductive solid. The thermallyGeothermal System
[0033] conductive solid may be graphite, aluminium oxide, or any other suitable heat conducting materials, or mixture thereof. The heat conducting material may be provided as solid mass units of a thermally conductive solid, or as units of cased compressed particles of one or more thermally conductive solids, or a mixture thereof.
[0034] The heat transfer column extends below surface to a heat source K. The heat source generally comprises hot dry rock or an aquifer. In the present system, a thermal or heat conducting material or element is one which facilitates heat dissipation from the heat source K to the surface U and may also be described as a heat dissipation material or element.
[0035] Figure 2 shows a section of the heat transfer unit J as it exits to the surface. As noted above, the heat transfer unit J has a thermally conductive core F comprising a solid mass or compressed particles of one or more solids. The heat transfer unit J is preferably formed into sectional columns to meet drilling industry range 2 requirements. Preferably, the heat transfer units J are 30 feet in length to meet industry standards. Alternatively the heat transfer units may be 45 feet to minimise the number of heat transfer units J required - in this case two heat transfer units may be used instead of three thereby minimising the cost of the system. Preferably, a portion of a heat transfer unit J extends above the surface. More preferably, the heat transfer unit J extends 1.5 feet or more above the surface. Details of the prepared tubing are described in more detail with reference to Figure 3.
[0036] The thermally conductive core F is preferably encapsulated in a wrap S. The wrap S is a thermally conductive wrap of preferably either a Graphene Pipe or Graphene Foil. The wrap may function to reflect heat, thereby preventing the egress of heat from the thermally conductive core F. The wrap S is preferably encased in steel or composite production tubing, which can be lowered sectionally to the total depth of the well, as a retractable and connected column reaching to the heat source K, thereby thermally connecting the heat source K to the surface U. Variable dimensions may be used, subject to requirements and availability of heat source level.
[0037] Preferably, the solid material in the thermally conductive core F is selected to withstand high temperatures and to provide thermal conduction. Preferably the core is able to withstand temperatures in excess of 250 or 300 °C. As such, graphite and / or aluminium oxide are particularly suitable materials to transport energy from the heat source to the surface.
[0038] The wrap S (which may be a Graphene or steel pipe) surrounding the thermally conductive core F will act as an insulation, to secure heat transmission along the heat transfer column.Geothermal System
[0039] As shown in figure 2, a heat exchange unit C (i.e. a heat exchanger) is coupled to the above ground portion of the heat transfer unit J. The heat exchange unit C comprises a heating chamber which in use is proximate to a thermally conductive core F. The heating chamber comprises baffle plates X which accelerate heat exchange and will vary in size and number subject to the size of heat exchange unit required, relative to the available heat received from the heat source K.
[0040] An outlet pipe P allows the egress of a heated gas (e.g. steam) from the heating chamber of the heat exchange unit C to the turbine D, which then drives the generator B. A return pipe Q allows the return of a heat transfer liquid (e.g. water) to a return chamber. The heat transfer liquid passes from the return chamber to be reheated in the heating chamber into a gas (e.g. steam). Thus, the heat exchange unit C preferably has an enclosed circulation loop.
[0041] Preferably, the heat exchange unit C has an insulated outer wall Z. Preferably the heat exchange unit C comprises a helical or corrugated structured baffle plate J preferably located between the ingress and egress of the heating chamber to further enhance the flow of liquid through the heat exchange unit through convection. Alternatively, the baffle plate J may be a powered screw drive A support collar R is provided at the connecting point of the heat exchange unit C to the Surface U to support the heat exchange C. The depth of support collar R will determine the length of the thermally conductive core F within the heat exchange unit. Thus, the hight of the support collar may be selected based on the heat received from the heat source K. Preferably, the depth of the support collar R is adjustable to increase or decrease the length of the heat transfer unit F within the heat exchange unit C.
[0042] To reduce or expand the length of the heat exchanger if required, the heat exchange unit C may be connected to a variable diameter graphite block or composite within a modified heat exchange unit C.
[0043] The wrap S may be located within or integral to production tubing. The borehole casing T anchors into the heat transmission zone.
[0044] Figure 3 illustrates the heat transfer unit J which may be thermally connected to the thermally conductive core F of another heat transfer unit by a heat transfer plug V. As noted above, the heat transfer unit is shaped as a column. The heat transfer plug V is located at a first end of this column. The heat transfer unit also comprises a positioning sub W at the first end. The heat transfer unit also comprises a shoe termination Y at a second end of the column which is opposed the first end. In use, when heat transfer units J are stacked within the heat transfer column, theGeothermal System
[0045] positioning sub W positions the shoe termination Y such that the shoe termination is in physical contact with the heat transfer plug. This provides a thermal bridge between heat transfer units F.
[0046] The sub W also preferably provides a means for connecting heat transfer units J together. The connection mechanism is configured to provide a smooth outer profile for the connected cartridges, facilitating insertion of the heat transfer units insert into an existing borehole. Ideally, the borehole is a vertical borehole. In this case, there will be a direct vertical flow of heat into the primary heat exchanger. Furthermore, a vertical borehole facilitates removal and servicing of used heat transfer units J and / or installing replacements. Preferably, the borehole is an uncased borehole. As a result, heat may be obtained using heat transfer units having a 4 to 43 / 8 inch diameter.
[0047] The heat transfer plug V preferably provides is configured to provide a thermal joint which compensate for the expansion of the heat transfer units. In particular, the heat transfer plug V may be a solid mass of a conductive material such as Aluminium or Aluminium Nitride. The heat transfer plug extends a distance from the thermally conductive core F. This distance defines the length of the heat transfer plug V. Prior to instillation, length of the heat transfer plug is less than the distance between the first end of the heat transfer unit and the shoe termination Y. On instillation, heat will cause the heat transfer plug to expand thereby increasing its length. As a result, a good contact may be formed between the heat transfer plug V and the shoe termination Y without damaging the heat transfer unit.
[0048] Preferably, the length of the heat plug V may be varied along the borehole in use. For example, the heat plug V may be cut to a predetermined length and attached to the heat transfer unit J by an attachment means such as thread and screw. Preferably, the thermal gradient from the heat source K to the surface U may be measured. As a result, the temperature at a specific point in the borehole may be known. As it is possible to calculate how much the solid mass of a conductive material will expand at a given temperature, it is possible to provide a heat transfer unit J with a heat transfer plug V that provides the correct length of conductive material to provide a good connection between heat transfer units at the location where the heat transfer will be located. The heat plug may be attached to the heat transfer unit J by an attachment means such as thread and screw. Prior to instillation, the thermal gradient from the heat source K to the surface U may be measured.
[0049] As an alternative, the heat transfer plug V may comprise particles of Aluminium or Aluminium Nitride. The heat transfer plug may comprise a thermally conductive surface for engagement with the shoe termination Y. Preferably the side walls of the heat transfer plug V (i.e.Geothermal System
[0050] the walls thermally conductive core F and the thermally conductive surface for engagement with the shoe termination Y) are formed from a resilient material that is able to withstand temperatures in excess of 250 or 300 °C.
[0051] Preferably the heat transfer unit J has a standard 31' cartridge length. This is advantageous for ease of emplacement and removal, and for servicing.
[0052] The shoe termination Y is preferably a rigid thermally conductive connection from the exterior of the heat transfer unit J to the thermally conductive core F. The shoe termination may be constructed from any suitable thermally conductive material. For example, the shoe termination may be formed from sintered tungsten carbide and diamond or equivalent depending on the heat the shoe is required to withstand.
[0053] Figure 4 represents the layout of the heat exchange unit C, turbine D, and generator B. As described above with reference to figure 2, heat is transferred by a gas provided using a closed loop water or liquid heat exchange C to conventional turbines D through the outlet pipe P. The turbine D powers the electric generator B. A port L is provided on the return pipe Q to provide access for e.g. fluid top up or maintenance access.
[0054] A second heat exchange unit M may be provided to facilitate transferring excess heat for external purposes. The second heat exchange unit M has inlet and outlet water pipes M. The second heat exchange may be used for domestic and / or industrial heat requirements - e.g. the second heat exchange may be connected directly to domestic central heating systems. The generator may generate electrical power which may be provided to the power transmission cable A to provide an outlet to a power grid.
[0055] As a result the present disclosure provides a system that only requires a single well to operate, that facilitates the extraction of heat from the hot dry rock through a single column of heat conducting material to the surface, where a heat exchanger converts water to steam to power the turbines of the generator. As a result a system in accordance with the present disclosure avoids fracking, does not interfere with aquifers, avoids the risk of water table contamination, avoids the risk of heat loss through water dissipation or water ingress, and reduces costs of installation and maintenance over common prior art three well solutions.
[0056] This invention is unique by way of drilling a single bore hole to the heat source reservoir, sealing the hole wall with cemented conventional casing, and working as a self-contained, sealed system, maximising heat transfer and preventing any contamination.Geothermal System
[0057] The heat transfer unit is e.g. a cartridge that provides a solid or granulated sectionized column of Graphite will be encapsulated in either a Graphene Pipe or Graphene Foil wrap encased in steel production tubing, then lowered to the total depth of the well, as a retractable column connecting the heat source with the surface.
[0058] Variable dimensions can be used, subject to requirements and availability of heat source level. Graphite's ability to transmit heat and withstand very high temperatures is the ideal material to transport energy from a heat source to a surface heat exchange unit
[0059] The Graphene acts as an insulation. In particular, graphene has a higher heat dissipation rate and will secure the energy transmission of heat within the graphite core.
[0060] Adjusting the heat exchanger length will be determined by the actual temperature received on the surface. To reduce the length of the heat exchanger and if required the Graphite column would be connected to a vastly increased diameter block or composite of Graphite within a modified heat exchanger. At the surface, the heat is transferred using a sealed water system through the heat exchanger to conventional turbines to generate electricity.
[0061] The Steam flow from the turbines will exit through a pipe into a heat exchanger, from there it will begin the circular flow through a heating chamber in the heat exchange unit and then to the turbines again. Preferably, an access point is provided for enclosed fluid maintenance.
[0062] As a result, the system provides an efficient and effective means of using geothermal heat to generate sustainable power over long timescales with low maintenance costs. Thus, a power continuum system that will keep producing Ad infinitum is provided.
Claims
Geothermal SystemClaims1. A system for extracting geothermal energy from a heat source comprising:a heat transfer column comprising a plurality of heat conductive units containing thermal heat dissipating materials cojoined by heat transfer subs containing thermal heat dissipation plugs thereby in use transferring energy from source along a single hole drilled into a heat source formation to a surface heat exchanger without interaction with a subterranean water course, wherein:the surface heat exchanger extracts energy from the heat transfer column for the generation of electricity with a turbine; andthe surface heat exchanger comprises a return pipe to provide an enclosed circulation loop.
2. The system of claim 1, wherein a length of thermally conductive material from the heat transfer column is located within the surface heat exchanger.
3. The system of claim 2, wherein the length is adjustable.
4. The system of claim 3, wherein the heat exchanger is mounted on a support collar, and the length is adjusted by varying the thickness of the support collar.
5. The system of any preceding claim, wherein the heat dissipation plug is configured to provide a thermal connection between the heat conductive units.
6. The system of claim 5, wherein the length of the heat dissipation plug is shorter than the distance between the heat conductive units it is configured to thermally connect prior to use, whereby in use the heat dissipation plug expands due to heat to thermally connect the heat conductive units.
7. The system of any preceding claim, wherein a heat conductive units comprises a thermally conductive core.Geothermal System8. The system of claim 7, wherein the thermally conductive core is aluminium rod, and / or aluminium oxide with graphite.
9. The system of claim 7 or 8, wherein the thermally conductive core is provided with a wrap of a graphene pipe or graphene foil.
10. The system of any preceding claim, comprising a second heat exchange unit.
11. The system of any preceding claim, wherein the heat conductive units are 30-31 or 45 inches in length.
12. The system of any preceding claim, wherein the heat transfer subs configured to provide a connection having a smooth outer profile for the heat conductive units.
13. The system of any preceding claim, wherein the heat transfer column is configured to operate in temperature of greater than 250 °C or 300 °C.
14. The system of any preceding claim wherein the heat exchanger comprises a heating chamber for converting a liquid to a gas and a return chamber for receiving liquid from a turbine.
15. The system of claim 15, wherein the heating chamber comprises baffle plates to accelerate heat exchange.
16. The system of claims 14 or 15, wherein the heating chamber comprises helical or corrugated structured baffle plate located between the ingress and egress of the heating chamber.