AU2021100825A4

AU2021100825A4 - A geothermal pumping station

Info

Publication number: AU2021100825A4
Application number: AU2021100825A
Authority: AU
Inventors: Warren Ross Strange
Original assignee: Good Water Energy Ltd
Current assignee: Good Water Energy Ltd
Priority date: 2021-02-10
Filing date: 2021-02-10
Publication date: 2021-04-22
Anticipated expiration: 2029-02-10

Abstract

The present disclosure is directed to a geothermal pumping station, comprising: a primary liquid circuit circulating liquid into a geothermal well and returning heated liquid from a well head of the geothermal well; a turbine driven off the heated liquid to produce a mechanical output; and a pump driven from the mechanical output to pump fluid from a fluid source to a fluid output through a condenser, wherein the liquid of the primary liquid circuit is drawn across the condenser to cool before being returned to the geothermal well to be reheated. 9208840_1 (GHMatters) KERRYD 1/4 0 > 00 u C-4 (N4 (N

Description

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(N A GEOTHERMAL PUMPING STATION TECHNICAL FIELD

The invention is directed to a geothermal pumping station. Specifically, the invention relates to a geothermal water or gas pipeline pumping station using a primary circuit and also to a geothermal water or gas pump using a secondary circuit.

BACKGROUND Australia is getting hotter and drier and as a result fresh water is getting scarce and the ability to get that water to the places it is needed is becoming more difficult and costly. Additionally, people are becoming more environmentally aware and are seeking cleaner and greener solutions.

While solar energy and wind energy have low emissions, they cannot presently deliver affordable baseload electricity. In contrast, geothermal power has the ability to provide limitless, zero emission, baseload energy but drilling costs have historically made it expensive to do so, and restricted its use to locations where high geological temperatures are at shallow depth.

Previous attempts at large scale geothermal energy production in Australia were thwarted by high drilling costs and both technological and environmental problems using conventional oil and gas drilling techniques. However, the ability to harness deep thermal heat and to utilise this energy to provide low cost pumping with or without electricity generation is desirable.

People typically link geothermal power to countries such as New Zealand, Indonesia and the Philippines which are geologically active and where drilling to 2000m or less is sufficient to provide access to the high geological temperatures required to produce usable energy. However, it would be desirable to drawn on geothermal energy to provide low cost pumping anywhere in the world.

It is estimated that in most parts of Australia, an 8000m to 10,000m deep well could be capable of supplying enough thermal energy to generate 4MW of base-load electricity which would be sufficient to meet the demand of 2500 homes. The cost of this electricity generation is calculated to be competitive with existing fossil-fuel stations

9208840_1 (GHMatters) KERRYD while producing zero emissions. Alternatively to electricity generation, this thermal energy could be used to directly drive a pump or a compressor to deliver available water (or gas) supply to those in need. The only waste product is heat which could be used to support additional spin-off industries.

The present invention was conceived with these shortcomings in mind.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, a limited number of the exemplary methods and materials are described herein.

SUMMARY OF THE INVENTION

In a first aspect the invention provides a geothermal pumping station, comprising: a primary liquid circuit circulating liquid into a geothermal well and returning heated liquid from a well head of the geothermal well; a turbine driven off the heated liquid to produce a mechanical output; and a mechanical pump driven from the mechanical output to pump fluid from a fluid source to a fluid output through a condenser, wherein the liquid of the primary liquid circuit is drawn across the condenser to cool before being returned to the geothermal well to be reheated.

The fluid being pumped may be water or gas.

In some embodiments, the liquid circulated in the primary liquid circuit may be water.

A portion of the heated liquid may be subject to a pressure change to produce a vapour to drive the turbine. The heated liquid may be subject to pressure change in a separator or flash separator.

In some embodiments, the exhausted liquid/vapour from the turbine may be communicated to a condenser before returning to the geothermal well to be reheated.

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The pumped fluid or gas may be circulated through the condenser to draw heat energy away from the liquid of the single liquid circuit before being drawn back into the geothermal well.

In some embodiments, the fluid source may be any one of a dam, a reservoir, a pumping station, a pipe line, a receiving tank and a suction tank. The fluid output may be any one of a pipeline, a damn, a reservoir, a subsequent pumping station, a receiving tank, a suction tank and a storage vessel.

In some embodiments, the turbine may be substituted for one of a screw expander, a steam engine, and an ORC turbine. The turbine may comprise a plurality of turbines.

In some embodiments, the compressor may be a screw compressor or a piston compressor.

The primary liquid circuit flow is sustained by a thermal syphoning effect, providing a flow of the primary liquid to a surface of a deep geothermal well. The primary fluid can be water.

This thermal syphoning effect is responsible for the movement of the liquid in the primary circuit, once it begins to flow. The effect occurs when fresh water at a temperature of approximately 5 0 °Celsius is allowed to be drawn down into an annulus of the geothermal well and to be heated by the hot geology and water within the well. The liquid, which can be water, heats on its journey down into the ground and the temperatures gained by the water can be varied by the depth of the well and the content and potential flow rate of the ground water through the hot rocks. The thermal syphoning effect is responsible for pushing the heated liquid (water) back to the surface of the well and thus delivery of thermal energy to the surface requires little to no energy input to maintain the thermal energy flow from the well.

The present invention utilises a pump (or compressor) to pump a resource such as water or gas, where the pump is driven by the thermal heat energy, to at least reduce (or eliminate) the requirement for electricity in moving the valuable resource from a fluid source to a fluid output. The source may be a pipeline, a tank, a damn, a

9208840_1 (GHMatters) KERRYD reservoir or the like, while the outlet may be any one of a pipeline, a dam, a reservoir, a pumping station, a receiving tank, a suction tank and a storage vessel.

The invention uses a screw expander, turbine, ORC turbine, engine, steam engine or water wheel that converts energy from the liquid in the primary liquid circuit (thermal energy from the fluid flow) into a mechanical output in the form of a rotary force or reciprocal piston action. This mechanical output can directly or indirectly drive a pump, or a compressor or alternatively can be used to drive a generator for electricity generation.

A secondary pump can be integrated into the primary liquid circuit on the surface to facilitate the start-up of the thermal syphoning effect. This pump can be driven by pressure in the fluid pipeline, to eliminate (or at least reduce) the need for any additional electricity.

From a safety perspective, the present invention provides advantages in reducing (and in some cases eliminating) the use of dangerous electricity in the water pumping environment.

The invention provides lower operating costs for a water or gas pipeline pumping stations, when compared to conventional pumping stations using fossil fuel or solar/ wind / battery generated electricity to drive an electric pump.

The geothermal pumping station of the present invention creates zero emissions, as geothermal energy is used to provide all energy and pumping requirements.

Thermal Syphoning effect provides all thermal energy delivery under pressure to the surface and away from the geothermal well with no well pumping required once the primary liquid circuit is running, providing low-cost renewable energy.

It is calculated that 100 to 500 horsepower of pumping energy could be obtained from one single geothermal well, and this energy source is almost constant as opposed to solar or wind energy which can fluctuate greatly depending on the time of day and the time of the year and requires expensive battery storage systems or other energy storage systems such as hydrogen to provide a baseload or constant electricity supply.

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Additional comparisons with both wind and solar power shows geothermal energy to have a very small physical footprint, thus leaving surrounding land untouched, and available for alternative use. Additionally, this greatly reduces the environmental impact of a pumping station as there is no requirement for power lines, clearing of trees, no emissions, no toxic waste produced, and the land above and around the geothermal well can be rehabilitated after installation.

The present invention provides additional advantages in that there is low pumping maintenance required, no power line maintenance or power losses through long distance transmission, no solar panels and batteries to clean and dispose of regularly. The use of steam engines and steam expanders has a long life and a track record for proven reliability, known examples operating for up to 100 years.

Once drilled and installed a single, deep, vertical geothermal well which requires no fracking and no extraction of ground water, will produce thermal energy for hundreds of years while the well head flow can be controlled remotely to adjust the pumping volumes achieved.

The above advantages provide for significant reductions in typical pumping costs and significant reductions in C02 emissions. Preliminary calculations suggest a possible cost reduction of 50% compared to coal or gas electric driven pumping stations and more than 75% compared to diesel engine driven pumping stations.

In a second aspect the invention provides a geothermal pumping station, comprising: a primary liquid circuit circulating liquid into a geothermal well and returning heated liquid from a well head of the geothermal well; a heat exchanger heated by the heated liquid of the primary circuit to heat and vaporise a working medium of a secondary circuit, wherein the heated vaporised working medium of the secondary circuit drives a turbine to produce a mechanical output; and a mechanical pump driven from the mechanical output to pump fluid from a fluid source to a fluid outlet through a condenser, wherein the liquid of the primary liquid circuit is cooled as it passes through the heat exchanger and returned to the geothermal well to be reheated and the fluid from the fluid source is pumped through the condenser, to cool and condense the working medium before re entering the heat exchanger to be re-heated.

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Fluid in the secondary (or binary circuit) may be water or other fluids with lower boiling points such as N-Pentane.

In some embodiments, the geothermal pumping station may be configured such that no electricity or fossil fuels are required to drive a mechanical pump.

In some embodiments, the fluid may be water or gas.

In some embodiments, the exhausted working medium from the turbine may be passed through the condenser to be cooled and condensed into a liquid state before returning to the heat exchanger. The working medium may be passed through the condenser to reduce a temperature of the working fluid within the secondary circuit, before being drawn into a pump which circulates the working medium within the secondary circuit.

In some embodiments, the fluid source to be pumped may be drawn from any one of a dam, a reservoir, a pumping station, a pipeline, a receiving tank and a suction tank.

In some embodiments, the fluid output may be any one of a pipeline, a damn, a reservoir, a subsequent pumping station, a receiving tank, a pipeline a suction tank and a storage vessel.

In some embodiments, the turbine may be substituted for one of a screw expander, a steam engine, an ORC turbine or any mechanism to convert thermal energy into mechanical force. The turbine may comprises a series of turbines.

In some embodiments, the compressor may be a screw compressor or a piston compressor. In some embodiments the turbine may be substituted for a steam engine.

The circuit pump (also referred to as a secondary pump or binary circuit pump) can be driven by water pressure and flow generated by the pipeline pump, or by air pressure created by a compressor driven by the same mechanical force that is driving the pipeline pump.

The geothermal pumping stationof the invention provides all of the advantages set-out above in relation to the geothermal pumping station of the first aspect, including zero

9208840_1 (GHMatters) KERRYD emissions, reduced installation costs and maintenance costs, long usable life-span, comparatively small physical footprint (as compared to wind or solar), no toxic waste, and a reliable, steady long term energy supply.

In a third aspect the invention provides a method of pumping water or gas from a source to an outlet, powered by geothermal energy, comprising the steps: feeding liquid into a geothermal well and drawing heated liquid from the well head of the geothermal well to form a primary liquid circuit; vaporising the heated liquid from the primary liquid circuit and communicating the vapour to a turbine to produce a mechanical output; and driving a pump directly from the mechanical output to pump water or gas from the source to the outlet through a condenser, wherein the vaporised liquid of the primary liquid circuit is drawn through the condenser to cool and condense before being returned to the geothermal well to be reheated.

In some embodiments the turbine may be substituted for a steam engine. In some embodiments, the mechanical pump may be substituted for a compressor. The source may be a fluid pipeline.

In some embodiments, the method may comprises directly communicating the heated liquid from the primary liquid circuit to drive the turbine. A portion of the heated liquid may be drawn into a separator to create vapour to drive the turbine.

In some embodiments, liquid/vapour from the primary liquid circuit may be exhausted from the turbine is mixed with the liquid exiting the separator and directed to the condenser to be cooled to maintain circulation in the primary liquid circuit.

In some embodiments, the method may comprise communicating the heated liquid from the primary liquid circuit to a secondary circuit to heat a working fluid of the secondary circuit to drive the turbine.

In some embodiments, heat transfer between the primary and the secondary circuits may be effected via a heat exchanger.

In some embodiments, the method may comprise a pump pumping the secondary or binary working fluid around the secondary or binary circuit. The secondary or binary

9208840_1 (GHMatters) KERRYD circuit pump may be driven by pressure in a supply line of the water or gas source or from thermal energy in the primary circuit prior to, or after the heat exchanger

The circuit pump may be selected from: an air pump; a fluid driven pump; and a direct driven pump driven by a turbine using thermal energy from the primary fluid circuit.

In some embodiments, the turbine may be substituted for one of a screw expander, a steam engine, and an ORC turbine. The turbine comprises a series of turbines. In some embodiments, the compressor may be a screw compressor or a piston compressor.

Various features, aspects, and advantages of the invention will become more apparent from the following description of embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are illustrated by way of example, and not by way of limitation, with reference to the accompanying drawings, of which: Figure 1 is a schematic view of a geothermal water or gas pumping station according to one aspect of the invention; Figure 2 is a schematic view of a geothermal pumping station using a secondary (binary or Organic Rankine Cycle'ORC') circuit; Figure 3A is a cross-sectional view of a geothermal well, illustrating a steady reduction in a diameter of the well, as the well extends into the substrate; Figure 3B is a cross-sectional view of a well head of the geothermal well, illustrating a series of valves and seals for controlling the flow of liquid into and out of the geothermal well within the primary liquid circuit; and Figure 4 is a diagrammatic view of a method of pumping water or gas from a source to an outlet, powered by geothermal energy.

Embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments, although not the only possible embodiments, of the invention are shown. The invention may be embodied in many

9208840_1 (GHMatters) KERRYD different forms and should not be construed as being limited to the embodiments described below.

DETAILED DESCRIPTION OF EMBODIMENTS

Whist the geothermal fluid pumping station of the invention is described herein in applications for pumping water, it is contemplated that the invention can also be applied to other fluids, such as oil and gas.

While the term "turbine" is used herein to describe a machine that produces mechanical work by passing a fluid flow over a rotor or impeller to impart rotational motion thereto, it is understood that the "turbine" can be exchanged for other mechanical devices, such as a steam engine, an Organic Rankine Cycle (ORC) turbine or a screw expander. Those skilled in the art will appreciate that different expanders are suitable for different power ranges and applications.

The term "liquid" has been used herein to refer to the liquid of the single or primary liquid circuit.

The fluid resource to be pumped whether liquid, gas, oil or water is referred to as "fluid" to clearly distinguish from the liquid of the primary circuit. Additionally a secondary or binary circuit is described to have a "working medium" circulating in a closed loop and purely used as a working medium to transfer energy. It is understood that the liquid, the fluid and the working medium could, in some embodiments, could be water or other fluids with a lower boiling point such as N-Pentane

With reference to Figure 1, there is illustrated a schematic view of a geothermal pumping station (100), comprising: a primary liquid circuit (1) circulating liquid (3) into a geothermal well (5) and returning heated liquid from a well head (7) of the geothermal well; a turbine (10) driven off the heated liquid (4) to produce a mechanical output (12); and a pump (14) driven from the mechanical output to pump fluid (16) from a fluid source (18) to a fluid outlet (20) through a cooler or a condenser (22), wherein the liquid of the primary liquid circuit (1) is drawn across the cooler or condenser (22) to cool before being returned to the geothermal well (5) to be reheated.

9208840_1 (GHMatters) KERRYD

In Figure 1 the primary liquid circuit (1) is illustrated as a dashed-line, that circulates the primary liquid (3), for example water, as it is drawn into the geothermal well (5) to be heated by the hot geology deep within the well. The depths of the well can be between 3000m to 10,000m.

In Figure 1, the primary circuit (1) is shown in dashed line, and the fluid (16) to be pumped from the fluid source (18) to the outlet (20) is shown in solid line.

As the single circuit liquid (3) is drawn into a wellhead inlet and into an annulus defined by an outer ring (5a) of the geothermal well (5) it is heated (show in Figure 1 as arrows directed toward the well (5) and the heated liquid (4) rises up through a central ring or conduit (5b) defined by an insulated casing (122) bringing the heated liquid (4) up the inside of the insulated casing (122) to ground level at the well head (7).

The heated liquid (4) temperature as it exits the well head is between 1500C and 3000C depending on the location of the well (5), the depth of the well (5) and the geology of the area.

Once the primary liquid circuit (1) is initiated by fluid pressure in the pipeline or stored fluid pressure, the thermal syphon effect action of the heated liquid (4) rising continues to draw cooler liquid (3) into the well (5) thus propagating the thermal syphoning effect.

Further details of the geothermal well (5) are described in relation to Figures 3A and 3B herein.

The heated liquid (4) is drawn into a separator (25) where the pressure drops. This drop in pressure forces a portion of the heated liquid (4) to vaporise, and where the primary liquid (4) is water, to create steam (6). The steam (6) is communicated to the turbine (10) or steam engine where the flow of steam (6) drives the turbine (10) or steam engine to produce a mechanical output (12) schematically illustrated in Figure 1 as a shaft that is rotated or is moved with a reciprocal piston movement. The mechanical output (movement of the shaft) is then transmitted to a pump (14) and / or a compressor to pump a fluid resource (16). All of the thermal energy drawn from the geology of the well (5) is used to drive the pump (14) or compressor connected to the turbine (10) (subject to any unavoidable energy losses in the system).

9208840_1 (GHMatters) KERRYD

Where a compressor is substituted for the pump (14), the compressor can be situated within a pipe-line from a source (18), for example a gas pipeline or a water pipeline.

The fluid resource (16) can be water, or oil or gas.

The fluid (16) is drawn from the source (18) which can be a natural reservoir or a dam, or a manmade reservoir that forms a portion of a pipeline (27) or pipeline system.

The fluid (16) is pumped from the source (18) to the outlet (20). The outlet can be a subsequent reservoir or dam, whether natural or manmade. Alternatively, the outlet (20) can be the inlet of a further pipeline or geothermal pumping station (100) where the fluid is tapped or stored for use such as initiating the single circuit fluid movement.

As the heated primary liquid/vapour (4,6) exits the turbine (10) the temperature and pressure of the primary liquid orvapour has reduced. Downstream of the turbine (10) the liquid or vapour exiting the turbine, exhaust (9) is mixed back into the primary liquid circuit (1) with the residual heated liquid (8) from the separator (25). These two streams (8, 9) once combined are communicated into the condenser (22) before being directed back to the geothermal well (5) to be reheated.

Residual heated liquid (8) can also be used to drive a compressor, pump or generator to operate a start-up pump (36a) and other ancillary energy requirements.

The primary liquid circuit (1) is a closed loop (at least outside of the well (5)). The liquid or vapour (4,6) is cooled or condensed, as it travels through the condenser (22), by the pipeline gas or fluid (16) being pumped between the source (18) and the outlet (20). The fluid (16) to be pumped is at a lower temperature than that of the primary circuit liquid or vapour (4,6), and draws heat from the primary circuit liquid (3) in the condenser (22). The primary liquid or vapour (4,6) is cooled within the condenser (to a temperature between 50OC-70°C) before being drawn back into the geothermal well (5).

As the liquid in the primary circuit (1) emerges or exits under pressure from the well head (7) at between 150OC-300°C, the flash separator (25) is used to provide a vapour

9208840_1 (GHMatters) KERRYD

(for example steam 6) to drive the turbine (10). Alternatively, the heated single circuit fluid (4) can be directed under pressure in a liquid state directly to a wet steam, screw expander or other type of mechanical device that operates with heated fluid in a pressurised liquid state.

The heated liquid (4) is fed from the well head (7) to the separator (25) where the liquid (4) enters the separator (25) typically via a throttling valve reducing the pressure of the liquid (4) to initiate flash evaporation. A portion of the liquid (4) immediately "flashes" into vapour, or steam (6) where water is the selected liquid. The steam (6) is then drawn off the top of the separator (25) to drive the turbine (10).

After flashing, the remaining liquid (8) of the primary circuit (1) exits the separator (25) via an outlet or drain (26). This output from the separator (25) is then mixed with the exhaust (9) of the turbine (10) before being directed to the condenser (22).

The liquid or vapour (4,6) of the primary circuit (1) then continues to the condenser (22) to be reduced in temperature and or condensed before being directed back to the well (5) to continue the thermal syphoning effect.

Several stages of flash separators can be configured to provide for additional energy to be harvested. In some arrangements a series of flash separators are interlinked with the products of each separator driving a single turbine (10), alternatively the product of each separator can be individual channelled to drive a series of turbines/expanders.

In one such multi-flash embodiment, the exhaust (9) from the turbine (10), is directed to a second stage of flash (using the same process as described herein in relation to separator (25)). The secondary separator is in fluid communication with a second, lower pressure turbine that is driven by vapour evaporated in the secondary separator to again convert thermal energy into a supplementary mechanical force. The exhaust from the second turbine is then reintroduced into the primary liquid circuit (1) before being directed to the condenser (22) to condense and cool.

The secondary turbine can be substituted for a wet steam or similar mechanical device. The supplementary mechanical force can be directed to drive a compressor, pump or generator to operate the start-up pump (36a).

9208840_1 (GHMatters) KERRYD

It is contemplated that a start-up pump (36a) illustrated in Figures 1 and 2 can be integrated into the primary liquid circuit (1) to initiate the circulation of liquid in the circuit (1). To avoid the requirement for added electricity, the start-up pump (36a) can be driven from the pressure in the pipeline (27) that is created from a previous pumping station. The start-up pump (36a) can alternatively be an air driven pump or a fluid driven pump.

When the well (5) has been sitting (outlet and inlet closed), the total volume of water in the well (5a and 5b) is equally heated according to thermal gradients of the geology. This means that the total liquid temperature will be around 1300C at 3000m, 1900C at 4000m, 3000C at 6000m, 4200C at 8000m and 5500C at 10000m.

To start the thermal syphoning effect in the well (5), a small amount of water movement is required and this will take a 10KW or smaller start-up pump to initiate this flow, or a store of ambient temperature water held in an elevated tank that can be delivered into an annulus of the well head (7) which would avoid the requirement for additional energy. As soon as a volume of cooler liquid is added into the well head (7), the weight of the newly added cooler liquid in the annulus (5a) will be heavier than the weight of the hotter liquid (4) inside of the insulated casing (122) and a flow from the well head (7) will increase as the cooler liquid continues to be added and drawn into the annulus of the well (5a). Within a few minutes, the start-up pump (36a) can be turned off as thermal syphoning effect increases to provide all flow movement from the well head at high pressure.

Depending on the mechanical output required the skilled person can selectively substitute the above described turbine (10) for alternative machines, for example: a direct stream turbine, an ORC turbine, a screw expander, a steam engine or the like.

In some embodiments of the invention a compressor can be substituted for the mechanical pump (14). Here the compressor can be selected from either screw compressors or piston compressors, where a screw compressor will be better suited to a large volume of fluid under lower pressure and a piston compressor will be better suited to a larger pressure with less volume.

9208840_1 (GHMatters) KERRYD

A geothermal pumping station with an organic Rankin cycle

A second aspect of the invention is shown in Figure 2, which illustrates a geothermal pumping station (101), comprising: a primary liquid circuit (1) circulating liquid (3) into a geothermal well (5) and returning heated liquid (4) from a well head (7) of the geothermal well (5); the heated liquid (4) being fed to a heat exchanger (30) to heat a working medium (33) of a secondary circuit (2), wherein the heated and vaporised working medium (34) of the secondary circuit (2) drives a turbine (10) to produce a mechanical output (12); and a pump (14) driven from the mechanical output (12) to pump fluid (16) from a fluid source (18) to a fluid outlet (20) through a condenser (22), wherein the heated and / or vaporised working fluid (34) of the primary liquid circuit (1) is directed through the condenser (22) to cool or condense the working medium (33) before being directed via a circuit pump (36b) to the heat exchanger (30) to be reheated.

The heated liquid (4) from the geothermal well (5) can be fed under pressure in a liquid state to the heat exchanger (30). The liquid (4) of the primary circuit (1) is cooled as it passes through the heat exchanger (30) before being directed back into the geothermal well annulus (5a) by the pressure created by the thermal syphoning effect.

Heat is transferred in the heat exchanger (30) into the working fluid (33) in the secondary circuit (2) causing the working medium (33) to vaporise or turn into steam. The secondary circuit (2) can be referred to as a binary circuit.

The heated and / or vaporised working medium (34) is exhausted from the turbine (10) in a state of lower pressure and temperature when compared to the heated and / or vaporised working medium (34) entering the turbine (10).

The cool or condensed working medium (33) of the secondary circuit (2) or binary circuit is in a liquid state before being directed to the circuit pump (36b) or binary fluid circuit pump.

This is another embodiment of a geothermal pump that requires no electricity and uses the thermal syphoning effect for all energy requirements.

9208840_1 (GHMatters) KERRYD

An Organic Rankin Cycle (ORC) system has been incorporated into the first aspect of the invention to provide mechanical output (12) when the geological temperature is not hot enough for a direct steam or direct screw expander system. This mechanical output (12) is then fed to the pump (14) or a compressor, to pump the fluid (16) from the source (18) to the outlet (20). The pump (14) or compressor uses 100% of the energy provide by the turbine (10) and can provide between 100hp-500hp. The compressor can be a rotary or a piston compressor depending on the required fluid volumes.

The primary liquid circuit (1) operates in the same manner as described herein in relation to the first aspect of the invention; however, the turbine (10) is not driven off the primary liquid circuit (1).

In Figure 2, the primary circuit (1) is shown in dashed line, while the secondary circuit (2) is shown in dot-dot-dashed line, and the fluid or gas (16) to be pumped from source (18) to outlet (20) is shown in solid line.

In contrast to the first aspect of the invention, the ORC system of the geothermal pumping station (101) uses a heat exchanger (30) to transfer the geothermal heat from the primary circuit (1) into a working medium (33) in a secondary circuit (2) that is separated from the primary liquid circuit (1) of the well (5). The secondary circuit (2) is a closed circuit.

The secondary circuit (2) can also incorporate a condenser (22) for cooling the working medium (33) to propagate the ORC and the circuit pump (36b), as illustrated in Figure 2. The energy required to drive the circuit pump (36b) is provided by the primary circuit fluid either before the heat exchanger of after the heat exchanger (30) where a small turbine can be installed. The secondary or binary circuit (2) (ORC system) can use a working medium that has a low boiling point such as N-Pentane.

Similar to the first embodiment described above, the circuit pump (36b) can be driven off the pressure in the pipeline (27), but is preferably driven from the primary circuit fluid (3) either before or after the heat exchanger to eliminate any need for an electrical power source to drive the fluid movement of the secondary circuit (2).

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The circuit pump (36b) draws the cooled liquid state working medium (33) from the condenser (22) at a temperature between 30OC-70°C and pumps it towards the heat exchanger (30) to heat it up to about 1450C to 2500C, depending on the temperature of the primary circuit fluid (4) coming from the geothermal well (5). The circuit pump (36b) can be an air pump or a direct driven pump.

It is contemplated that the secondary, binary or ORC circuit pump (36b) illustrated in Figure 2 can be driven by the pipeline pressure and flow (27) or preferably by an additional turbine integrated into the primary circuit (1). To avoid the requirement for added electricity, the circuit pump (36b) can be driven by compressed air created by a compressor driven from the additional or waste thermal energy contained in flow (4) of the primary circuit (1) after the primary circuit fluid has exited the heat exchanger (30) or from the heated flow (4) prior to the heated primary circuit fluid (4) entering the heat exchanger (30). The circuit pump (36b) can be an air pump or a fluid driven pump.

The secondary circuit (2) passes working medium (33) through the heat exchanger (30) to heat, which turns the working medium to a heated vapour (34). The heated vapour (34) is then fed to the expander or turbine (10) to generate the mechanical output (12) to drive the pump (14) or compressor.

The fluid (16) is drawn from the source (18) and is pumped through the condenser (22) by the pump (14). The source (18) is illustrated in Figure 2, as a dam or tank, fed from a pipeline (27). The fluid (16) may be pumped from an originating source (19) by a subsequent pumping station (40) and fed via pipeline (27) to the source (18). The originating source (19) can be 1-150kms away from the fluid source (18). It will be appreciated that where fluid such as water (20) is pumped across great distances or to a higher elevation and or the thermal energy delivery from one geothermal well is not sufficient to meet the pumping energy requirements, that a plural of geothermal wells (5) and / or a plural of geothermal pumps (14) may be required to meet the pumping energy requirements.

It is further contemplated that the term outlet (20) may not be the final outlet for the fluid, as the fluid (16) can then be sent to a subsequent pipeline, tank, dam, vessel or plant for use.

9208840_1 (GHMatters) KERRYD

Geothermal well The geothermal well (5) and well head (7) are further described in relation to Figures 3A and 3B, which are excerpts from Australian Patent No. AU 2020101487. Although Figures 3A and 3B illustrate only one well (5) it is understood that multiple wells can be used in series or in parallel to increase the potential mechanical output (12) of the geothermal pumping station (100).

A single well (5) is illustrated in Figure 3A to provide a means for transferring geothermal heat through a below ground liquid reservoir and also to provide additional heat transfer properties or performance to heat the liquid (3) as it travels down the annulus (5a) of the well (5) and up the return conduit (5b), for supplying a heated primary circuit liquid (4) from the well head (7). The channels (5a, 5b) are arranged co axially in tubing strings within the well (5) and separated by insulated casing (122).

Shown in Figure 3A, the well (5) includes a pipe inlet 112, a pipe outlet (114), the first channel or annulus (5a) (inlet) and the second channel or conduit (5b) (outlet) disposed concentrically therein.

The first annulus channel (5a) receives liquid from the pipe inlet (112) and is defined between an outer casing (120) and an inner casing (122). The second channel or conduit (5b) is defined by the inner insulated casing (122) positioned within the outer casing (120). The conduit (5b) provides heated liquid (4) to be pushed by the thermal syphoning effect to the wellhead outlet (114).

Additional casings can be nested to extend the well downwards with a decreasing diameter. For example, first outer casing (170) extends from the well head (7) and geological surface inward towards the well end (e.g., into the ground). In some embodiments, the first outer casing (170) extends axially into the ground to a depth of approximately 100 metres. The first outer casing (170) may have a diameter of 30 inches. A second outer casing (172) is positioned within, and may abut, the first outer casing (170) and extends from the well head and geological surface inward towards the well end (e.g. into the ground) at a depth greater than the first outer casing (170). In some embodiments, the second outer casing (172) extends axially into the ground to a depth of approximately 1500 metres. The second outer casing (172) may have a diameter of 20 inches. A third outer casing (174) can be positioned within, and may

9208840_1 (GHMatters) KERRYD abut, the second outer casing (172) and extends from the well head and geological surface inward towards the well end (e.g. into the ground) at a depth greater than the second outer casing (172). In some embodiments, the third outer casing (174) extends axially into the ground to a depth of approximately 3000 metres. The third outer casing (174) may have a diameter of 13 3/8 to 16 inches.

An outer wall (120) is positioned with the third outer casing (174) and extends past the third outer casing (174) and defines a bottom of the well (5). The outer wall (120) is defined by the geological layers such that hot geological liquid can flow into the permeable through a portion (124) of the outer wall (120) in the permeable geological layer. In some embodiments, the permeable portion (124) of the outer wall (120) is at a depth between 7500 metres and 9000 metres. In some embodiments, the outer wall (120) extends axially into the ground to a depth of approximately 8,800 metres. The outer wall (120) may have a diameter of 12 tol4.5 inches. The permeable portion (124) of the outer wall (120) may be configured to allow a liquid flow path (104) through the permeable rock toward a secondary well. The outer wall may be consolidated rock such as granite that contains no groundwater, but has high levels of heat that will transfer into the cooler liquid (3) as the liquid is drawn down the annulus (5a) and comes into contact with the walls (120) of the well (5).

The inner insulated casing (122) is positioned within the outer well (120) and is configured to receive the heated flow of liquid (4) through the first channel (5a) at an end of the inner casing (122). In some embodiments, the end (128) of the inner casing (122) includes an intake screen and/or intake filter that receives the heated fluid flow from the channel (5a) and the thermal syphoning effect pushes the heated fluid (4) up the inside of the conduit (5b) of the insulated casing (122)

In one embodiment, the wellhead inlet (112) of the first well (5) receives a flow of between 5 and 30 kg/sec (e.g., mass flow rate) at a temperature of 500C to 700C that flows through or down the first channel or annulus (5a) towards the bottom of the well. The injection velocity through the first channel (5a) may be 0.1 to 1 m/sec. The liquid is heated as it passes through or past the lower layers of geology.

In some embodiments, liquid from the surrounding geology may enter into the first channel (5a) through the permeable portion (124) of the outer wall (120). The liquid

9208840_1 (GHMatters) KERRYD enters and may expand within the gap (126) as it enters the intake screen (128) of the inner casing (122) and into the outer channel or conduit (5b). The temperature of the liquid may be between 1500C and 3000C s as the liquid travels through the gap (126) toward the second channel (5b). The heated liquid (126) may lose some of the heat contained in the fluid as it is pushed to the surface, through the insulted casing (122) and into the downward fluid flow (5a). Approximately 100C is lost between a bottom (126) of the well (5) and the wellhead outlet (114) but this heat is not lost totally, as it is transferred into downward flow (5a) and increases the heating rate of the downward fluid flow (5a). The flow exiting the well head (114) will have a pressure of between 50 and 200 BAR a flow rate of between 1 and 30 kg/sec at a temperature of between 2900C and 1400C. The well (5) with a bottom hole rock or geology temperature of 4000C may produce a thermal energy output of between 5 and 20 MW, for example 18.92 MW if the well head exit flow is 270 degree C with a flow rate of 20kg per second.

An expanded view of the well head (7) is shown in Figure 3B. The well head (7) includes a plurality of seals (510), an exterior support member (512), and other features to provide proper support and outlet for of the well (5).

The thermal syphoning effect is responsible for the movement of liquid in this system once the start-up pump (36a) initiates the flow. In some embodiments, 500C liquid (water cooled after generating a mechanical output) is drawn down the well (5) where the liquid (3) is heated up on its journey to the bottom of the well (5) and then pushed to the surface at the well head (7). The increased temperature and the pressure created from the heat forces the heated liquid up the production casing to the surface.

In some embodiments, an open well configuration may include the well (5) having a slotted portion at the bottom of the well in-line with the permeable geology such that the liquid can flow in and/or out of the well (5), through the geology, and downstream to a secondary well in series.

In one particular embodiment of the thermal syphoning system, the system may be a six well system, with injection flow rates being: Well 1 -50kg/s, Well 2 -30kg/s, Well 3 kg/s, Well 4 -30kg/s, Well 5 -30kg/s, Well 6 -10kg/s with the total injected being 180kg/second. In this embodiment, the production flow rate may be: Well 1 -30kg/s,

9208840_1 (GHMatters) KERRYD

Well 2 -30kg/s, Well 4 -30kg/s, Well 5 30kg/s and Well 6 -30kg/s. Total production of the embodiment may result in a flow rate of about 180kg/second and 116 MW of thermal energy or 24MW of electricity.

In one arrangements of the well (5) using a thermal syphoning system, a 3000C or hotter bottom hole geology temperature, the natural flow rate out of a 6.3" insulated production casing at the surface is 30kg/s or a velocity of 2 m/s. While the liquid (4) may experience heat loss on the journey up the well (5), the outlet temperature will typically be 10°C less than the liquid temperature at the bottom of the well (5).

The well (5) can be configured for a few thousand metres depth up to about 12,000m deep into almost any geology including granite. The geothermal heat is exchanged at depth via a closed-loop system rather than bringing deep geothermal brine to the surface. This form of well (5) has a production life of 100+ years, with relatively low maintenance costs. The well (5) has a small physical footprint and has minimal impact on surface ground water systems, as the layers of casings around the well (5) provide protection.

In a third aspect the invention provides a method of pumping water or gas from a source (18) to an outlet (20), powered by geothermal energy, comprising the steps: feeding liquid into a geothermal well (5) and drawing heated liquid (4) from the well head (5) of the geothermal well (5) to form a primary liquid circuit (step 400); vaporising the heated liquid from the primary liquid circuit (1) and communicating the vapour to a turbine (10) to produce a mechanical output (12) (step 401); and driving a pump (14) directly from the mechanical output (12) to pump water or gas from the source (18) to the outlet (20) through a condenser (22) (step 402), wherein the liquid (3) of the primary liquid circuit (1) is drawn through the condenser (22) to cool and condense before being returned to the geothermal well (5) to be reheated (step 403).

The method of pumping water or gas from a source or a supply line to an outlet is described further in relation to Figure 4.

In some embodiments the turbine (10) is driven directly off the primary liquid circuit (1). Alternatively, the primary liquid circuit (1) can be configured to transfer heat energy to a

9208840_1 (GHMatters) KERRYD secondary circuit (2) via a heat exchanger (30), and the turbine (10) is then driven off the secondary circuit (2).

In some embodiments the method further comprises a step of pumping a working medium (33) around the secondary circuit (2) to draw cool working medium (33) through the condenser (22) before it is sent back to the heat exchanger (30) to be increased in temperature and / or vaporised.

It is further contemplated that step (402) of driving the pump (14) can be exchanged for driving a compressor, depending on the nature and volume of the fluid (16) to be moved.

It will be appreciated by persons skilled in the art that numerous variations and modifications may be made to the above-described embodiments, without departing from the scope of the following claims. The present embodiments are, therefore, to be considered in all respects as illustrative of the scope of protection, and not restrictively.

As used herein and in the appended claims, the singular form of a word includes the plural, unless the context clearly dictates otherwise. Thus, the references "a," "an" and "the" are generally inclusive of the plurals of the respective terms. For example, reference to "a feature" includes a plurality of such "features." The term "and/or" used in the context of "X and/or Y" should be interpreted as "X," or "Y," or "X and Y.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary

9208840_1 (GHMatters) KERRYD implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

9208840_1 (GHMatters) KERRYD

LEGEND No. Description No. Description 100 Geothermal pumping station 101 Geothermal pumping station i Primary liquid circuit 29 2 Secondary liquid circuit 30 Heat exchanger 3 Cooled primary liquid eg. water 31 4 Heated water/vapour 32 Geothermal well Cooled and I or condensed 5 33 working medium Annulus of well (primary liquid Heated working medium or 5a 34 injection path) vapour Second channel or conduit for 5b 35 heated fluid 6 Steam

7 Wellhead Start-up pump (or pnmary circuit pump)

Residual heated liquid 36b Circuit (secondary or binary) 8 pump 9 Turbine exhaust 38 10 Turbine 40 Subsequent Pumping station 12 Mechanical output 112 Well Head inlet 14 Mechanical pump 114 Well Head outlet 15 120 Outer casing 16 Pump intake fluid 122 Insulated casing 17 170 First casing 18 Fluid storage tank of dam 172 Second casing 19 Intialfluid source 174 Third casing 20 Fluid outlet 510 Seals 22 Condenser 512 Exterior support members 25 Flash separator 400 Heating liquid step 26 Drain 401 Driving turbine step 27 Pipe-line system 402 Pumping step 28 403 Coolingliquid step

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Claims

CLAIMS 1. A geothermal pumping station, comprising: a primary liquid circuit circulating liquid into a geothermal well and returning heated liquid from a well head of the geothermal well; a turbine driven off the heated liquid to produce a mechanical output; and a mechanical pump driven from the mechanical output to pump fluid from a fluid source to a fluid output through a condenser, wherein the liquid of the primary liquid circuit is drawn across the condenser to cool before being returned to the geothermal well to be reheated.
2. The geothermal pumping station of claim 2, wherein a portion of the heated liquid is subject to a pressure change to produce a vapour to drive the turbine.
3. A geothermal pumping station, comprising: a primary liquid circuit circulating liquid into a geothermal well and returning heated liquid from a well head of the geothermal well; a heat exchanger heated by the heated liquid of the primary circuit to heat and vaporise a working medium of a secondary circuit, wherein the heated vaporised working medium of the secondary circuit drives a turbine to produce a mechanical output; and a mechanical pump driven from the mechanical output to pump fluid from a fluid source to a fluid outlet through a condenser, wherein the liquid of the primary liquid circuit is cooled as it passes through the heat exchanger and returned to the geothermal well to be reheated and the fluid from the fluid source is pumped through the condenser, to cool and condense the working medium before re-entering the heat exchanger to be re-heated.
4. The geothermal pumping station of any one of claims 1-3, wherein the mechanical pump is substituted for a compressor.
5. The geothermal pumping station of any one of claims 1-4, wherein the fluid is water or gas.

9208840_1 (GHMatters) KERRYD