GEOTHERMAL HEAT PUMP BELOW THE EARTH’S SURFACE

The invention relates to a system for installing a geothermal probe of a geothermal heat pump below the Earth’s surface. The invention also relates to a method for installing a geothermal probe of a geothermal heat pump below the Earth’s surface

Heat pumps are a proven technology that have been used for decades for both heating and cooling in particular for buildings. Basically, a heat pump is an electrically driven device that extracts heat from a low temperature place (a source), and delivers it to a higher temperature place (a sink), or vice versa. Heat pump typically make use of an air source, wherein the heat pump draws heat from the outside air during the heating season and rejects heat outside during the summer cooling season. It is also conceivable that a ground source is used instead of an air source. An example of such heat pump is a geothermal heat pump. Geothermal heat pumps make use of the relatively constant temperature of the earth as the exchange medium instead of the outside air temperature. A geothermal heat pump typically comprises at least one geothermal probe which is located underground and which is attached to the heat pump at ground level. During use, a heat transfer fluid, such as water and/or anti-freeze, is pumped into the geothermal probe and absorbs the heat that naturally occurs and is stored in the ground. The returned heat transfer fluid is typically compressed and passed through a heat exchanger, which extracts the heat and transfers it to the heat pump. The heat is then transferred to for example a heating system of a building.

A drawback of making use of a ground source type of heat pumps is that the geothermal probe needs to be positioned below the Earth’s surface, preferably in a vertical configuration to make optimal use of the cooling capacity of the earth and to minimize the overall space which is needed at the surface. Installing a geothermal probe via a conventional method and system is rather expensive due to need of using costly machines, the process is time consuming and requires highly specialized and qualified staff. It is not possible to install a geothermal probe at every place because of the needed space for both the system itself, but also for the installation process. Typically, the installation of a geothermal probe is done by making use of a drilling system and method wherein a bore hole is drilled and consolidated by making use of multiple 4 or 5m pipes. Once the bore hole is at sufficient depth, the drill pipes need to be removed such that the geothermal probe can be placed into the bore shaft. During this process, the drilling fluid need to be present in the bore hole in order to prevent collapsing thereof. Once the geothermal probe is installed, the grouting process can start to consolidate the geothermal probe. The drilling fluid is removed from the shaft during the grouting process. As can be understood, it requires at least three to four subsequent steps to position and consolidate a geothermal probe in the shaft. During each step, the shaft can get damaged and the longer the shaft is open the more the risk for damages. This is undesired since the overall process is very costly and collapsing of the shaft may have not only financial consequences but may also cause harmful landslides. Hence, there is a desire for a more efficient and reliable system and method to install geothermal probes.

It is a goal of the invention to provide and improved system and/or method for the installing a geothermal probe of a geothermal heat pump below the Earth’s surface.

The invention provides thereto a system for installing at least one geothermal probe of a geothermal heat pump below the Earth’s surface; said system comprising:

- at least one drilling tube;

- at least one drilling device (directly or indirectly) connected or connectable to the at least one drilling tube, said drilling device comprising at least one mud motor and at least one drilling head, wherein the drilling device is configured for drilling at least one bore hole;

- at least one connection element configured for at least temporarily attaching at least one geothermal probe; wherein at least one drilling tube is configured to provide drilling fluid in particular to the drilling device and/or configured for the provision of grout into the bore hole.

The system according to the present invention has several benefits over conventional systems for installing at least one geothermal probe of a geothermal heat pump below the Earth’s surface. The system according to the invention enables that the drilling of the bore hole, positioning of the geothermal probe and grouting of the bore hole can be done in a single run. Prior art systems make use of open hole drilling methods wherein drill pipes are applied to provide a bore hole, or bore shaft. Once bore hole, or bore shaft, is complete, drill tools are removed from the bore hole and subsequently, the geothermal probe(s) is installed in the bore hole. Typically, in the prior art, either water flush open hole drilling techniques or compressed air open hole drilling are to be used in order to prevent the bore hole from collapsing. Once the geothermal probe is positioned, a grouting step is to be performed. Grouting is a critical factor for vertically positioned geothermal probes. This essential step should be completed as soon as possible when the geothermal prove is inserted in the bore hole. Waiting a day or more to complete this task is prohibited and can lead to environmental and thermal conductivity issues as proper grouting provides for an important environmental surface barrier and thermal connection between the geothermal probe and the ground surrounding it. Hence, the conventional method make use of at least three separate and subsequent runs wherein timing is critical. The use of a system which benefits of the combination of at least one drilling tube which is connected to a drilling device comprising at least one drilling head and at least one mud motor, and which system comprises at least one connection element configured for at least temporarily attaching at least one geothermal probe, wherein at least one drilling tube is configured to provide drilling fluid to the drilling device and/or configured for the provision of grout into the bore hole enables that all essential steps of the installing procedure of the geothermal probe(s) can be done in a single run. The drilling tube enables the provision of drilling fluid during the initial boring by the drilling device. Due to the efficient boring characteristics of the drilling device comprising at least one drilling head and at least one mud motor, it is possible to insert the geothermal probe during the initial boring. The connection element enables that the geothermal probe actually can be taken with into the bore hole during the initial boring. Due to the multifunctional character of the drilling tube, wherein the drilling tube is both configured to provide drilling fluid to the drilling device and for the provision of grout into the bore hole it is possible that the grouting process is started directly when the geothermal probe has reached the desired position. The drilling process by the drilling device will be stopped when the geothermal prove has reached the desired position in the bore hole. The geothermal probe can be disconnected from the system, either with or without the connection element. The providing of drilling fluid can be stopped and the drilling tube can then be used for the provision of grout into the bore hole in particular such that the bore hole is filled with grout thereby consolidating the geothermal probe in the bore hole. During (and/or after) the grouting process the drilling device can be pulled up again and thereby removed from the bore hole. Reducing the number of runs will not only be beneficial in view of the required labor but this will also significantly reduce the time which is needed to install the geothermal probe. Yet a further benefit of the system to the invention is that the system is relatively simple compared to prior art system, which results in the system being significantly cheaper as such and in operation than conventional systems.

In addition to the reduction of process steps, the system and method according to the present invention have several further benefits. In the conventional method and system, the bore hole must be relatively large to ensure that the geothermal probe fits in. A margin in the diameter of the bore hole is to be taken into account for example to be able to compensate for any damages in the side walls which occurred during any of the processing steps. Due to the efficient system and method according to the invention, the geothermal probe is taken directly towards the final position during the initial boring process resulting in that the diameter of the bore hole can be minimalized. In fact, the diameter of the bore hole can be adapted based on the geothermal probes applied and/or based upon the drilling device. Minimizing the diameter of the bore hole has several benefits. At first, significantly less grout is needed to fill up the bore hole which is beneficial from material and economical point of view. Less grout surrounding the geothermal probe is also beneficial for the thermodynamic performance of the geothermal probe itself, and thus also for the performance and the efficiency of the overall (geothermal) heat pump system. The grout has an isolating effect which can negatively influence the heat exchange between the (fluid inside) the geothermal probe and the ground surrounding it.

The drilling tube is in particular a substantially longitudinal and/or hollow tube. The drilling tube is configured for the trough put of fluids, such as drilling fluid and grout. The drilling tube can also be referred to as functional tube and/or grouting tube. It is conceivable that at least part of at least one drilling tube is substantially flexible. It is also conceivable that at least part of at least one drilling tube is reinforced. At least one drilling tube is in particular configured such that the weight of the drilling device can be retained by the drilling tube. The drilling tube typically comprises at least one first opening and at least and second opening which in particular oppose another. The first opening can be present at the a first end of the drilling tube and a second opening can be present at a second end of the drilling tube. The drilling tube can be made of any material which is suitable for the throughput of fluids, amongst which grout and/or drilling fluid. The drilling tube can for example be at least partially made of a polymer material, for example a reinforced polymer material. It is also conceivable that at least part of the drilling tube is a rubber reinforced hydraulic hose.

At least one connection element according to the invention is in particular configured to at least temporarily attach at least one geothermal probe. The connection element is preferably configured to retain at least one geothermal probe during the provision of the bore hole, in particular during the drilling thereof by the at least one drilling device. At least one connection element can for example be configured to attached at least one geothermal probe to the drilling device and/or to the drilling tube. At least one geothermal probe typically comprises at least one tube, for example a polymer tube. At least one geothermal probe is typically substantially U-shaped.

The drilling device according to the invention comprises at least one mud motor and at least one drilling head. The drilling head can also be referred to as cutting head. The mud motor can be a conventional mud motor suitable for (vertical and/or horizontal) drilling. The mud motor can for example be configured to operate at at least 100 rpm, preferably at least 150 rpm, more preferably at least 200 rpm. It is for example conceivable that at least one mud motor is configured to operate in a range of 100 to 300 rpm. The drilling device is preferably at least configured for substantially vertically drilling. Alternatively the drilling device can be suitable for substantially horizontal drilling.

At least one drilling tube can be coupled directly or indirectly to the drilling device. It is conceivable that at least one drilling tube and at least one drilling device are coupled in a releasable manner. This is beneficial at least for maintenance purposes. It is also possible that at least one drilling tube and at least one drilling device comprise complementary coupling elements for mutual coupling of the drilling tube and the drilling device. In a preferred embodiment, at least one drilling tube is coupling to the drilling device under the interference of at least one coupling structure. It is conceivable that the system according to the invention comprises at least one coupling structure provided between at least one drilling tube and at least one drilling device. The coupling structure preferably comprises at least one opening, in particular an opening configured for the throughput of fluids. Such opening could also be referred to as fluid opening. The provision of at least one coupling structure can further improve the ease of use of the system. The coupling between the drilling tube and the drilling device can be established in an efficient manner when a coupling structure is applied. It is in particular beneficial if at least one coupling structure comprises at least one (side) opening for the throughput of fluids. In this way, the throughput of at least grouting material via the coupling structure can be facilitated. In a further preferred embodiment, at least one coupling structure comprises a hollow body comprising at least one side wall, wherein said hollow body extends between an upper opening and a bottom opening. Preferably, said upper opening of the coupling structure is connected (or connectable) to at least one drilling tube and said bottom opening of the coupling structure is connected (or connectable) to at least one drilling device. At least one side wall of the hollow body preferably comprises at least one side opening configured for fluid flow through the hollow body in particular between at least the upper opening and the at least one side opening. In this way, the coupling structure can enable the outflow of fluid via a side wall of the coupling structure in an efficient manner. The coupling structure could for example also be referred to as a circulation structure or circulation sub.

In a preferred embodiment, at least part of the coupling structure comprises a substantially cylindrical side wall. The use of a substantially cylindrical side wall is beneficial since it further contributes to the provision of an efficient system. The drilling tube is typically substantially cylindrical. It is also conceivable that at least part of the drilling device is at least partially cylindrical. Hence, coupling of the coupling structure and the drilling tube and/or the drilling device will be simplified. The substantially cylindrical shape is also beneficial for the throughput of fluid and for the ease of cleaning of the components after use.

It is conceivable that at least one coupling structure comprises a plurality of opening, in particular side openings. The use of multiple side openings can contribute to the efficient (out)flow of fluid, in particular grout, through the openings. It is for example conceivable that at least one coupling structure comprises at least two (side) openings, wherein said openings are positioned at a predetermined distance from another. It is for example conceivable that at least two openings substantially oppose each other. It is also conceivable, for a specific embodiment, that at least two openings are positioned at a distance from another over a circumference of the substantially cylindrical side wall of the coupling structure. At least one opening is preferably positioned at a lower part of the coupling structure. Preferably, at least one opening is located near the bottom opening of the coupling structure. In this way, efficient flow of fluid through the opening can be facilitated. It is for example imaginable that at least one opening is located in a lower region of the coupling structure. It is noted that the terms upper and lower are non-limiting and are chosen to indicate a vertical position during use of the system in a vertical boring process.

In a preferred embodiment, the system comprises at least one closing element for closing at least one opening, for example a side opening, of the coupling structure, in particular wherein at least one closing element is displaceable between at least an opened position and a closed position. The use of at least one closing element can contribute to the controllability and thus the ease of use of the system. Typically, in the closed position at least one opening is at least partially and preferably fully closed and in the open position at least one opening is at least partially and preferably fully open. It is imaginable that at least one closing element forms part of the closing structure. It is also conceivable that at least one closing element is a separate component. In case the coupling structure comprises multiple (side) openings, it is conceivable that the system comprises multiple closing element. It is for example conceivable that the system comprises an equal number of (side) openings and closing element. However, it is also conceivable that at least one closing element is applied to close and/or open multiple (side) openings at the same time. It is also conceivable that at least one closing element is configured to open at least one opening, in particular at least one side opening, whilst simultaneously close at least one bottom opening, or vice versa. In a preferred embodiment, at least one closing element is closable and/or openable from a distance. This will enable control of the closing element from a distance. It is also conceivable that the system comprises at least one further closing element for closing at least part of the bottom opening of the coupling structure, in particular wherein at least one further closing element is displaceable between at least an opened position and a closed position. Typically, in the closed position of the further closing element, at least one further opening is at least partially and preferably fully closed and in the open position at least one further opening is at least partially and preferably fully open. The further closing element may possibly form part of the closing structure.

In a further beneficial embodiment, the system comprises at least one activator, wherein said activator is at least configured for displacing at least one closing element from the closed position to the opened position and/or vice versa. At least one activator can be configured to close and/or open at least one closing element of at least one side opening and/or at least one further closing element of the bottom opening. It is also imaginable that at least one activator is configured to activate at least one closing element of at least one side opening and at least one further closing element of at least one bottom opening subsequently or even substantially simultaneously. In a further preferred embodiment, at least one activator is displaceable at least through the drilling tube. Hence, at least activator can be pumped and/or provided via the drilling tube into the coupling structure. It is for example conceivable that at least one activator is a displaceable activator. At least one activator could also comprise at least one displaceable component, such as but not limited to a ball. It is also imaginable that at least one activator is or comprises a secondary closing element. It is for example conceivable that at least one activator, or secondary closing element, is configured to close the bottom opening whilst activating at least one closing element of at least one (side) opening. It is for example possible that at least one closing element is formed by an internal sleeve which is activated via at least one displaceable activator. Activation of at least one closing element can for example be done via at least one spring. It is for example conceivable that at least one closing element is a spring activated closing element.

In a possible embodiment, at least one coupling structure forms part of the drilling tube and/or at least one coupling structure forms part of the drilling device. It is for example imaginable that at least one coupling structure forms integral part of the drilling tube. It is also possible that at least one coupling structure forms part of a distal end of at least one drilling tube.

In a preferred embodiment, at least one drilling device comprises at least one hole opener. It is beneficial to apply at least one hole opener as this could control the diameter of the bore hole in an efficient and effective manner. At least one hole opener can for example be configured to enlarge the bore hole during the drilling thereof. At least one hole opener, if applied, is preferably positioned between the drilling head and the mud motor. At least one hole opener can for example be a hydraulically actuated hole opener. It is also conceivable that at least one hole opener is a spring activated hole opener. The hole opener may comprise for example a plurality of arms or wings, for example two or three arms (or wings). It is also conceivable that the hole opener comprises at least one wing which is displaceable between an opened position and a collapsed position. In a preferred embodiment, the hole opener can be configured to be activated during the drilling process and deactivated during the grouting process. Hence, in an interesting embodiment, it is conceivable that at least one hole opener is urged to the collapsed position upon closure of the bottom opening of the coupling structure, if applied.

It is also conceivable that at least one drilling device comprises at least one stabilizer element. Said stabilizer element can for example be configured to (mechanically) stabilize at least part of the drilling device. It is also conceivable that at least one stabilizer element is configured to reduce vibration of at least part of the drilling device.

At least part of at least one drilling tube is preferably reinforced. The drilling tube is preferably of sufficient strength to carry the weight of the drilling device and at least one geothermal probe and to facilitate a grouting process. At least part of the drilling tube is preferably substantially flexible. This will be beneficial for the ease of use of the drilling tube. It is also beneficial if at least part of the drilling tube is substantially flexible such that the drilling tube can be provided upon a roll. It is also conceivable that at least part of the drilling tube is an armoured drilling tube. The system comprises at least one connection element which is configured for at least temporarily attaching at least one geothermal probe. In this way, the geothermal probe can be taken into the bore hole in an effective and efficient manner. At least one connection element is in a preferred embodiment substantially hook shaped. It is also imaginable that at least one connection element comprises at least one hook shaped member. A hook shape can provide for temporary attachment in an effective way. It is possible that at least one connection element is releasably connected to at least one drilling tube. It is also conceivable that at least one connection element is releasably connected to at least one drilling device. Preferably, at least part of at least one connection element is connected to a coupling part of drilling tube, if applied. The application of the connection element may vary in practice, based upon the method and/or system applied. It is for example conceivable that at least part of the connection element is detached together with the geothermal probe and thus stays in the bore hole. It is also possible that at least one connection element releases the geothermal probe, such that the connection element can be reused for a subsequent geothermal probe positioning.

At least one geothermal probe is typically at least partially made of plastic and/or at least one polymer, preferably a thermoplastic polymer. At least one geothermal probe can for example be at least partially made of polyethylene. The geothermal probe is typically relatively rigid. Due to stiffness in combination with the relatively large dimensions of the geothermal probe, in particular in length, it is conceivable that (part of) the geothermal probe gets curved and/or partially bended. In order to further optimize the process of applying the geothermal probe into the bore hole, it is desired that the geothermal probe, or at least the tubes thereof, are substantially straight. It is thus conceivable that the system further comprises at least one heating element for heating at least part of the geothermal probe, in particular prior to the geothermal probe is provided in the bore hole. The system may also comprise at least one guiding structure, for straightening at least part of the geothermal probe, in particular prior to the geothermal probe is provided in the bore hole. Hence, a combination of at least one heating element and at least one guiding structure can be applied to substantially straighten the at least one geothermal probe. At least one guiding structure could also comprise at least one heating element. A substantially straight geothermal probe may further optimize the system and method according to the present invention as the geothermal probe will cause less friction within the bore hole, and the grout and/or drilling fluid will be more efficiently used with less clogging and/or fouling. At least one heating element is preferably configured to heat at least part of the geothermal probe to a predetermined temperature, for example in the range of 5 to 40 degrees Celsius, preferably 10 to 30 degrees Celsius, more preferably 20 to 25 degrees Celsius. The guiding structure can for example comprise multiple guiding rollers, for example at least three guiding rollers, through which at least part of the geothermal probe can be guided preferably in a straight configuration. At least two adjacent rollers can for example be stationary, whilst at least one opposing roller can displaceable. At least one opposing roller is preferably configured for providing a pressure towards the geothermal probe. It is also imaginable that at least one heating element is integrated in at least one roller or at least one roller can be configured to be a heated.

The system may also include at least one device for the provision of drilling fluid and/or at least one sieve, in particular at least one vibrating sieve. Said sieve is preferably configured to filter at least part of the drilling fluid. It is also conceivable that at least one vibrating sieve is referred to as a shaker. The system may also comprise at least one grout reservoir and/or at least one grout pump. The system may further comprise at least one pump for pumping drilling fluid and/or grout in particular into the drilling pipe.

Possibly, the system according to the present invention can be provided upon a mobile device. The system according to the invention can be relatively compact, in particular compared to conventional systems for installing a geothermal probe of a geothermal heat pump system below the Earth’s surface, which is beneficial for the mobility of the system. It is also imaginable that at least part of the system is mobile. For example at least one grout reservoir, at least one grout pump, at least one drilling fluid reservoir and/or at least one pump for pumping drilling fluid and/or grout into the drilling pipe can be displaceable and/or mobile.

The invention also relates to the use of a system according to the present invention. The invention further relates to a method for installing at least one geothermal probe of a geothermal heat pump below the Earth’s surface, in particular by making use of a system according to the present invention, said method comprising the steps of: a) drilling at least one bore hole by means of at least one drilling device, said drilling device comprising at least one mud motor and at least one drilling head, wherein said drilling device is connected (directly or indirectly) with at least one drilling tube and wherein during the drilling of the bore hole drilling fluid is provided to the drilling device via the at least one drilling tube; b) providing at least one geothermal probe in the bore hole, wherein at least one geothermal probe is at least temporarily attached to the at least one drilling device and/or to the at least one drilling tube in particular by means of at least one connection element; c) filling at least part of the bore hole with grout, wherein the grout is provided via the at least one drilling tube.

The method according to present invention benefits of the same advantageous as described for the corresponding system according to the present invention. Any of the described embodiment and benefits of the system apply also to the method. The drilling device applied can be any of the described embodiment as applied in a system according to the present invention which also applies for the drilling tube and the further components of the system. The method according to the invention enables that the drilling of the bore hole, positioning of the geothermal probe and grouting of the bore hole can be done in a single run whereas conventional methods make use of at least three separate and subsequent runs. The method further benefits from fact that the geothermal probe is taken directly towards the final position during the initial boring resulting in that the diameter of the bore hole can be minimalized.

The method is in particular configured to perform steps a), b) and/or c) substantially subsequently and/or in a single run. In particular provide the system and method for a solution wherein the drilling fluid and the grout are provided via the same drilling tube. The grouting step c) is preferably performed during removal of the drilling device from the bore hole. In this way, grouting of the bore hole can be performed in an efficient and effective manner. In a possible embodiment, at least one bore hole is flushed with drilling fluid prior to the grouting step.

In a preferred embodiment, at least one drilling tube is coupling to the drilling device under the interference of at least one coupling structure which coupling structure comprises at least one opening, in particular an opening configured for the throughput of fluids. More preferably, the system comprises at least one closing element for closing at least one opening, for example a side opening, of the coupling structure, in particular wherein at least one closing element is displaceable between at least an opened position and a closed position. The method may include the step of displacing at least one closing element from the closed position to the open position, or vice versa. In case the system comprises at least one further closing element for closing at least part of the bottom opening of the coupling structure, in particular wherein at least one further closing element is displaceable between at least an opened position and a closed position, the method may also include the step of displacing said further closing element from an open position to a closed position, or vice versa. The system may also comprise at least one activator, wherein said activator is at least configured for displacing at least one closing element from the closed position to the opened position and/or vice versa. The method may include the step of activating at least one activator. It is for example imaginable that at least one activator is configured to activate at least one closing element of at least one side opening and at least one further closing element of at least one bottom opening subsequently or even substantially simultaneously. The method may for example comprise the step of providing or pumping at least activator via the drilling tube into the coupling structure, in particular such that at least one closing element of at least one side opening is activated and/or at least one further closing element of at least one bottom opening is activated. In a preferred embodiment, the step of providing at least one activator in at least one drilling tube will result in that the activator, or secondary closing element, closes the bottom opening whilst activating at least one closing element of at least one (side) opening. The method may also comprise the step of sieving at least part of the drilling fluid, in particular prior to and/or after the drilling process. The sieving step can for example be done by means of at least one sieve, in particular at least one vibrating sieve. As indicated above, the system and method according to the invention enable that the drilling of the bore hole, positioning of the geothermal probe and grouting of the bore hole can be done in a single run whereas conventional methods make use of at least three separate and subsequent runs. It is beneficial to make use of a relatively viscous drilling fluid, as this would enable good cleaning of the bore hole. Filtering and/or sieving of the drilling fluid is preferred in order to prevent for example sand to sink and thus foul the bore hole. Downhole tools will last a lot longer without low amounts of sands in the drilling fluid. A relatively viscous drilling fluid is for example also beneficial as this enables a relatively low pumping capacity.

The method could optionally include the step of heating and/or straightening at least part of at least one geothermal probe, in particular prior to or at the moment that the geothermal probe is provided in the bore hole. This step could be applied via use of at least one heating element and/or at least one guiding structure for substantially straightening at least part of the at least one geothermal probe.

The invention will be further elucidated by means of non-limiting exemplary embodiments illustrated in the following figure, in which:

- figure 1 shows a possible embodiment of a system according to the present invention

Within these figures, similar reference numbers correspond to similar or equivalent elements or features.

Figure 1 shows a schematic representation of a system 100 according to the present invention, which system 100 is configured for installing at least one geothermal probe 200 of a geothermal heat pump (not shown) below the Earth’s surface. The system 100 comprises a drilling tube 101 and a drilling device 102 connected to said drilling tube 101. The drilling device 102 comprising a mud motor 103 and a drilling head 104. The drilling device 102 is configured for drilling at least one bore hole into the ground wherein the geothermal probe 200 can be positioned. At least part of the drilling device 102 is configured to provide a rotational movement such that the drilling head 104 can cut into the ground. The drilling tube 101 is configured to provide drilling fluid to the drilling device 102 and configured for the provision of grout into the bore hole. The system 100 further comprises at least one connection element 105 configured for at least temporarily attaching the geothermal probe 200. The connection element 105 is in the nonlimiting example of the shown embodiment substantially hook shaped. In the embodiment as shown, the connection element 105 is (releasably) attached to the drilling tube 101. The system 100 further comprising a coupling structure 106 which is provided between the drilling tube 101 and the drilling device 102. The coupling structure 107 comprises at least one opening 108 for the throughput of fluid. In the shown embodiment is part of the coupling structure 106 provided as a substantially hollow body which connects to the drilling tube 101 . In this way, the drilling fluid provided via the drilling tube 101 can be supplied to the drilling device 102 via the coupling structure 106. The (outer and/or inner) diameter of the coupling structure 106 is substantially equal to the (outer and/or inner) diameter of the drilling tube 101 . The opening 107 of the coupling structure 106 is configured for the throughput of grout during the grouting step. The opening 107 can be closed during the provision of drilling fluid to the drilling device 102 during the drilling process. Hence, the system 100 preferably comprises at least one closing element for closing at least one opening 107 of the coupling structure 106. Likewise, the system may comprise at least one further closing element for closing at least part of the bottom opening of the coupling structure 106 though which the drilling fluid flows towards the drilling device 102. Said closing elements are preferably at least partially internally positioned in the coupling structure 106 and can optionally be activated by at least one activator. The drilling device 102 comprises in the shown embodiment a hole opener 108. The hole opener 108 can be used to enlarge the bore hole during the drilling step. This is beneficial to ensure that the geothermal probe 200 can be fitted inside the bore hole. In the shown embodiment, the hole opener 108 extends between the drilling head 104 and the mud motor 103. The hole opener 108 is provided with (preferably spring activated) wings which are displaceable between an opened position and a collapsed position. Optionally, the drilling device 102 comprises a stabilizer element 109 which is configured to mechanically stabilize the drilling device within the bore hole in order to avoid unintentional sidetracking, and vibrations to ensure the quality of the bore hole being drilled. In the shown embodiment, the system 100 comprises a heating element 110 and a guiding structure 111 configured to substantially straighten the geothermal probe 200. The guiding structure 111 comprises multiple guiding rollers 112a, 112b, 112c through which the geothermal probe 200 guided. The combination of heating and guiding will achieve a straightening effect for the geothermal probe 200. In the shown embodiment, the at least one heating element 110 is positioned prior to guiding rollers 112a, 112b, 112c, such that the geothermal probe 200 is at least partially heated before being guided through the guiding structure 111. It is also imaginable that the roller 112a, 112b, 112c itself are configured to be heated. In the shown embodiments, the two adjacent rollers 112a, 112b are substantially stationary, whilst the opposing roller 11b is displaceable such that a pressure towards the geothermal probe 200, and the stationary rollers 112a, 112b can be provided.

It will be clear that the invention is not limited to the exemplary embodiments which are illustrated and described here, but that countless variants are possible within the framework of the attached claims, which will be obvious to the person skilled in the art. In this case, it is conceivable for different inventive concepts and/or technical measures of the above-described variant embodiments to be completely or partly combined without departing from the inventive idea described in the attached claims.

The verb 'comprise' and its conjugations as used in this patent document are understood to mean not only 'comprise', but to also include the expressions 'contain', 'substantially contain', 'formed by' and conjugations thereof.