A device, system and method for reaming a substantially horizontal directional tunnel for installation of a casing pipe for utilities

Abstract

A device, system and method for reaming a substantially horizontal bore for installation of a casing pipe for utilities. The device for draining loosened ground from reaming of a substantially horizontal bore for installation of a casing pipe for utilities. The device comprises a trailing pipe for being trailed behind a reamer head. The trailing pipe forming at least part of a drainage channel for draining loosened ground therethrough. The device comprises a pump unit for being connected between a leading end of the trailing pipe and the reamer head. The pump unit is configured for drawing the loosened ground into the drainage channel and pumping the loosened ground through the drainage channel away from the reamer head.

Description

[0001] Title: A device, system and method for reaming a substantially horizontal directional tunnel for installation of a casing pipe for utilities

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to systems and methods for installation of a casing pipe for utilities. In particular, the invention relates to systems and methods for drilling and reaming a substantially horizontal bore for installation of a casing pipe for utilities.

[0004] BACKGROUND

[0005] Utilities provide people with electricity, telecommunications, water, gas, sewerage, ventilation and / or air conditioning. Many types of utilities are generally installed using casing pipes. Casing pipes for utilities are known to be installed in ground. Thereto, a pilot bore (horizontal directional tunnel) is produced along a drilling line by moving a steerable drill head underground from a first point to a second point. The drilling line is generally horizontal. The pilot bore is expanded in a plurality of successive reaming steps by driving a reamer head along the drilling line. After a pass along the drilling line, a subsequent pass is executed with a larger diameter reamer head. Upon reaching the desired diameter, a casing pipe is inserted in the bore.

[0006] Drilling and reaming of the bore typically involves a supply of drilling fluid under pressure into the bore hole. The drilling fluid fills the interstitial space between the drill shaft and the bore boundary. The drilling fluid facilitates the drilling and reaming by exerting hydrostatic pressure to keep the bore stable and prevent it from collapsing, as well as suspending loosened ground. The drilling fluid is typically supplied in large volumes and at a high pressure via supply line to the drill or reamer head, and evacuated from the bore via the interstitial space.

[0007] It can nonetheless occur in practice that the bore partly collapses, for example due to shifting of the ground, creating a blockage for the drilling fluid to be drained from the bore. The pressure build-up as a result of continued supply of drilling fluid into the bore and the inability of the drilling fluid to be evacuated from the bore can cause a so-called blowout event, where the drilling fluid is uncontrollably released from the bore, and often breaks and / or leaks through the ground surface.

[0008] SUMMARY

[0009] It is an object to provide an improved device for installation of a casing pipe for utilities, and an improved system and method for reaming a substantially horizontal directional bore for installation of a casing pipe for utilities. It is particularly an object to eliminate or at least reduce the risk of blowout events

[0010] Hereto, a device is provided for draining loosened ground from reaming of a substantially horizontal directional bore for installation of a casing pipe for utilities, as well as a system and method for reaming a substantially horizontal directional bore for installation of a casing pipe for utilities.

[0011] According to a first aspect is provided a device for draining loosened ground from reaming of a substantially horizontal directional bore for installation of a casing pipe for utilities. It will be appreciated that a substantially horizontal bore is a generally nonvertically extending underground tunnel, that particularly spans a horizontal distance between entrance pit a ground surface exit pit. The substantially horizontal bore need not be entirely straight, but may include bends, particularly as at towards its ends.

[0012] The device comprises a trailing pipe for being trailed behind a reamer head. The substantially horizontal bore can be reamed to an expand the bore diameter using the device and the reamer head. After reaming of the substantially horizontal bore, the bore may be ready for installation of the casing pipe for utilities therein. The device can be a drainage device. The trailing pipe forms at least part of a drainage channel for draining loosened ground therethrough. The device comprises a pump unit for being connected between a leading end of the trailing pipe, , e.g. at a swivel, and the reamer head. The pump unit is configured for drawing the loosened ground into the drainage channel and pumping the loosened ground through the drainage channel away from the reamer head. Ground particles can be loosened from surrounding ground by the reamer head such that these particles become loosened ground. The device can be configured to draw and move said loosened ground, optionally in combination with the drilling fluid, from at or near the reamer head, e.g. along part of the expanded bore, into the drainage channel away from the reamer head. In case of a collapse of part of the bore, the device thus secures evacuation of the loosened ground and the drilling fluid from the bore, as the trailing pipe provides the drainage channel. Pressure build-up in the bore as a consequence of a partial collapse of the bore and the associated risk of a blowout event can thus be eliminated. Furthermore, the drainage of the loosened ground and drilling fluid is driven by the pump unit, which provides for a controlled evacuation of the loosened ground and drilling fluid from the bore. Also, as the risk for a blowout event is eliminated or at least greatly reduced, the device enables for reaming the pilot bore in one pass to the desired diameter. The time for installing casing pipes may therefore be greatly reduced.

[0013] Optionally, the pump unit comprises an outer pump part for being rotationally coupled to the reamer head, the outer pump part forming at least part of the drainage channel therethrough for draining the loosened ground away from the reamer; an inlet for the loosened ground to enter into the drainage channel; and an inner pump part arranged in the drainage channel and configured for cooperating with the outer pump part for drawing the loosened ground through the inlet into the drainage channel and pumping the loosened ground through the drainage channel away from the reamer.

[0014] Optionally, the outer pump part is configured for being rotationally coupled to the reamer head. Hence, the outer pump part can be fixed with respect to the reamer head such that the outer pump part corotates with the reamer head. The outer pump part may hence be rotated in synchrony with reamer head. The outer pump part can form at least part of the drainage channel therethrough for draining the loosened ground away from the reamer. The pump unit can comprise an inlet for allowing the loosened ground to enter into the drainage channel. The inlet can be configured to allow for loosened ground particles to pass there through. The inlet can provide for fluid communication between the space in the expanded bore close to the reamer and the drainage channel. The pump unit can comprise an inner pump part arranged in the drainage channel. The inner pump part can be positioned at least partially radially inward with respect to the outer pump part. The inner pump part can be configured for cooperating with the outer pump part for drawing the loosened ground through the inlet into the drainage channel and pumping the loosened ground through the drainage channel away from the reamer. The outer pump part can accordingly be the rotor of the pump unit, by being rotationally coupled to the reamer, while the inner pump part can be the stator of the pump unit.

[0015] Optionally, the inner pump part is configured for being rotationally coupled to the reamer head to corotate therewith. Hence, the inner pump part can be fixed with respect to the reamer head such that the inner pump part corotates with the reamer head. The inner pump part may hence be rotated in synchrony with reamer head. The inner pump part can accordingly be the rotor of the pump unit, while the outer pump part can be the stator of the pump unit.

[0016] Optionally, the outer pump part is configured for being rotatably coupled, e.g. bearing-mounted, to the reamer head. This allows for a relative rotation between the reamer head and the outer pump part. The outer pump part may be rotatably coupled to the reamer at a leading end of the outer pump part, and be fixed to the trailing pipe at a trailing end of the outer pump part.

[0017] Optionally, the outer pump part is spaced apart from the reamer head in axial direction of the drainage channel to form an interstitial space for collecting loosened ground between the outer pump part and the reamer head, and wherein the inner pump part extends in leading direction out of the outer pump part into the interstitial space. The inner pump part may accordingly extend beyond the outer pump part, at a leading end of the outer pump part. This may enhance the pump unit efficacy in drawing the loosened ground from the interstitial space into the drainage channel.

[0018] Optionally, the pump unit is arranged for having an adjustable pumping speed. The pump can be configured for having the pumping speed be adjusted in response to a user input. The pumping speed can be adjusted over time. The pumping speed can be adjusted gradually and / or instantly over time. The pump speed of the pump unit is particularly controllable from above ground surface, for example at or near an end of the bore.

[0019] Optionally, the inner pump part includes a worm or auger and the outer pump part is arranged to cooperate with the worm or auger to form a progressive cavity pumping mechanism. The pump unit may hence include a progressive cavity pumping mechanism, such as a worm pump or auger pump. Relative rotational movement between the inner pump part and the outer pump part can draw loosened ground via the inlet into the drainage channel. The inner pump part, e.g. including the worm or auger, may be the stator of the pump unit.

[0020] Optionally, the device comprises a control rod connected to the inner pump part. The control rod can be configured for controlling a relative rotational speed between the inner pump part and the outer pump part. The control rod can be configured for selectively increasing or decreasing a rotational speed difference between the inner pump part and the outer pump part. When the inner pump part is braked, the absolute rotational speed of the inner pump part is decreased. Hence, in use, if the outer pump part is driven in rotation, e.g. along with the reamer, the relative rotational speed between the inner pump part and the outer pump part can be increased by braking the inner pump part. Hence, by braking the inner pump part, the relative rotational speed between the inner and outer pump parts can be controlled, to consequently control the pumping speed of the pump unit. When the inner pump part is released, it can corotate with the outer pump part. Hence, when released, i.e. not braked, the relative rotational speed between the inner and outer pump parts can decrease, to consequently decrease the pumping speed of the pump unit.

[0021] Optionally, the control rod extends through a hollow drill shaft in a leading direction through the bore. The hollow drill shaft may be used to drive the reamer in rotation and pull the reamer along the drilling line. The outer pump part when rotationally coupled to the reamer may be corotatingly driven by the drill shaft as well. By providing a hollow drill shaft, and having the control rod extending therethrough, a relative rotation between the drill shaft and the control rod can be effectively realized, particularly at the same end of the bore. The drill shaft and the trailing pipe may hence extend from the reamer in opposing direction along the drilling line, e.g. the trailing pipe in a trailing direction and the drilling pipe in a leading direction. It will be appreciated that these directions may be reverse.

[0022] Optionally, the device comprises a connecting rod hingedly connected between the inner pump part and the control rod. The connecting rod can be configured to accommodate for radially off-center movement of the leading end of the inner pump part. It will be appreciated that the device can also comprise the control rod without connecting rod. The control rod may for example be directly coupled to the inner pump part.

[0023] Optionally, the inlet is formed by a substantially conical shaped body that broadens in trailing direction. The conical shaped body can be provided with through openings for the loosened ground to pass therethrough into the drainage channel.

[0024] Optionally, the device comprises a drill shaft for driving the reamer head in rotation. The drill shaft particularly extends in a leading direction through the bore.

[0025] Optionally, the drill shaft is hollow, and the control rod extends through the hollow drill shaft, particularly in the leading direction.

[0026] Optionally, the control rod is bearing-mounted to the conical shaped body. The bearing between the control rod and the conical shaped body can seal the hollow drill shaft to prevent loosened ground and drilling fluid from entering into the drill shaft. Optionally, the device comprises a drilling fluid supply nozzle configured for supplying drilling fluid. The pump unit can be configured for drawing the drilling fluid through the inlet into the drainage channel and pumping the drilling fluid through the drainage channel away from the reamer. The nozzle may be connected to a drill fluid supply line connected to a drilling fluid pump.

[0027] Optionally, the device comprises a swivel arranged between the trailing pipe and the pump unit, configured for allowing the outer pump part to rotate relative to the trailing pipe. The trailing pipe may hence be nonrotating in use.

[0028] Optionally, the device is configured for installation of the casing pipe for utilities in non-rocky ground, such as sand, gravel, clay and / or peat soil.

[0029] Optionally, the device is configured for installation of the casing pipe for utilities relatively superficial to a ground surface, such as at a depth of at most 8 meters, preferably at a depth of at most 6 meters, more preferably at a depth of at most 4 meters.

[0030] Optionally, the device is configured for installation of the casing pipe for utilities having a diameter of at most 1000 mm, preferably at most 800 mm, more preferably at most 600 mm.

[0031] According to a second aspect is provided a system for reaming a substantially horizontal bore for installation of a casing pipe for utilities. The system comprises a reamer head rotationally drivable by a drill shaft that extends from the reamer in a leading direction through the bore. The system comprises a device as described herein trailing the reamer head.

[0032] Optionally, the system comprises the casing pipe. The trailing pipe can extend through the casing pipe.

[0033] Optionally, the system comprises a drilling fluid supply unit having a drilling fluid supply line configured for supplying drilling fluid. The pump unit can be configured for drawing the drilling fluid through the inlet into the drainage channel and pumping the drilling fluid through the drainage channel away from the reamer. Optionally, the bore is a pilot bore. The reaming can comprise expanding a diameter of the pilot bore in a single pass, such as by at least a factor two, optionally by at least a factor three, optionally by a least a factor four. As the risk for a blowout event is eliminated or at least greatly reduced, the device and system as described herein allow for reaming the pilot bore in one pass to the desired diameter.

[0034] According to a third aspect is provided a method for reaming a substantially horizontal bore for installing of a casing pipe for utilities, using a device as described herein and / or a system as described. The system can comprise the casing pipe.

[0035] Optionally, the reaming is through non-rocky ground, such as sand, gravel, clay and / or peat soil.

[0036] Optionally, the substantially horizontal bore is at a maximum depth of at most 4 meters.

[0037] Optionally, the reaming of the bore expands the bore to a diameter of at most 600 mm.

[0038] Optionally, the bore is a pilot bore. The reaming can comprise expanding a diameter of the pilot bore in a single pass such as by at least a factor two, optionally by at least a factor three, optionally by a least a factor four.

[0039] Optionally, the method comprises inserting the casing pipe into the expanded bore in said single pass. Hence, after drilling the pilot bore, the casing pipe can be inserted in a single reaming pass. The casing pipe may hence trail the reamer, wherein the drainage device is for example arranged between the reamer and the casing pipe.

[0040] It will be appreciated that any of the aspects, features and options described in view of the device for draining loosened ground from reaming of a substantially horizontal bore for installation of a casing pipe for utilities apply equally to the system for reaming a substantially horizontal bore for installation of a casing pipe for utilities, the method for reaming a substantially horizontal bore for installing of a casing pipe for utilities, and vice versa. It will also be clear that any one or more of the above aspects, features and options can be combined.

[0041] BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings in which:

[0043] Figure 1 shows an illustration of a schematic representation of an example of a system for reaming a substantially horizontal bore;

[0044] Figure 2 shows an illustration of a schematic representation of an example of a device for draining loosened ground from reaming of a substantially horizontal bore;

[0045] Figure 3 shows an illustration of a schematic representation of an example of a system for reaming the substantially horizontal bore; and

[0046] Figures 4A, 4B and 4C show illustrations of a schematic representation of an example of a method for installing of a casing pipe for utilities.

[0047] DETAILED DESCRIPTION

[0048] Figure 1 shows an illustration of a schematic representation of an example of a system 1 for reaming a substantially horizontal bore 2. The system 1 comprises a device 4 and a reamer head 6. In this example, the device 4 is a drainage device. The drainage device 4 is configured for draining loosened ground 8 from reaming of a substantially horizontal bore 2 for installation of a casing pipe 10 for utilities. It will be appreciated that the drilling and reaming of horizontal bores refers to bores or tunnels that extend underground between a ground surface entrance point a ground surface exit point, wherein the bore in between the entrance and exit point extends underground in a non-vertical direction. The bore 2 thus need not be entirely horizontal.

[0049] The device 4 comprises a trailing pipe 12 and a pump unit 14. The trailing pipe 12 is configured for being trailed behind a reamer head 6. The trailing pipe 12 forms at least part of a drainage channel 16 for draining loosened ground 8 therethrough. The pump unit 14 is configured for being connected between a leading end 18, e.g. at a fluid swivel, of the trailing pipe 12 and the reamer head 6. The pump unit 14 is configured for drawing the loosened ground 8 into the drainage channel 16 and pumping the loosened ground 8 through the drainage channel 16 away from the reamer head 6. The loosened ground 8 is drawn through the drainage channel 16 in Fig. 1 in positive z-direction.

[0050] The reamer head 6 is in this example rotationally drivable by a drill shaft 20 that extends from the reamer 6 in a leading direction through the bore 2. Hence the reamer head 6 is fixed with respect to the drill shaft 20. The drill shaft 20 extends from the reamer head 6 in the negative z-direction in Fig. 1. In this example, after the substantially horizontal bore 2 is reamed using the device 4 and the reamer head 6, said expanded bore 22 is ready for installation of a casing pipe 10 for utilities therein. The drainage device 2 is configured for trailing the reamer head 6, so as to draw ground particles 8 that are loosened from surrounding ground 15 and moved from at or near the reamer head 6 along part of the expanded bore 22 into the drainage channel 16 away from the reamer head 6. In this example, the pump unit 14 comprises an outer pump part 24, an inlet 26 and an inner pump part 28. These parts of the pump unit 14 are explained in more detail in view of Figure 2.

[0051] In this example, the system 1 comprises the casing pipe 10. The trailing pipe 12 extends through the casing pipe 10. In an alternative embodiment, the system 1 can not comprise the casing pipe 10. The casing pipe 10 can thereto e.g. be installed in the expanded bore 22 separately at a later moment in time. Here, the system 1 comprises a drilling fluid supply unit having a drilling fluid supply line configured for supplying drilling fluid. The drilling fluid may for example include a water-based drilling mud, such as comprising bentonite clay with optional additives. The drilling fluid is particularly supplied to the reamer head 6 via a spacing between the casing pipe 10 and the expanded bore 22. In absence of the casing pipe 10, the drilling fluid can be supplied to the reamer head 6 via a spacing between a dedicated drainage channel and the expanded bore 22. The pump unit 14 is configured for drawing the drilling fluid through the inlet 26 into the drainage channel 16 and pumping the drilling fluid through the drainage channel 16 away from the reamer 6. In this example, the bore 2 is a pilot bore. The reaming in this example comprises expanding a diameter of the pilot bore 2 in a single pass by at least a factor two, optionally by at least a factor three, optionally by a least a factor four. In this example, the reaming comprises expanding a diameter of the pilot bore 2 in a single pass by at least a factor four.

[0052] Figure 2 shows an illustration of a schematic representation of an example of the device 4 for draining loosened ground 8 from reaming of the substantially horizontal bore 2 for installation of the casing pipe 10 for utilities. The device 4 of Fig. 2 comprises the features of the device 4 comprised in the system 1 for reaming the substantially horizontal bore 2 of Fig. 1. The outer pump part 24 is in this example configured for being rotationally coupled to the reamer head 6. The outer pump part 24 in this example accordingly corotates with the reamer head 6. Hence the outer pump part 24 is fixed with respect to the reamer head 6. Here, the outer pump part 24 forms at least part of the drainage channel 16 therethrough for draining the loosened ground 8 away from the reamer 6. The inlet 26 is configured for allowing the loosened ground 8 to enter into the drainage channel 16 in this example. The inner pump part 28 is in this example arranged in the drainage channel 16. Here, the inner pump part 28 is configured for cooperating with the outer pump part 24 for drawing the loosened ground 8 through the inlet 26 into the drainage channel 16 and pumping the loosened ground 8 through the drainage channel 16 away from the reamer 6.

[0053] The pump unit 14 is in this example arranged for having an adjustable pumping speed. In this example, the inner pump part 28 includes a worm or auger and the outer pump part 24 is arranged to cooperate with the worm or auger to form a progressive cavity pumping mechanism. A relative rotational speed between the inner pump part 28 and the outer pump part 24 drives the loosened ground through the drainage channel 16. In the embodiment of Fig. 2, the device 4 comprises a control rod 30 connected to the inner pump part 28 for controlling a relative rotational speed between the inner pump part 28 and the outer pump part 24. The control rod 30 in this example extends through a hollow drill shaft 20 in a leading direction through the bore 2. It will be appreciated that the device 4 can in a different embodiment comprise other means for controlling the relative rotational speed of the inner and outer pump parts 28, 24.

[0054] The control rod 30 can be configured for controlling the relative rotational speed between the inner pump part 28 with respect to the outer pump part 24. The control rod 30 is in this example particularly be configured for controlling the absolute rotational speed of the inner pump part 28. The control rod 30 here is arranged to brake the inner pump part 28 so as to decrease its rotational speed with respect to the outer pump part 24. When the inner pump part 28 rotates in the same direction and at the same speed as the outer pump part 24, no relative motion is present between the inner and outer pump parts 28, 24, and hence the pumping output is zero. In this example, if outer pump part 24 is driven in rotation along with the reamer, the inner pump part 28 would be entrained with the outer pump part 24 when the inner pump part 28 were to be released. This renders no pump output. When the rotational speed of the inner pump part 28 is controlled to differ from that of the outer pump part 24, the pumping speed of the pump unit increases. In this example, the control rod 30 is arranged to brake the inner pump part 28 so as to increases the rotational speed difference between the inner and outer pump parts 28, 24.

[0055] In this example, the device 4 further comprises a connecting rod 32 hingedly connected between the inner pump part 28 and the control rod 30. The connecting rod 32 is configured to accommodate for radially off-center movement of the leading end 34 of the inner pump part 28. It will be appreciated that the device 4 can in another example be formed without the connecting rod 32, as the control rod 30 is then directly coupled to the inner pump part 28. The inlet 26 is in this example formed by a substantially conical shaped body 36 that broadens in trailing direction, i.e. in the positive z- direction. The conical shaped body 36 is provided with through openings 38 for allowing the loosened ground 8 to pass therethrough into the drainage channel 16. The control rod 30 is in this example bearing-mounted to the conical shaped body 36 with bearings 40.

[0056] The device 4 in this example further comprises a drilling fluid supply nozzle configured for supplying drilling fluid, e.g. to the reamer head 6. The pump unit 14 is configured for drawing the drilling fluid through the inlet 26 into the drainage channel 16 and pumping the drilling fluid through the drainage channel 16 away from the reamer 6. Here, the device 4 is configured for installation of the casing pipe 10 for utilities in non-rocky ground 15, such as sand, gravel, clay and / or peat soil. The device 4 is configured for installation of the casing pipe 10 for utilities relatively superficial to a ground surface in this example, preferably at a depth of at most 4 meters. The device 4 is in this example configured for installation of the casing pipe 10 for utilities having a diameter of at most 600 mm.

[0057] Figure 3 shows an illustration of a schematic representation of an example of the system 1 for reaming the substantially horizontal bore 2. The system 1 of Fig. 3 is similar to the system 1 shown in Figure 1. The drainage device 4 is configured for draining loosened ground 8 from reaming of a substantially horizontal bore 2 for installation of a casing pipe 10 for utilities. The outer pump part 24 is in this example rotatably coupled, particularly bearing-mounted, to the reamer head 6 via bearings 51. Hence, in this example, the reamer head 6 is rotatable relative to the outer pump part 24. The outer pump part 24 at a trailing side hereof is in this example coupled to the casing pipe 10. Therefore the outer pump part 24 may be rotationally stationary , while the reamer head 6 is driven in rotation by the drill shaft 20. Here, the inner pump part 28 is rotationally coupled to the reamer head 6, such that the inner pump part 28 corotates with the reamer head 6. The inner pump part is accordingly fixed with respect to the reamer head 6 and the drill shaft 20. In this example, the inlet 26 comprises one or more funneling elements 37 that funnel loosened ground in trailing direction, here in the positive z-direction, into the outer pump part 28. The one or more funneling elements 37 are passable for a drilling fluid to reach the reamer head and mix with the loosened ground 8. The inlet 26 is in this example integrated with the reamer head 6. The trailing pipe 12 is connected at its leading end 18 with the pump unit 14, particularly to the outer pump part, and the trailing pipe 12 forms at least part of the drainage channel 16. The pump unit 14 is connected via the inlet 26 to the reamer head 6. Upon rotation of the reamer head 6, the inner pump part 28 corotates with the reamer head 6 to create a relative rotation between the inner pump part 28 and the outer pump part 24. This accordingly drives the pump unit 14 for drawing loosened ground 8 from the space inside the expanded bore 22 via the inlet 26 into the drainage channel 16.

[0058] The leading part 34 of the inner pump part 28 extends in leading direction out of the outer pump part 24 for being directly connected to the reamer head 6. The rotation of the inner pump part 28, in particular the rotation of the leading part 34 thereof, aids in drawing the loosened ground 8 into the drainage channel 16.

[0059] Compared to the example of figure 1, the example of figure 3 may be more robust and more power efficient. The example of figure 1 may on the other hand provide more control over the pump speed of the pump unit 14, as it allows control over the relative rotational speed between the inner and outer pump part, e.g. using the control rod.

[0060] Figures 4A, 4B and 4C show illustrations of a schematic representation of an example of a method for installing of a casing pipe 10 for utilities. The method can e.g. be performed using a system 1 as described in view of Figure 1 or Figure 3, with a device 4 as described in view of Figure 2 or in view of Figure 3.

[0061] Figure 4A shows a first step of drilling a pilot bore 2 by moving a steerable drill tool 42 along a predetermined drilling line 44 from an entrance point A to an exit point B through the ground 15. The pilot bore 2 is the first bore. The pilot bore defines the substantially horizontal bore. The drill tool 42 can comprise the device 4 and / or the system 1 as described. Alternatively, when the drill tool 42 exits the ground 15 at point B, the drill tool 42 can be swapped for device 4 and / or the system 1 as described, such that the drill tool 42 is ready for the step of expanding described in view of Figure 4B.

[0062] The pilot bore 2 is expanded in Figure 4B using the device 4 connected to a reamer 6 at a leading side of the device 4, schematically shown as ‘4+6’ in Fig. 4B. The device 4 and reamer 6 are configured for loosening the ground 15 along the drilling line 44 from point B to point A for expanding the pilot bore 2 into an expanded bore 22. The expanded bore 22 has a larger diameter than the pilot bore 2. Loosened ground 8, here suspended by a drilling fluid, is drawn via the inlet 26 into the drainage channel 16 of the device 4. The casing pipe 10 is inserted into the expanded bore hole 22 in the same pass using the device 4.

[0063] Figure 4C shows the resulting installed casing pipe 10 for utilities. Here, the reaming is performed through non-rocky ground 15, such as sand, gravel, clay and / or peat soil. The substantially horizontal bore 2 is at a maximum depth of at most 4 meters in this example. The reaming of the bore 2 expands the bore 2 in this example to an expanded bore 22 having a diameter of at most 600 mm. Here, the bore 2 is a pilot bore, and the reaming comprises expanding a diameter of the pilot bore 2 in a single pass by at least a factor two, optionally by at least a factor three, optionally by a least a factor four. The method in this example comprises inserting the casing pipe 10 into the expanded bore 22 in said single pass.

[0064] Herein, the invention is described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein, without departing from the essence of the invention. For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, alternative embodiments having combinations of all or some of the features described in these separate embodiments are also envisaged. However, other modifications, variations, and alternatives are also possible. The specifications, drawings and examples are, accordingly, to be regarded in an illustrative sense rather than in a restrictive sense.

[0065] For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

[0066] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word ‘comprising’ does not exclude the presence of other features or steps than those listed in a claim. Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to ‘only one’, but instead are used to mean ‘at least one’, and do not exclude a plurality. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to an advantage.

Claims

Claims1. A device for draining loosened ground from reaming of a substantially horizontal bore for installation of a casing pipe for utilities, the device comprising: a trailing pipe for being trailed behind a reamer head, the trailing pipe forming at least part of a drainage channel for draining loosened ground therethrough, and a pump unit for being connected between a leading end of the trailing pipe and the reamer head and configured for drawing the loosened ground into the drainage channel and pumping the loosened ground through the drainage channel away from the reamer head.

2. The device according to claim 1, wherein the pump unit comprises: an outer pump part forming at least part of the drainage channel therethrough for draining the loosened ground away from the reamer; an inlet for the loosened ground to enter into the drainage channel; and an inner pump part arranged in the drainage channel and configured for cooperating with the outer pump part for drawing the loosened ground through the inlet into the drainage channel and pumping the loosened ground through the drainage channel away from the reamer.

3. The device according to claim 2, wherein the outer pump part is configured for being rotationally coupled to the reamer head to corotate therewith.

4. The device according to claim 2, wherein the inner pump part is configured for being rotationally coupled to the reamer head to corotate therewith.

5. The device according to claim 2 or 4, wherein the outer pump part is configured for being rotatably coupled, e.g. bearing mounted, to the reamer head.

6. The device according to any of claims 2-5, wherein the outer pump part is spaced apart from the reamer head in axial direction of the drainage channel to form an interstitial space for collecting loosened ground between the outer pump part and the reamer head, and wherein the inner pump part extends in leading direction out of the outer pump part into the interstitial space.

7. The device according to any of the preceding claims, wherein the pump unit is arranged for having an adjustable pumping speed.

8. The device according to any of the preceding claims, wherein the inner pump part includes a worm or auger and the outer pump part is arranged to cooperate with the worm or auger to form a progressive cavity pumping mechanism.

9. The device according to any of claims 1-3 or 6-7, comprising a control rod connected to the inner pump part for controlling a relative rotational speed between the inner pump part and the outer pump part.

10. The device according to claim 9, wherein the control rod extends through a hollow drill shaft in a leading direction through the bore.

11. The device according to claim 9 or 10, comprising a connecting rod hingedly connected between the inner pump part and the control rod.

12. The device according to any of claims 2-11, wherein the inlet is formed by a substantially conical shaped body that broadens in trailingdirection, the conical shaped body being provided with through openings for the loosened ground to pass therethrough into the drainage channel.

13. The device according to claim 12 when dependent on any of claims 9-11, wherein the control rod is bearing-mounted to the conical shaped body.

14. The device according to any of the preceding claims, further comprising a drilling fluid supply nozzle configured for supplying drilling fluid, and wherein the pump unit is configured for drawing the drilling fluid through the inlet into the drainage channel and pumping the drilling fluid through the drainage channel away from the reamer.

15. The device according to any of the preceding claims, wherein the device is configured for installation of the casing pipe for utilities in non- rocky ground, such as sand, gravel, clay and / or peat soil.

16. The device according to any of the preceding claims, wherein the device is configured for installation of the casing pipe for utilities relatively superficial to a ground surface, such as at a depth of at most 8 meters, preferably at a depth of at most 6 meters, more preferably at a depth of at most 4 meters.

17. The device according to any of the preceding claims, wherein the device is configured for installation of the casing pipe for utilities having a diameter of at most 1000 mm, preferably at most 800 mm, more preferably at most 600 mm.

18. A system for reaming a substantially horizontal bore for installation of a casing pipe for utilities, the system comprising: a reamer head rotationally drivable by a drill shaft that extends from the reamer in a leading direction through the bore, anda device according to any of the preceding claims trailing the reamer head.

19. The system according to claim 18, comprising the casing pipe, wherein the trailing pipe extends through the casing pipe.

20. The system according to claim 18 or 19, comprising a drilling fluid supply unit having a drilling fluid supply hne configured for supplying drilling fluid, and wherein the pump unit is configured for drawing the drilling fluid through the inlet into the drainage channel and pumping the drilling fluid through the drainage channel away from the reamer.

21. The system according to claim 18, 19 or 20, wherein the bore is a pilot bore, and the reaming comprises expanding a diameter of the pilot bore in a single pass by at least a factor two, optionally by at least a factor three, optionally by a least a factor four.

22. A method for reaming a substantially horizontal bore for installing of a casing pipe for utilities, using a system of any of claims 18-21.

23. The method according to claim 22, wherein the reaming is through non-rocky ground, such as sand, gravel, clay and / or peat soil.

24. The method according to claim 22 or 23, wherein the substantially horizontal bore is at a maximum depth of at most 4 meters.

25. The method according to any of claims 22-24, wherein the reaming of the bore expands the bore to a diameter of at most 600 mm.

26. The method according to any of claims 22-25, wherein the bore is a pilot bore, and the reaming comprises expanding a diameter of the pilotbore in a single pass by at least a factor two, optionally by at least a factor three, optionally by a least a factor four.

27. The method according to claim 26, comprising inserting the casing pipe into the expanded bore in said single pass.

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