EP3397831B1 - Drill pipe, and system and method for laying a pipeline - Google Patents

Description

The invention relates to a drill pipe for use in creating a borehole in a ground from a starting point to a target point along a predetermined drilling line, in particular for laying underground cables or underground lines close to the surface in the ground, wherein the borehole is opened by means of a drilling device with a drilling tool for loosening the ground when the drill pipes are pushed forward, wherein the drill pipe has at least one connection section at each of its ends for a tensile, releasable connection to another element of a drill string, wherein the drill pipe has at least one element for establishing a tensile connection with a corresponding element of a feed device for pushing and/or retracting the drill pipe into the borehole, wherein an outer wall of the drill pipe is made in one piece, wherein the connection via the respective connection sections of the drill pipe to another element of the drill string is made in the form of a positive and/or non-positive connection, and wherein the drill pipe has a first connection section at its first end and a second connection section corresponding to the first connection section at its opposite second end. wherein the drill pipe has at least two line sections arranged in the interior of the drill pipe on the outer wall and running parallel along the outer wall, wherein the at least two line sections each have a connecting element at their ends for producing a connection between line sections of interconnected drill pipes. Furthermore, the invention relates to a system and a method for use in creating a borehole.

When constructing a power grid, for example when building a 380 kV line, it is necessary not only to build overhead lines but also to lay these lines underground.

Open trench construction is used for laying underground cables, underground lines and also pipes (such as pipelines) close to the surface. This sometimes leads to considerable interventions along the route and is associated with a not inconsiderable amount of work when digging the trench and backfilling the trench. To create a 380 kV cable route, for example, two trench profiles, each 5.5 m wide and 2.15 m deep, have to be created. Separating the individual soil layers has proven to be particularly complex and requires several separate piles. This is necessary in order to restore the soil quality to its original state when the trench is later backfilled. Furthermore, an area of around 40 m must be kept free for construction work, while a cable protection strip of around 23 m must be kept accessible after construction work has been completed. These interventions during the construction phase and the effects after completion of the work within the framework of open laying justify the need to develop an underground laying method that meets requirements.

In order to keep the impact on nature during the construction phase and the construction costs to a minimum, it is necessary to achieve long pipe lengths. Pipe lengths of up to 1500 m or more are desirable. The problem with laying pipes close to the surface is the low level of cover of the pipe and possibly also the small distance between the individual boreholes (both of which may be just 2 to 6 m each). The diameter of the pipes to be laid here is in the range of less than 500 mm, often less than 300 mm.

Trenchless drilling methods from pipeline construction are already available (microtunneling, HDD), but it is not yet possible to cover the necessary parameters with these methods.

There are already drilling methods that can cover the desired diameter range, but for technical reasons these methods are limited to much shorter distances, which is mainly due to the supply of drilling fluid. This includes, for example, microtunnel drilling technology up to 300 mm. For a section length of up to more than 1.5 km, microtunnel drilling technology with a diameter of around 1000 mm would currently have to be used. However, the space required for the construction site equipment and the costs increase significantly with increasing diameter. This is why this technology has not been economically viable to date. Furthermore, pipes in microtunnel drilling technology are only plugged in, so that only compressive forces can be transmitted, not tensile forces.

With the Horizontal Directional Drilling (HDD) method, it would be possible to lay the pipe in accordance with the diameter and length requirements. This method is already used specifically for crossing under rivers or roads. With this method, a pilot bore is first created using a rotating drill head and drill rod from the starting point towards the target point. The positional accuracy is ensured by a surveying system that is installed behind the drill head. The mined material is brought to the surface with a bentonite suspension. The bentonite suspension is pumped through the drill rod directly to the nozzles attached to the drill head. The suspension mixes with the loosened soil and flows back to the starting point through the annular space between the drill rod and the ground. However, high flushing pressures are required to ensure that the loosened soil is removed cleanly. In order to prevent unwanted flushing from escaping to the surface, the HDD method requires laying depths and thus cover of more than 30 m. The drill pipes of the pilot drill string are coupled together via a force-locking connection in which the drill pipes are directly screwed together via a screw thread connection. This is also how the connection to the drive of the so-called HDD rig is made. Screwing the drill string elements together requires a corresponding amount of set-up time.

Developments in drilling and pumping technology with regard to supplying the drilling device with drive and flushing fluid have made it possible to overcome the 1000 mm diameter barrier for the use of microtunneling processes, for example. However, the successive installation of drill pipes is problematic with regard to the regular extension of the supply lines for the drilling device and the removal of drilling cuttings. For installation lengths of up to or more than 1500 m, this results in considerable performance losses due to set-up times.

Furthermore, with regard to laying cables close to the surface, it is necessary to insert a pipeline into the ground after or during the drilling, preferably made of plastic (other materials such as polymer concrete, GRP or similar are also possible), in order to then lay the cable in it. The problem here is that it is not possible to create the borehole directly by inserting plastic pipes into the ground, since the plastic pipe is not suitable for transmitting the necessary forces without damage, especially when laying long lengths. It is therefore necessary to use drill pipes that are suitable for providing the necessary forces required for drilling. Here, too, the successive insertion described above is problematic.

Once the target point has been reached, the drilling device is removed. The laid drill pipes are then removed and the plastic pipe is inserted into the ground at the same time or at a different time. It is necessary to transfer tensile forces to and via the drill pipes and, after removing a drill pipe from the borehole, to separate it from the drill string so that it can be reused.

Drill pipes according to the generic term are made of US20110266062 A1 known. From DE 19925731 C1 , DE 1234163 B and WO 2015152729 A1 Flange-like connections between the drill pipes are also known. DE 19512123 A1 bolted plug connections in an auger drilling process.

The object of the invention is therefore to overcome the aforementioned disadvantages, in particular to reduce the set-up times and to make tensile forces transferable in the drill string.

This object is achieved with regard to a drill pipe in that the first connection section and the second corresponding connection section, in the assembled state, form a flange connection which has connecting elements and/or bores for attaching a bolt connection, that the first connection section has a support section in which the bores are provided, that a recess is provided in the outer wall of the drill pipe behind the support section, and that the recess can be closed with a cover.

In this way, a tensile connection between the drill pipes can be provided easily and cost-effectively.

A further teaching of the invention provides that the element for establishing a tensile connection with the corresponding element of the feed device is a recess in the outer wall of the drill pipe. This makes it possible in a simple manner to enable the drill pipe to be moved in a tensile manner via a movement device such as a press frame, with a considerable reduction in set-up time.

A further teaching of the invention provides that the depression can be provided with a cover. This is advantageous in order to prevent stones and the like from becoming jammed in the depression in the ground.

The drill pipe has at least one line section arranged in the outer wall and/or in the interior of the drill pipe on the outer wall and running parallel along the outer wall, wherein the at least one line section has a connecting element at its ends for establishing a connection between line sections of interconnected drill pipes or elements of the drill string. The lines are used, for example, to transport bentonite, as a drive line for the Drive a pump, as a feed line for the removal of drilling cuttings, for the installation of electrical cables, as a high-pressure line or as a conveying line for the mixture of flushing fluid and drilling cuttings/dissolved soil. The lines have, for example, a plug-in sleeve system with seals if necessary, so that the lines can be plugged into one another. This significantly reduces the set-up times when providing the supply lines.

Advantageously, the drill pipes according to the invention have a length of more than 8m. This also significantly reduces the set-up times.

A further teaching of the invention provides that the drill pipe has at least one recess in its wall for establishing a connection with a feed device for advancing and/or retracting the drill pipe into the borehole. This can create a positive connection for easier transmission of feed forces to the outer surface.

The solutions described above are not limited to laying pipelines, underground cables or underground lines close to the surface in the ground. Rather, the above-mentioned task can also be used for classic microtunneling with larger diameters, for example with concrete pipes. Here too, the solutions can reduce set-up times and essentially eliminate the problem of extending supply lines and installing feed pipes in the drilling area with regard to installations and supply lines.

Furthermore, the drill pipe can also be a product pipe that remains in the ground as such and is not removed from the ground again to pull in the product pipe.

• Figur 1A, 1B eine Seitenansicht einer ersten Ausführungsform eines erfindungsgemäßen Bohrrohrs,
• Figur 2A einen ersten Anschlussabschnitt des erfindungsgemäßen Bohrrohrs,
• Figur 2B einen zweiten Anschlussabschnitt des erfindungsgemäßen Bohrrohrs,
• Figur 2C der Anschlussabschnitt zu Figur 2A ohne Abdeckung,
• Figur 2D eine Seitenansicht zu Figur 2C,
• Figur 3A der Verbindungsabschnitt zweier miteinander verbundener erfindungsgemäßer Bohrrohre,
• Figur 3B eine Schnittansicht zu Figur 3A,
• Figur 4A eine räumliche Ansicht einer ersten Ausführungsform einer erfindungsgemäßen Vorrichtung zum Bewegen eines Bohrrohrs in einer ersten Position,
• Figur 4B eine räumliche Ansicht der erfindungsgemäßen Vorrichtung zum Bewegen eines Bohrrohrs in einer zweiten Position,
• Figur 5A eine räumliche Ansicht analog Figur 4A mit der ersten Ausführungsform des erfindungsgemäßen Bohrrohr,
• Figur 5B eine räumliche Ansicht analog Figur 4B mit der ersten Ausführungsform des erfindungsgemäßem Bohrrohr
• Figur 5C eine Draufsicht zu Figur 5A,
• Figur 5D eine Draufsicht zu Figur 5B,
• Figur 6A eine Seitenansicht eines ersten erfindungsgemäßen Übertragungselements der ersten Ausführungsform der erfindungsgemäßen Vorrichtung mit Eingriffselementen in einer ersten Position,
• Figur 6B eine analoge Ansicht zu Figur 6A mit erfindungsgemäßen Eingriffselementen in einer zweiten Position,
• Figur 7 eine schematische Darstellung eines ersten erfindungsgemäßen Systems in räumlicher Ansicht nach Beendigung des Bohrvorgangs,
• Figur 8 eine schematische Darstellung in räumlicher Ansicht zu Beginn des Einziehens der Leitung.

The invention is explained in more detail below using an embodiment in conjunction with a drawing.

• Figure 1A, 1B a side view of a first embodiment of a drill pipe according to the invention,
• Figure 2A a first connection section of the drill pipe according to the invention,
• Figure 2B a second connection section of the drill pipe according to the invention,
• Figure 2C the connection section to Figure 2A without cover,
• Figure 2D a side view to Figure 2C ,
• Figure 3A the connecting section of two interconnected drill pipes according to the invention,
• Figure 3B a sectional view of Figure 3A ,
• Figure 4A a spatial view of a first embodiment of a device according to the invention for moving a drill pipe in a first position,
• Figure 4B a spatial view of the device according to the invention for moving a drill pipe in a second position,
• Figure 5A a spatial view analogous Figure 4A with the first embodiment of the drill pipe according to the invention,
• Figure 5B a spatial view analogous Figure 4B with the first embodiment of the drill pipe according to the invention
• Figure 5C a top view of Figure 5A ,
• Figure 5D a top view of Figure 5B ,
• Figure 6A a side view of a first transmission element according to the invention of the first embodiment of the inventive device with engagement elements in a first position,
• Figure 6B an analogous view to Figure 6A with engagement elements according to the invention in a second position,
• Figure 7 a schematic representation of a first system according to the invention in a spatial view after completion of the drilling process,
• Figure 8 a schematic representation in spatial view at the beginning of the pulling in of the cable.

Figure 1A, 1B show a side view of a first embodiment of a drill pipe 10 according to the invention. The drill pipe 10 has a first connection section 11 at its first end and a second connection section 12 at its opposite second end, wherein the first connection section 11 corresponds to the second connection section 12 in that they can be connected to one another or plugged into one another. The first connection section 11 and the second connection section 12 are provided in such a way that they form a flange connection in a first embodiment according to the invention, wherein the first connection section 11 has a support section 13 in which holes 14 are provided. Behind the support section 13, a recess 15 is provided in the outer wall 16 of the drill pipe 10. (See Figure 2A to 2D ). Recesses 17 are provided in the recess 15 corresponding to the holes 14. Furthermore, holes 18 are provided in the carrier section 13, which are designed such that centering pins 19, which are provided on the second connection section 12, can engage in them.

The second connection section 12 also has a carrier element 20 on which bolts 21 are either fixedly arranged, or in which bores 31 are provided which contain a thread into which loose bolts 21 which are inserted into the Recesses 17 are screwed through the holes 14 into the threaded holes 31 in the support section 20.

The recess 15 can be closed with a cover 22. The cover 22 is fastened in the recess 15, for example by means of screws. The cover serves to ensure that no objects can collect in the recess 15 or in the recesses 17 while the drill pipe 10 moves in the borehole.

Several lines are permanently arranged inside the drill pipe 10. These are a conveyor line 23 for conveying away loosened soil or drilling cuttings in conjunction with drilling fluid/drilling/bentonite suspension, a grouting line 24, with which, for example, a bentonite suspension is introduced for introduction as a lubricant between the drill pipes and the borehole wall, a drive line 25, with which, for example, drive fluid is transported to the drilling device in order to drive a jet pump (not shown) that may be present there, a feed line 26, with which, for example, a bentonite suspension is transported to the drill head, with which the drilling cuttings or the loosened soil is then transported out of the borehole and the working face is supported in front of the drilling tool, and a channel 27, in which, for example, high-pressure lines for spraying the cutting tools or electrical lines for supplying energy to the drilling device are provided.

The lines are connected via a plug-in sleeve system, whereby the first connection section 11 has spigots 28 which are provided with seals, whereas the second connection section 12 has sleeves 29 into which the spigots 28 of the lines 23-26 and, if applicable, 27 engage. This is made, for example, of Figure 3B visible.

Figure 3A and Figure 3B show a first drill pipe 10, which is connected to a second drill 10' via a flange connection 30. The first connection section 11 of the first drill pipe 10 is connected to the second connection section 12 of the drill pipe 10'. The carrier section 13 and the carrier section 20 touch each other. The bolts 21 are inserted through the holes 14 into the Threaded holes 31 are screwed in. For this purpose, the bolts 21 are inserted into the recesses 17 and into the holes 14 of the support section 13 of the first connection section 11.

To connect the first connection section 11 to the second connection section 12, the drill pipes 10, 10' are arranged in relation to one another in such a way that the centering pins 19 can be inserted into the corresponding holes 18. In this case, the spigot ends 28 of the lines 23-27 should also correspond to the sockets 29 of the lines 23-26 or 27. The drill pipes 10, 10' are then pushed against one another so that the spigot ends 28 snap into the socket 29. The bolts 21 are then inserted into the recesses 17 and pushed into the holes 14. The bolts 21 are then screwed into the threaded holes 31 of the support section 20 of the second connection section 12.

The drill pipe 11' is then detached from the drill pipe 10 by unscrewing the bolts 21 from the threaded holes 31 and removing the bolts 21 from the recesses 17. The drill pipe 10' can then be removed from the drill string, whereby the spigot ends 28 of the lines 23-26 or 27 separate from the socket 29 of the lines 23-26 or 27.

Figure 4A and Figure 4B show a spatial view of a device 40 according to the invention for moving at least one drill pipe into or out of a borehole, in particular when creating a borehole close to the surface in a ground 100 from a starting point 101 to a target point 102 and/or when introducing a pipeline, underground line or underground cable 105 into the ground 101 from a starting point 101 to a target point 102 or in the opposite direction. This is referred to below as press frame 40. The press frame 40 has a base 41 which has a frame-shaped structure. Rails 42 are provided on the base 41, on which guide elements 43 are provided which can be moved on the rails 42. The transmission element 44 is arranged on the guide elements 43.

An abutment 45 is arranged directly or operatively connected to the base 41. This means that two actuators 46, which are here used as Double-stroke cylinders 47 are connected. A double-stroke cylinder 47 has two hydraulic cylinders 48 which are connected to one another via a plate 49. The cylinders 48 are designed here as telescopic cylinders. The plate 49 is also connected to a guide element 43 so that the plate 49 can be moved and guided on the rails 42. The double-stroke cylinders 47 are designed such that, when fully extended, they can move the transmission element 44 essentially to the front end of the base 41 on the opposite side of the abutment 45.

Supports 50 are provided on the base 41, on which a drill pipe 10 or another element of the drill string can be placed. The supports 50 are vertically erected when a drill pipe 10 is to be placed on it. During the movement of the transmission element 44 in relation to the base 41, the supports 50 are folded away horizontally. (See Figure 4B ).

Figure 5A to Figure 5D show a drill pipe 10, which points with its second connection section 12 in the direction of the bore. Here, a starting seal (not shown) would also be provided at the end of the base 41 facing the borehole. The first connection section 11 or its recess 15 forms a positive connection with an engagement element 53 of the transmission element 44, in that the engagement element 53 engages in the recess to enable the drill pipe 10 to move.

The transmission element 44 has a connection plate 51, which the double cylinders 47 engage. The transmission element 44 has an opening 52, into which the drill pipe 10 is inserted. Furthermore, a form-fitting element is provided, which in this case has two engagement elements 53. The engagement elements 53 are each connected to a hydraulic cylinder 54, which are aligned horizontally. The engagement elements 53 are provided so as to be horizontally movable in relation to the transmission element 44. Here, the movement is preferably carried out by the hydraulic cylinders 54. The engagement elements 53 can be moved from an open position ( Figure 6A ) into a closed engagement position ( Figure 6B ) can be moved. In the engagement position shown here, the engagement elements 53 engage in the recesses 15 of the Drill pipe 10 and thereby create a positive connection between the drill pipe 10 and the press frame 40. The actuators 46 can be used to move the transmission element 44 along the rails 42 toward or away from the borehole. The positive connection of the engagement elements 53 with the recess 15 allows both compressive and tensile forces to be applied so that the drill pipe 10 can be moved out of or into the borehole. Alternatively, the engagement elements 53 can also consist of several elements that are moved spatially, or with two engagement elements 53, a vertical movement is also possible.

On the back of the transmission element 44, connections 55 are provided for the lines 23 - 26 and 27, which function as quick connectors with the lines 23 - 26 and 27, respectively. With regard to the channel 27, it may be necessary to manually insert hoses or lines into a new drill pipe to be connected before connecting and to couple them with the hoses or lines of the previous drill pipe 10' in the channel 27. In this case, it is also possible to keep couplings as low as possible by making these lines or hoses longer than a drill pipe 10.

Figure 7 shows a schematic representation of the system according to the invention in a spatial representation. A starting pit 101 is provided in the ground 100, from which a bore (not shown) is made to a target pit 102. A press frame 40 is provided in the starting pit 101. The distance between a starting pit 101 and a target pit 102 can be up to 1500 m and more. In Figure 7 it can be seen how a drilling device 103 has arrived in the target pit 102. The drilling device 103 is then released from the drill string and removed from the target pit 102. An adapter 104 is arranged on the first drill pipe 10 of the drill string, which is connected to a protective pipe 105 to be laid or, if this is not necessary, directly to the ground line or the ground cable. In the starting pit, in this embodiment, the press frame 40 is turned over so that the abutment 45 is located at the borehole starting point (not shown) and supports it here. Alternatively, it is also possible for the press frame 40 to be designed in such a way is that the necessary forces are available both in the extension direction of the hydraulic cylinders 48 and in the retraction direction of the hydraulic cylinders 48, so that the press frame does not have to be rotated.

When creating the borehole, individual drill pipes 10 or several drill pipes that are already connected to one another are connected to the drill string and are pushed into the ground 100 through the press frame 40. The drill pipes 10 are removed by pulling them out of the borehole through the press frame 40. Once a drill pipe 10 has been completely pulled out, it is separated from the drill string and removed, for example as described above. Alternatively, several drill pipes connected to form a drill string section can also be dismantled. When the drill pipes are pulled out, the protective pipe 105 or the ground line or the ground cable is simultaneously inserted directly into the borehole in the ground 100.

List of reference symbols

10 Drill pipe 50 Support 11 first connection section 51 Connection plate 12 second connection section 52 opening 13 Carrier section 53 Intervention element 14 Drilling 54 Hydraulic cylinder 15 Deepening 55 Connection 16 Exterior wall 100 Floor 17 Recess 101 Starting pit 18 Drilling 102 Target pit 19 Centering pin 103 Drilling device 20 Carrier section 104 adapter 21 Bolt 105 Protective pipe/underground cable/ground line 22 cover 23 Conveyor line 24 Injection line 25 Drive line 26 Feed line 27 channel 28 Spigot end 29 sleeve 30 Flange connection 31 Threaded hole 40 Fixture/press frame 41 base 42 rail 43 Guide element 44 Transmission element 45 Abutment 46 Actuator 47 Double stroke cylinder 48 cylinder 49 plate

Claims (8)

1. Drill pipe for use during the creation of a borehole in ground from a starting point (101) to a target point (102) along a predetermined drill line, wherein the borehole is gradually created by means of a drilling device (103) comprising a drilling tool for loosening the ground (100) as the drill pipes (10) are advanced, wherein the drill pipe (10) has at each of its ends at least one connection section (11, 12) for detachably connecting it to a further element of a drill string in a tensile-resistant manner, wherein the drill pipe (10) has at least one element for producing a tensile-resistant connection to a corresponding element of an advancing device for advancing the drill pipe (10) into and/or retracting it from the borehole, wherein an outer wall (16) of the drill pipe (10) is made in one piece, wherein the connection by the respective connection sections (11, 12) of the drill pipe (10) to another element of the drill string occurs in the form of a positive-locking and/or a non-positive-locking connection, and wherein the drill pipe (10) has at its first end a first connection section (11) and at its opposite second end a second connection section (12) corresponding to the first connection section (11), wherein the drill pipe (10) has at least two conduit sections arranged in the inner space of the drill pipe (10) at the outer wall (16) and extending in parallel along the outer wall (16), wherein the at least two conduit sections (23, 24, 25, 26, 27) have at each of their ends a connection element (28) for producing a connection between conduit sections (23, 24, 25, 26, 27) of interconnected drill pipes (10), wherein the first connection section (11) and the second corresponding connection section (12) form, in the mounted state, a flange connection which has connection elements (21) and/or bores (14, 31) for placement of a bolt connection, wherein the first connection section (11) has a support section (13) in which the bores (14) are provided, characterized in that, behind the support section (13), an indentation (15) is provided in the outer wall (16) of the drill pipe (10), and in that the indentation (15) can be closed with a covering (22).
2. System for use during the creation of a borehole in the ground (100) from a starting point (101) to a target point (102) along a predetermined drill line for the near-surface laying of underground cables or underground lines (105) in the ground (100), wherein the borehole is gradually created by means of a drilling device (103) comprising a drilling tool for loosening the ground (100) as drill pipes (10) are advanced, characterized in that the drill pipes (10) are drill pipes (10) according to Claim 1, and in that an advancing device (40) is provided for moving the drilling device, said advancing device being a device for moving at least one drill pipe (10) into or out of a borehole, with at least one base (41), with at least one abutment (45), with at least one actuator (46) for moving the at least one drill pipe (10), being operatively connected to the base (41), with a transmission element (44), being operatively connected to the actuator (46), for transmitting the movement produced by the at least one actuator (46) to the at least one drill pipe (10), wherein a guide element (43) is provided which is movable relative to the base (41) and operatively connected to the transmission element (44), in that the transmission element (44) has at least one positive-locking element for transmission of the movement, being designed such that a tensile-resistant releasable connection exists between transmission element (44) and drill pipe (10), wherein the positive-locking element has at least one engaging element which provides the tensile-resistant releasable connection by engaging in an engaging section of the drill pipe (10), and wherein the at least one engaging element is designed such that it encloses the drill pipe (10), or wherein the at least one engaging element is a connection section (11, 12) corresponding to a connection section of the drill pipe (10), and wherein the connection sections (11, 12) form a tensile-resistant flange connection.
3. System according to Claim 2, characterized in that the at least one actuator (46) of the advancing device (40) is a hydraulic cylinder and/or a rack and pinion drive.
4. System according to Claim 2 or 3, characterized in that the positive-locking element of the advancing device (40) has at least two engaging elements (53).
5. System according to Claim 4, characterized in that the engaging elements (53) are arranged horizontally and/or vertically movably in the positive-locking element (44) .
6. System according to one of Claims 2 to 5, characterized in that near-surface is understood to mean a laying depth of 2 to 6 m.
7. Method for creating a borehole in the ground (100) from a starting point (101) to a target point (102) along a predetermined drill line for the near-surface laying of underground cables or underground lines (105) in the ground, wherein the borehole is gradually created by means of a drilling device (103) comprising a drilling tool for loosening the ground (100) as drill pipes (10) are advanced, characterized in that drill pipes (10) according to Claim 1 are used which are mounted to form a drill string and are moved in the borehole by means of an advancing device (40), wherein the drill pipes (16) and the advancing device (10) are a system according to one of Claims 2 to 6.
8. Method according to Claim 7, characterized in that near-surface is understood to mean a laying depth of 2 to 6 m.

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