Abrasive suspension removal unit, and system and method for removing deposits

Abstract

The invention relates to an abrasive suspension removal unit (6), which is designed for advancing in a cavity and has at least one discharge nozzle (32) designed for discharging an abrasive agent suspension (20, 22) and at least one rotating mechanical removal tool (34), which is located on the removal unit behind the at least one discharge nozzle (32) in an intended advancing direction (X), and to an abrasive suspension removal system having such a removal unit, and to a method for removing deposits (4) in boreholes (2).

Description

[0001] Title:

[0002] Abrasive suspension removal unit and system and method for removing deposits

[0003] Description

[0004]

[0001] The invention relates to an abrasive suspension removal unit, an abrasive suspension removal system with such a removal unit, and a method for removing deposits in boreholes or pipelines.

[0005]

[0002] Abrasive suspension removal systems are known which are used to remove deposits or other elements or material inside pipelines or boreholes in order to clear the cross-section of the borehole or pipeline of this material or deposits. Such a system is known, for example, from EP 3631 149 Bl. Such systems are used to work on boreholes, particularly in the oil and gas industry. With such systems, sealed pipelines or boreholes can be opened, or deposits or objects in such pipelines or boreholes can be removed.

[0006]

[0003] For material removal, a high-pressure suspension jet or several high-pressure suspension jets are used, which are applied to the borehole or pipeline through nozzles. The difficulty lies in controlling the high-pressure suspension jets in such a way that unintentional damage to the pipe wall or pipelines does not occur.

[0004] Against this background, the object of the invention is to improve an abrasive suspension removal unit and an abrasive suspension removal system in such a way that reliable material removal inside pipelines or boreholes is possible while simultaneously reliably preventing unintentional damage to the pipe or borehole wall.

[0007]

[0005] This problem is solved by an abrasive suspension removal unit according to claim 1, an abrasive suspension removal system according to claim 16, and a method with the features according to claim 17. Preferred embodiments are described in the dependent claims, the following description, and the accompanying figures.

[0008]

[0006] The abrasive suspension removal unit or EDM unit according to the invention is designed to be advanced into a cavity, for example a pipeline or bore, in order to remove unwanted deposits or unwanted material in this cavity. Such deposits can, for example, be blockages or result from a misalignment of the bore. The removal unit has at least one discharge nozzle designed for dispensing an abrasive suspension. The at least one discharge nozzle is designed to discharge a high-pressure jet of abrasive suspension, which impacts the material to be removed and comminutes and abrades it. The abraded material is flushed away by the liquid of the suspension. In addition to this at least one discharge nozzle, the removal unit according to the invention has at least one rotating mechanical removal tool.This removal tool also serves to break down material or unwanted deposits. The at least one discharge nozzle and the mechanical removal tool are arranged on the removal unit such that, in a feed direction intended for use of the removal unit, the mechanical removal tool is located behind the discharge nozzle. The intended feed direction is the direction in which the removal unit is advanced within a cavity to remove contaminants, deposits, or other material. The aforementioned arrangement of the at least one discharge nozzle and the removal tool ensures that the suspension discharged by the nozzle first comes into contact with the material to be removed. In this way, the suspension can loosen and remove an initial portion of the material to be removed. This is particularly the material in the central region of the cavity.The subsequently advanced removal tool then enables precise, dimensionally accurate machining of the cavity, particularly adjacent to a cavity wall, without damaging it. In other words, the removal unit according to the invention enables a two-stage removal process in which, in a first step, material is loosened and flushed away using an abrasive suspension, and then further machining is carried out using a mechanical removal tool. The suspension jet can thus create a pilot bore, which is subsequently enlarged by the mechanical removal tool. The mechanical removal tool has the advantage that it can have a defined geometry adapted to the cavity being machined and is guided precisely within it, so that machining without damaging the cavity wall, for example, a pipe wall, is possible.This creates a hybrid tool that combines the advantages of an abrasive suspension cutting system with those of a mechanical removal tool. The abrasive suspension removal process offers the advantage of easily removing a wide variety of materials with high material removal rates. Simultaneously, the fluid used ensures that the removed material is flushed away. The mechanical removal tool offers the advantage of a defined cutting geometry, enabling more precise machining of cavities, particularly in the wall area.

[0009]

[0007] According to a preferred embodiment, the discharge direction of the at least one discharge nozzle is directed forward in the intended feed direction. That is, the central axis of the discharge direction is oriented such that the suspension jet is directed essentially forward in the feed direction, meaning that its main directional component is preferably directed forward. The angle of the discharge direction, that is, the central axis of the discharge direction, to a feed axis defining the feed direction is preferably less than 45°, more preferably less than 30°, and even more preferably less than 20° or less than 10°. This ensures that the suspension jet is preferably not directed directly at the pipe wall or the wall of a bore within which the machining takes place. The suspension jet is preferably directed at the pipe wall at an acute angle, if at all.This type of jet direction prevents the suspension jet from directly impacting the wall, thus minimizing the risk of unintentional damage. If at least one suspension jet, or multiple suspension jets, are angled relative to the feed axis, a higher material removal rate can be achieved and / or material removal can be carried out over a larger area. The angle relative to the feed axis is preferably no greater than described above, preferably greater than 5 degrees, and more preferably greater than 10 degrees. However, other angles between 5 and 45 degrees, and more preferably between 10 and 30 degrees, are also conceivable.In a particular embodiment, the suspension jet or jets can preferably be directed with their main emission directions parallel to the intended feed direction, or, in the case of an angled arrangement, preferably directed inwards, i.e., away from the wall of a cavity to be processed. With the discharge nozzles directed forward, material removal is preferably achieved in the central region of the cavity to be processed; that is, the material removal preferably does not extend to the circumferential wall of the cavity. Material removal in the region of the circumferential wall is preferably carried out by the subsequent mechanical removal tool, which is defined in its geometry and can therefore be guided along the wall in a defined manner.

[0010]

[0008] Preferably, the removal unit has several discharge nozzles, each designed to dispense an abrasive suspension, and whose discharge directions are preferably directed forward in the intended feed direction, as described above. The arrangement of several discharge nozzles enables removal over a larger cross-sectional area. This increases the removal rate.

[0011]

[0009] In another possible embodiment of the invention, the at least one discharge nozzle or the multiple discharge nozzles are arranged on a rotatable nozzle head, i.e., a nozzle head rotatable with respect to the material removal unit. In this way, the discharge nozzles are moved or rotated during material removal so that they can cover a larger surface area, thereby also increasing the material removal rate. The rotatable nozzle head is preferably rotatable about an axis of rotation that extends parallel to or along the intended feed direction. Thus, the rotation moves the discharge nozzles, or the at least one discharge nozzle, over a cross-sectional area that extends transversely to the axis of rotation and therefore transversely, in particular perpendicularly, to the intended feed direction or feed axis. The rotatable nozzle head allows the nozzles to rotate relative to the material removal unit during its feed.The removal unit can be advanced in a rotating manner, but it can also rotate itself at a speed different from the speed of the nozzle head, so that a relative rotary movement is achieved between the nozzle head and at least one other part of the removal unit.

[0012]

[0010] In a further possible embodiment of the invention, the at least one mechanical removal tool is rotatable about an axis of rotation which extends parallel to or along the intended feed direction. In this way, material removal is achieved in the circumferential region of the removal tool concentrically to the axis of rotation. The removal tool can preferably fill the interior of a cavity to be machined such that its circumferential wall is located concentrically to the central axis of the cavity, which extends along the feed direction, so that, for example, in a pipe with a circular cross-section, the entire inner wall can be machined by the rotating removal tool. Alternatively, it is conceivable to design the mechanical removal tool with a smaller diameter and to rotate the axis of rotation of the removal tool about a further axis of rotation, so that the axis of rotation moves in a circular path.The mechanical removal tool can thus be moved circumferentially along the inner wall of a cavity, for example, a pipe, while preferably being advanced simultaneously. The removal tool would therefore perform a helical movement along the inner wall of the pipe or bore. Preferably, the removal tool is rotatable separately or independently of a nozzle head as described above. This means, in particular, that the removal tool and the nozzle head can rotate at different speeds, so that they rotate relative to each other. Most preferably, the removal tool and the nozzle head can each be arranged to rotate with respect to a stationary, i.e., non-rotating, part of the removal unit.

[0013]

[0011] The mechanical removal tool and the rotatable nozzle head can have a common drive unit. This common drive unit can be designed such that the removal tool and the nozzle head rotate at the same rotational speed. That is, in this embodiment, they are rotatable together. In a special embodiment, the removal tool and the nozzle head can rotate about the same axis of rotation. However, it is also possible to rotate the nozzle head and the removal tool at different rotational speeds using suitable gear units. Furthermore, it is also possible for the axes of rotation of the removal tool and the nozzle head to be arranged parallel to each other and / or at an angle to each other.

[0014]

[0012] The mechanical removal tool and / or the rotatable nozzle head preferably have an electric or hydraulic drive unit. The electric drive unit can be one or more electric motors integrated into the removal unit and advanced together with it. A hydraulic drive can be powered by a supplied fluid. This fluid is more preferably a flushing fluid, sludge, or the like, and particularly preferably the suspension that is supplied to the at least one discharge nozzle. Such a hydraulic drive has the advantage that no additional electrical supply lines need to be routed to the removal unit. In another possible embodiment, the removal tool and / or the rotatable nozzle head can be connected to a rotatable drive shaft, which rotates in the pipe or cavity and is advanced together with the removal unit.This allows the rotary drive to be positioned outside the cavity, i.e., outside the bore or pipe. However, this requires a long rotatable shaft. If the nozzle head and the mechanical removal tool are rotated together, a common drive unit, such as a common electric or hydraulic drive motor, is preferably provided. The nozzle head and the mechanical removal tool can also have different drives. For example, the nozzle head could be hydraulically driven, while the mechanical removal tool is electrically driven, or vice versa. Furthermore, the mechanical removal tool could also be driven by a motor located outside the bore or pipe.The drive arranged in the pipe, for example together with the entire removal unit, is rotated, while the nozzle head is driven independently via another drive, for example a hydraulic or electric drive.

[0015]

[0013] In a particular embodiment, the removal unit can have several discharge nozzles whose discharge directions are at least partially angled to one another. In particular, the discharge nozzles can be angled such that their discharge directions intersect downstream of the discharge nozzles. In this way, a particularly high removal rate can be achieved. However, other angled arrangements of the discharge directions are also possible, for example, to enable removal or processing on a large surface.

[0016]

[0014] In a preferred embodiment, the mechanical material removal tool has several cutting edges distributed around its circumference. The mechanical material removal tool can thus be designed essentially like a milling cutter. The cutting edges are preferably arranged such that, in cross-section, they lie on a common circumferential line extending concentrically to the axis of rotation, and thus machine the same circumferential surface around the axis of rotation. The cutting edges can extend parallel to the axis of rotation or be angled or curved along a circumferential surface extending concentrically to the axis of rotation. A helical orientation of the cutting edges is also conceivable.

[0017]

[0015] According to a further possible embodiment, the mechanical removal tool can have a diameter transverse to its axis of rotation which corresponds to the inner diameter of a pipe or bore to be machined. This enables precise machining directly against the inner wall of the pipe or cavity to be machined, so that deposits or unwanted material can be removed essentially completely in this area.

[0018]

[0016] In a further possible embodiment, the mechanical removal tool has at least one channel that connects a front side of the removal tool (in the feed direction) with a rear side of the removal tool (in the feed direction) for fluid passage. If the at least one discharge nozzle is located in front of the mechanical removal tool in the intended feed direction, this channel allows the fluid or suspension dispensed from the discharge nozzle(s) to flow through or around the mechanical removal tool in the opposite direction of feed. The fluid serves as a flushing fluid and carries away the removed material. Preferably, the channels in the removal tool can be designed as a plurality of recesses located on the outer circumference of the removal tool and extending along the axial length of the removal tool from a front to a rear side.These depressions simultaneously form spaces through which the material removed by the mechanical removal tool can be discharged, particularly by the fluid dispensed via the discharge nozzles. However, additional flushing nozzles can also be arranged on the removal unit, through which, for example, a fluid without abrasives could be dispensed to increase the flushing capacity.

[0019]

[0017] According to a further preferred embodiment, the machining unit according to the invention has a centering device designed to position the mechanical machining tool centrally in a tube or bore. For this purpose, the centering device preferably has contact elements, in particular at least two or more preferably three contact elements, which contact the wall of the tube at spaced-apart circumferential positions and bear against the wall. The centering device is particularly preferably designed such that the axis of rotation of the mechanical machining tool is aligned with the longitudinal axis of the tube. The centering or defined positioning of the machining tool in the tube enables precise machining of the wall using the machining tool.

[0020]

[0018] In a further particular embodiment of the removal unit, it has at least one rear discharge nozzle which has a discharge direction directed rearward opposite to the intended feed direction. The rear discharge nozzle can also be designed to dispense abrasive suspension or a pure rinsing fluid and, for example, serve to flush away removed material against the feed direction. The at least one rear discharge nozzle preferably has a discharge direction whose main directional component is directed opposite to the feed direction but parallel to it. Thus, the main axis or main direction of the discharge direction is preferably directed at an angle of less than 45°, more preferably less than 30°, and further preferably less than 20° or less than 10° to the feed axis of the feed direction. That is, a discharge direction at an acute angle to the rear is created.Rearward-facing discharge nozzles can also support or cause forward motion through recoil.

[0021]

[0019] The at least one or the several rear discharge nozzles are preferably arranged in the provided feed device behind the mechanical removal tool. This means that the fluid exiting the rear discharge nozzle or nozzles does not have to pass through the mechanical removal tool.

[0022]

[0020] According to a further preferred embodiment, the abrasive suspension removal unit has a feed device by which the removal unit can be advanced in the provided feed device, in particular in the longitudinal direction through a tube or bore. The feed device can, for example, be a supply tube attached to the rear of the removal unit, through which the removal unit is advanced in the tube or bore to be processed. Alternatively or additionally, the feed unit can have a feed device that acts directly on the feed unit. For this purpose, the feed unit can have a releasable fixing device, for example, a clamping device, which is designed so that it can be releasably fixed in a tube. Thus, the fixing device can, for example, clamp itself inside the tube and serve to support the feed device in the tube.The feed mechanism can be designed such that, after the clamping device is locked, it advances the cutting unit a certain distance within the tube. The clamping device can then be released, allowing the feed mechanism to retract and thus move forward in the feed direction. After this forward movement, the clamping device can be re-locked or tightened within the tube, and the cutting unit can be advanced again. This allows for a stepwise advancement of the cutting unit. The described releasable clamping device can simultaneously serve to center the mechanical cutting tool or assist in its centering.For example, a combined fixing and centering device could be provided, which serves on the one hand to center the mechanical removal tool and on the other hand to support the feed device inside the tube or bore.

[0023]

[0021] In addition to the abrasive suspension removal unit described above, the invention relates to an abrasive suspension removal system with such a removal unit as described above. Besides the removal unit described above, the abrasive suspension removal system includes a suspension source. This suspension source comprises at least one high-pressure pump for generating a high-pressure fluid flow and a mixing device for adding an abrasive to a fluid pumped by the high-pressure pump. The abrasive can be added upstream or downstream of the high-pressure pump. The suspension source thus provides a high-pressure abrasive suspension. This suspension is supplied to the removal unit via a high-pressure line that connects the removal unit to the suspension source.When processing a pipe or borehole, the suspension source is preferably located outside the pipe or borehole, and the high-pressure line is advanced into the pipe or borehole along with the cutting unit. The high-pressure line can simultaneously drive or assist the advancement of the cutting unit.

[0024]

[0022] The invention further relates to a method for inspecting for deposits in boreholes or pipelines, or pipes, in particular boreholes or pipelines such as those used in gas or oil production, i.e., in gas or oil production pipes. The method can be carried out, in particular, using an abrasive suspension removal unit and / or an abrasive suspension removal system as described above. It should be understood that the preferred embodiments described above are also to be considered preferred embodiments of the method according to the invention. According to the method according to the invention, a two-stage process is carried out. First, deposits in a central area of ​​the borehole or pipeline to be processed are removed with at least one high-pressure suspension jet.Such a suspension jet is preferably discharged through at least one discharge nozzle, as described above. Preferably, more than 50 percent, and more preferably more than 80 percent, of the cross-sectional area of ​​the pipe or bore is removed. This means that the majority of the material is removed by the high-pressure suspension jet. Subsequently, deposits or material in the edge region of the pipe or bore being treated, adjacent to a wall of the bore or pipeline, are removed using a mechanical removal tool. Removal using the suspension achieves a high removal rate for a wide variety of materials inside the pipelines.Subsequent mechanical processing of the pipe wall using a mechanical removal tool ensures precise machining of the bore or pipeline with a reduced risk of wall damage. This subsequent mechanical processing preferably removes less than 50 percent, and more preferably less than 20 percent, of the material in the cross-section of the pipe or bore. In this way, the high removal rate of the high-pressure suspension jet or multiple high-pressure suspension jets is combined in an optimized manner with the precise machining achieved by a mechanical removal tool.

[0025]

[0023] The material removal with the at least one high-pressure suspension jet and the subsequent material removal with a mechanical removal tool are particularly preferably carried out in a single operation in which the discharge nozzle dispensing the high-pressure suspension jet and a mechanical removal tool are advanced simultaneously. The mechanical removal tool is located downstream of the discharge nozzle in the feed direction, so that the mechanical processing follows the hydraulic processing by the high-pressure suspension jet.

[0026]

[0024] The invention is described below by way of example with reference to the attached figures. In this figure:

[0027] Fig. 1 schematically shows an application example of an abrasive suspension removal system according to the invention for machining a deep sea borehole,

[0028] Fig. 2 schematically shows the structure of an abrasive suspension removal system according to the invention,

[0029] Fig. 3 shows a schematic sectional view of an abrasive suspension removal unit according to a first embodiment,

[0030] Fig. 4 shows a schematic sectional view of an abrasive suspension removal unit according to a second embodiment, and Fig. 5 shows a schematic sectional view of an abrasive suspension removal unit according to a third embodiment.

[0031]

[0025] The abrasive suspension removal system according to the invention is designed for processing boreholes or pipelines. Figure 1 shows an example of processing a deep-sea borehole 2 to remove material 4 that is blocking the borehole 2. For this purpose, an abrasive suspension removal unit, as described in more detail with reference to Figures 3 to 5, is advanced into the borehole 2. In this embodiment, the borehole 2 is located in the earth below the seabed 8. The abrasive suspension removal unit is controlled and the suspension is supplied from a platform 10 above sea level 12. The suspension is supplied via a drilling fluid line or supply line 14. An abrasive supply and a high-pressure pump are located on the platform 10, as described below with reference to Figure 2.

[0032]

[0026] In the system shown in Figure 2, the drilling fluid is essentially circulated. The abrasive suspension removal system has a suspension source which includes a mixing device 16 in which an abrasive 20 is added to a liquid or water stream 18. The suspension 22 formed by mixing the liquid 18 and the abrasive 20 is fed to a high-pressure pump 24, which pressurizes the suspension, preferably to a pressure greater than 50 bar, more preferably greater than 100 bar or greater than 200 bar. The high-pressure suspension 26 thus formed is fed to the abrasive suspension removal unit 6 in the borehole 2 via the supply line 14.The liquid exiting the abrasive suspension removal unit 6 is returned to the suspension source as rinsing fluid via a return line 28, whereby impurities and abrasives 20 are separated from the liquid in a separation unit 30. The liquid exiting the separation unit 30 is returned to the mixing device 16 as a liquid stream 18.

[0033]

[0027] Three exemplary embodiments of the abrasive suspension removal unit 6 are described in more detail with reference to Figures 3 to 5. The abrasive suspension removal unit 6 shown in Figure 3 can be advanced along the feed axis X in the bore 2. At its forward end in the feed direction X, the abrasive suspension removal unit 6 has a nozzle head 31 with several discharge nozzles 32, the discharge directions of which are directed forward parallel to the feed axis X. That is, in this exemplary embodiment, the central axis of the discharge direction or of the suspension jets 33 extends parallel to the feed axis X, so that the suspension jet 33 exiting from the discharge nozzles 32 is not directed directly at the wall of the bore 2. The suspension 26, which is under high pressure, is supplied to the discharge nozzles 32 via the supply line 14.The high-pressure suspension jets 33 emerging from the discharge nozzles 32 hit the deposit or material 4 and remove it over a surface area in the central region of the bore 2.

[0034]

[0028] Viewed in the feed direction X, behind the discharge nozzles 32, the abrasive suspension removal unit 6 has a mechanical removal tool 34. The mechanical removal tool 34 is designed as a milling cutter and is rotatable about the feed axis X. The mechanical removal tool 34 has an outer diameter which essentially corresponds to the inner diameter of the bore 2 to be machined. On its outer circumference, the removal tool 34 has several cutting edges 36, between which recesses or grooves 38 are located. The cutting edges 36 and the recesses 38 located between them extend along the outer circumference of the removal tool 34 over its entire axial length from a front to a rear end (viewed in the feed direction X).This creates channels through which the liquid exiting the discharge nozzles 32, together with the removed material 4, can be conveyed through the rear of the mechanical removal tool 34 or its recesses 38. The liquid is then returned to the suspension source via the return line 28.

[0035]

[0029] The nozzle head 31 with the discharge nozzles 32 and the mechanical removal tool 34 rotate together in the direction of rotation D, the rotary drive being achieved by rotating the supply line 14, which forms a rotatable shaft. For advancement, the removal unit 6 is fixed inside the bore 2 by means of an anchor 40. Starting from the anchor 40, the front part of the removal device 6 with the mechanical removal tool 34 and the nozzle head 31 can be advanced. After a certain advancement movement, the anchor 40 can be released, repositioned, and re-anchored.To precisely center the mechanical removal tool 34 in the bore 2, so that the axis of rotation of the mechanical removal tool 34 is aligned with the central axis of the bore 2, an additional centering device 42 can be provided, which is supported on the inner wall of the bore 2 and thus centers the removal device 6 with the mechanical removal tool 34 centrally in the bore 2.

[0036]

[0030] The abrasive suspension removal unit 6, as designed in this way, enables a two-stage inspection of the deposits or material 4. In the first stage, a pilot bore is created in the central area, meaning that the material 4 in the central area is removed by the suspension jets 33, which emerge from the discharge nozzles 32. The material directly adjacent to the inner wall of the bore 2 is not removed in this process. This material is subsequently removed by the rotating mechanical removal tool 34. The mechanical removal tool 34 enables precise machining of the inner diameter of the bore 2 without damaging the pipe wall.

[0037]

[0031] The removal unit 6' according to the second embodiment, which is shown in Figure 4, differs from the removal unit 6 described above in that it has a drive device 44 in the removal unit 6', which causes the rotation of the mechanical removal tool 34 and the nozzle head 31 in the direction of rotation D. The drive device 44 can, for example, be an electric drive motor or a hydraulic motor, the hydraulic motor preferably being driven by the supplied drilling fluid, in particular the suspension, which is supplied to the discharge nozzles 32.

[0038]

[0032] In the third embodiment, shown in Figure 5, the removal unit 6” has rear discharge nozzles 46, which, viewed in the feed direction X, are arranged at the rear of the mechanical removal tool 34 and have a jet direction directed obliquely to the rear, opposite to the feed direction X. That is, their fluid jets 48 are directed obliquely to the rear. Thus, the rear discharge nozzles 46 can support the feed in the direction of the feed axis 6 and simultaneously support the outflow of the removed material to the return 48. The fluid jets 48 are directed at an acute angle to the inner wall of the bore 2, so that they do not strike the inner wall in such a way as to damage it. The fluid jets 48 can be formed by rinsing fluid or by suspension.The rear discharge nozzles 46 preferably rotate together with the nozzle head 31, in which the discharge nozzles 32 are arranged, and the mechanical removal tool 34. It should be understood that a drive unit 44 could also be arranged in the removal unit 6" in the third embodiment. Likewise, the rear discharge nozzles 46 could also be arranged in the removal unit 6" in the first embodiment according to Figure 3 or in the removal unit 6' in the second embodiment according to Figure 4.

[0039] List of reference symbols

[0040] 2 holes

[0041] 4. Material, deposit

[0042] 6, 6', 6" Abrasive Suspension Removal Unit

[0043] 8 Seeboden

[0044] 10 platforms

[0045] 12 Sea level

[0046] 14 Supply line

[0047] 16 Mixing device

[0048] 18 Liquid flow

[0049] 20 abrasives

[0050] 22 Suspension

[0051] 24 High-pressure pump

[0052] 26 High-pressure suspension

[0053] 28 Return

[0054] 30 separation units

[0055] 31 nozzle head

[0056] 32 discharge nozzles

[0057] 33 Suspension jets

[0058] 34 mechanical removal tool

[0059] 36 cutting edges

[0060] 38 depressions

[0061] 40 anchors

[0062] 42 Centering device

[0063] 44 Drive unit

[0064] 46 rear discharge nozzles

[0065] 48 liquid jets

[0066] X Feed direction, feed axis

[0067] Direction of rotation

Claims

Claims 1. Abrasive suspension removal unit (6) which is designed for feeding in a cavity and has at least one discharge nozzle (32) designed for dispensing an abrasive suspension (20, 22) and at least one rotating mechanical removal tool (34) which is arranged on the removal unit in a provided feed direction (X) behind the at least one discharge nozzle (32).

2. Abrasive suspension removal unit (6) according to claim 1, wherein a discharge direction of the at least one discharge nozzle (32) is directed forward in the intended feed direction (X), wherein the angle to a feed axis (X) defining the feed direction (X) is less than 45°, preferably less than 30° and further preferably less than 20° or less than 10°.

3. Abrasive suspension removal unit (6) according to claim 1 or 2, which has several discharge nozzles (32) each designed to dispense an abrasive suspension (20, 22) and whose discharge directions are preferably directed forward in the intended feed direction (X).

4. Abrasive suspension removal unit (6) according to one of the preceding claims, in which the at least one discharge nozzle (32) is arranged on a rotatable nozzle head (31) which is preferably rotatable about an axis of rotation which extends parallel or along the intended feed direction (X).

5. Abrasive suspension removal unit (6) according to one of the preceding claims, wherein the at least one mechanical The cutting tool (34) is rotatable about a rotary axis which extends parallel to or along the intended feed direction (X).

6. Abrasive suspension removal unit (6) according to one of the preceding claims, wherein the mechanical removal tool (34) and the rotatable nozzle head (31) have a common drive device (44) by means of which they are preferably rotatable together.

7. Abrasive suspension removal unit (6) according to one of the preceding claims, wherein the mechanical removal tool (34) and / or the rotatable nozzle head (31) have an electrical or hydraulic drive device (44) or are connected to a rotatable drive shaft.

8. Abrasive suspension removal unit (6) according to one of the preceding claims, which has several discharge nozzles (32) whose discharge directions are at least partially angled to each other.

9. Abrasive suspension removal unit (6) according to one of the preceding claims, wherein the mechanical removal tool (34) has several cutting edges (36) arranged distributed over its circumference.

10. Abrasive suspension removal unit (6) according to one of the preceding claims, wherein the mechanical removal tool (34) has a diameter transverse to its axis of rotation which corresponds to an inner diameter of a tube or bore (2) to be machined.

1. Abrasive suspension removal unit (6) according to one of the preceding claims, wherein the mechanical removal tool (34) has at least one channel connecting a front side of the removal tool in the feed direction (X) with a rear side of the removal tool in the feed direction (X) for fluid passage, wherein the removal tool preferably has a plurality of recesses (38) on its outer circumference, which extend over the axial length of the removal tool from the front to the rear side.

12. Abrasive suspension removal unit (6) according to one of the preceding claims, which has a centering device (42) which is designed to position the mechanical removal tool (34) centered in a tube.

13. Abrasive suspension removal unit (6) according to one of the preceding claims, which has at least one rear discharge nozzle (46) having a discharge direction directed rearward opposite to the intended feed direction (X), wherein the angle to a feed axis (X) defining the feed direction (X) is less than 45°, preferably less than 30° and further preferably less than 20° or less than 10°.

14. Abrasive suspension removal unit (6) according to claim 13, in which the at least one rear discharge nozzle (46) is arranged behind the mechanical removal tool (34) in the intended feed direction (X).

15. Abrasive suspension removal unit (6) according to one of the preceding claims, comprising a feed device by which the removal unit is moved in the intended feed direction- tung (X) is advanceable, wherein the feed device preferably has a releasable fixing device which is designed in such a way that it can be releasably fixed in a tube.

16. Abrasive suspension removal system with a removal unit according to one of the preceding claims, with a suspension source comprising a high-pressure pump (24) for generating a high-pressure liquid flow (18) and a mixing device (16) for adding an abrasive (20) to a liquid supplied by the high-pressure pump (24), and with a high-pressure line connecting the removal unit to the suspension source.

17. Method for inquiring about deposits (4) in boreholes (2) or pipelines, in particular using an abrasive suspension removal unit (6) according to one of claims 1 to 15 or an abrasive suspension removal system according to claim 16, in which deposits (4) are first removed in a central area of ​​the borehole (2) or pipeline with at least one high-pressure suspension jet and subsequently deposits in the peripheral area adjacent to a wall of the borehole (2) or pipeline are removed with a mechanical removal tool (34).

18. Method according to claim 17, in which the removal with the at least one high-pressure suspension jet and the subsequent removal with a mechanical removal tool (34) are carried out in one operation under feed of at least one discharge nozzle (32) discharging the high-pressure suspension jet and a mechanical removal tool (34) arranged behind the nozzle in the feed direction (X).

Images