Liquid-abrasive cutting system comprising cutting monitoring device and method

Abstract

The invention relates to a liquid-abrasive cutting system comprising a cutting head (2) which is designed to be introduced into a pipe (4) to be cut and comprises at least one cutting nozzle (16) for emitting a suspension jet (18) formed by liquid and abrasive medium, comprising a cutting monitoring device (38) and at least one first sensor (42), which is connected to the cutting monitoring device (38) and is designed to be arranged on an outer face of a wall of the pipe (4) to be cut, and wherein the cutting monitoring device is designed such that it monitors a severing of the wall of the pipe (4) by means of signals from the at least one first sensor (42). The invention also relates to a method for severing the wall of a pipe.

Description

[0001] Applicant: ANT Applied New Technologies AG

[0002] Title: Liquid Abrasive Cutting Onylophones

[0003] Our reference: ANTP 3849 WO

[0004] Description

[0005]

[0001] The invention relates to a liquid abrasive cutting device for cutting pipes and a method for cutting through the wall of a pipe using a suspension jet.

[0006]

[0002] Liquid abrasive cutting systems, for example water abrasive cutting systems, have been used for cutting a wide variety of materials and objects. For example, a water abrasive cutting system is known from WO 2016 / 131483 Al, which is designed for cutting pipes, in particular oil production pipes below the seabed. For cutting, a cutting head is inserted into the interior of the pipe, and a high-pressure suspension jet is directed from a cutting nozzle on the cutting head from the inside onto the wall of the pipe in order to cut through it in a desired area. The difficulty lies in the fact that the cutting is carried out without visual control and that it is difficult to determine whether the pipe wall has been completely cut through in the desired area, for example, completely cut through in the radial direction over the entire circumference.This is particularly difficult with oil production pipes, as such pipes are generally multi-layered, consisting of several nested metal tubes, with the spaces between the metal tubes being completely or partially filled with cement. Furthermore, the individual tubes are not always centered relative to each other, and the spaces between them are not always completely filled, or even filled at all. This results in quite varying cutting conditions. From WO 2016 / 131483 Al, it is known to arrange at least one hydrophone and another sensor on the cutting head, and to use their signals to determine the complete cutting process.

[0007] Patent attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026 Penetrating and / or cutting through the wall of the pipe can be detected.

[0008]

[0003] It is an object of the invention to improve a liquid abrasive cutting system and a method for cutting pipes using a suspension jet in such a way that better control of the cutting process is possible. This object is achieved by a liquid abrasive cutting system with the features specified in claim 1 and by a method with the features specified in claim 18. Preferred embodiments are described in the dependent claims, the following description, and the accompanying figures.

[0009]

[0004] The liquid-abrasive cutting system according to the invention is designed for cutting with a liquid-abrasive jet, in particular a suspension jet. For this purpose, a liquid, preferably water, optionally with additives, is mixed with abrasive and dispensed under high pressure from a cutting nozzle as a suspension jet. To increase performance, the suspension jet can additionally be sheathed in gas, or a gas habitat or gas sheath can be created in which the suspension jet is dispensed. For this purpose, one or more gas nozzles can be arranged in the circumferential region of the cutting nozzle, from which gas is dispensed in the circumferential region of the cutting nozzle to create the gas sheath.The cutting system can, in a known manner, comprise a high-pressure source and a mixing device for adding the abrasive to the liquid, wherein the mixing device can be arranged upstream or downstream of the high-pressure source, for example, a high-pressure pump. The cutting system has a cutting head designed to be inserted into the interior of a pipe to be cut. The cutting head includes the cutting nozzle from which the liquid is drawn.

[0010] Patent Attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026. The abrasive is applied as a suspension jet, with the cutting nozzle positioned so that it is directed towards the wall of the pipe to cut through it in a desired area. One or more optional gas nozzles, as described above, may also be arranged on the cutting head in the vicinity of the cutting nozzle.

[0011]

[0005] The cutting system also includes a cutting monitoring device. Furthermore, at least one first sensor is provided which is connected to the cutting monitoring device for signal transmission, so that output signals from the sensor are transmitted to the cutting monitoring device. According to the invention, the at least one sensor is designed for arrangement outside the pipe to be cut. For example, the at least one first sensor can be designed for arrangement on the outside of a wall of the pipe to be cut. Alternatively, the at least one first sensor can also be designed, for example, for arrangement in a material that surrounds the pipe to be cut, for example, as a measuring lance for insertion into the seabed surrounding the pipe. If several first sensors are provided, for example, a first sensor could also be arranged on the wall and another first sensor in the seabed.However, it is also conceivable to arrange several first sensors on the wall of the pipe and / or several sensors in or on the seabed, e.g., in the form of measuring lances. The cutting monitoring device is designed such that it monitors the cutting of the pipe wall by means of signals it receives from this at least one first sensor. According to the invention, the at least one first sensor is therefore not located inside the pipe or on the cutting head, but is positioned away from the cutting head during the cutting process, either outside the pipe to be cut or on the outside of the wall.

[0012] Patent attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026 of the pipe to be cut. This allows signals to be recorded directly at the pipe wall or signals transmitted from the pipe wall to the outside, in particular vibrations or structure-borne sound signals, which enable better evaluation and recording of the cutting process. This is particularly advantageous when cutting multi-layered pipe assemblies, since the cutting of the outermost layer of the pipe can be reliably detected on the outside of the outermost pipe and / or in its vicinity, even if air or gases are present between individual layers of the pipe. Vibrations or signals caused by the cutting suspension jet inside the pipe are transmitted over considerable distances within the pipe material and can be picked up there.For example, if a cutting operation is carried out in an oil production pipe below the seabed, particularly the seabed, at least one sensor can be placed above the seabed and, if necessary, above the water surface to detect signals from the cutting operation within the pipe, which is performed at a greater axial distance from the sensor. Direct signal acquisition at the pipe wall allows for more precise control and monitoring of the cutting operation by the cutting monitoring device. Such signals can also be detected outside the pipe, for example, in the seabed.

[0013]

[0006] Preferably, the cutting system includes several first sensors which are signal-connected to the cutting monitoring device, wherein the cutting monitoring device is designed such that it monitors whether the wall of the pipe is cut using signals from the several first sensors. Evaluating the signals from several first sensors enables even more precise detection of the cut and, for example, also localization of the

[0014] Patent attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026 Cutting or piercing through the entire thickness of the pipe wall.

[0015]

[0007] According to a further preferred embodiment, several first sensors are arranged at different angular positions around the longitudinal axis of the pipe and are preferably distributed evenly around the circumference of the pipe. These can be first sensors designed for attachment to the outer circumference of the pipe, and / or first sensors arranged in the vicinity of the pipe on or in the seabed, for example in the form of measuring lances carrying first sensors. Such an arrangement facilitates the localization of a puncture or complete penetration of the pipe wall with respect to an angular position around the longitudinal axis of the pipe.Determining the angular position can be helpful, for example, to prevent damage to adjacent elements such as neighboring pipes or pipelines after cutting, by stopping the cutting process by interrupting the suspension jet or by reducing the cutting power. Preferably, the cutting monitoring device is designed to determine the angular position of the cut from the signals of several first sensors. The cutting monitoring device can, for example, be configured to analyze and compare the signals of the several, and in particular several first, sensors with regard to their signal strength in order to determine an angular position of the cut between the known angular positions of the first sensors.

[0016]

[0008] The at least one first sensor can, for example, be a vibration, structure-borne sound, and / or acceleration sensor. Such a sensor can, for example, detect mechanical vibrations in the wall of the pipe to be cut, which are caused by the suspension jet.

[0017] Patent attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026 during the cutting process. Depending on whether the wall is completely cut through or not, the signal changes, e.g., the signal strength, so that the cutting process can be monitored and, if necessary, controlled based on signal changes.

[0018]

[0009] In a preferred embodiment, a holding device is provided which is connected to the at least one first sensor and which is designed to fix the at least one first sensor to the outside of the wall of the pipe to be cut. The holding device can, for example, be designed as a magnetic holding device or as a mechanical holding device. The magnetic holding device can adhere to a metallic wall of the pipe by means of magnets. In the case of a mechanical holding device, for example, fixing or gripping elements can be provided which circumferentially grip the pipe to fix the sensor to the outside of the pipe wall. Attachment by means of a differently designed clamping connection or a screw connection, e.g. by means of a thread, would also be possible.The holding device is particularly preferably designed such that it can be attached to the pipe by an automated handling device, for example, a handling robot, and especially also underwater. The holding device is further preferably designed to fix two or more first sensors to the pipe, preferably at defined positions. For example, two or more first sensors can be attached to the holding device such that, when the holding device is attached to the pipe, they are evenly distributed around its circumference.

[0019]

[0010] According to a further possible embodiment, at least one first sensor is for use underwater and is particularly preferred.

[0020] Patent attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026. The sensor is designed for water depths greater than 30 or 100 meters. This makes it suitable for offshore use, for example, when oil production pipes are to be cut underwater using the cutting system. In this case, it is possible to place at least one sensor on the outside of the pipe wall underwater. Alternatively, the sensor could be designed to be positioned above the water surface.

[0021]

[0011] The cutting monitoring device can be connected to the at least one first sensor or several first sensors via a data connection that allows the cutting monitoring device to be arranged at a distance from the sensor and preferably above a water surface. For example, the cutting monitoring device can be arranged on a work platform or a ship, while the cutting process can take place inside the pipe underwater, preferably below the seabed, using the cutting head. The at least one first sensor can, for example, be arranged underwater on the pipe above the seabed or above the water surface, but at a distance from the cutting monitoring device. Data transmission is preferably wired, for example electrically or optically. A wireless communication link could also be provided for data transmission.The distanced arrangement of the sensor(s) from the cutting monitoring device has the advantage that at least one first sensor or several first sensors can be optimally placed on the outer wall of the pipe or in the vicinity of the pipe on or in the seabed, regardless of where the cutting monitoring device is located.

[0022] Patent Attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026

[0012] According to another possible embodiment of the invention, at least one second sensor is arranged in or on the cutting head, which is connected to the cutting monitoring device via a signal transmission mechanism, for example via a cable connection. The cutting monitoring device is preferably designed such that it monitors the cutting of the wall of the pipe to be cut by means of signals from the at least one first sensor, preferably several first sensors and the at least one second sensor.While the first sensor(s) can detect signals on or near the pipe wall at a distance from the cutting point, the second sensor (or sensors) detects signals directly in the vicinity of the cutting area, for example, from the fluid surrounding the cutting area, mechanical vibrations occurring directly in the cutting head, or similar sources. Signal transmission can occur via a separate sensor line or via a control line of the cutting head, for example, using electrical or optical signals. The second sensor(s) on the cutting head, which are thus located inside the pipe, are well-suited for detecting punctures or cuts in an inner pipe shell, while the first sensors reliably detect punctures or cuts in the outer pipe wall or shell.If the cutting monitoring device is preferably designed to evaluate the signals of the first and second sensors together, a complete cutting or a complete penetration of the pipe wall, for example also of a multi-layered pipe wall, can thus be detected with greater reliability.

[0023]

[0013] The at least one second sensor is preferably a hydrophone, a pressure sensor, an acceleration sensor, a vibration sensor and / or a structure-borne sound sensor. Two second sensors are particularly preferred.

[0024] Patent Attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026. The device provides a hydrophone and a further sensor, which are arranged on or in the cutting head. The at least one second sensor, or the multiple second sensors, can be inserted into the interior of the pipe together with the cutting head and moved to the desired cutting position. At least one second sensor could be designed such that it is brought into contact with the interior of the pipe wall by the cutting head, for example, by arranging the at least one second sensor on or in a holding or clamping element that is pressed against the interior of the pipe wall. The hydrophone is preferably in contact with the liquid, in particular water, surrounding the cutting head in order to be able to record vibrations or noise in the water.The arrangement and design of the second sensors could, for example, be as described in EP 3259 100 Bl. By using at least one first sensor and at least one second sensor in the manner described, particularly accurate monitoring of the cutting result can be achieved, especially since signals can be received both inside and outside the pipe, i.e., by arranging the at least one first sensor on the outside of the outer wall.

[0025]

[0014] In particular, to be able to detect the cutting result more accurately around the circumference when cutting through the pipe wall over its entire circumference, it is conceivable to arrange several first sensors at different circumferential positions on or near the pipe wall, especially evenly distributed around the outer circumference of the pipe. For this purpose, it is conceivable that the holding device described above for the at least one first sensor is designed such that it fixes several first sensors at defined positions relative to each other on the pipe wall. Alternatively, it is also conceivable to provide several holding devices to accommodate several

[0026] Patent attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026: First sensors can be attached independently of each other to the pipe wall. Multiple first sensors can also be arranged, each detecting different physical properties.

[0027]

[0015] In a further embodiment of the invention, the cutting head can have at least one drive, preferably a rotary drive, wherein the drive is configured to move the cutting nozzle. The drive is particularly preferably configured to move the cutting nozzle circumferentially around the longitudinal axis of the pipe, wherein the cutting nozzle is preferably oriented radially such that a suspension jet is directed at least partially in a radial direction. By a complete rotation of 360 degrees with the aid of the drive, the pipe can thus be cut or separated over its entire circumference.To create holes or slots in the pipe wall, for example, the drive can also be configured for other movements. For instance, it can move a suspension jet, at least partially radially directed, around a similarly radially directed axis of rotation to cut a hole in the pipe's circumferential wall. Linear movement of the cutting nozzle via a suitable drive is also conceivable. Furthermore, the cutting head can have multiple cutting nozzles, which are moved by a common or independent drive. The drive can be, for example, electric or hydraulic. In a specific embodiment, a hydraulic drive can be powered by a supplied fluid, such as a cutting fluid or a suspension.

[0028]

[0016] The at least one drive for moving the cutting nozzle is preferably controlled by the cutting monitoring device. The cutting monitoring device can, for example, switch the drive on and off.

[0029] Patent attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026. Alternatively or additionally, the movement speed can be controlled by the monitoring device. According to a further preferred embodiment, the monitoring device can be designed such that desired cutting contours can be traced by controlling the drive of the cutting nozzle in order to make desired cuts in the wall of the pipe. According to a further preferred embodiment, the cutting monitoring device and the drive are designed such that the drive is controlled or regulated by the cutting monitoring device depending on the signals of the at least one first sensor and preferably of the at least one second sensor.For example, the speed of the drive can be adjusted to the cutting result achieved, and it can be ensured during movement that the suspension jet always cuts through the entire pipe wall.

[0030]

[0017] The cutting monitoring device can further be configured to detect a cut or complete penetration of the pipe wall based on a change in the signal, preferably the signal strength of the signal from the at least one first sensor, and preferably based on a change in the signals, preferably the signal strength of the signals from the at least one first sensor and the at least one second sensor. Optionally, several first sensors and / or several second sensors could be provided, on the basis of which the cut in the wall is detected by the cutting monitoring device. The change in the signal particularly preferably represents a change in the vibrations or sound waves in the pipe wall and / or the liquid surrounding the cutting head.

[0031] Patent Attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026

[0018] In addition to the cutting system described above, the invention also relates to a method for cutting through the wall of a pipe, preferably using a liquid-abrasive cutting system as described above and claimed in claims 1 to 16. Preferred embodiments of the cutting system described above are also to be considered preferred variants of the method. Furthermore, preferred method variants as defined in the claims and described below are also to be considered preferred embodiments of the cutting system. The method according to the invention provides that a cutting head with a cutting nozzle is arranged inside the pipe to be cut. A high-pressure suspension jet, consisting of liquid, for example water, and an abrasive, is ejected from the cutting nozzle.The high-pressure suspension is preferably fed to the cutting nozzle via a high-pressure line.

[0032]

[0019] The cutting nozzle is arranged such that the suspension jet is directed at the desired cutting point on the wall of the pipe. To increase performance, the suspension jet can be additionally enveloped with gas during application, or a gas habitat or gas environment can be created in which the suspension jet is applied and through which the suspension jet preferably travels to the pipe wall.

[0033]

[0020] According to the invention, the cutting process, and in particular the cutting or piercing of the pipe wall, is monitored by means of at least one first sensor arranged on the outside of the pipe wall and / or at least one in the vicinity of the pipe, e.g., in the seabed. This first sensor can, in particular, detect mechanical vibrations on or from the outside of the

[0034] Patent attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026. The sensor measures the pipe wall, and changes in its surface can be used to detect complete penetration of the pipe wall by the suspension jet from the inside out. Positioning the sensor on the outside of the pipe or in its vicinity allows for reliable detection of complete penetration or cutting of the pipe wall.

[0035]

[0021] To carry out the method, several first sensors can also be arranged, in particular distributed around the circumference of the outer wall of the pipe. In a particular embodiment of the method, one or more second sensors can also be used on or in the cutting head, as described above. Preferably, the cutting process is monitored with the aid of several first sensors arranged outside or on the outside of the wall of the pipe to be cut. This makes it possible to detect a puncture more precisely and, if necessary, to locate it, as described above. More preferably, the angular position of the cutting is determined with the aid of several first sensors arranged outside or on the outside of the wall of the pipe to be cut, which are arranged at different, preferably evenly distributed, angular positions around the longitudinal axis of the pipe.For example, two primary sensors can be positioned diametrically opposite each other on the pipe. Based on the different signal strengths of the sensors, it is possible to detect or determine the angular range between the sensors in which a puncture occurred.

[0036]

[0022] The at least one sensor is advantageously arranged on the outside of the pipe wall at a distance in the direction of the pipe axis from the cutting head, i.e., the area in which the pipe is cut. This is particularly advantageous when the

[0037] Patent Attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026. The cutting process is carried out in an area where the outside of the pipe is inaccessible, for example, below the water surface and / or below the seabed. In such a cutting process, the at least one sensor can be arranged, for example, above the water surface or above the seabed. As described above, in a preferred embodiment of the method, the cutting process is carried out underwater, for example, when cutting oil production pipes below the sea surface. The at least one first sensor can be arranged on the wall of the pipe above or below the water surface, for example, depending on the water depth at which the cutting process is carried out.

[0038]

[0023] The pipe to be cut can, for example, be multi-layered and have several nested walls, the spaces between the walls being, for example, completely or partially filled with cement. When cutting such a pipe, the at least one first sensor is preferably arranged on the outside of the outer wall of the pipe or in the vicinity of the outer wall or layer. This allows for reliable detection that all layers or shells, including this outer wall, have been cut through by detecting and / or monitoring vibrations or noises in the outer wall.

[0039]

[0024] The invention is described below by way of example with reference to the accompanying figures. These show:

[0040] Fig. 1 shows a schematic sectional view of a cutting head inside a pipe to be cut.

[0041] Patent attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026. Fig. 2 a schematic sectional view of a larger area of ​​the pipe to be cut with sensors arranged, and

[0042] Fig. 3 shows a schematic top and cross-sectional view of the pipe to be cut with sensors arranged on it.

[0043]

[0025] In the example shown in Figure 1, a cutting head 2 is arranged in a pipe 4 to cut through or sever this pipe. The pipe shown is multi-layered. It is formed by three nested metal pipes 6, 8, and 10, with the spaces 12 between the inner pipe 6 and the middle pipe 8, as well as between the middle pipe 8 and the outer pipe 10, being filled with cement 12. The cutting head 2 is arranged inside the inner metal pipe 6 and has a nozzle head 14 with a cutting nozzle 16. The cutting nozzle 16 is designed to dispense a suspension jet 18. In a special embodiment, the nozzle head 14 could additionally have one or more gas outlet nozzles, which are not shown here, and which can serve to create a gas jacket or gas habitat surrounding the suspension jet 18, within which the suspension jet 18 extends.Such gas injection could, for example, be carried out in a manner known from DE 202011 100 047 Ul or O 2023 / 117082 Al.

[0044]

[0026] In the example shown here, the cutting nozzle 16 is oriented such that the suspension jet 18 extends substantially radially to the longitudinal axis x of the pipe 4. The nozzle head 14 is rotatable about the longitudinal axis x via a rotary drive 20, so that when the nozzle head 14 is rotated with the suspension jet 18, the wall of the pipe 4 can be cut over its entire circumference.

[0045] Patent Attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026

[0027] The cutting head 2 is connected to a supply unit 24 (see Figure 2) via a pressure line 22. The cutting head 2 can be clamped inside the inner tube 6 during the cutting process by means of clamping devices 26, which are arranged on the outer circumference of the cutting head 2. The clamping devices 26 can, for example, have hydraulically actuated clamping jaws that can be moved radially outwards. In a special embodiment, a packer (not shown here) can also be used, which closes or seals the inner metal tube 6 above the cutting head 2 during the cutting process in order to create an underwater habitat for the cutting head 2 inside the tube 6. The packer can, for example, have an inflatable or inflatable elastic element which seals against the inner circumference of the inner metal tube 6.

[0046]

[0028] Figure 2 schematically shows a view of the pipe 4 during the cutting process. The pipe 4, as also described with reference to Figure 1, is an oil delivery pipe that extends upwards from the seabed 28 to above the water surface 30. The cutting head 2 is located inside the pipe 4 below the seabed 28, so that the wall of the pipe 4 below the seabed 28 can be cut by the suspension jet 18. The cutting head 2 is connected to the supply unit 24 via the pressure line 22. This unit has a high-pressure source, for example a high-pressure pump 32, and a mixing device 34, which serves to add an abrasive to a liquid stream 36, for example a water stream. The abrasive can be added upstream or downstream of the high-pressure pump 32.

[0047] Patent Attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026

[0029] A cutting monitoring device 38, or control device, is provided for monitoring and controlling the cutting process. The cutting monitoring device 38 is connected to first sensors 42, 43, 45 via suitable communication links 40, e.g., data cables 40. The first sensors 42, 43, and 45 can be arranged at various positions outside the pipe 4. The arrangements shown here as examples in different positions can be used alternatively or in combination. The sensors 42 (42a, 42b) are arranged underwater on the outside of the pipe wall. The first sensors 43 (43a, 43b) are arranged above the water surface 30 on the outside of the pipe wall. The first sensors 45 (45a, 45b) are arranged in the circumferential region of the pipe outside the pipe in the seabed 28. The individual variations of the arrangement are described in more detail below.

[0048]

[0030] The first sensors 42a, 42b, 43a, 43b arranged on the tube are attached, for example, by means of retaining devices 44, for instance in the form of tension bands, to the outside or outer wall of the outer metal tube 10, as shown schematically in Figures 1 and 2. In this example, the first sensors 42 are located below the water surface 30 and above the seabed 28, and further first sensors 43 are located above the water surface 30. However, it should be understood that in alternative embodiments only one first sensor 42 or only several first sensors 42a, 42b could be arranged below the water surface 30, or only one first sensor 43 or only several first sensors 43a, 43b could be arranged above the water surface 30.It is also possible to combine a first sensor 42 underwater with one or more first sensors 43 above the water surface or to combine several first sensors 42 underwater with a first sensor 43 above the water surface.

[0049] Patent Attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026. It is understood that, depending on the application, one or more first sensors 42 could, in principle, be arranged at any axial position of the tube 4, i.e., essentially in the region between the positions shown in Fig. 2. Furthermore, at an axial position along the longitudinal axis of the tube 4, several first sensors 42a and 42b as well as 43a and 43b could be arranged distributed around the outer circumference of the tube 4, for example, diametrically opposite each other, as shown in this example. Furthermore, as also shown by way of example in Fig. 2, alternatively or additionally, one or more first sensors 45 could be arranged on or in the seabed 28, for example, in the form of measuring lances inserted into the seabed 28. These first sensors 45 are also located outside the tube 4 in its circumferential region.The first sensors 42, 43, 45 are designed as acceleration and / or vibration sensors, which detect vibrations in the outer tube 10 or in a material surrounding the outer tube 10 and transmit corresponding signals to the cutting monitoring device 38 via the communication links 40. Based on these signals, and in particular on changes in the signals, such as a change in signal strength, the cutting monitoring device 38 can determine whether the wall of the tube 4, consisting of the metal tubes 6, 8, and 10 and the intervening cement layers 12, is completely penetrated by the suspension jet 18. Based on these signals, the cutting monitoring device 38 can also control the power supply unit 34 and / or the rotary drive 20 in the cutting head 2 via a suitable signal connection.For this purpose, the cutting monitoring device 38 is connected to the cutting head 2 via a communication link 46, for example a data line located on the pressure line 22.

[0050] Patent Attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026

[0031] As shown in Figure 1, further sensors, here referred to as second sensors 48 and 50, can be arranged on the cutting head 2. The two second sensors 48 shown as examples are located on the outside of the cutting head 2, so that they can come into contact with the liquid inside the tube 4. These second sensors 48 can be, for example, a hydrophone, an accelerometer, and / or a pressure sensor. The second sensors 50 are arranged in this example in a contact surface on the fixing device 26, so that they come into contact with the inner wall of the inner tube 6. These second sensors 50 can be, for example, a structure-borne sound sensor and / or an accelerometer.The second sensors 48, 50 are also connected to the cutting monitoring device 38 via the communication link 46, enabling the latter to monitor and control the cutting process based on signals from the first sensors 42, 43, 45 and the second sensors 48 and 50. The first sensor(s) 42, 43, 45 are arranged at a distance along the longitudinal axis x from the cutting area on the outside of the pipe 4, while the second sensors 48 and 50 are located near the cutting area inside the pipe 4. This allows signals reflecting the cutting result, in particular sound and / or vibration signals, to be recorded in the area inside the pipe and on the outside or in the circumferential area of ​​the pipe 4. This enables reliable detection of penetration of the entire pipe wall by the suspension jet 18 in the radial direction. In particular, this allows for monitoring throughout the entire cutting process, i.e.,During the entire rotation of the nozzle head 14, it must be monitored that the suspension jet 18 always penetrates the entire pipe wall of the pipe 4 in a radial direction, i.e., all three metal pipes 6, 8 and 10 as well as the intermediate cement layers 12. From the cutting monitoring...

[0051] Patent attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026 device 38 the rotary drive 20 can, for example, be controlled in such a way that the rotational speed is selected so that a complete cutting of the wall of the tube 4 is always ensured, i.e. in particular the drive is not rotated too quickly.

[0052]

[0032] The paired arrangement of first sensors shown in this example, that is, a pair of first sensors 4sa, 42b, a pair of first sensors 43a, 43b and / or a pair of first sensors 45a, 45b, has the advantage that the position, that is, the angular position of the average stitch 50 with respect to the longitudinal axis x, can be determined. Figure 3 shows the paired arrangement of the first sensors 42a, 42b and 45a, 45b, whereby it should be understood that the first sensors 43a, 43b can be arranged in accordance with the first sensors 42a, 42b. In the example shown here, two first sensors 42a, 42b or 43a, 43b and / or 45a, 45b are located diametrically opposite each other with respect to the longitudinal axis X of the tube 4. It should be understood that different numbers of first sensors 42, 43 and 45 can also be arranged distributed around the circumference of the tube 4, preferably evenly distributed.Because the signal strength of the signals recorded by the sensors 42, 43, and 45 distributed around the circumference varies depending on the angular position at which the puncture 50 occurs, the cutting monitoring device 38 can determine the angular position of the puncture 50 based on the detected sensor signals. This is important for protecting adjacent pipes 52, as shown by way of example in Fig. 3. Thus, if the puncture occurs near an adjacent pipe 50, the cutting process can be stopped, or the cutting power can be reduced to prevent damage to the adjacent pipes 52.

[0053] Patent attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026 Reference list

[0054] 2 cutting heads

[0055] 4 pipe

[0056] 6, 8, 10 metal pipes

[0057] 12 cement, cement layers

[0058] 14 nozzle heads

[0059] 16 Cutting nozzle

[0060] 18 Suspension jet

[0061] 20 Rotary drive

[0062] 22 Pressure line, supply line

[0063] 24 supply units

[0064] 26 Fixing device

[0065] 28 Seabed

[0066] 30 Water surface

[0067] 32 High-pressure pump

[0068] 34 Mixing device

[0069] 36 Fluid flow

[0070] 38 Cutting monitoring device

[0071] 40 Communication link to the sensors

[0072] 42, 43, 45 first sensors

[0073] 44 holding facilities

[0074] 46 Communication link to the supply unit 48, 50 second sensors

[0075] 52 breakthrough

[0076] x Longitudinal axis of the pipe

[0077] Patent attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026

Claims

22 / 28 Claims 1. Liquid-abrasive cutting system with a cutting head (2) designed for insertion into a pipe (4) to be cut, which has at least one cutting nozzle (16) for dispensing a suspension jet (18) formed from liquid and abrasive, characterized by a cutting monitoring device (38) and at least one first sensor (42, 43, 45) connected to the cutting monitoring device (38), which is designed to be arranged outside the pipe (4) to be cut, and wherein the cutting monitoring device is designed such that it monitors a cutting (50) of the wall of the pipe (4) by means of signals from the at least one first sensor (42, 43, 45).

2. Liquid abrasive cutting system according to claim 1, characterized by several first sensors (42, 43, 45) which are connected to the cutting monitoring device (38), wherein the cutting monitoring device is designed such that it monitors a cutting of the wall of the pipe (4) by means of signals from the first sensors (42, 43, 45).

3. Liquid abrasive cutting system according to claim 2, characterized in that the several first sensors (42a, 42b; 43a, 43b; 45a, 45b) are arranged at different angular positions around the longitudinal axis of the tube (4) and are preferably arranged evenly distributed over the circumference of the tube (4).

4. Liquid abrasive cutting system according to claim 2 or 3, characterized in that the cutting monitoring device (38) is configured such that it derives from the signals of the Attorneys at Law Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026 several first sensors (42a, 42b; 43a, 43b; 45a, 45b) determine an angular position of the cutting.

5. Liquid abrasive cutting system according to one of the preceding claims, characterized in that the at least one first sensor (42, 43) is designed for arrangement on an outside of a wall of the tube (4) to be cut or for arrangement (45) in a material surrounding this wall on the outside.

6. Liquid abrasive cutting system according to one of the preceding claims, characterized in that at least a first sensor (45) is designed as a measuring lance for insertion into the seabed (28) surrounding the tube (4).

7. Liquid abrasive cutting system according to one of the preceding claims, characterized in that the at least one first sensor (42, 43, 45) is a vibration, structure-borne sound and / or acceleration sensor.

8. Liquid abrasive cutting system according to one of the preceding claims, characterized by a holding device (44) connected to the at least one first sensor (42, 43), which is designed to fix the at least one first sensor (42, 43) to the outside of the wall of the pipe (4) to be cut.

9. Liquid abrasive cutting system according to one of the preceding claims, characterized in that the at least one Attorneys at Law Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026 first sensor (42, 45) designed for use underwater and especially preferably in water depths greater than 30 or 100 m.

10. Liquid abrasive cutting system according to one of the preceding claims, characterized in that the cutting monitoring device (38) is connected to the at least one first sensor (42, 43, 45) via a data connection which enables the arrangement of the cutting monitoring device (38) at a distance from the sensor (42, 43, 45) and preferably above a water surface (30).

11. Liquid abrasive cutting system according to one of the preceding claims, characterized in that at least one second sensor (48, 50) is arranged in or on the cutting head (2), which is connected to the cutting monitoring device (38) in a signal-transmitting manner, wherein the cutting monitoring device (38) is designed such that it monitors a cutting (50) of the wall of the pipe (4) to be cut by means of signals from the at least one first sensor (42, 43, 45) and the at least one second sensor (48, 50).

12. Liquid abrasive cutting system according to claim 11, characterized in that the at least one second sensor (48, 50) is a hydrophone, a pressure sensor, an acceleration sensor, a vibration sensor and / or structure-borne sound sensor.

13. Liquid abrasive cutting system according to one of the preceding claims, characterized in that at least one gas nozzle is arranged in the circumferential region of the cutting nozzle (16) in such a manner Attorneys Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026, argues that it creates a gas sheath surrounding the suspension jet.

14. Liquid abrasive cutting system according to one of the preceding claims, characterized in that the cutting head (2) has at least one drive, preferably a rotary drive (20), for moving the cutting nozzle (16).

15. Liquid abrasive cutting system according to claim 14, characterized in that the at least one drive (20) is controlled by the cutting monitoring device (38) and is controlled or regulated in particular depending on the signals of the at least one first sensor (42, 43, 45) and preferably of the at least one second sensor (48, 50).

16. Liquid abrasive cutting system according to one of the preceding claims, characterized in that the cutting monitoring device (38) is designed such that it detects a cutting of the wall of the tube (4) on the basis of a change in the signal of the at least one first sensor (42, 43, 45) and preferably on the basis of a change in the signals of the at least one first sensor (42, 43, 45) and the at least one second sensor (48, 50).

17. Liquid abrasive cutting system according to one of the preceding claims, characterized in that the cutting monitoring device (38) is designed such that it detects a cutting (50) of the wall of the tube (4) by means of a change in the signal strength of the signal of at least one first sensor atentanwälte Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026(42, 43, 45) and preferably detects based on a change in the signal strength of the signals of at least one first sensor (42, 43, 45) and of at least one second sensor (48, 50).

18. Method for cutting through the wall of a pipe (4) in which a cutting head (2) with a cutting nozzle (16) is arranged inside the pipe (4) and a suspension jet (18) formed from liquid and abrasive is ejected from the cutting nozzle (16), characterized in that the cutting process and in particular a cutting (50) of the wall of the pipe (4) to be cut is monitored by means of at least one first sensor (42, 43, 45) arranged outside or on the outside of the wall of the pipe (4) to be cut.

19. Method according to claim 18, characterized in that the cutting process is monitored by means of several first sensors (42, 43, 45) arranged outside or on the outside of the wall of the tube (4) to be cut.

20. Method according to claim 18 or 1 , characterized in that an angular position of the cutting (50) is determined by means of several first sensors (42a, 42b; 43a, 43b; 45a, 45b) arranged outside or on the outside of the wall of the tube (4) to be cut.

21. Method according to one of claims 18 to 20, characterized in that the at least one first sensor (42, 43, 45) is arranged on the outside of the wall of the tube (4) spaced apart in the direction of the tube axis (x) from the cutting head (2). Attorneys at Law Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 202622. Method according to one of claims 18 to 21, characterized in that the cutting process is carried out underwater and the at least one first sensor (42, 43, 45) is arranged on the wall of the pipe (4) above or below a water surface (30).

23. Method according to one of claims 18 to 22, characterized in that the tube (4) has several nested walls (6, 8, 10) and that the at least one first sensor (42, 43) is arranged on the outside of the outer wall (10) of the tube (4).

24. Method according to one of claims 18 to 23, characterized in that at least one second sensor (48, 50) is arranged in or on the cutting head (2) and that the cutting process and in particular the cutting (50) of the wall of the pipe (4) to be cut is monitored by means of signals from at least one first sensor (42, 43, 45) and the at least one second sensor (48, 50). Attorneys at Law Hemmer Lindfeld Frese ANTP 3849 WO, 10 / 02 / 2026

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