A tooling and method for accurate mapping of deformation defects in subsea pipelines

Abstract

This invention discloses a tooling and method for precise mapping of deformation defects in subsea pipelines, relating to the field of subsea pipeline inspection technology. It includes an outer frame, a scanning chamber, a scanning chamber drive device, a 3D scanner, a 3D scanning drive device, and a scanning chamber pumping device. The scanning chamber is housed within the outer frame. The pumping device removes seawater from the scanning chamber. The scanning chamber comprises a left scanning chamber and a right scanning chamber, which can be closed by the drive device, sealing the target mapping section of the subsea pipeline within the scanning chamber. The 3D scanner and the 3D scanning drive device are both located within the scanning chamber. The drive device enables the 3D scanner to perform a 3D scan of the target mapping section within the scanning chamber. This invention allows for normal underwater mapping in turbid or turbulent waters, and possesses advantages such as high positioning accuracy and high shape adaptability, enabling non-contact and non-destructive 3D mapping.

Description

Technical Field

[0001] This invention relates to the field of submarine pipeline inspection technology, and in particular to a tooling and method for accurately mapping deformation defects in submarine pipelines. Background Technology

[0002] The ocean, known as the "blue territory," contains abundant energy minerals such as oil, natural gas, and natural gas hydrates, playing a crucial role in my country's marine resource development and utilization. Subsea oil pipelines are a vital means of transporting marine oil and gas resources, bearing the significant responsibility of ensuring national energy security. However, long-term subsea pipelines are affected by reciprocating forces (tidal currents), seawater corrosion, ship operations (anchoring), and biological adhesion, resulting in pits and bumps on their surfaces, and in severe cases, overall bending deformation within a few meters. Therefore, effectively identifying and detecting defects in subsea pipelines and promptly detecting leaks is crucial for ensuring my country's seabed oil and gas resource extraction capabilities, and even more so for my country's energy security and marine cleanliness. Currently, domestic underwater pipeline inspection methods typically involve magnetic flux leakage internal detection and mechanical internal detection. However, these methods suffer from numerous problems, including low positioning accuracy, low image resolution, and long mapping times. Furthermore, internal detection technology struggles to accurately reconstruct the pipeline's shape. External detection methods are subject to foreign technological embargoes, and foreign equipment for laser mapping in non-dry environments remains unsuitable for highly turbid waters. Other technical methods, including acoustic imaging and mechanical contact mapping, have many drawbacks such as low resolution and slow imaging time. Summary of the Invention

[0003] The purpose of this invention is to provide a tooling and method for accurate mapping of deformation defects in submarine pipelines, in order to solve the problems existing in the prior art. It can be used for normal underwater mapping in turbid waters and turbulent waters, and has the advantages of high positioning accuracy and high shape adaptability. It can perform three-dimensional mapping without contact or damage.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] This invention provides a precision mapping fixture for deformation defects in subsea pipelines, comprising an outer frame, a scanning chamber, a scanning chamber drive device, a 3D scanner, a 3D scanning drive device, and a scanning chamber pumping device. The scanning chamber is disposed within the outer frame. The scanning chamber pumping device is used to pump out seawater from the scanning chamber. The scanning chamber includes a left scanning chamber and a right scanning chamber. The left and right scanning chambers can be closed under the drive of the scanning chamber drive device, sealing the target mapping section of the subsea pipeline within the scanning chamber. The 3D scanner and the 3D scanning drive device are both disposed within the scanning chamber. The 3D scanning drive device can drive the 3D scanner to perform a 3D scan of the target mapping section within the scanning chamber from all directions.

[0006] Preferably, the outer frame also includes a floating hull, which is connected to the scanning chamber via a pumping pipe. A three-way valve is installed on the pumping pipe, with two ports connected to the pipe and the third port connected to the outside. The scanning chamber pumping device includes a submersible pump, located within the scanning chamber and connected to the pumping pipe, used to pump seawater from the scanning chamber to the floating hull or the outside via the pumping pipe. The floating hull has a hull pipe connecting to the outside, and a butterfly valve is installed on the hull pipe. Both the floating hull and the scanning chamber have air inlets connected to an air pump, used to regulate the air pressure within the hull and scanning chamber. The floating hull also has a human-shaped opening.

[0007] Preferably, the tops of the left and right scanning compartments are rotatably connected to the outer frame via a pivot. The scanning compartment drive device includes hydraulic cylinders, which are connected to the outer sides of both the left and right scanning compartments. Each hydraulic cylinder is connected to the outer frame and can drive the left and right scanning compartments to rotate around the pivot to close or open. Sealing strips are provided on the sealing contact surfaces between the left and right scanning compartments and between the left and right scanning compartments and the subsea pipeline.

[0008] Preferably, the system further includes counterweights, with one counterweight on each side of the outer frame. The two counterweights are used to suspend the subsea pipeline on both sides. The counterweights are connected to a hydraulic winch installed on the outer frame via steel wire ropes, which can tighten or loosen the steel wire ropes. Both the outer frame and the counterweights are provided with lifting lugs. Steel cable conduits are fixed on both sides of the outer frame. The lifting lugs are used to connect to the hoisting steel cable, and the hoisting steel cable is threaded through the steel cable conduits to connect to the lifting lugs on the counterweights.

[0009] Preferably, the 3D scanning drive device includes a linear guide rail, an axial lead screw, a linear motor, an arc guide rail, an arc rack, a rotary motor, and an angle motor. The arc guide rail is slidably connected to the linear guide rail via a slider, and the slider is threadedly connected to the axial lead screw. The linear motor is connected to the axial lead screw to drive the axial lead screw to rotate. The arc rack is slidably connected to the arc guide rail. The output shaft of the rotary motor is provided with a gear that meshes with the arc rack. The rotary motor can drive the arc rack to move along the arc guide rail. A mounting base is connected to the arc rack. The angle motor is mounted on the mounting base. The housing of the angle motor is connected to the 3D scanner compartment via a connecting plate. The 3D scanner compartment is rotatably connected to the connecting plate via a scanning shaft. The output shaft of the angle motor is driven to the scanning shaft via an angle transmission device. The 3D scanner is disposed in the 3D scanner compartment. The angle motor can drive the 3D scanner compartment to rotate, thereby driving the 3D scanner to rotate.

[0010] Preferably, the outer frame is equipped with an attitude sensor for detecting the attitude of the surveying tool on the seabed; the outer frame is also equipped with a ladder.

[0011] Preferably, the scanning chamber is equipped with a lighting unit, a camera, a battery compartment, a control compartment, a lighting-monitoring compartment, and a drive compartment. The lighting-monitoring compartment is used to drive the lighting unit and the camera. The drive compartment is used to drive the linear motor, the rotary motor, and the angle motor. The control compartment is used for all underwater control of the surveying fixture. The battery compartment is used to power all electronic equipment of the surveying fixture.

[0012] Preferably, position switches are provided at both ends and at the bottom of the scanning cabin corresponding to the sealing contact surface. The position switches at both ends are used to detect the closure and sealing status of the scanning cabin at both ends and the subsea pipeline, and the position switch at the bottom is used to detect the closure and sealing status of the sealing contact surface at the bottom of the scanning cabin.

[0013] Preferably, both the buoyancy chamber and the scanning chamber are equipped with level gauges, which are used to detect the water level in the buoyancy chamber and the scanning chamber, respectively.

[0014] This invention also provides a method for accurately mapping deformation defects in subsea pipelines, using the aforementioned tooling for accurately mapping deformation defects in subsea pipelines, and includes the following steps:

[0015] S1: The entire surveying fixture is hoisted into the sea so that the target surveying section of the submarine pipeline is located between the left half of the scanning compartment and the right half of the scanning compartment;

[0016] S2: The scanning chamber drive device drives the left half of the scanning chamber and the right half of the scanning chamber to close, sealing the target mapping segment inside the scanning chamber;

[0017] S3: The seawater inside the scanning chamber is extracted using the scanning chamber pumping device;

[0018] S4: The three-dimensional scanner is driven by the three-dimensional scanning drive device to perform an all-round scan of the target mapping section inside the scanning chamber.

[0019] The present invention achieves the following technical effects compared to the prior art:

[0020] The present invention provides a tooling and method for precise mapping of deformation defects in subsea pipelines. By closing the left and right half of the scanning chamber, the target mapping section of the subsea pipeline can be sealed inside the scanning chamber. The seawater inside the scanning chamber can be pumped out by the scanning chamber pumping device to form an underwater empty chamber. This facilitates the use of a 3D scanning drive device to drive a 3D scanner to perform a full-range scan of the target mapping section inside the scanning chamber, thereby obtaining high-precision point cloud data of the pipeline's outer surface. Since the mapping is carried out in the empty chamber, the turbidity and turbulence of the water will not affect the mapping inside the empty chamber. Normal underwater mapping can be carried out in turbid waters and turbulent waters. The use of a 3D scanner for scanning mapping significantly improves the modeling resolution and mapping speed. It has the advantages of high positioning accuracy and high shape adaptability, and can perform high-precision 3D mapping without contact or damage. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A three-dimensional structural schematic diagram of the tooling for accurately mapping deformation defects in subsea pipelines provided by the present invention;

[0023] Figure 2 A side view of the tooling for accurately mapping deformation defects in subsea pipelines provided by this invention;

[0024] Figure 3 A top view of the precision mapping tool for deformation defects in subsea pipelines provided by this invention;

[0025] Figure 4 A schematic diagram of the internal structure of one end of the precision mapping tool for deformation defects of submarine pipelines provided by the present invention.

[0026] Figure 5A schematic diagram of the internal structure of the other end of the precision mapping tool for deformation defects of submarine pipelines provided by the present invention.

[0027] Figure 6 This is a three-dimensional structural diagram of the three-dimensional scanning driving device in this invention;

[0028] Figure 7 This is a partial schematic diagram of the connection structure between the rotary motor, the circular arc rack, and the 3D scanner cabin in this invention;

[0029] In the diagram: 1-Outer frame, 2-Scanning chamber, 3-3D scanning drive device, 4-Scanning left half chamber, 5-Scanning right half chamber, 6-Subsea pipeline, 7-Floating chamber, 8-Pumping pipeline, 9-Three-way valve, 10-Floating chamber pipeline, 11-Butterfly valve, 12-Rotating shaft, 13-Hydraulic cylinder, 14-Counterweight, 15-Wire rope, 16-Hydraulic winch, 17-Lifting lug, 18-Steel cable conduit, 19-Linear guide rail, 20-Axial lead screw, 21-Straight motor, 22-Circular arc guide rail, 23-Circular arc rack, 24-Rotary motor, 25-Angle motor, 26-Slider, 27-Mounting base, 28-Connecting plate, 29-3D scanner chamber, 30-Attitude sensor, 31-Escalator, 32-Battery compartment, 33-Control compartment, 34-Lighting-monitoring compartment, 35-Driver compartment, 36-Level gauge, 37-Humanoid opening. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The purpose of this invention is to provide a tooling and method for accurate mapping of deformation defects in submarine pipelines, in order to solve the problems existing in the prior art. It can be used for normal underwater mapping in turbid waters and turbulent waters, and has the advantages of high positioning accuracy and high shape adaptability. It can perform three-dimensional mapping without contact or damage.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figures 1-7As shown, this embodiment provides a tooling for precise mapping of deformation defects in subsea pipelines, including an outer frame 1, a scanning chamber 2, a scanning chamber drive device, a 3D scanner, a 3D scanning drive device 3, and a scanning chamber pumping device. The scanning chamber 2 is located inside the outer frame 1. The scanning chamber pumping device is used to pump out seawater from the scanning chamber 2. The scanning chamber 2 includes a left scanning chamber 4 and a right scanning chamber 5. The left scanning chamber 4 and the right scanning chamber 5 can be closed under the drive of the scanning chamber drive device, sealing the target mapping section of the subsea pipeline 6 inside the scanning chamber 2. The 3D scanner and the 3D scanning drive device 3 are both located inside the scanning chamber 2. The 3D scanning drive device 3 can drive the 3D scanner to perform a full-range scan of the target mapping section inside the scanning chamber 2.

[0034] By closing the left half-cabin 4 and the right half-cabin 5, the target mapping section of the subsea pipeline 6 can be sealed inside the scanning cabin 2. The seawater inside the scanning cabin 2 can be pumped out by the scanning cabin pumping device to create an underwater empty cabin. This allows the 3D scanning drive device 3 to drive the 3D scanner to perform a full-range scan of the target mapping section inside the scanning cabin 2, thereby obtaining high-precision point cloud data of the pipeline's outer surface. Since the mapping is carried out in the empty cabin, the turbidity and turbulence of the water will not affect the mapping inside the empty cabin. Normal underwater mapping can be carried out in turbid waters and turbulent waters. Using a 3D scanner for scanning mapping greatly improves the modeling resolution and mapping speed. It has the advantages of high positioning accuracy and high shape adaptability. It can perform high-precision 3D mapping without contact or damage, thereby expanding the health assessment capabilities of subsea oil and gas pipelines, ensuring the safe operation of subsea pipelines, ensuring the security of energy supply, and avoiding environmental pollution caused by pipeline oil and gas leaks.

[0035] In this embodiment, a floating hull 7 is also provided inside the outer frame 1. The floating hull 7 is connected to the scanning chamber 2 via a water pumping pipe 8. A three-way valve 9 is provided on the water pumping pipe 8. Two ports of the three-way valve 9 are connected to the water pumping pipe 8, and the third port of the three-way valve 9 is connected to the outside. The scanning chamber water pumping device includes a submersible pump, which is located inside the scanning chamber 2 and connected to the water pumping pipe 8. It is used to pump seawater from the scanning chamber 2 to the floating hull 7 or the outside through the water pumping pipe 8. The floating hull 7 is provided with a floating hull pipe 10 that is connected to the outside. A butterfly valve 11 is provided on the floating hull 10. Both the floating hull 7 and the scanning chamber 2 are provided with air inlets, which are connected to air pumps. The air pumps are used to regulate the air pressure inside the floating hull 7 and the scanning chamber 2. The floating hull 7 is also provided with a human-shaped hole 37. By switching the three-way valve 9, seawater in the scanning chamber 2 can be selectively pumped to the floating hull 7 or the outside. The connection between the floating hull 7 and the outside seawater is controlled by opening and closing the butterfly valve 11. The pressure inside the float 7 and scanning chamber 2 is regulated by an air pump to increase or decrease the air pressure. The anthropomorphic opening 37 is used for internal welding and reinforcement by workers. The internal space of the float 7 is reinforced according to strength requirements to prevent it from being flattened by the internal and external pressure difference. Based on the strength requirements of the float 7, the internal and external pressure difference should not be set too large; generally, 0.1 MPa-0.2 MPa is sufficient. The float 7 has a square shape, but is not limited to an equilateral square. Other shapes such as cylindrical, polygonal, and elliptical are also within the scope of this invention, and commercially available floats can be used instead of the float 7.

[0036] In this embodiment, the tops of the left scanning half-cabin 4 and the right scanning half-cabin 5 are rotatably connected to the outer frame 1 via a rotating shaft 12. The scanning cabin drive device includes hydraulic cylinders 13, with hydraulic cylinders 13 connected to the outer sides of both the left and right scanning half-cabins 4 and 5. Each hydraulic cylinder 13 is connected to the outer frame 1, and can drive the left and right scanning half-cabins 4 and 5 to rotate around the rotating shaft 12 to close or open. Sealing strips are provided on the sealing contact surfaces between the left and right scanning half-cabins 4 and 5, as well as between the left and right scanning half-cabins 4 and 5 and the subsea pipeline 6. Three hydraulic cylinders 13 are connected to the outer sides of both the left and right scanning half-cabins 4 and 5. When closed, either hydraulic cylinder 13 can be controlled individually, or both cylinders can be controlled simultaneously. The extension and retraction strokes of the hydraulic cylinders 13 are acquired by sensors and fed back to the host computer, and the numerical values ​​are used to determine whether the closed state has been reached. The sealing strip ensures the airtightness of the scanning chamber 2 after closure, and this, combined with pumping and inflation, forms and maintains the underwater dry chamber seal. The scanning chamber 2 is an equilateral hexagon, but not limited to it; other shapes such as cylindrical, square, and polygonal are also within the scope of this invention. Due to its large size, the scanning chamber 2 experiences immense seabed pressure. To balance this external pressure, inflation is the primary technical means to prevent deformation of the scanning chamber 2. In addition, numerous reinforcing ribs, including circumferential and transverse flat steel, are installed in the scanning chamber 2 to ensure its strength. The applicable surveying depth of this surveying fixture can be determined based on the internal air pressure, increasing the applicable water depth by 10 meters beyond the maximum air pressure. The size of the sealable seabed pipe 6 is optional, and the dimensions of the annular openings and sealing strips at both ends are determined based on the seabed pipe 6.

[0037] In this embodiment, a counterweight 14 is also included. A counterweight 14 is provided on each side of the outer frame 1. The two counterweights 14 are used to suspend the subsea pipeline 6 on both sides. The counterweights 14 are connected to hydraulic winches 16 mounted on the outer frame 1 via steel wire ropes 15. The hydraulic winches 16 can tighten or loosen the steel wire ropes 15. Both the outer frame 1 and the counterweights 14 are provided with lifting lugs 17. Steel cable conduits 18 are fixedly provided on both sides of the outer frame 1. The lifting lugs 17 are used to connect lifting cables. The lifting cables are threaded through the steel cable conduits 18 to connect to the lifting lugs 17 on the counterweights 14. Specifically, each side of the outer frame 1 has two hydraulic winches 16 and two steel cable conduits 18. Each end of the counterweight 14 has two lifting lugs 17. The lifting lugs on the inner side of the counterweight 14 are connected to the hydraulic winches 16 via steel wire ropes 15, and the lifting lugs on the outer side of the counterweight 14 are connected to the lifting cables passing through the steel cable conduits 18. The entire surveying fixture is lowered and lifted using hoisting steel cables. The tension of the steel wire rope 15 is used to determine the tension applied to the outer frame 1, ensuring the levitation of the surveying fixture. The subsea pipeline 6 is a type of pipeline deeply buried on the seabed (e.g., an oil pipeline). Before formal surveying, the subsea pipeline 6 undergoes trenching and surface demolition. The scanning cabin's pumping device can also be equipped with a pneumatic diaphragm pump, which can be continuously operated as needed. Counterweights 14 are pre-positioned on both sides of the target surveying section of the subsea pipeline 6 to counteract the buoyancy generated by the emptying of the scanning cabin 2. Cement counterweights 14 can be selected. The distance between the counterweights 14 and the outer frame 1 should not be too large. Calculations based on the seabed friction and horizontal tension are needed to determine the weight of the counterweights 14 and the distance between the counterweights 14 and the surveying fixture, or the angle between the steel wire rope 15 and the horizontal plane.

[0038] In this embodiment, the three-dimensional scanning drive device 3 includes a linear guide rail 19, an axial lead screw 20, a linear motor 21, an arc guide rail 22, an arc rack 23, a rotary motor 24, and a corner motor 25. The arc guide rail 22 is slidably connected to the linear guide rail 19 via a slider 26. The slider 26 is threadedly connected to the axial lead screw 20. The linear motor 21 is connected to the axial lead screw 20 to drive the axial lead screw 20 to rotate. The arc rack 23 is slidably connected to the arc guide rail 22. The output shaft of the rotary motor 24 is provided with a gear that meshes with the arc rack 23. The rotary motor 24 can drive the arc rack 23 to move along the arc guide rail 22. The arc rack 23 is connected to a mounting... Mounting base 27, the angle motor 25 is mounted on mounting base 27, the housing of the angle motor 25 is connected to the 3D scanner compartment 29 through connecting plate 28, the 3D scanner compartment 29 is rotatably connected to the connecting plate 28 through scanning shaft, the output shaft of the angle motor 25 is connected to the scanning shaft through angle transmission device, the angle transmission device can be selected to be a synchronous belt and a synchronous pulley transmission method, a synchronous pulley is fixedly connected to the output shaft of the angle motor 25 and the scanning shaft respectively, and the two synchronous pulleys are connected through synchronous belt transmission, the 3D scanner is set in the 3D scanner compartment 29, the angle motor 25 can drive the 3D scanner compartment 29 to rotate to drive the 3D scanner to rotate. The linear guide rails 19 can be provided in two or more, preferably three. The two ends of the arc guide rail 22 are connected to the two linear guide rails 19 via two sliders 26, and the middle of the arc guide rail 22 is connected to one linear guide rail 19 via a slider 26. Each of the two linear guide rails 19 at both ends is equipped with an axial lead screw 20 and a linear motor 21. The linear motor 21 synchronously drives the axial lead screw 20 to rotate, thereby driving the arc guide rail 22 to move axially, thus realizing the axial linear motion of the 3D scanner. The middle linear guide rail 19 guides the axial movement of the arc guide rail 22, ensuring its smooth movement. Alternatively, the middle linear guide rail 19 can also be equipped with a linear motor 21 and an axial lead screw 20 driven by the linear motor 21, with the slider 26 threadedly connected to the axial lead screw 20. A rotary motor 24 is located at each end of the arc-shaped guide rail 22. These two motors drive the arc-shaped rack 23 to move along the guide rail 22, thus achieving the circumferential rotation of the 3D scanner. Through the axial linear motion and circumferential rotation of the 3D scanner, a comprehensive scan of the target mapping section of the subsea pipeline 6 is performed within the scanning chamber 2. An angle motor 25 drives the 3D scanner chamber 29 to rotate, thereby increasing the side-scanning range of the 3D scanner. A 3D laser scanner can be selected as the 3D scanner.

[0039] In this embodiment, an attitude sensor 30 is provided on the outer frame 1 to detect the attitude of the surveying tool on the seabed; a ladder 31 is also provided on the outer frame 1. The attitude sensor 30 obtains the attitude of the surveying tool on the seabed so that the personnel on board can adjust the attitude of the surveying tool using the ship's crane. The ladder 31 facilitates welding, assembly, and maintenance operations.

[0040] In this embodiment, the scanning chamber 2 is equipped with lighting, cameras, a battery compartment 32, a control compartment 33, a lighting-monitoring compartment 34, and a drive compartment 35. The lighting-monitoring compartment 34 drives the lighting and cameras, the drive compartment 35 drives the linear motor 21, the rotary motor 24, and the angle motor 25, the control compartment 33 provides all underwater control for the surveying fixture, and the battery compartment 32 provides power to all electronic equipment of the surveying fixture. The installation and distribution of the lighting and cameras are designed according to actual needs to ensure real-time monitoring of the 360° range within the chamber.

[0041] In this embodiment, position switches are provided at both ends and at the bottom of the scanning chamber 2, corresponding to the sealing contact surfaces. The position switches at both ends are used to detect the closure and sealing status between the scanning chamber 2 and the subsea pipeline 6, while the position switch at the bottom is used to detect the closure and sealing status of the sealing contact surface at the bottom of the scanning chamber 2. A signal output from the position switch proves that the scanning chamber 2 is closed. To avoid issues with the reliability of single data points, a position switch is provided at each end of the scanning chamber 2. Due to the relatively long length of the scanning chamber 2 cavity itself, two additional position switches are provided in the middle section of the scanning chamber 2 to prevent incomplete closure caused by deformation of the axial sealing end face, thus eliminating the possibility of incomplete closure by the hydraulic cylinder 13.

[0042] In this embodiment, both the float 7 and the scanning chamber 2 are equipped with level gauges 36, which are used to detect the water level in the float 7 and the scanning chamber 2, respectively, to provide an information basis for buoyancy control.

[0043] A method for accurately mapping deformation defects in subsea pipelines, employing the aforementioned tooling for accurate mapping of deformation defects in subsea pipelines, includes the following steps:

[0044] S1: The entire surveying equipment is hoisted into the sea so that the target surveying section of the submarine pipeline 6 is located between the left half-scanning compartment 4 and the right half-scanning compartment 5.

[0045] S2: The left half of the scanning chamber 4 and the right half of the scanning chamber 5 are closed by the scanning chamber drive device, sealing the target mapping section inside the scanning chamber 2;

[0046] S3: The seawater inside scanning chamber 2 is pumped out using the scanning chamber pumping device;

[0047] S4: The three-dimensional scanner is driven by the three-dimensional scanning drive device 3 to perform a full-range scan of the target mapping section inside the scanning chamber 2.

[0048] Due to ocean currents and tides, the lowering of the subsea pipeline mapping equipment must be carried out during the slack tide period. To ensure the accuracy of the mapping equipment's attitude, attitude data is acquired through two attitude sensors 30 on the top layer of the floating pod 7 of the outer frame 1, providing data for attitude adjustments during the ship-mounted crane operation. During the lowering process, air is injected into the floating pod 7 multiple times through the air inlet to control the internal and external pressure of the floating pod 7 within 0.1 MPa (i.e., the pressure at a water depth of 10 meters).

[0049] After lowering, the control compartment 33 commands the drive compartment 35 to extend the hydraulic cylinders 13 to close the scanning compartment 2. The hydraulic cylinders 13 are divided into two groups of three, located on the left and right sides of the scanning compartment 2. Closure can be controlled individually on either side or simultaneously. The extension and retraction strokes of the hydraulic cylinders 13 are acquired by sensors and fed back to the host computer, which uses numerical values ​​to determine whether the closure has been achieved. To avoid issues with the reliability of single data points, position switches are installed near the closing contact surfaces of the two half-compartments of the scanning compartment 2. A total of four position switches are installed throughout the scanning compartment. Two position switches near the annular sealing end face monitor the closure and sealing status of the axial end. Due to the relatively long length of the scanning compartment 2 itself, two additional position switches are installed in the middle section of the scanning compartment 2 to prevent incomplete closure caused by deformation of the axial sealing end face, thus eliminating the possibility of incomplete closure by the hydraulic cylinders 13.

[0050] After the scanning chamber 2 is closed, the full seawater makes the weight of the entire surveying equipment greater than its buoyancy. The weight is balanced by the upper hoisting cables, resulting in minimal force exerted by the surveying equipment on the subsea pipeline 6. To further reduce the overall weight of the surveying equipment, the ship's crane is removed, allowing the equipment itself to perform surveying work on the seabed. Inflation is performed using the air inlet, increasing the air pressure inside the scanning chamber 2 to balance the water pressure outside. Simultaneously, the large and small submersible pumps and pneumatic diaphragm pumps inside the scanning chamber 2 are activated to transfer water from the scanning chamber 2 to the floating pod 7. Since the volume of the scanning chamber 2 is greater than that of the floating pod 7, after transferring a portion of the water from the scanning chamber 2 to the floating pod 7, the remaining water from the scanning chamber 2 is discharged into the external seawater environment once the floating pod 7 is full. During the internal conversion process, there is no change in the buoyancy of the tooling. Only after the float 7 is full of water and the water in the scanning chamber 2 is drained will the buoyancy of the tooling increase, achieving a balance between gravity and buoyancy, and reaching a suspended state.

[0051] After the scanning chamber 2 is completely emptied, the 3D scanning drive device 3, under the control of the host computer, performs a 360° scan of the entire length of the target mapping segment. The scan is performed in multiple segments, and then the scanned segments are stitched together. The multiple scans need to ensure that the two stitched data have 1 / 3 overlap. After all the surface data of the subsea pipeline has been acquired, the medium in the scanning chamber 2 of the mapping fixture is reset, and then the hydraulic cylinder 13 is driven to open the scanning chamber 2, preparing for the lifting of the mapping fixture.

[0052] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A tooling for precise mapping of deformation defects in subsea pipelines, characterized in that: The system includes an outer frame, a scanning chamber, a scanning chamber drive unit, a 3D scanner, a 3D scanning drive unit, and a scanning chamber water pumping device. The scanning chamber is housed within the outer frame. The scanning chamber water pumping device is used to pump out seawater from the scanning chamber. The scanning chamber includes a left scanning chamber and a right scanning chamber. The left and right scanning chambers can be closed under the drive of the scanning chamber drive unit to seal the target mapping section of the subsea pipeline within the scanning chamber. The 3D scanner and the 3D scanning drive unit are both located within the scanning chamber. The 3D scanning drive unit can drive the 3D scanner to perform a 3D scan of the target mapping section within the scanning chamber from all directions. The outer frame also includes a floating pod, which is connected to the scanning chamber via a pumping pipe. The pumping pipe is equipped with a three-way valve, with two ports connected to the pumping pipe and the third port connected to the outside. The scanning chamber pumping device includes a submersible pump, which is located inside the scanning chamber and connected to the pumping pipe. The submersible pump is used to pump seawater from the scanning chamber to the floating pod or the outside via the pumping pipe. Both the float and the scanning chamber are equipped with air inlets, which are connected to an air pump for adjusting the air pressure inside the float and the scanning chamber. It also includes a counterweight, which is connected to a hydraulic winch mounted on the outer frame via a steel wire rope. The hydraulic winch can tighten or loosen the steel wire rope. Position switches are provided at both ends and at the bottom of the scanning cabin, corresponding to the sealing contact surface. The position switches at both ends are used to detect the closure and sealing status between the two ends of the scanning cabin and the seabed pipeline, and the position switch at the bottom is used to detect the closure and sealing status of the sealing contact surface at the bottom of the scanning cabin. The 3D scanning drive device includes a rotary motor and a mounting base. The rotary motor is mounted on the mounting base, and the rotating shaft of the rotary motor is connected to the 3D scanner compartment via a connecting plate. The 3D scanner is set in the 3D scanner compartment. The rotary motor can drive the 3D scanner compartment to rotate, thereby driving the 3D scanner to rotate and increasing the side scanning range of the 3D scanner.

2. The tooling for precise mapping of deformation defects in subsea pipelines according to claim 1, characterized in that: The floating hull is equipped with a floating hull pipe that connects to the outside world, and the floating hull pipe is equipped with a butterfly valve; the floating hull is also equipped with a human-shaped opening.

3. The tooling for precise mapping of deformation defects in subsea pipelines according to claim 1, characterized in that: The tops of the left and right scanning compartments are rotatably connected to the outer frame via a pivot. The scanning compartment drive device includes hydraulic cylinders, which are connected to the outer sides of both the left and right scanning compartments. Each hydraulic cylinder is connected to the outer frame and can drive the left and right scanning compartments to rotate around the pivot to close or open. Sealing strips are provided on the sealing contact surfaces between the left and right scanning compartments and between the left and right scanning compartments and the subsea pipeline.

4. The tooling for precise mapping of deformation defects in subsea pipelines according to claim 1, characterized in that: Each side of the outer frame is provided with a counterweight block, and the two counterweight blocks are used to suspend the subsea pipeline on both sides; both the outer frame and the counterweight blocks are provided with lifting lugs, and steel cable conduits are fixedly provided on both sides of the outer frame. The lifting lugs are used to connect the hoisting steel cable, and the hoisting steel cable is used to pass through the steel cable conduit to connect the lifting lugs on the counterweight blocks through the hoisting steel cable.

5. The tooling for precise mapping of deformation defects in subsea pipelines according to claim 1, characterized in that: The three-dimensional scanning drive device further includes a linear guide rail, an axial lead screw, a linear motor, an arc guide rail, an arc rack, and a rotary motor. The arc guide rail is slidably connected to the linear guide rail via a slider, and the slider is threadedly connected to the axial lead screw. The linear motor is connected to the axial lead screw to drive the axial lead screw to rotate. The arc rack is slidably connected to the arc guide rail. The output shaft of the rotary motor is provided with a gear that meshes with the arc rack. The rotary motor can drive the arc rack to move along the arc guide rail. The mounting base is connected to the arc rack.

6. The tooling for precise mapping of deformation defects in subsea pipelines according to claim 1, characterized in that: An attitude sensor is provided on the outer frame to detect the attitude of the surveying tool on the seabed; a ladder is also provided on the outer frame.

7. The tooling for precise mapping of deformation defects in subsea pipelines according to claim 5, characterized in that: The scanning chamber is equipped with lighting, cameras, battery compartment, control compartment, lighting-monitoring compartment, and drive compartment. The lighting-monitoring compartment is used to drive the lighting and cameras. The drive compartment is used to drive the linear motor, the rotary motor, and the angle motor. The control compartment is used for all underwater control of the surveying fixture. The battery compartment is used to power all electronic equipment of the surveying fixture.

8. The tooling for precise mapping of deformation defects in subsea pipelines according to claim 2, characterized in that: Both the buoy and the scanning chamber are equipped with level gauges, which are used to detect the water level in the buoy and the scanning chamber, respectively.

9. A method for accurately mapping deformation defects in subsea pipelines, characterized in that, The precision mapping tooling for deformation defects of subsea pipelines as described in any one of claims 1 to 8 includes the following steps: S1: The entire surveying fixture is hoisted into the sea so that the target surveying section of the submarine pipeline is located between the left half of the scanning compartment and the right half of the scanning compartment; S2: The scanning chamber drive device drives the left half of the scanning chamber and the right half of the scanning chamber to close, sealing the target mapping segment inside the scanning chamber; S3: The seawater inside the scanning chamber is extracted using the scanning chamber pumping device; S4: The three-dimensional scanner is driven by the three-dimensional scanning drive device to perform an all-round scan of the target mapping section inside the scanning chamber.

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