Pipeline additive repairing method

Abstract

The invention discloses a pipeline additive repairing method. The method comprises the steps that the size information of defects in a pipeline is obtained through the laser technology; according to the size information of the defect, an additive repairing technology and a printing path are determined; and the additive repairing technology repairs the defect according to the printing path. The method solves the problems that an existing repairing method adopts a manual welding method, depends on experience, is unstable in quality and the like, and meanwhile, additive manufacturing repairing has the technical advantages that intelligent control is achieved, repairing precision is high, pipeline heat influence damage is small, and pipe wall metal burnthrough instability is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas pipeline repair, and particularly to a pipeline additive repair method. Background Art

[0002] Currently, major foreign pipeline companies mostly refer to the "Pipeline Repair Manual" promulgated by PRCI (Pipeline Research Council International) to perform oil and gas pipeline repair operations. The repair methods recommended by PRCI mainly include grinding, B-type sleeve, surfacing, and bolted fastening fixture repair methods.

[0003] Among them, B-type sleeve repair is the mainstream repair method in China. However, there are the following problems: the connection between the pipe body and the sleeve mostly adopts manual welding, the fillet weld lap joint structure has weak annular steps, the welding quality and process are not easy to be intelligently controlled, and the fillet weld cannot be flaw detected nondestructively, etc. Summary of the Invention

[0004] The purpose of the present invention is to provide a pipeline additive repair method to solve the above problems.

[0005] To achieve the above purpose, the present invention provides a pipeline additive repair method, the method comprising: obtaining size information of a defect in a pipeline by using laser technology; determining an additive repair technology and a printing path according to the size information of the defect; and repairing the defect according to the printing path by using the additive repair technology.

[0006] The present invention also provides a pipeline additive repair device, the device comprising: an obtaining unit for obtaining size information of a defect in a pipeline by using laser technology; a determining unit for determining an additive repair technology and a printing path according to the size information of the defect; and a repairing unit for repairing the defect according to the printing path by using the additive repair technology.

[0007] Technical Effects and Advantages of the Present Invention

[0008] The present invention provides a pipeline additive repair method, the method comprising: obtaining size information of a defect in a pipeline by using laser technology; determining an additive repair technology and a printing path according to the size information of the defect; and repairing the defect according to the printing path by using the additive repair technology. This method solves the problems of the existing repair method using manual welding, relying on experience, and unstable quality. At the same time, additive manufacturing repair also has technical advantages such as intelligent control, high repair accuracy, small thermal influence damage to the pipeline, and avoiding problems such as burn-through instability of the pipe wall metal.

[0009] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention. The objectives and other advantages of the present invention may be realized and attained by the structure particularly pointed out in the specification and the drawings. Description of the Drawings

[0010] Figure 1 It is a flow chart of the pipeline additive repair method;

[0011] Figure 2 It is a repair path diagram when the distance between the defect and the inner wall of the pipeline is greater than the threshold;

[0012] Figure 3 It is a repair path diagram when the distance between the defect and the inner wall of the pipeline is less than the threshold. Detailed Embodiments

[0013] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings provided by the present invention. Moreover, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0014] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented. Therefore, they do not have a substantial technical meaning. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the objectives that can be achieved, should still fall within the scope that can be covered by the technical content disclosed by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration, rather than used to limit the scope of implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope that the present invention can implement.

[0015] As the ultimate presentation method of three-dimensional digital technology, additive remanufacturing technology (3D printing) has become an important means for the repair and remanufacturing of high-end equipment in the military, aerospace and other fields because it can achieve flexible on-site matching repair and remanufacturing of complex shapes and positions. The Army Academy of Armored Forces Engineering in China has carried out research on GMAW remanufacturing forming technology based on robots and built an on-site mobile emergency repair platform.

[0016] Therefore, the present invention patent proposes a method for repairing oil and gas pipelines based on additive manufacturing. A high-power laser is used to scan and clean the defective position, and then the defective position is scanned and reconstructed immediately. According to the position of the defect, the size of the defect, and the repair working conditions, an additive repair process using arc (Cold Metal Transfer CMT arc additive manufacturing technology), laser + arc composite (laser powder feeding high-speed cladding additive technology + Cold Metal Transfer CMT arc additive manufacturing technology or TIG arc additive technology) is used to repair the pipeline. This method solves the problems of existing repair methods that rely on manual welding, depend on experience, and have unstable quality. At the same time, additive manufacturing repair also has technical advantages such as intelligent control, high repair accuracy, small thermal influence damage to the pipeline, and avoidance of instability such as metal burn-through of the pipe wall.

[0017] The following combines Figure 1 to explain the pipeline additive repair method in detail.

[0018] A pipeline additive repair method, the method comprising:

[0019] 1. Obtain the size information of the defect in the pipeline using laser technology.

[0020] Specifically: Use pulsed laser to remove the metal coating and clean the oil layer in the pipeline area to be repaired; Use a laser vision camera to scan the scanned area to determine the geometric size of the defect. Of course, other laser technologies can also be used as long as they can perform laser scanning to determine the defect size.

[0021] Among them, the average power of pulsed laser cleaning is 180W - 220W, the pulse width is 200 - 240ns, the pulse repetition frequency is 300 - 500kHz, the cleaning moving speed is 100m - 600m / min, and the spot scanning diameter is 1 - 3mm.

[0022] Among them, determining the geometric size of the defect specifically: Use a laser vision camera to measure the defect size. The measurement shape error should not be higher than 100μm, the scanning speed should not be lower than 10000 points / s, and after scanning, use software to measure the length, width, and distance from the inner wall of the defect.

[0023] 2. Determine the additive repair technology and printing path according to the size information of the defect.

[0024] Specifically: According to the size of the defect and the thickness from the inner surface, match the repair equipment and process from the processes of CMT additive, laser powder feeding high-speed cladding, and TIG additive; And through reverse reconstruction software, establish a three-dimensional model of the defect, and use slicing software to design the printing path (select the printing direction and substrate according to the thickness from the inner surface).

[0025] Among them, according to the dimensional information of the defect, an additive repair technique and a printing path are determined, including: according to the dimensional information of the defect, determining the distance between the defect and the inner wall of the pipeline;

[0026] When the distance between the defect and the inner wall of the pipeline is greater than a threshold value (preferably 6.4 mm, because when it is less than 6.4 mm, the probability of burn-through increases significantly), it is determined to use the cold metal transfer CMT arc additive manufacturing technique to repair the defect, and a printing path is designed with the bottom of the defect on the pipe body as the printing substrate, as Figure 2 shown.

[0027] When the distance between the defect and the inner wall of the pipeline is less than the threshold value, it is determined to first use the laser powder feeding high-speed cladding additive technique to build up the defect to the threshold value, and then use the cold metal transfer CMT arc additive manufacturing technique or the TIG arc additive technique to repair the defect. After laser cladding, a printing path is designed with the pipe wall thickness as the printing substrate, as Figure 3 shown.

[0028] Figure 3 In, 1 is the pipe body, 2 is the laser powder feeding additive cladding layer, 3 is the CMT or TIG arc additive layer, and the numbers such as ① are the additive sequence of the arc additive layer. The specific additive steps are as follows: After using the laser powder feeding additive cladding process to build up to 6.4 mm, use the CMT or TIG arc additive process to print with the left side groove wall as the substrate. The overall additive sequence is from left to right. At this time, the occurrence of burn-through can be prevented to the greatest extent, ensuring the safety of the repair process. When printing to the nth pass, the working space of the printing device is gradually limited. According to the Figure 3 sequence shown, additive is first carried out from the side close to the groove wall, which can also effectively prevent burn-through. Subsequently, the additive sequence becomes from bottom to top, and additive repair is completed on the basis of ensuring the working space.

[0029] Among them, when using the cold metal transfer CMT arc additive manufacturing technique, a gradual wire feeding speed is set. As the number of printing layers increases, the wire feeding speed increases by 0.2 m / min layer by layer. The welding torch movement speed is 5 - 6 m / min, the scanning speed is 10 - 15 m / min, and the shielding gas is 80% Ar + 20% CO 2 ; when using the TIG arc additive process, the wire feeding speed increases by 0.1 m / min layer by layer, the wire feeding speed is 0.2 - 0.4 m / min, and the welding torch movement speed is 10 cm / min - 20 cm / min; when using the laser powder feeding high-speed cladding additive technique, the laser power is 4000 - 5000 W, the cladding speed is 15 - 25 m / min, the single pass lateral shift is 0.4 - 0.65 mm, and the powder feeding rotation speed is 4 - 6 r / min.

[0030] 3. The additive repair technique repairs the defect according to the printing path.

[0031] Specifically: adopt the selected additive manufacturing process parameters to complete the repair of defects along the designed printing path; after additive repair, use ultrasonic inspection on the repaired area.

[0032] It should be noted that during the additive repair of the pipeline, an infrared temperature measurement device is used to monitor the temperature change of the pipeline in real time.

[0033] It should also be noted that the requirements for the selection of repair materials are as follows: (1) According to API 5L, the wire steel grade is higher than the pipeline steel grade. Preferably, the wire steel grade should be one level higher than the pipeline steel grade; (2) The impact toughness of the wire is higher than 90J (-20°C).

[0034] It should also be noted that the pipeline in the present invention is preferably a steel pipe.

[0035] Adopt the additive repair process for oil and gas pipelines of the present invention, and the entire repair process is fully automated, with high quality stability and controllability. During laser high-speed cladding, the temperature around the pipe body does not exceed 200°C; during CMT and TIG additive repair, the peak temperature on the inner wall is lower than 400°C, and there is no danger of burn-through and instability. The structure of the additive repair area is fine and uniform, without microcrack initiation, and the ultrasonic results show that the repair quality meets the requirements of the existing welding process evaluation.

[0036] To better understand this solution, the following embodiments are also provided.

[0037] Embodiment 1

[0038] For the defect repair of X65 pipeline steel pipe, the length of the surface defect of the steel pipe is about 10mm, the width is about 8mm, and the height is about 3mm.

[0039] The specific steps are as follows: First, use tools such as a grinding wheel to remove the defect, and then use laser cleaning to thoroughly clean impurities such as surface oil and anti-corrosion materials, and ablate local micro-mutation areas to ensure the surface of the defect repair part is flat. Among them, a 500W laser cleaner is used for laser cleaning, the laser wavelength is 1064nm, the repetition frequency is 500kHz, the average power of cleaning is 180W, the pulse repetition frequency is 500Khz, the cleaning moving speed is 600m / min, the spot scanning diameter is 3mm, and the pulse width is 200 - 240ns.

[0040] Use a laser profile scanning system to scan the shape of the defect, the blue light wavelength is 450nm, and the actual size of the defect is determined to be 10.5mm × 8.3mm × 3.2mm.

[0041] Select the CMT cold metal transfer arc additive manufacturing process, and use the bottom of the pipe body defect as the printing substrate, as Figure 2As shown in the figure, gradient wire feeding is used for printing. The process parameters of CMT for the first layer printing are as follows: current 175A, voltage 15V, wire feeding speed 5m / min, interlayer temperature 100 - 120°C, and the welding wire is AWS A5.29 E71T8-Ni1.

[0042] After additive repair, the structure is fine and uniform, and the non-destructive testing results meet the standard requirements.

[0043] Example 2

[0044] For the defect repair of X80 longitudinal submerged arc welded pipe, the length of the surface defect of the steel pipe is about 8mm, the width is about 5mm, and the height is about 12mm.

[0045] The specific steps are as follows: First, use a hair dryer to blow out the impurities inside the defect, and then use laser cleaning to thoroughly clean the internal oil stains, anticorrosive materials and other impurities, and ablate the local micro-mutation area to ensure the surface of the defect repair part is flat. Among them, a 300W laser cleaner is used for laser cleaning, the laser wavelength is 1064nm, the repetition frequency is 500kHz, the average power of cleaning is 180W, the pulse frequency is 500kHz, the cleaning moving speed is 600m / min, and the spot scanning diameter is 2mm.

[0046] Use a laser profile scanning system to scan the shape of the defect. The blue light wavelength is 450nm, and the actual size of the defect is determined to be 8.5mm × 5.5mm × 11.8mm.

[0047] Due to the relatively high pressure bearing of X80, laser cladding process printing is selected. The laser power is 4000W, the cladding speed is 15m / min; the single-pass lateral movement is 0.5mm; the powder feeding rotation speed is 4r / min, and the single-layer thickness is about 0.5mm. Then, taking the pipe wall thickness as the printing substrate, the printing path is designed, as Figure 3 shown. Use a TIG arc additive manufacturing equipment for repair, the wire feeding speed is 0.3m / min, and the welding torch movement speed is 10cm / min.

[0048] After additive repair, the powder cladding structure is fine and uniform, and the non-destructive testing results meet the standard requirements.

[0049] The present invention also provides a pipeline additive repair device, which includes: an acquisition unit for obtaining the size information of the defect in the pipeline by using laser technology; a determination unit for determining the additive repair technology and the printing path according to the size information of the defect; a repair unit for repairing the defect according to the printing path by using the additive repair technology.

[0050] Since the content protected by this device is similar to that protected by the above method, no further introduction will be made here. For details, please refer to the discussion part of the above method.

[0051] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for additive repair of pipelines, characterized in that, the method includes: obtaining size information of defects in the pipeline by using laser technology; determining an additive repair technology and a printing path according to the size information of the defects; repairing the defects according to the printing path by using the additive repair technology.

2. The method according to claim 1, characterized in that, obtaining size information of defects in the pipeline by using laser technology includes: cleaning the area to be repaired of the pipeline by using pulsed laser to obtain the area to be repaired after cleaning; scanning the defects in the area to be repaired after cleaning by using a laser vision camera to obtain size information of the defects.

3. The method according to claim 2, characterized in that, the conditions for cleaning the area to be repaired by using the pulsed laser include: the average power of laser cleaning is 180W - 220W, the pulse width is 200 - 240ns, the pulse repetition frequency is 300 - 500kHz, the cleaning moving speed is 100m - 600m / min, and the spot scanning diameter is 1 - 3mm.

4. The method according to claim 1, characterized in that, determining an additive repair technology and a printing path according to the size information of the defects includes: determining the distance between the defects and the inner wall of the pipeline according to the size information of the defects; when the distance between the defects and the inner wall of the pipeline is greater than the threshold, determining to use cold metal transfer CMT arc additive manufacturing technology to repair the defects, and determining to design a printing path with the bottom of the pipe body defect as the printing substrate; when the distance between the defects and the inner wall of the pipeline is less than the threshold, determining to first use laser powder feeding high-speed cladding additive technology to lay the defects to the threshold, and then using cold metal transfer CMT arc additive manufacturing technology or TIG arc additive technology to repair the defects, and after laser cladding, determining to design a printing path with the pipe wall thickness as the printing substrate.

5. The method according to claim 4, characterized in that, When using Cold Metal Transfer (CMT) arc additive manufacturing technology to repair defects, the parameter settings include: the wire feeding speed increases by 0.2 m / min layer by layer, the welding torch movement speed is 5 - 6 m / min, the shielding gas is 80% Ar + 20% CO 2 , and the scanning speed is 10 - 15 m / min.

6. The method according to claim 4, characterized in that, the parameter settings for laying the defects to the threshold by using laser powder feeding high-speed cladding additive technology include: the laser power is 4000 - 5000W, the cladding speed is 15 - 25m / min, the single-pass lateral shift is 0.4 - 0.65mm, and the powder feeding rotation speed is 4 - 6r / min.

7. The method according to claim 4, characterized in that, the parameter settings for repairing the defects by using TIG arc additive technology include: the wire feeding speed increases by 0.1m / min layer by layer, the wire feeding speed is 0.2 - 0.4m / min, and the welding torch movement speed is 10cm / min - 20cm / min.

8. The method according to claim 1, characterized in that, the requirements for the repair material used in the additive repair technology include: according to API 5L, the wire steel grade is higher than the pipeline steel grade; the impact toughness of the wire is higher than 90J under the condition of -20°C.

9. The method according to claim 1, characterized in that, the method further includes: during the process of repairing the defects, using a temperature measuring device to monitor the temperature of the pipeline in real time.

10. The method according to claim 1, characterized in that, The method further includes: performing non-destructive testing on the repaired defect to determine whether the repair meets the requirements.

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