Method and system for evaluating pipeline with volumetric defects

Abstract

The invention discloses a method and system for evaluating a pipeline with volumetric defects, and the method comprises the steps: scanning a to-be-detected pipeline through employing a three-dimensional shape measurement technology, and obtaining the size feature information of the volumetric defects at different positions of the pipeline; establishing a pipeline defect model according to the size feature information of different defects and the geometric parameters of the pipeline; calculating the residual strength of the pipeline of the pipeline defect model by using preset pipeline maintenance parameters; and according to the residual strength of the pipeline, analyzing the influence of the volumetric defect of the pipeline on the safety performance of the pipeline. According to the method, the volume defect detection efficiency and the residual strength calculation precision can be effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of pressure pipeline safety evaluation, and in particular to a method and system for evaluating a pipeline containing volume defects. Background Art

[0002] Pressure pipelines are an important part of industrial infrastructure and have important applications in oil and gas transportation. With the increase in demand for energy, the oil and gas industry has developed rapidly. By the end of 2021, there were 757,500 kilometers of registered pressure pipelines in my country. Pressure pipelines will have volumetric defects on the inner and outer walls during production, construction, and service. Volumetric defects refer to the loss of metal on the pipe wall, which will reduce the pressure-bearing capacity of the pipeline, cause pipeline perforation, and cause accidents such as oil and gas leaks. In order to ensure that the pipeline can operate normally under the specified pressure and ensure its normal service, it is necessary to conduct residual strength evaluation on pipelines containing volumetric defects.

[0003] At present, the commonly used methods for evaluating the residual strength of pipelines with volumetric defects are: (1) using semi-empirical fracture mechanics relationships for calculation, and the relevant standards include ASME B31G, API579, and GB / T19624; (2) using numerical analysis methods based on elastic-plastic mechanics for evaluation. ASME B31G is the most commonly used standard for studying the residual strength of pipelines, but its evaluation method only uses the depth and length of defects for evaluation, mainly targeting isolated defects, and the results are conservative. Compared with the ASME B31G evaluation method, the use of numerical simulation to solve the residual strength of pipelines with volumetric defects has higher accuracy.

[0004] Specifically, the numerical simulation method needs to model each volume defect separately and set the corresponding calculation conditions, which greatly increases the workload of the staff. Parametric modeling refers to the use of certain parameters to define geometric figures, constrain the relationship between the dimensions of the figures, and then provide the designer with the corresponding geometric model. The pipeline structure is suitable for the parametric modeling process, that is, the shape characteristics are described by geometric constraints, mathematical equations and relationships. Although parametric modeling can effectively eliminate repeated operations in the modeling process and speed up modeling efficiency, for the volume defects of the pipeline, its position and size information relative to the pipeline is difficult to obtain.

[0005] Therefore, the prior art needs to provide a measurement solution that can efficiently and accurately obtain the distribution and three-dimensional size of pipeline volume defects. Summary of the invention

[0006] The object of the present invention is to provide a solution for improving the detection efficiency of pipes containing volumetric defects and at the same time improving the accuracy of solving the residual strength.

[0007] In order to solve the above technical problems, an embodiment of the present invention provides a method for evaluating a pipeline containing volume defects, comprising: using a three-dimensional morphology measurement technology to scan the pipeline to be inspected to obtain size characteristic information of volume defects at different positions of the pipeline; establishing a pipeline defect model according to the size characteristic information of different defects and pipeline geometric parameters; using preset pipeline maintenance parameters to calculate the pipeline residual strength of the pipeline defect model; and analyzing the impact of the volume defects contained in the pipeline on the safety performance of the pipeline according to the pipeline residual strength.

[0008] Preferably, the step of establishing a pipeline defect model according to the size characteristic information of different defects and the pipeline geometric parameters includes: establishing a pipeline physical model according to the pipeline geometric parameters; establishing defects on the pipeline physical model using Boolean operations according to the position information and size characteristic information of different volume defects to obtain the pipeline defect model; and meshing the pipeline defect model using a preset single grid size to calculate the pipeline residual strength using the gridded pipeline defect model.

[0009] Preferably, according to the position information and size characteristic information of different volume defects, simplified defects are established on the pipeline physical model by using Boolean operations to obtain the pipeline defect model, which includes: establishing initial defects on the pipeline physical model according to the position and size characteristic information of each volume defect on the pipeline; defining the starting point and end point of each initial defect, based on which, establishing multiple sections perpendicular to the axial direction of the pipeline for each initial defect; performing approximate fitting of simple geometric shapes on the defect area on each section; superimposing all the fitted sections to obtain simplified defects at various locations, based on which, in combination with the pipeline physical model, the pipeline defect model is obtained by using Boolean operations.

[0010] Preferably, the simple geometric shape is selected from one or a combination of polygons, circles and ellipses, wherein the geometric shape fitting is performed on the defect area on each section according to the following approximate fitting criteria:

[0011] x = argmin(f(x)-g)

[0012] f(x)=s-s1

[0013] g=s-s2

[0014] Among them, x represents different geometric shape fitting methods, f(x) represents the metal loss of the current section after shape fitting, g represents the metal loss of the current section before shape fitting, s represents the section area when the current section is complete, s1 represents the remaining section area excluding the simplified defect part after the defect simplification of the current section, and s2 represents the actual remaining area of ​​the current section excluding the defect part under actual measurement.

[0015] Preferably, in the process of calculating the residual strength of the pipeline, the following steps are included: S1, recording the residual strength of the pipeline calculated based on the preset single grid size; S2, performing mesh encryption processing on the pipeline defect model based on the preset single grid size to obtain the corresponding residual strength of the pipeline; S3, detecting whether the relative error of the residual strength of the pipeline calculated twice in the most recent consecutive time is less than a preset error boundary; if so, using the residual strength of the pipeline calculated multiple times to analyze the influence of the volumetric defects contained in the pipeline on the safety performance of the pipeline; if greater than or equal to, returning to step S2 to continue to calculate the corresponding residual strength of the pipeline by mesh encryption processing of the pipeline defect model.

[0016] Preferably, the pipeline maintenance parameters include simulation parameters and simulation conditions, wherein the simulation parameters include but are not limited to pipeline materials and pipeline unit types, and the simulation conditions include but are not limited to applied loads and applied constraints.

[0017] Preferably, the step of using three-dimensional morphology measurement technology to scan the pipeline to be inspected and obtain size feature information of volume defects at different positions of the pipeline includes: using three-dimensional morphology measurement technology to perform two-dimensional detection on the pipeline to be inspected to obtain position information of volume defects at different positions, and simultaneously performing three-dimensional measurement on the pipeline to be inspected to obtain size information of volume defects at different positions.

[0018] Preferably, the simple geometric shape is selected from one or a combination of triangles, quadrilaterals, circles and ellipses; the distance between adjacent sections in the same defect is an integer multiple of the preset single grid size; and the superposition is to connect adjacent sections into a solid along the pipeline trajectory.

[0019] On the other hand, an embodiment of the present invention further provides a system for evaluating a pipeline containing volumetric defects, wherein the system is used to implement the method described above, wherein the system includes: a feature information acquisition module, which is configured to use a three-dimensional morphology measurement technology to scan the pipeline to be inspected to obtain size feature information of volumetric defects at different positions of the pipeline; a defect model construction module, which is configured to establish a pipeline defect model based on the size feature information of different defects and pipeline geometric parameters; a pipeline residual strength calculation module, which is configured to use preset pipeline maintenance parameters to calculate the pipeline residual strength of the pipeline defect model; and a pipeline safety analysis module, which is configured to analyze the impact of the volumetric defects contained in the pipeline on the pipeline safety performance based on the pipeline residual strength.

[0020] Preferably, the defect model building module includes: an original physical model generation unit, which is configured to establish a pipeline physical model according to the pipeline geometric parameters; a defect model generation unit, which is configured to establish defects on the pipeline physical model using Boolean operations according to the position information and size feature information of different volume defects to obtain the pipeline defect model; a model preprocessing unit, which is configured to grid the pipeline defect model using a preset single grid size, so as to calculate the residual strength of the pipeline using the gridded pipeline defect model.

[0021] Preferably, the defect model generation unit establishes the pipeline defect model according to the following steps: establishing an initial defect on the pipeline physical model according to the position and size feature information of each volume defect on the pipeline; defining the starting point and end point of each initial defect, based on which, establishing multiple sections perpendicular to the axial direction of the pipeline for each initial defect; performing approximate fitting of simple geometric shapes on the defect area on each section; superimposing all the fitted sections to obtain simplified defects at various locations, based on which, combined with the pipeline physical model, using Boolean operations to obtain the pipeline defect model.

[0022] Preferably, the characteristic information acquisition module is further configured to adopt three-dimensional morphology measurement technology to perform two-dimensional detection on the pipeline to be inspected to obtain position information of volume defects at different positions, and simultaneously perform three-dimensional measurement on the pipeline to be inspected to obtain size information of volume defects at different positions.

[0023] Compared with the prior art, one or more embodiments of the above scheme may have the following advantages or beneficial effects:

[0024] The present invention proposes a method and system for evaluating a pipeline containing volumetric defects. The method and system directly use the measured three-dimensional size and position data of the defect as input parameters and input them into the residual strength model, thereby directly obtaining the residual strength for quantitative use evaluation of the pipeline. To this end, the present invention solves the problem that the results obtained by using semi-empirical formulas to calculate the residual strength of pipelines in the prior art are relatively conservative, and also solves the problem that the prior art directly uses numerical simulation methods to calculate the residual strength of pipelines, which requires repeated modeling and repeated setting of calculation parameters and conditions.

[0025] In this way, the present invention can be widely used in non-contact defect measurement and residual strength calculation of volume defects in pipelines in the petroleum and chemical industries. The measurement process has no requirements on the material of the inspected equipment, and the calculation process is executed in the background, which can effectively improve the detection efficiency of volume defects and the calculation accuracy of residual strength.

[0026] Specifically, the present invention adopts a three-dimensional measurement combined with numerical simulation to calculate the residual strength of a pipeline containing volumetric defects. Compared with the method of calculating using a semi-empirical formula, the obtained result is closer to the actual situation. Moreover, except for the measurement and necessary parameter input, all residual strength calculation processes are executed by the program background, which effectively reduces the repetitive work of the entire process of calculating the residual strength of a pipeline containing volumetric defects. At the same time, a simplified method for a pipeline defect model is proposed to simplify the defect modeling process.

[0027] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 Schematic diagram of the steps of a method for evaluating a pipeline containing volume defects according to an embodiment of the present application.

[0030] Figure 2 This is a schematic diagram of a specific process in a method for evaluating a pipeline containing volumetric defects according to an embodiment of the present application.

[0031] Figure 3 This is a simplified schematic diagram of volumetric defects in a method for evaluating a pipeline containing volumetric defects according to an embodiment of the present application.

[0032] Figure 4 Schematic diagram of the volumetric defect superposition effect in the method for evaluating a pipeline containing volumetric defects according to an embodiment of the present application.

[0033] Figure 5 It is a simplified schematic diagram of various fitting shapes in the method for evaluating a pipe containing volume defects according to an embodiment of the present application.

[0034] Figure 6 This is a schematic diagram of the structure of a system for evaluating a pipeline containing volumetric defects according to an embodiment of the present application. DETAILED DESCRIPTION

[0035] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that as long as there is no conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

[0036] In addition, the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions. Also, although a logical sequence is shown in the flowchart, in some cases, the steps shown or described can be performed in a sequence different from that here.

[0037] The terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "one", "one" and "item" used herein are also intended to include plural numbers. It should also be understood that the terms "include" and / or "comprise" used herein specify the existence of stated features, integers, steps, operations, units and / or components, without excluding the existence or addition of one or more other features, integers, steps, operations, units, components and / or combinations thereof.

[0038] Pressure pipelines are an important part of industrial infrastructure and have important applications in oil and gas transportation. With the increase in demand for energy, the oil and gas industry has developed rapidly. By the end of 2021, there were 757,500 kilometers of registered pressure pipelines in my country. Pressure pipelines will have volumetric defects on the inner and outer walls during production, construction, and service. Volumetric defects refer to the loss of metal on the pipe wall, which will reduce the pressure-bearing capacity of the pipeline, cause pipeline perforation, and cause accidents such as oil and gas leaks. In order to ensure that the pipeline can operate normally under the specified pressure and ensure its normal service, it is necessary to conduct residual strength evaluation on pipelines containing volumetric defects.

[0039] At present, the commonly used methods for evaluating the residual strength of pipelines with volumetric defects are: (1) using semi-empirical fracture mechanics relationships for calculation, and the relevant standards include ASME B31G, API579, and GB / T19624; (2) using numerical analysis methods based on elastic-plastic mechanics for evaluation. ASME B31G is the most commonly used standard for studying the residual strength of pipelines, but its evaluation method only uses the depth and length of defects for evaluation, mainly targeting isolated defects, and the results are conservative. Compared with the ASME B31G evaluation method, the use of numerical simulation to solve the residual strength of pipelines with volumetric defects has higher accuracy.

[0040] Specifically, the numerical simulation method needs to model each volume defect separately and set the corresponding calculation conditions, which greatly increases the workload of the staff. Parametric modeling refers to the use of certain parameters to define geometric figures, constrain the relationship between the dimensions of the figures, and then provide the designer with the corresponding geometric model. The pipeline structure is suitable for the parametric modeling process, that is, the shape characteristics are described by geometric constraints, mathematical equations and relationships. Although parametric modeling can effectively eliminate repeated operations in the modeling process and speed up modeling efficiency, for the volume defects of the pipeline, its position and size information relative to the pipeline is difficult to obtain.

[0041] Therefore, the prior art needs to provide a measurement solution that can efficiently and accurately obtain the distribution and three-dimensional size of pipeline volume defects.

[0042] In order to solve the technical problems in the above-mentioned background technology, the embodiments of the present application propose a method and system for evaluating pipelines containing volumetric defects. The method and system are a technology for measuring and analyzing the three-dimensional morphology of the surface of an object, and can understand the details of the surface morphology and size of the object. Since the accuracy of the three-dimensional measurement technology can reach the micron level, the size information of volumetric defects can be accurately obtained. To this end, the method and system for evaluating pipelines containing volumetric defects based on three-dimensional measurement provided by the present invention obtain the three-dimensional size information of defects on the inner and outer walls of the pipeline through three-dimensional measurement; automatically establish a pipeline geometric model through parametric modeling; and automatically execute the calculation process according to the pre-set calculation conditions through interaction with numerical simulation software to directly solve the residual strength of the pipeline. In this way, the present invention can effectively improve the detection efficiency of pipelines containing volumetric defects and improve the accuracy of solving the residual strength.

[0043] Embodiment 1

[0044] Figure 1 Schematic diagram of the steps of a method for evaluating a pipeline containing volume defects according to an embodiment of the present application. Figure 2 This is a schematic diagram of a specific process in the method for evaluating a pipeline containing volume defects in an embodiment of the present application. Figure 1 and Figure 2 , the specific steps and processes of the method for evaluating a pipeline containing volume defects (also referred to as a "pipeline evaluation method") described in an embodiment of the present invention are described.

[0045] Step S110 uses three-dimensional shape measurement technology to scan the pipeline to be inspected to obtain size characteristic information of volume defects at different positions of the pipeline.

[0046] In step S110, a three-dimensional shape measurement technology is used to perform two-dimensional detection on the pipeline to be inspected to obtain position information of volume defects at different positions, and at the same time, a three-dimensional measurement is performed on the pipeline to be inspected to obtain size information of volume defects at different positions.

[0047] Specifically, the three-dimensional shape measurement method performs two-dimensional detection and three-dimensional measurement simultaneously. The position of each defect is located by two-dimensional detection, and the size information of each defect is obtained by three-dimensional measurement. In this way, the defect position information obtained by two-dimensional detection and the defect size information obtained by three-dimensional measurement are combined, so that step S110 described in the embodiment of the present invention can use three-dimensional shape measurement technology to obtain an original three-dimensional point cloud set containing the position information and size information of volume defects at different positions of the pipeline, thereby entering step S120.

[0048] Step S120 establishes a pipeline defect model based on the size feature information of different defects and the pipeline geometric parameters. Further, a pipeline defect (3D) model is established based on the size feature information of different defects on the pipeline shown in the original 3D point cloud set and the pipeline geometric parameters.

[0049] In step S120, first, a pipeline physical model is established according to the pipeline geometric parameters. Specifically, numerical simulation software is called, and the pipeline physical model is established according to the pipeline geometric parameters using numerical simulation technology and parametric modeling.

[0050] Then, according to the location information and size characteristic information of different volume defects, Boolean operations are used to establish defects on the pipeline physical model to obtain the pipeline defect model.

[0051] In one embodiment, based on the location information and size characteristic information of different volume defects, Boolean operations are used to establish simplified defects on the pipeline physical model, thereby obtaining a pipeline defect model.

[0052] In the process of constructing simplified defects and forming a pipeline defect model, in the first step, an initial defect is established on the constructed pipeline physical model according to the position information and size characteristic information of each volume defect on the pipeline. That is, in the first step, the initial defects are respectively established on the pipeline model according to the position and three-dimensional size of each defect measured in step S110, so that each defect is projected onto the pipeline physical model according to the measured size and position.

[0053] The second step is to define the starting point and end point of each initial defect, and establish multiple sections perpendicular to the axial direction of the pipeline for each initial defect based on the starting point and end point of each initial defect. That is to say, for each single or interconnected volume defect, it is necessary to define the starting point and end point of the defect for each defect according to the axial direction of the pipeline, and establish M sections from the starting point of the defect to the end point of the defect (i.e., divide each defect into M parts along the axial direction of the pipeline). Each section is perpendicular to the axial direction of the pipeline.

[0054] In one embodiment, the distance between adjacent sections in the same defect is an integer multiple of the preset single grid size described below. Therefore, the value of M is determined according to the preset grid size parameter, thereby ensuring that the distance between two consecutive sections is an integer multiple of the single grid size.

[0055] The third step is to perform an approximate fitting of a simple geometric shape on the defect area on each section. In one embodiment, a simple geometric shape is approximated for the defect area on each section. Figure 3 The simple geometric shape to be fitted is selected from one or a combination of polygons, circles and ellipses.

[0056] Preferably, the fitted simple geometric shape is selected from one or a combination of triangle, quadrilateral, circle and ellipse.

[0057] In the actual fitting process, the embodiment of the present invention performs simple geometric shape fitting on the defect area on each section according to the following approximate fitting criteria:

[0058] x = argmin(f(x)-g)

[0059] f(x)=s-s1

[0060] g=s-s2

[0061] Among them, x represents different geometric shape fitting methods, f(x) represents the metal loss of the current section after shape fitting, g represents the metal loss of the current section before shape fitting, s represents the section area when the current section is complete, s1 represents the remaining section area excluding the simplified defect part after the defect simplification of the current section, and s2 represents the actual remaining area of ​​the current section excluding the defect part under actual measurement.

[0062] It can be seen from the above expression that in the actual fitting process, on the one hand, it is necessary to obtain the (first) difference f(x) between the cross-sectional area of ​​the complete pipeline and the remaining cross-sectional area excluding the simplified defects after fitting, that is, to obtain the amount of metal loss in the pipeline after defect simplification; and it is also necessary to obtain the (second) difference g between the cross-sectional area of ​​the complete pipeline and the actual remaining area excluding the defective part under actual measurement, that is, to obtain the amount of metal loss in the pipeline before defect simplification, so that the best fitting method is expressed as the minimum value of the first difference and the second difference.

[0063] In the process of fitting and simplifying the defects, the type of simple geometric shape that needs to be made for the current defect is determined based on the actual defect contour to be fitted, thereby obtaining the above-mentioned metal loss amount after fitting.

[0064] In the first embodiment, when performing circular fitting on the defect contour on each section, it is necessary to obtain the minimum circumscribed circle of the defect contour.

[0065] In the second embodiment, when performing elliptical fitting on the defect contour on each section, it is necessary to obtain the minimum circumscribed ellipse of the defect contour.

[0066] In the third embodiment, when a rectangle is fitted to the outline of the defect on each section (for example, the defect outline on the corresponding section is a long strip), the second starting point and the second end point of the defect are defined in the circumferential direction of the corresponding section, and 1 / K of the chord length corresponding to the arc between the two is used as the width of the fitted rectangle, so that the defect outline on the section is fitted with K rectangles of equal width. For example, K is preferably 3 to 10.

[0067] In the fourth embodiment, when performing a combined elliptical and square fitting on the defect contour on each section (for example, the defect contour on the corresponding section is a step-shaped concave defect), it is necessary to obtain the circumscribed arc for the relatively large defect contour, and use quadrilateral fitting for the relatively small defect contour.

[0068] In the fourth step, all the fitted sections are superimposed to obtain simplified defects at different positions. Then, according to each simplified defect and combined with the above pipeline physical model, Boolean operations are used to obtain a pipeline defect model containing information including the simplified volumetric defect distribution position and three-dimensional size characteristics, so that each simplified defect is projected onto the pipeline physical model according to the fitted size and actual measurement position.

[0069] In one embodiment, for a single or continuous defect, the superposition is to connect adjacent sections along the pipeline trajectory into a solid body, see Figure 4 .

[0070] After the pipeline defect model is constructed, step S120 described in the embodiment of the present invention further uses a preset single grid size to grid the pipeline defect model, so as to use the gridded pipeline defect model to calculate the pipeline residual strength in step S130.

[0071] Specifically, the pipeline defect model is subjected to three-dimensional mesh division processing according to a preset single mesh size parameter, and after the three-dimensional mesh division is completed, the process proceeds to step S130.

[0072] Step S130 uses preset pipeline maintenance parameters to calculate the pipeline residual strength of the pipeline defect model obtained in step S120 after three-dimensional meshing.

[0073] In step S130, first, step S1 records the pipeline residual strength calculated based on the preset single grid size. That is, in step S1, the pipeline residual strength of the pipeline defect model obtained in step S120 after three-dimensional gridding is calculated according to the preset pipeline maintenance parameters.

[0074] In the embodiment of the present invention, the pipeline maintenance parameters include: simulation parameters and simulation conditions. The simulation parameters include but are not limited to: pipeline material and pipeline unit type. The simulation conditions include but are not limited to: applied load and applied constraint.

[0075] In step S1, the pipeline maintenance parameters used for simulation can be pre-set according to the actual situation of the pipeline operation condition, and then the numerical simulation algorithm is used to simulate the pipeline residual strength of the pipeline defect model obtained in step S120 after three-dimensional grid processing under the preset pipeline maintenance parameters, so as to obtain the pipeline residual strength (simulation value).

[0076] Then, step S2 performs mesh encryption processing on the pipeline defect model based on the preset single mesh size to obtain the corresponding pipeline residual strength.

[0077] In step S2, mesh encryption is performed on the pipeline defect model at the current mesh density, and then a numerical simulation algorithm is used to simulate the pipeline residual strength of the pipeline defect model at the current mesh density under the preset pipeline maintenance parameters, so as to obtain the pipeline residual strength (simulation value) again, and then enter step S3.

[0078] Step S3 detects whether the relative error of the pipeline residual strength (simulation value) calculated twice in succession is less than a preset error limit (N).

[0079] In one embodiment, if the relative error of the two most recently calculated pipeline residual strengths is less than a preset error limit (N), the process proceeds to step S140 to analyze the impact of the volumetric defects contained in the pipeline on the pipeline safety performance using the multiple calculated pipeline residual strengths.

[0080] In another embodiment, if the relative error of the pipeline residual strength calculated two times in a row is greater than or equal to the preset error boundary (N), the process returns to step S2 to continue calculating the corresponding pipeline residual strength by mesh encryption processing of the pipeline defect model under the current mesh density, so as to enter step S3 again to determine whether the residual strength analysis conditions are met.

[0081] In one embodiment, N is preferably 5%.

[0082] Thus, when it is determined in step S130 that the pipeline defect model after the final encryption process has satisfied the residual strength analysis condition, the process proceeds to step S140.

[0083] Step S140 analyzes the impact of volumetric defects contained in the pipeline to be inspected on the safety performance of the pipeline according to the residual strength of the pipeline.

[0084] Specifically, step S140 can comprehensively analyze the impact of the volume defects contained in the current pipeline to be inspected on the overall safety performance of the pipeline based on the residual strength of the pipeline defect model corresponding to the final grid density when the encryption processing is terminated in step S3, and the positions and three-dimensional sizes of different simplified defects on the pipeline defect model.

[0085] In the process of evaluating the impact of volumetric defects contained in the pipeline to be inspected on the overall safety performance of the pipeline, the failure criterion is used as the basis for judging failure (the impact on the overall safety performance of the pipeline, that is, if there is an impact on the overall safety performance of the pipeline, it fails, and if there is no impact, it can continue to be used).

[0086] In one embodiment, the main failure mode of the buried pressure pipeline is local plastic failure, and VonMises stress can be used as a failure judgment indicator. VonMises equivalent stress is calculated based on the principal stresses in three directions, and the calculation formula is:

[0087]

[0088] Among them, σ represents the VonMises equivalent stress, and σ1, σ2, and σ3 represent the principal stresses in three directions. When the equivalent stress σ in the defective area of ​​the externally corroded pipeline is greater than the yield strength σ of the pipe s When the externally corroded pipeline is judged to be failed, the failure pressure corresponding to the equivalent stress is the residual strength. It should be noted that the failure pressure refers to the pressure that the pipeline is subjected to when the pipeline is judged to be failed.

[0089] Embodiment 2

[0090] Based on the above-mentioned embodiment 1, the steps involved in the pipeline evaluation method described in the embodiment of the present invention are described.

[0091] S1: Scan the pipeline to be inspected by three-dimensional shape measurement to obtain the position and three-dimensional size information of the volume defect on the pipeline. The three-dimensional scanning method performs two-dimensional detection and three-dimensional measurement at the same time, locates the defect position by detecting the two-dimensional image, and obtains the size information of the defect by three-dimensional measurement.

[0092] S2: Call the relevant interfaces of ABAQUS through Python language, and establish the pipeline physical model by parametric modeling according to the geometric parameters of the pipeline (wall thickness, inner diameter and length). Simplify the defects according to the location and size of the volumetric defects obtained in S1. And establish the simplified defects on the pipeline geometric model through Boolean operations. Divide the grid according to the preset grid size parameters.

[0093] Wherein, the defect simplification step comprises:

[0094] S21: For single or interconnected volume defects, define the starting and ending points of the defects according to the axial direction of the pipeline;

[0095] S22: Starting from the first starting point of the defect to the first end point of the defect, M sections are established, where the value of M is determined according to a preset grid size parameter, and the principle is to ensure that the distance between two consecutive sections is 3 times the size of a single grid;

[0096] S23: Perform quadrilateral fitting on the defect contour on each section. Figure 3 The fitted quadrilaterals are superimposed in the following way: the quadrilaterals fitted by two consecutive sections are modeled in the form of solid lofting to establish a simplified defect model. Figure 4 shown.

[0097] S3: Set the parameters and conditions required for calculation and calculate the remaining strength of the pipeline. During calculation, record the current calculation results and grid size parameters; after encrypting the grid, calculate again; repeat this process until the relative error between two adjacent calculation results is less than 5%.

[0098] The calculation parameters include specified materials and unit types, and the calculation conditions include applied loads and constraints; the calculation parameters and conditions are preset before scanning according to the working conditions of the pipeline.

[0099] S4: Analyze the impact of volumetric defects contained in the pipeline on the safety performance of the pipeline and complete the evaluation process.

[0100] Embodiment 3

[0101] Based on the above-mentioned embodiment 1, the present embodiment 3 adopts a method similar to that of the embodiment 2 to evaluate the pipeline containing volume defects, except that in the present embodiment 3:

[0102] Use a three-dimensional scanning device to scan the pipeline to be inspected to obtain the location and size information of the volumetric defects on the pipeline. The scanning process uses a three-dimensional scanner to scan the entire pipeline to be inspected, establish an overall geometric model, and define the coordinate origin;

[0103] According to the fact that the depth of the defective part is greater than that of the normal part, the position and size of the volume defect relative to the pipeline model are determined, and the defect is simplified in a manner similar to that of Example 2; the relevant interface of ABAQUS is called through the Python language, and the pipeline physical model is established by parametric modeling according to the geometric parameters (wall thickness, inner diameter and length) of the pipeline. Then, the simplified defect is established on the pipeline geometric model through Boolean operations. The grid is divided according to the preset grid size parameters.

[0104] The remaining steps are similar to those of the second embodiment.

[0105] Embodiment 4

[0106] Based on the above-mentioned embodiment 1, this embodiment 4 adopts a method similar to that of embodiment 2 to evaluate the pipeline containing volume defects, except that in this embodiment 4:

[0107] From the defect start point to the defect end point, M sections are established. The value of M is determined according to the preset grid size parameter. The principle is to ensure that the distance between two consecutive sections is 3 times the size of a single grid.

[0108] Fit the defect contour on each section into a quadrilateral, circle or ellipse. The fitting criteria are:

[0109] x=arg min(h)=arg min(f(x)-g)

[0110] Where x is a different geometric shape fitting method; f(x) is the metal loss of the current section after shape fitting; g is the metal loss of the current section before shape fitting.

[0111] The metal loss amount is calculated as follows:

[0112] h=ss remaining

[0113] In the formula, h is the metal loss to be solved; s is the area of ​​the current section when it is complete; s remaining The actual area of ​​the current section

[0114] For two continuous sections, the fitted simple collective shape is modeled in the form of solid lofting to establish a simplified defect model.

[0115] The remaining steps are similar to those of the second embodiment.

[0116] Embodiment 5

[0117] Based on the above-mentioned embodiment 1, the present embodiment 5 adopts a method similar to that of the embodiment 2 to evaluate the pipeline containing volume defects, except that in the present embodiment 5:

[0118] A circular fitting is performed on the defect contour on each section. The fitting principle is to obtain the minimum circumscribed circle of the defect contour.

[0119] The remaining steps are similar to those of the second embodiment.

[0120] Embodiment 6

[0121] Based on the above-mentioned embodiment 1, this embodiment 6 adopts a method similar to that of embodiment 2 to evaluate the pipeline containing volume defects, except that in this embodiment 6:

[0122] An ellipse is fitted to the defect contour on each section, and the fitting principle is to obtain the minimum circumscribed ellipse of the defect contour.

[0123] The remaining steps are similar to those of the second embodiment.

[0124] Embodiment 7

[0125] Based on the above-mentioned embodiment 1, this embodiment 7 adopts a method similar to that of embodiment 2 to evaluate the pipeline containing volume defects, except that in this embodiment 7:

[0126] From the defect start point to the defect end point, M sections are established. The value of M is determined according to the preset grid size parameter. The principle is to ensure that the distance between two consecutive sections is 3 times the size of a single grid.

[0127] A rectangular fit is performed on the defect contour on each section. The fitting criteria are:

[0128] The second starting point and the second end point of the defect are defined by the circumference of the current section, and the width of the fitted rectangle is 1 / K of the chord length of the arc between the two. That is, K rectangles of equal width are used to fit the defect contour on the section.

[0129] Among them, the value of K is 3 to 10.

[0130] The remaining steps are similar to those of the second embodiment.

[0131] Embodiment 8

[0132] Based on the above-mentioned embodiment 1, this embodiment 8 adopts a method similar to that of embodiment 2 to evaluate the pipeline containing volume defects, except that in this embodiment 8:

[0133] like Figure 5 As shown, a combination of elliptical and square fitting is performed on the defect contour on each section. The fitting object is a step-shaped concave defect. The fitting principle is to obtain the circumscribed arc for the relatively large contour of the defect, and to use quadrilateral fitting for the relatively small contour of the defect, and perform Boolean operations on the fitted geometric shapes.

[0134] The remaining steps are similar to those of the second embodiment.

[0135] Embodiment 9

[0136] Based on the pipeline evaluation method described in the first to eighth embodiments, the present invention further provides a system for evaluating pipelines containing volumetric defects (also referred to as a "pipeline evaluation system"). The pipeline evaluation system is used to implement the pipeline evaluation method described in the first to eighth embodiments.

[0137] Figure 6 Schematic diagram of the structure of the system for evaluating a pipeline containing volume defects according to an embodiment of the present application. Figure 6 As shown, the pipeline evaluation system described in the embodiment of the present invention includes: a feature information collection module 61, a defect model construction module 62, a pipeline residual strength calculation module 63 and a pipeline safety analysis module 64.

[0138] The feature information acquisition module 61 is implemented according to the method described in the above step S110, and is configured to use three-dimensional morphology measurement technology to scan the pipeline to be inspected to obtain the size feature information of volume defects at different positions of the pipeline; the defect recognition module 52 is implemented according to the method described in the above step S120, and is configured to establish a pipeline defect model based on the size feature information of different defects and the pipeline geometric parameters; the statistical analysis module 53 is implemented according to the method described in the above step S130, and is configured to use the preset pipeline maintenance parameters to calculate the pipeline residual strength of the pipeline defect model; the risk assessment module 54 is implemented according to the method described in the above step S140, and is configured to analyze the impact of the volume defects contained in the pipeline on the pipeline safety performance based on the pipeline residual strength.

[0139] In one embodiment, the feature information acquisition module 61 is further configured to use three-dimensional morphology measurement technology to perform two-dimensional detection on the pipeline to be inspected to obtain position information of volume defects at different positions, and simultaneously perform three-dimensional measurement on the pipeline to be inspected to obtain size information of volume defects at different positions.

[0140] In one embodiment, the defect model building module 62 includes: an original physical model generating unit 621 , a defect model generating unit 622 and a model preprocessing unit 623 .

[0141] Specifically, the original physical model generation unit 621 is configured to establish a pipeline physical model according to pipeline geometric parameters; the defect model generation unit 622 is configured to establish defects on the pipeline physical model using Boolean operations according to location information and size feature information of different volume defects to obtain a pipeline defect model; the model preprocessing unit 623 is configured to grid the pipeline defect model using a preset single grid size, so as to calculate the residual strength of the pipeline using the gridded pipeline defect model.

[0142] In one embodiment, the defect model generation unit 622 establishes the pipeline defect model according to the following steps:

[0143] According to the position and size characteristic information of each volume defect on the pipeline, an initial defect is established on the physical model of the pipeline;

[0144] Define the starting point and end point of each initial defect, based on which, establish multiple sections perpendicular to the axial direction of the pipeline for each initial defect;

[0145] Approximately fit the defect area on each section with a simple geometric shape;

[0146] All fitted sections are superimposed to obtain simplified defects at various locations. Based on this, combined with the pipeline physical model, Boolean operations are used to obtain the pipeline defect model.

[0147] The present invention discloses a method and system for evaluating a pipeline containing volumetric defects. The method and system directly use the measured three-dimensional size and position data of the defect as input parameters and input them into the residual strength model, thereby directly obtaining the residual strength so as to quantitatively evaluate the use of the pipeline. To this end, the present invention solves the problem that the results obtained by using the semi-empirical formula to calculate the residual strength of the pipeline in the prior art are relatively conservative, and also solves the problem that the prior art directly uses the numerical simulation method to calculate the residual strength of the pipeline, which requires repeated modeling and repeated setting of calculation parameters and conditions.

[0148] In this way, the present invention can be widely used in non-contact defect measurement and residual strength calculation of volume defects in pipelines in the petroleum and chemical industries. The measurement process has no requirements on the material of the inspected equipment, and the calculation process is executed in the background, which can effectively improve the detection efficiency of volume defects and the calculation accuracy of residual strength.

[0149] Specifically, the present invention adopts a three-dimensional measurement combined with numerical simulation to calculate the residual strength of a pipeline containing volumetric defects. Compared with the method of calculating using a semi-empirical formula, the obtained result is closer to the actual situation. Moreover, except for the measurement and necessary parameter input, all residual strength calculation processes are executed by the program background, which effectively reduces the repetitive work of the entire process of calculating the residual strength of a pipeline containing volumetric defects. At the same time, a simplified method for a pipeline defect model is proposed to simplify the defect modeling process.

[0150] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person familiar with the technology within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0151] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0152] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0153] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0154] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" appearing in various places throughout the specification do not necessarily refer to the same embodiment.

[0155] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0156] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A method for evaluating a pipeline containing volumetric defects, characterized in that: include: Use 3D shape measurement technology to scan the pipeline to be inspected and obtain the size characteristic information of volume defects at different positions of the pipeline; Establish pipeline defect model based on the size characteristic information of different defects and pipeline geometric parameters; Calculating the pipeline residual strength of the pipeline defect model using preset pipeline maintenance parameters; According to the residual strength of the pipeline, the influence of volumetric defects contained in the pipeline on the safety performance of the pipeline is analyzed.

2. The method according to claim 1, characterized in that The steps of establishing a pipeline defect model according to the size characteristic information of different defects and the pipeline geometric parameters include: Establishing a pipeline physical model according to the pipeline geometric parameters; According to the position information and size characteristic information of different volume defects, defects are established on the pipeline physical model by using Boolean operation to obtain the pipeline defect model; The pipeline defect model is meshed using a preset single grid size, so as to calculate the pipeline residual strength using the meshed pipeline defect model.

3. The method according to claim 2, characterized in that According to the location information and size characteristic information of different volume defects, simplified defects are established on the pipeline physical model by using Boolean operations to obtain the pipeline defect model, which includes: According to the position and size characteristic information of each volume defect on the pipeline, an initial defect is established on the physical model of the pipeline; Define the starting point and end point of each initial defect, based on which, establish multiple sections perpendicular to the axial direction of the pipeline for each initial defect; Approximately fit the defect area on each section with a simple geometric shape; All fitted sections are superimposed to obtain simplified defects at various locations. Based on this, combined with the pipeline physical model, Boolean operations are used to obtain the pipeline defect model.

4. The method according to claim 3, characterized in that The simple geometric shape is selected from one or a combination of polygons, circles and ellipses, wherein the geometric shape fitting is performed on the defect area on each section according to the following approximate fitting criteria: x = argmin(f(x)-g) f(x)=s-s1 g=s-s2 Among them, x represents different geometric shape fitting methods, f(x) represents the metal loss of the current section after shape fitting, g represents the metal loss of the current section before shape fitting, s represents the section area when the current section is complete, s1 represents the remaining section area excluding the simplified defect part after the defect simplification of the current section, and s2 represents the actual remaining area of ​​the current section excluding the defect part under actual measurement.

5. The method according to any one of claims 2 to 4, characterized in that: The process of calculating the residual strength of the pipeline includes: S1. Recording the residual strength of the pipeline calculated based on the preset single grid size; S2. Perform mesh encryption processing on the pipeline defect model based on a preset single mesh size to obtain the corresponding pipeline residual strength; S3, detecting whether the relative error of the pipeline residual strength calculated twice in the most recent consecutive time is less than a preset error boundary, if so, using the pipeline residual strength calculated multiple times to analyze the impact of the volumetric defects contained in the pipeline on the pipeline safety performance, if greater than or equal to, returning to step S2 to continue to calculate the corresponding pipeline residual strength by mesh encryption processing of the pipeline defect model.

6. The method according to any one of claims 1 to 5, characterized in that: The pipeline maintenance parameters include simulation parameters and simulation conditions. The simulation parameters include but are not limited to pipeline materials and pipeline unit types. The simulation conditions include but are not limited to applied loads and applied constraints.

7. The method according to any one of claims 1 to 6, characterized in that: The steps of scanning the pipeline to be inspected by using the three-dimensional shape measurement technology to obtain the size characteristic information of volume defects at different positions of the pipeline include: By adopting the three-dimensional shape measurement technology, the pipeline to be inspected is subjected to two-dimensional detection to obtain the position information of volume defects at different positions, and at the same time, the pipeline to be inspected is subjected to three-dimensional measurement to obtain the size information of volume defects at different positions.

8. The method according to claim 3 or 4, characterized in that: The simple geometric shape is selected from one or a combination of triangle, quadrilateral, circle and ellipse; The distance between adjacent sections in the same defect is an integer multiple of the preset single grid size; The superposition is to connect adjacent sections along the pipeline trajectory into a solid.

9. A system for evaluating a pipeline containing volumetric defects, characterized in that: The system is used to implement the method according to any one of claims 1 to 8, wherein the system comprises: A feature information acquisition module is configured to use a three-dimensional shape measurement technology to scan the pipeline to be inspected, and obtain size feature information of volume defects at different positions of the pipeline; A defect model building module configured to build a pipeline defect model based on size feature information of different defects and pipeline geometric parameters; A pipeline residual strength calculation module, configured to calculate the pipeline residual strength of the pipeline defect model using preset pipeline maintenance parameters; The pipeline safety analysis module is configured to analyze the impact of volumetric defects contained in the pipeline on the safety performance of the pipeline based on the residual strength of the pipeline.

10. The system according to claim 9, characterized in that The defect model building module includes: An original physical model generating unit, configured to establish a pipeline physical model according to the pipeline geometric parameters; A defect model generating unit configured to establish defects on the pipeline physical model using Boolean operations according to location information and size feature information of different volume defects to obtain the pipeline defect model; The model preprocessing unit is configured to mesh the pipeline defect model using a preset single grid size, so as to calculate the pipeline residual strength using the meshed pipeline defect model.

11. The system according to claim 10, characterized in that The defect model generation unit establishes the pipeline defect model according to the following steps: According to the position and size characteristic information of each volume defect on the pipeline, an initial defect is established on the physical model of the pipeline; Define the starting point and end point of each initial defect, based on which, establish multiple sections perpendicular to the axial direction of the pipeline for each initial defect; Approximately fit the defect area on each section with a simple geometric shape; All fitted sections are superimposed to obtain simplified defects at various locations. Based on this, combined with the pipeline physical model, Boolean operations are used to obtain the pipeline defect model.

12. The system according to any one of claims 9 to 11, characterized in that: The characteristic information acquisition module is further configured to use three-dimensional morphology measurement technology to perform two-dimensional detection on the pipeline to be inspected to obtain position information of volume defects at different positions, and simultaneously perform three-dimensional measurement on the pipeline to be inspected to obtain size information of volume defects at different positions.

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