Non-contact identifying and positioning method for circumferential weld of buried steel pipeline

Abstract

The invention discloses a buried steel pipeline circumferential weld non-contact identification positioning method, and relates to the technical field of pipeline weld detection, the pipeline path of a target pipeline is determined, the pipeline axis corresponding to the determined pipeline path is determined, and the target pipeline is divided into a plurality of detection intervals according to the determined pipeline axis; setting a magnetic force measurement route, and obtaining magnetic force data of each detection interval through a non-contact scanning magnetometer along the set magnetic force measurement route; according to the obtained magnetic data, gradient components and gradient moduli of all detection intervals of the target pipeline are obtained; carrying out noise reduction processing on the obtained magnetic data, carrying out circumferential weld identification on the target pipeline through the magnetic data subjected to noise reduction processing, and evaluating the comprehensive stress level and risk level of the weld after identifying the position of the weld; and according to a risk grade evaluation result, determining a welding seam point, and according to the determined welding seam point, setting a corresponding reinspection area.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline weld detection, in particular to a non-contact identification and positioning method for a buried steel pipeline girth weld. Background Art

[0002] In-pipeline inspection is a non-destructive inspection method that has been developed earlier and has the most mature technology. During in-pipeline inspection, a weld sensor is generally installed on the detector. The girth weld is identified from the data collected by the weld sensor based on the weld point identification and matching method. The girth weld identification in pipeline in-line inspection is to identify the girth weld from the signal collected by the weld sensor. The probe of the girth weld detector is placed close to the inner wall of the pipeline to simulate the detector moving forward, collect the weld signal, and the odometer moves synchronously;

[0003] In practical applications, pipeline weld sensors are subject to various interferences. The degree of fit between the sensor and the pipe wall changes with the forward speed of the detector, which will interfere with the data collected by the weld sensor coil. These interferences will cause errors in the identification of girth welds, so that multiple excavations of detection pits are required to find the corresponding girth weld positions, which not only increases costs but also increases the corresponding operational risks. For this reason, a non-contact identification and positioning method for girth welds of buried steel pipelines is provided. Summary of the invention

[0004] The purpose of the present invention is to provide a non-contact identification and positioning method for the girth weld of a buried steel pipeline.

[0005] The purpose of the present invention can be achieved by the following technical solution: A non-contact identification and positioning method for a buried steel pipeline girth weld comprises the following steps:

[0006] Step S1: determining a pipeline path of a target pipeline, determining a corresponding pipeline axis for the determined pipeline path, and dividing the target pipeline into a plurality of detection intervals according to the determined pipeline axis;

[0007] Step S2: setting a magnetometry route, and obtaining magnetic data of each detection interval along the set magnetometry route by a non-contact scanning magnetometer;

[0008] Step S3: Obtaining the gradient component and gradient modulus of each detection interval of the target pipeline according to the obtained magnetic data;

[0009] Step S4: performing noise reduction processing on the obtained magnetic data, identifying the girth weld of the target pipeline through the noise-reduced magnetic data, and evaluating the comprehensive stress level and risk level of the weld after identifying the weld position;

[0010] Step S5: Determine the weld points according to the risk level assessment result, set the corresponding re-inspection area according to the determined weld points, and perform X-ray photography and detection on the target pipeline in the re-inspection area.

[0011] Further, the pipeline path of the target pipeline is determined, and the corresponding pipeline axis is determined for the determined pipeline path, and the process of dividing the target pipeline into a plurality of detection intervals according to the determined pipeline axis includes:

[0012] Select the target pipeline to be tested, and set the test start point and test end point;

[0013] Several marking points are set on the ground according to the pipeline path between the detection starting point and the detection end point of the target pipeline, and the corresponding pipeline axis is marked on the ground according to the distribution position of the markers;

[0014] The pipeline length of the target pipeline is obtained, and according to the pipeline length of the target pipeline, the target pipeline detection starting point and the detection terminal are divided into a number of detection intervals with equal path lengths through the interval division point.

[0015] Furthermore, a magnetometry route is set, and a process of obtaining magnetic data of each detection interval along the set magnetometry route by a non-contact scanning magnetometer includes:

[0016] A first measurement route is set along the pipeline axis of the target pipeline, and a second measurement route is set on one side of the target pipeline;

[0017] A technician holds a non-contact scanning magnetometer and moves along a first measurement route; wherein the non-contact scanning magnetometer includes a first magnetic sensor and a second magnetic sensor;

[0018] When the technician moves along the first measurement route while holding the non-contact scanning magnetometer, the technician keeps the first magnetic sensor of the non-contact scanning magnetometer above the first measurement route and keeps the second magnetic sensor of the non-contact scanning magnetometer above the second measurement route;

[0019] Obtain the distance between the first magnetic sensor and the second magnetic sensor, which is the length L of the magnetometer probe;

[0020] The magnetic data specifically refers to three components of the magnetic field measured by the first magnetic sensor and the second magnetic sensor on the first measurement route and the second measurement route respectively;

[0021] The three components of the magnetic field obtained by the first magnetic sensor on the first measurement route are denoted as (B x1 , B y1 , B z1 );

[0022] The three components of the magnetic field obtained by the second magnetic sensor on the second measurement route are denoted as (B x2 , B y2 , B z2 ).

[0023] Furthermore, the process of obtaining the gradient component and the gradient modulus of each detection interval of the target pipeline according to the obtained magnetic data includes:

[0024] The three components of the magnetic field obtained by the first magnetic sensor and the second magnetic sensor are the three components obtained by the contactless scanning magnetometer in the X, Y, and Z directions, and the gradient components of the contactless scanning magnetometer in the X direction are obtained, which are respectively recorded as in

[0025]

[0026] The corresponding gradient modulus is obtained according to the obtained gradient component, which is recorded as dQ;

[0027] in,

[0028] Furthermore, the process of performing noise reduction processing on the obtained magnetic data includes:

[0029] The magnetic data corresponding to each detection interval are summarized to obtain the corresponding magnetic data set, and the obtained magnetic data set is recorded as C total ;

[0030] The obtained magnetic data set C total The denoising process is performed by using the Matlab wavelet signal denoiser. The gradient components and gradient moduli of each detection interval are then loaded into the main interface of wavelet analysis as weld signals. The corresponding wavelet basis function, denoising method and number of decomposition layers are selected. After setting the threshold, the loaded gradient components and gradient moduli are analyzed and reconstructed to complete the denoising of the magnetic data.

[0031] Furthermore, the girth weld of the target pipeline is identified by using the noise-reduced magnetic data. After the weld position is identified, the comprehensive stress level and risk level of the weld are evaluated in the following process:

[0032] According to the obtained gradient modulus of each detection interval, the peak value of the gradient modulus at each position of the target pipeline is obtained. According to the obtained peak value of the gradient modulus, the position corresponding to the peak value is the position of the weld of the target pipeline;

[0033] Obtain a comprehensive magnetic anomaly index at the position of the target pipeline where the peak value is located, and record the obtained comprehensive magnetic anomaly index as F;

[0034] in

[0035] Where A is the correction coefficient, is the background quiet area along the pipeline axis, that is, the magnetic field intensity gradient of the earth, and e is the natural index;

[0036] Set the index threshold interval, denoted as [F1, F2);

[0037] The obtained magnetic anomaly comprehensive index is compared with the set index threshold range.

[0038] Further, according to the risk level assessment result, the weld points are determined, and the corresponding re-inspection area is set according to the determined weld points. The process of performing X-ray photography and detection on the target pipeline in the re-inspection area includes:

[0039] When F<F1, it means that the weld point at the corresponding weld position is an abnormal weld point and is marked as high risk;

[0040] When F1≤F<F2, the weld points at the corresponding weld positions are marked as medium risk;

[0041] When F ≥ F2, it means that the weld point at the corresponding weld position is of low risk;

[0042] The inspection area where the high-risk weld point is located is re-inspected by a non-contact scanning magnetometer, and the gradient modulus dQ value displayed in real time by the data acquisition software is observed. When the dQ value reaches the peak value, the inspection is suspended. This is the exact location of the weld.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. Accurately locate the girth weld position through segmented inspection methods and regional re-inspection, overcoming the problem of large deviation in finding welds only through internal inspection mileage. The mileage error is small, which reduces the operation risk and the cost of excavation of inspection pits, and improves the safety and integrity management level of pipelines, especially in mountainous areas;

[0045] 2. The detection is carried out by a non-contact scanning magnetometer, which does not require additional magnetization equipment. The geomagnetic field and stress are used to magnetize the pipeline, thereby generating a leakage magnetic signal. The detection operation is simple and fast, and large-scale detection can be achieved. Moreover, this method is an external detection technology, which is not limited by the structure and size of the pipeline, can be applied to complex and diverse terrain environments, and is suitable for the detection of buried steel pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0047] Figure 1 is a flow chart of the method of the present invention;

[0048] Figure 2 It is the weld signal diagram of the present invention;

[0049] Figure 3 This is an X-ray image of the weld of the present invention. DETAILED DESCRIPTION

[0050] like Figure 1 As shown, a non-contact identification and positioning method for a buried steel pipeline girth weld includes the following steps:

[0051] Step S1: determining a pipeline path of a target pipeline, determining a corresponding pipeline axis for the determined pipeline path, and dividing the target pipeline into a plurality of detection intervals according to the determined pipeline axis;

[0052] Step S2: setting a magnetometry route, and obtaining magnetic data of each detection interval along the set magnetometry route by a non-contact scanning magnetometer;

[0053] Step S3: Obtaining the gradient component and gradient modulus of each detection interval of the target pipeline according to the obtained magnetic data;

[0054] Step S4: performing noise reduction processing on the obtained magnetic data, identifying the girth weld of the target pipeline through the noise-reduced magnetic data, and evaluating the comprehensive stress level and risk level of the weld after identifying the weld position;

[0055] Step S5: Determine the weld points according to the risk level assessment result, set the corresponding re-inspection area according to the determined weld points, and perform X-ray photography and detection on the target pipeline in the re-inspection area.

[0056] It should be further explained that, in the specific implementation process, the pipeline path of the target pipeline is determined, and the corresponding pipeline axis is determined for the determined pipeline path. The process of dividing the target pipeline into a plurality of detection intervals according to the determined pipeline axis includes:

[0057] Select the target pipeline to be tested, and set the test start point and test end point;

[0058] According to the pipeline path between the detection starting point and the detection end point of the target pipeline, several marking points are set on the ground, and the corresponding pipeline axis is marked on the ground according to the distribution position of the markers; in the specific implementation process, when the pipeline path has a corner, a corresponding corner stake is set at the corner position, so that when the target pipeline is detected, the operator always walks on the pipeline axis to prevent the detection path from deviating from the pipeline path. At the same time, the mileage can be checked through the positions of these marking points and corner stakes;

[0059] The pipeline length of the target pipeline is obtained, and according to the pipeline length of the target pipeline, the interval between the detection starting point and the detection terminal of the target pipeline is divided into a plurality of detection intervals with equal path lengths through the interval division point;

[0060] Each detection interval is denoted as C 1 , C 2 , ..., C n ;

[0061] The detection starting point, interval segmentation point and detection focus are respectively recorded as M 1 , M 2 , ..., M n , M n+1 .

[0062] It should be further explained that, in the specific implementation process, the process of setting a magnetometry route and obtaining magnetic data of each detection interval along the set magnetometry route by a non-contact scanning magnetometer includes:

[0063] A first measurement route is set along the pipeline axis of the target pipeline, and a second measurement route is set on one side of the target pipeline;

[0064] A technician holds a non-contact scanning magnetometer and moves along a first measurement route; wherein the non-contact scanning magnetometer includes a first magnetic sensor and a second magnetic sensor;

[0065] When the technician moves along the first measurement route while holding the non-contact scanning magnetometer, the technician keeps the first magnetic sensor of the non-contact scanning magnetometer above the first measurement route and keeps the second magnetic sensor of the non-contact scanning magnetometer above the second measurement route;

[0066] Obtain the distance between the first magnetic sensor and the second magnetic sensor, which is the length L of the magnetometer probe;

[0067] The magnetic data specifically refers to three components of the magnetic field measured by the first magnetic sensor and the second magnetic sensor on the first measurement route and the second measurement route respectively;

[0068] The three components of the magnetic field obtained by the first magnetic sensor on the first measurement route are denoted as (Bx1 , B y1 , B z1 );

[0069] The three components of the magnetic field obtained by the second magnetic sensor on the second measurement route are denoted as (B x2 , B y2 , B z2 ).

[0070] It should be further explained that, in the specific implementation process, the process of obtaining the gradient component and the gradient modulus of each detection interval of the target pipeline according to the obtained magnetic data includes:

[0071] The three components of the magnetic field obtained by the first magnetic sensor and the second magnetic sensor are the three components obtained by the contactless scanning magnetometer in the X, Y, and Z directions, and the gradient components of the contactless scanning magnetometer in the X direction are obtained, which are respectively recorded as in

[0072]

[0073] The corresponding gradient modulus is obtained according to the obtained gradient component, which is recorded as dQ;

[0074] in,

[0075] It should be further explained that, in the specific implementation process, the process of denoising the obtained magnetic data includes:

[0076] The magnetic data corresponding to each detection interval are summarized to obtain the corresponding magnetic data set, and the obtained magnetic data set is recorded as C total ;

[0077] The obtained magnetic data set C total The denoising process is performed by using the Matlab wavelet signal denoiser. The gradient components and gradient moduli of each detection interval are then loaded into the main interface of wavelet analysis as weld signals. The corresponding wavelet basis function, denoising method and number of decomposition layers are selected. After setting the threshold, the loaded gradient components and gradient moduli are analyzed and reconstructed to complete the denoising of the magnetic data.

[0078] It should be further explained that, in the specific implementation process, the girth weld of the target pipeline is identified by using the noise-reduced magnetic data. After the weld position is identified, the comprehensive stress level and risk level of the weld are evaluated in the following process:

[0079] According to the obtained gradient modulus of each detection interval, the peak value of the gradient modulus at each position of the target pipeline is obtained. According to the obtained peak value of the gradient modulus, the position corresponding to the peak value is the position of the weld of the target pipeline;

[0080] Obtain a comprehensive magnetic anomaly index at the position of the target pipeline where the peak value is located, and record the obtained comprehensive magnetic anomaly index as F;

[0081] in

[0082] Where A is the correction coefficient, is the background quiet area along the pipeline axis, that is, the magnetic field intensity gradient of the earth, and e is the natural index;

[0083] Set the index threshold interval, denoted as [F1, F2);

[0084] Compare the obtained magnetic anomaly comprehensive index with the set index threshold range;

[0085] like Figure 2 As shown in the figure, in the specific implementation process, since the metallographic, microstructure, stress and magnetic distribution of the steel pipe girth weld are obviously different from those of the pipe base material, the gradient component at the weld At extreme values, and generally The magnitude is much larger than and Therefore, the gradient modulus dQ also reaches a peak value accordingly, and the position of the circumferential weld can be determined by this feature.

[0086] It should be further explained that, in the specific implementation process, the welding points are determined according to the risk level assessment results, and the corresponding re-inspection areas are set according to the determined welding points. The process of performing X-ray photography and detection on the target pipelines in the re-inspection area includes:

[0087] When F<F1, it means that the weld point at the corresponding weld position is an abnormal weld point and is marked as high risk;

[0088] When F1≤F<F2, the weld points at the corresponding weld positions are marked as medium risk;

[0089] When F ≥ F2, it means that the weld point at the corresponding weld position is of low risk;

[0090] The inspection area where the high-risk weld point is located is re-inspected by a non-contact scanning magnetometer, and the gradient modulus dQ value displayed in real time by the data acquisition software is observed. When the dQ value reaches the peak value, the inspection is suspended. This is the exact position of the weld, and the weld is excavated; then the weld is inspected by X-ray film to obtain the following Figure 3 Picture of weld shown.

[0091] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any modification or equivalent replacement of the above embodiments made according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A non-contact identification and positioning method for a buried steel pipeline girth weld, characterized in that: The following steps are involved: Step S1: determining a pipeline path of a target pipeline, determining a corresponding pipeline axis for the determined pipeline path, and dividing the target pipeline into a plurality of detection intervals according to the determined pipeline axis; Step S2: setting a magnetometry route, and obtaining magnetic data of each detection interval along the set magnetometry route by a non-contact scanning magnetometer; Step S3: Obtaining the gradient component and gradient modulus of each detection interval of the target pipeline according to the obtained magnetic data; Step S4: performing noise reduction processing on the obtained magnetic data, identifying the girth weld of the target pipeline through the noise-reduced magnetic data, and evaluating the comprehensive stress level and risk level of the weld after identifying the weld position; Step S5: Determine the weld points according to the risk level assessment result, set the corresponding re-inspection area according to the determined weld points, and perform X-ray photography and detection on the target pipeline in the re-inspection area.

2. The non-contact identification and positioning method for the girth weld of a buried steel pipeline according to claim 1 is characterized in that: The process of determining a pipeline path of a target pipeline, determining a corresponding pipeline axis for the determined pipeline path, and dividing the target pipeline into a plurality of detection intervals according to the determined pipeline axis includes: Select the target pipeline to be tested, and set the test start point and test end point; Several marking points are set on the ground according to the pipeline path between the detection starting point and the detection end point of the target pipeline, and the corresponding pipeline axis is marked on the ground according to the distribution position of the markers; The pipeline length of the target pipeline is obtained, and according to the pipeline length of the target pipeline, the target pipeline detection starting point and the detection terminal are divided into a number of detection intervals with equal path lengths through the interval division point.

3. The non-contact identification and positioning method for the girth weld of a buried steel pipeline according to claim 2 is characterized in that: The process of setting a magnetometry route and obtaining magnetic data of each detection interval along the set magnetometry route by a non-contact scanning magnetometer includes: A first measurement route is set along the pipeline axis of the target pipeline, and a second measurement route is set on one side of the target pipeline; A technician holds a non-contact scanning magnetometer and moves along a first measurement route; wherein the non-contact scanning magnetometer includes a first magnetic sensor and a second magnetic sensor; When the technician moves along the first measurement route holding the non-contact scanning magnetometer, the technician keeps the first magnetic sensor of the non-contact scanning magnetometer above the first measurement route and keeps the second magnetic sensor of the non-contact scanning magnetometer above the second measurement route; Obtain the distance between the first magnetic sensor and the second magnetic sensor, which is the length L of the magnetometer probe; The magnetic data are three components of the magnetic field measured by the first magnetic sensor and the second magnetic sensor on the first measurement route and the second measurement route respectively; The three components of the magnetic field obtained by the first magnetic sensor on the first measurement route are denoted as (B x1 , B y1 , B z1 ); The three components of the magnetic field obtained by the second magnetic sensor on the second measurement route are denoted as (B x2 , B y2 , B z2 ).

4. The non-contact identification and positioning method for the girth weld of a buried steel pipeline according to claim 3 is characterized in that: The process of obtaining the gradient components and gradient modulus of each detection interval of the target pipeline according to the obtained magnetic data includes: The three components of the magnetic field obtained by the first magnetic sensor and the second magnetic sensor are the three components obtained by the contactless scanning magnetometer in the X, Y, and Z directions, and the gradient components of the contactless scanning magnetometer in the X direction are obtained, which are respectively recorded as in The corresponding gradient modulus is obtained according to the obtained gradient component, which is recorded as dQ; in, 5. The non-contact identification and positioning method for the girth weld of a buried steel pipeline according to claim 4 is characterized in that: The process of denoising the acquired magnetic data includes: The magnetic data corresponding to each detection interval are summarized to obtain the corresponding magnetic data set, and the obtained magnetic data set is recorded as C total ; The obtained magnetic data set C total The denoising process is performed by using the Matlab wavelet signal denoiser. The gradient components and gradient moduli of each detection interval are then loaded into the main interface of wavelet analysis as weld signals. The corresponding wavelet basis function, denoising method and number of decomposition layers are selected. After setting the threshold, the loaded gradient components and gradient moduli are analyzed and reconstructed to complete the denoising of the magnetic data.

6. A non-contact identification and positioning method for a buried steel pipeline girth weld according to claim 5, characterized in that: The circumferential weld of the target pipeline is identified by using the noise-reduced magnetic data. After the weld position is identified, the comprehensive stress level and risk level of the weld are evaluated in the following process: According to the obtained gradient modulus of each detection interval, the peak value of the gradient modulus at each position of the target pipeline is obtained. According to the obtained peak value of the gradient modulus, the position corresponding to the peak value is the position of the weld of the target pipeline; Obtain a comprehensive magnetic anomaly index at the position of the target pipeline where the peak value is located, and record the obtained comprehensive magnetic anomaly index as F; in Where A is the correction coefficient, is the background quiet area along the pipeline axis, that is, the magnetic field intensity gradient of the earth, and e is the natural index; Set the index threshold interval, denoted as [F1, F2); The obtained magnetic anomaly comprehensive index is compared with the set index threshold range.

7. A non-contact identification and positioning method for a buried steel pipeline girth weld according to claim 6, characterized in that: According to the risk level assessment results, the weld points are determined, and the corresponding re-inspection areas are set according to the determined weld points. The process of performing X-ray inspection on the target pipelines in the re-inspection area includes: When F<F1, it means that the weld point at the corresponding weld position is an abnormal weld point and is marked as high risk; When F1≤F<F2, the weld points at the corresponding weld positions are marked as medium risk; When F ≥ F2, it means that the weld point at the corresponding weld position is of low risk; The inspection area where the high-risk weld point is located is re-inspected by a non-contact scanning magnetometer, and the gradient modulus dQ value displayed in real time by the data acquisition software is observed. When the dQ value reaches the peak value, the inspection is suspended. This is the exact location of the weld.

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