CN113138421B - Buried depth and trend detection method for buried metal pipeline - Google Patents
Buried depth and trend detection method for buried metal pipeline Download PDFInfo
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- CN113138421B CN113138421B CN202110484959.7A CN202110484959A CN113138421B CN 113138421 B CN113138421 B CN 113138421B CN 202110484959 A CN202110484959 A CN 202110484959A CN 113138421 B CN113138421 B CN 113138421B
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- 238000001514 detection method Methods 0.000 title claims abstract description 31
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 11
- 239000002184 metal Substances 0.000 title claims abstract description 11
- 230000005291 magnetic effect Effects 0.000 claims abstract description 41
- 238000000034 method Methods 0.000 claims abstract description 19
- 230000006698 induction Effects 0.000 claims description 16
- 238000005259 measurement Methods 0.000 claims description 8
- 238000004364 calculation method Methods 0.000 claims description 6
- 230000005358 geomagnetic field Effects 0.000 claims description 3
- 229910000838 Al alloy Inorganic materials 0.000 claims description 2
- 239000003302 ferromagnetic material Substances 0.000 claims description 2
- 239000002023 wood Substances 0.000 claims description 2
- 238000005516 engineering process Methods 0.000 abstract description 15
- 230000007547 defect Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000002689 soil Substances 0.000 description 2
- 238000009412 basement excavation Methods 0.000 description 1
- 238000009933 burial Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
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- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
- G01V3/08—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
- G01V3/081—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices the magnetic field is produced by the objects or geological structures
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Abstract
The invention is named as: a buried depth and trend detection method for a buried metal pipeline belongs to the technical field of nondestructive detection of pipelines. The invention aims to provide an external detection device based on a fluxgate sensor and a pipeline space positioning method. The method comprises the steps of utilizing two fluxgate sensors horizontally arranged on the left and right sides, continuously acquiring weak magnetic signals of a self-leakage magnetic field of the buried metal pipeline in real time, determining spatial positions such as the position of the pipeline, the buried depth height, the route trend and the like, and positioning a stress concentration area of the pipeline. The purpose of providing the spatial position information of the pipeline for the non-contact magnetic memory detection technology of the buried pipeline is achieved.
Description
II, the technical field is as follows:
the invention belongs to the technical field of nondestructive testing of pipelines.
Thirdly, background art:
3.1 background of the invention
The pipeline non-contact magnetic memory detection technology is developed and evolved on the basis of the metal magnetic memory detection technology. The non-contact type magnetic memory detection of pipeline is a nondestructive detection technology developed for ferromagnetic pipeline with a certain buried depth and magnetized by geomagnetic field. The method is based on three-component signals of magnetic induction intensity of a ground self-leakage magnetic field above the pipeline, and gradient signals of the pipeline self-leakage magnetic field are obtained through calculation, so that a stress concentration area of the pipeline is identified. The technology has the technical characteristics of high detection speed under the trenchless condition, no limitation of the size and the shape of the pipeline and capability of realizing 100 percent detection of pipeline equipment.
When the technology is applied to an actual field, the geographic factors such as the buried depth, the position, the trend and the like of the detected pipeline need to be determined so as to improve the accuracy of the acquired signal. However, the existing pipeline detection technologies all have different degrees of disadvantages, such as: the electromagnetic method has strict application conditions, large routing error, heavy equipment and instruments, inconvenient field carrying, complicated operation process and the like. The application of the magnetic memory method in the field of buried pipeline detection engineering in the weak magnetic environment is greatly limited.
3.2 prior art relating to the invention
3.2.1 technical solution of the prior art
When the pipeline non-contact magnetic memory detection technology is applied to stress detection of a buried pipeline, the pipeline needs to be detected in advance to determine the position and the trend of the detected pipeline. At present, the common underground pipeline trenchless detection technology at home and abroad is an electromagnetic method. The working principle of the electromagnetic method is as follows: the electromagnetic transmitter generates electromagnetic waves and transmits the electromagnetic waves to the buried pipeline, the buried pipeline generates induced current after sensing the electromagnetic waves, and the induced current is transmitted to a remote place along the buried pipeline. During the current propagation, electromagnetic waves are radiated to the ground at the same time. At the moment, a receiver for detecting on the ground can receive electromagnetic wave signals on the ground right above the buried pipeline, and the buried depth, position and trend of the buried pipeline are judged according to the strength change of the received signals.
3.2.2 disadvantages of the prior art
In practical engineering application, the electromagnetic method for detecting the route and the burial depth of the oil and gas pipeline has the following defects:
(1) when the electromagnetic method technology is actually used in a project, two persons need to operate simultaneously. One person holds the electromagnetic transmitter and the other person holds the electromagnetic signal receiver. The distance between the receiver and the transmitter is kept about 10m and the receiver and the transmitter stand opposite to each other. If the distance is too short, the receiver receives the signal directly transmitted by the transmitter instead of the secondary induction magnetic field excited by the measured pipeline. During engineering actual measurement, the distance between the receiver and the transmitter is too large, and the two persons walk synchronously and slowly, so that the operation is very inconvenient.
(2) The actual detection effect is related to the soil quality. The long-distance pipeline has complex surrounding environment, low soil moisture content, high resistivity and poor conductivity in partial areas; the secondary induced magnetic field measured by the receiver is weak. A great deal of practice proves that the electromagnetic method is extremely low in positioning precision when the pipeline trend is determined to be detected in winter in the north.
Fourth, the invention purpose and bright spot:
the invention aims to solve the problem of providing a method for determining spatial positions of the buried depth, the route trend and the like of a detected pipeline when a non-contact magnetic memory detection technology is applied to collecting a metal magnetic memory signal of the buried pipeline, so as to solve the defects of severe use conditions, easy environmental interference and the like of the existing electromagnetic method.
Fifthly, accompanying drawing explanation:
FIG. 1 is a schematic diagram of the relationship between the three-component distribution of the self-leakage magnetic field of the pipeline and the position of the pipeline in the present invention;
fig. 2 is a schematic view of a buried depth and trend detection method for a buried metal pipeline according to the present invention, in an embodiment, when a pipeline to be detected is located below between a left fluxgate sensor and a right fluxgate sensor, an upper magnetic field measurement is performed;
fig. 3 is a schematic diagram of measuring an upper magnetic field when a pipeline to be detected is located at the lower left of two fluxgate sensors according to the method for detecting the buried depth and the buried trend of a buried metal pipeline provided by the present invention.
Sixthly, description of the technical scheme (emphasis):
(1) the tester holds the specially-made three-axis fluxgate sensor magnetometer by hands, continuously walks along the axial direction of the pipeline at normal speed (usually between 3 km/h and 5 km/h) on the ground to detect magnetic signals; and acquiring three directional components of the pipeline self-leakage magnetic field of a detection position point where each three-component fluxgate sensor is positioned, and measuring the geomagnetic field of the position where the buried pipeline is positioned. And recording the magnetic signals into corresponding matched observation software by a data acquisition card.
The non-contact scanning magnetometer is composed of two three-axis fluxgate sensors. The two triaxial fluxgate sensors are arranged in an axis position alignment mode and fixed at two ends of a self-made cuboid plate. The plate is made of non-ferromagnetic materials such as aluminum alloy and wood. The distance between the two fluxgate sensors is the length of the plate, is marked as l, and can be obtained through measurement. This distance is simultaneously one of the reference lengths for the measurement calculation.
(2) In the matched observation software, the left side is respectively searchedMagnetic induction component B in vertical direction on the right two fluxgate sensorszThe value and direction of (A), the radial component B of the magnetic induction perpendicular to the axis of the pipeyThe magnitude and direction of (d).
(3) When a tester holds the non-contact scanning magnetometer to move along the axial direction of the pipeline, the transverse offset distances of the two fluxgate sensors at the left end and the right end from the central line of the pipeline are d respectivelys1And ds2. The distance between the center of the pipeline and the plane where the non-contact scanning magnetometer is positioned is dm。
The distance between two fluxgate sensors is l ═ ds1+ds2As known, the horizontal distance and the vertical distance of the buried pipeline relative to the sensor can be calculated by utilizing the geometric relation, and the height h of the sensor held by a detector and the ground is addedmSubstantially unchanged and measurable.
(4) If B isy1>0，By2>0, i.e. the radial component B of the magnetic induction intensity measured at the fluxgate sensors at the left and right endsyAll along the positive direction of the y axis, it indicates that the detected pipeline is located at the lower left of the non-contact scanning magnetometer, and the pipeline buried depth d can be calculated by the following equations (1) to (2):
d＝dm-hm-R (2)
if B isy1<0，By2>0, i.e. the radial component B of the magnetic induction measured at the left fluxgate sensory1The radial component B of the magnetic induction intensity measured at the right fluxgate sensor along the positive direction of the y axisy2In the negative y-axis direction. The detected pipeline is positioned under the non-contact scanning magnetometer, and the pipeline buried depth d can be calculated by the following formulas (3) to (4):
d＝dm-hm-R (4)
if B isy1<0，By2<0, i.e. the radial component B of the magnetic induction intensity measured at the fluxgate sensors at the left and right endsyAll along the negative direction of the y axis, it indicates that the detected pipeline is located at the lower right of the non-contact scanning magnetometer, and the pipeline buried depth d can be calculated by equations (5) to (6):
d＝dm-hm-R (6)
in three cases, the calculation methods of the lateral offset between the fluxgate sensors at the left end and the right end and the central line of the pipeline are the same, and are respectively calculated by the following formulas (7) to (8).
(5) In the actual detection process, a non-contact scanning magnetometer is used for continuously detecting and calculating the self-leakage magnetic field three-component magnetic induction intensity B of a plurality of measuring points of the pipeline on the ground above the pipelinex1、Bx2、Bx3、......Bxn；By1、By2、 By3、.......Byn；Bz1、Bz2、Bz3......Bzn. And (3) calculating the pipeline buried depth and the routing position of each point by applying the above formulas (1) to (8). And connecting all the point measurements with the calculated data to obtain the buried depth and the trend of the detected pipeline. The measurement and calculation results are automatically saved in the observation software in a file form.
Seventhly, the technical effects are as follows:
1. the invention relates to a matching auxiliary technology of non-contact magnetic memory detection of buried pipelines, which can carry out detection simultaneously. And according to the magnetic detection data recorded in real time, positioning a pipeline stress concentration area by combining the traveling mileage, namely positioning the position of the check pit to be excavated.
2. The invention can continuously measure the buried depth of the pipeline and record the position of the pipeline path. And the position and the trend of the underground pipeline are measured by adopting a non-excavation technology. And constructing a three-dimensional space position drawing containing the trend and elevation of the underground pipeline by combining the traveling mileage.
3. The method can assist the buried pipeline non-contact magnetic detection technology to judge and position the stress concentration area of the detected pipeline, and if the buried pipeline depth measured by the technology is greatly changed in a certain area, the possibility that the area is the stress concentration area is high.
4. The non-contact scanning magnetometer formed by the fluxgate sensor has the advantages of short detection period, good repeatability, convenient carrying of the detector, continuous detection in various complex environments and the like, effectively overcomes the defects of limited use conditions, large interference error and the like of the existing electromagnetic method, and reduces the equipment cost.
Claims (3)
1. A buried depth and trend detection method for buried metal pipelines is used for detecting and positioning pipelines and is characterized by comprising the following steps:
step 1, a detector holds a specially-made triaxial fluxgate sensor device, continuously walks along the axial direction of a pipeline at a speed of 3-5 km/h on the ground, collects three directional components of a pipeline self-leakage magnetic field of a detection position point where each three-component fluxgate sensor is located, and measures a geomagnetic field of a position where a buried pipeline is located;
step 2, respectively searching magnetic induction intensity components B in the vertical direction on the left fluxgate sensor and the right fluxgate sensor in matched observation softwarezThe value and direction of (A), the radial component B of the magnetic induction perpendicular to the axis of the pipeyThe magnitude and direction of (d);
step 3, if By1>0，By2>0, i.e. the radial component B of the magnetic induction intensity measured at the fluxgate sensors at the left and right endsyThe detected pipeline is positioned at the left lower part of the non-contact scanning magnetometer along the positive direction of the y axis; wherein l is the distance between the two fluxgate sensors; h ismThe height of the fluxgate sensor from the ground; r is the radius of the buried pipeline to be detected;
the buried depth d of the pipeline can be calculated by the following formula:
d＝dm-hm-R
step 4, if By1<0，By2>0, i.e. the radial component B of the magnetic induction measured at the left fluxgate sensory1The radial component B of the magnetic induction intensity measured at the right fluxgate sensor along the positive direction of the y axisy2Negative direction along the y-axis; the detected pipeline is positioned under the non-contact scanning magnetometer, and the pipeline buried depth d can be calculated by the following formula:
d＝dm-hm-R
step 5, if By1<0，By2<0, i.e. the radial component B of the magnetic induction intensity measured at the fluxgate sensors at the left and right endsyAll along the negative direction of the y axis, the pipeline to be detected is located at the lower right of the non-contact scanning magnetometer, and the pipeline buried depth d can be calculated by the following formula:
d＝dm-hm-R
and 6, under three conditions, the calculation methods of the transverse offset between the fluxgate sensors at the left end and the right end and the central line of the pipeline are the same, and the transverse offset is calculated according to the following formula:
step 7, continuously detecting and calculating the self-leakage magnetic field three-component magnetic induction intensity B of a plurality of measuring points of the pipeline on the ground above the pipeline by using a non-contact scanning magnetometerx1、Bx2、Bx3......Bxn；By1、By2、By3.......Byn；Bz1、Bz2、Bz3......Bzn(ii) a Calculating the pipeline buried depth and the routing position of each point by applying the steps 4 to 6; connecting all the point measurements with the calculated data to obtain the buried depth and the trend of the detected pipeline; the measurement and calculation results are automatically saved in the observation software in a file form.
2. The method for detecting the buried depth and the trend of the buried metal pipeline according to claim 1, wherein in the step 1, the left fluxgate sensor and the right fluxgate sensor are placed to satisfy the following relations:
the two triaxial fluxgate sensors are arranged in an axis position alignment mode and fixed at two ends of a self-made cuboid plate; the plate is made of aluminum alloy and wood non-ferromagnetic material; the distance between the two fluxgate sensors is the length of the plate, is marked as l, and can be directly measured.
3. The method for detecting the buried depth and the trend of the buried metal pipeline according to claim 1, wherein in the step 2, the position relationship between the pipeline to be detected and the two fluxgate sensors should satisfy the following relationship:
the transverse offset distances of the two fluxgate sensors at the left end and the right end from the central line of the pipeline are d respectivelys1And ds2(ii) a The distance between the center of the pipeline and the plane where the non-contact scanning magnetometer is positioned is dm(ii) a Height h between sensor held by detection personnel and groundmIs substantially unchanged and can be measured directly.
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| CN115875617A (en) * | 2021-09-28 | 2023-03-31 | 中国石油化工股份有限公司 | Method for detecting leakage point of sulfur-containing sewage pipeline |
| CN114199441B (en) * | 2021-12-17 | 2024-06-11 | 国家石油天然气管网集团有限公司 | Method, processor and apparatus for determining maximum service stress of buried pipeline |
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