CN111288883A - Method for detecting wall thickness of metal pipeline by transient electromagnetic method - Google Patents
Method for detecting wall thickness of metal pipeline by transient electromagnetic method Download PDFInfo
- Publication number
- CN111288883A CN111288883A CN201911338137.7A CN201911338137A CN111288883A CN 111288883 A CN111288883 A CN 111288883A CN 201911338137 A CN201911338137 A CN 201911338137A CN 111288883 A CN111288883 A CN 111288883A
- Authority
- CN
- China
- Prior art keywords
- pipeline
- wall thickness
- standard
- characteristic value
- transient electromagnetic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/02—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness
- G01B7/06—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness
- G01B7/10—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness using magnetic means, e.g. by measuring change of reluctance
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Abstract
The invention discloses a method for detecting the wall thickness of a metal pipeline by a transient electromagnetic method, which comprises the following steps: looking up information of a metal pipeline to be detected, determining the trend, the material and the size of the pipeline, manufacturing a standard pipeline test piece, optimizing a sensor according to the standard wall thickness, adopting a transient electromagnetic instrument to excite a step pulse as a transmitting signal, placing the selected sensor right above the standard pipeline test piece, collecting data of induced electromotive force attenuated along with time, and extracting a characteristic value called a standard characteristic value by utilizing an operation program; and detecting the position right above the pipeline to be detected by using a sensor, moving along the direction of the pipeline, continuously collecting induced electromotive force attenuation data, extracting a characteristic value, and calculating the metal loss of the corresponding pipeline by using the standard characteristic value and the characteristic value of the pipeline to be detected as a reference. The method disclosed by the invention is close to the actual detection working condition, the reliability of the reference datum data is high, the detection precision is high, the continuous data acquisition can be realized, the later-stage data imaging is facilitated, and the application range is wide.
Description
Technical Field
The invention relates to the technical field of nondestructive detection of the wall thickness of a metal pipeline, in particular to a method for detecting the wall thickness of the metal pipeline by a transient electromagnetic method.
Background
The pipeline wall thickness is reduced directly caused by corrosion along with the gradual corrosion of the underground pipeline due to the extension of the online service time, and potential safety hazards exist to people and the surrounding environment for the pressure operation pipeline. At present, the detection for the corrosion of the buried metal pipeline in China is mainly carried out through excavation, anti-corrosion layer stripping, ultrasonic thickness measurement, anti-corrosion layer repairing and backfilling, the detection cost is high, and the working efficiency is low. Although the detection in the pipeline is convenient to operate, the normal operation of the pipeline is influenced, a pipe cleaning process is required before the detection, and the requirements on the size of the pipe diameter and the straightness of the pipeline are high.
The traditional calculation method of the residual wall thickness of the buried metal pipeline is to obtain a theoretical curve of the pipeline to be detected by a forward method, compare a signal curve measured on site with the theoretical curve, and calculate the residual wall thickness of the pipeline by difference, wherein the following theoretical model of the traditional forward method is as follows:
in the formula:
is a measuring point signal; b is the outer radius of the cross section of the pipeline; n isTThe number of turns of the transmitting loop; n isRThe number of turns of the receiving loop;
respectively the values of the external diameter of pipeline, the side length of transmitting coil and the side length of receiving coil after the burial depth is normalized, L (α tau) is the transient response function of the pipeline to be measured, nkb is a zero-order Bessel function J (n)kb) Zero value solution of (d), tau is time, α comprehensive time constant of measured pipeline, muD、σDIs the magnetic permeability and the electric conductivity of the equivalent column. From the above forward modeling process, it can be seen that the conventional forward algorithm has the following disadvantages:
(1) the traditional positive algorithm is carried out on the premise that the physical properties (magnetic permeability and electric conductivity) of the metal pipeline are national standard, but for the metal pipeline which is in a complex underground environment for a long time, the physical properties of the pipeline are obviously changed under the combined action of the manufacturing process error and the external environment;
(2) the traditional forward algorithm is subject to the pipeline burial depth, so that the pipeline sections with larger burial depth difference need to be classified, different forward modeling theoretical models are respectively established, and thus, higher requirements on data processing are met.
Based on the above analysis, the conventional correction algorithm cannot guarantee the detection accuracy.
Disclosure of Invention
In order to solve the technical problems, the invention aims to provide a method for detecting the wall thickness of a metal pipeline by a transient electromagnetic method, which is used for detecting the wall thickness of the metal pipeline based on attenuation characteristic quantity of a signal in a time domain-amplitude value, not only solving the problems of high cost, complex process and the like of the traditional detection technology, but also realizing the thickness measurement of the pipeline with a non-metal coating or an anticorrosive coating and ensuring the accuracy of a detection result.
In order to achieve the purpose, the invention adopts the technical scheme that:
a method for detecting the wall thickness of a metal pipeline by a transient electromagnetic method comprises the following steps;
step1, looking up information of the pipeline to be tested, and determining the trend, the material and the wall thickness d of the pipeline;
step2. making two walls of thickness dmAnd dnWherein dmThe wall thickness d of the pipeline to be detected is the same, and a transient electromagnetic instrument is used for detecting to obtain output signals of two pipeline standard test pieces;
and Step3, extracting standard characteristic values of the output signals by using a computer program, and respectively finding out the standard characteristic values k of the two pipeline standard test piecesmAnd kn；
Step4, determining a measuring point according to the trend information of the pipeline to be measured obtained by looking up (A)1A2……..An) Using a transient electromagnetic instrument for each measurement point (A)1,A2……..An) Detecting and processing the output signal to obtain the attenuation rate k of the characteristic valuei，i＝1，2，3…n；
Step5. Using the two standard wall thicknesses (d) described abovem，dn) And the eigenvalue decay Rate (k)m，kn) And determining a correction coefficient α value as a reference, and obtaining the wall thickness of the pipeline to be measured by taking a standard test piece with the same wall thickness as the pipeline to be measured as a calculation reference.
Preferably, the extracting the feature value in Step3 includes the steps of:
the Step3.1 output signal has 30 measurement data (a)1,a2……..a30) Composition is carried out; and carrying out noise reduction and filtering processing on the output signal.
Step3.2 groups the processed signals, and each data point is divided into 25 groups (Mj, j is 1, 2, 3 … 25) of 5 data points, and each data group includes Mj { aj, aj +1 … ….. aj +4 }; using y as AekxFitting was performed to extract the attenuation ratio (ki, i ═ 1, 2, 3 … 25), where y: output signal, a: data set signal amplitude, k: attenuation rate, x: and outputting the attenuation time of the signal.
Step3.3 vs. extracted decay Rate kiThe numerical value is subjected to difference processing to obtain the attenuation rate k with the maximum differencemaxAs the standard characteristic value of the pipeline.
Preferably, in Step5, the method comprises the following steps:
step5.1 Standard test piece wall thickness (d) through pipelinem，dn) And (k)m，kn) Using the formula
Calculating a correction coefficient α value;
step5.2 Standard wall thickness dmAnd a standard characteristic value kmAs a calculation reference, a formula is used
Calculate the pipeline d to be measuredi。
The invention has the beneficial effects that:
according to the method for detecting the wall thickness of the metal pipeline by the transient electromagnetic method, the buried metal pipeline does not need to be excavated, and special treatment is not needed; the calculation reference is determined by using the same material size of the pipeline in the actual working condition, so that the accuracy of the calculation reference is ensured. The sensor continuously moves in the detection process, two-dimensional imaging can be generated on the continuous wall thickness in the later stage, the detection and scanning of the wall thickness of the metal pipeline are combined together, the wall thickness real-time monitoring and imaging of the metal pipeline to be detected on site are realized, and the safe and stable operation of the pipeline is ensured.
Drawings
FIG. 1 is a flow chart of wall thickness detection of a pipe to be detected.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
Step1, looking up information of the pipeline to be tested, and determining the trend, material and size of the pipeline;
step2, manufacturing two pipeline standard test pieces with different wall thicknesses according to the standard wall thickness dmAnd dnSelecting appropriate sensor, standard wall thickness dmThe thickness of the pipe wall is consistent with that of the pipe wall to be measured;
step3, adopting step type pulse excited by a transient electromagnetic instrument as a transmitting signal;
step4, placing the selected sensor right above the pipeline standard test piece to obtain induced electromotive force attenuation data, and extracting a standard characteristic value k by utilizing an operation programmAnd kn；
Step5, placing the sensor right above the pipeline to be detected, moving along the pipeline direction, continuously collecting induced electromotive force attenuation data, and extracting a characteristic value ki(k0，k1k2……..kn)；
Step6. use the two standard wall thicknesses dmAnd dnAnd determining a correction coefficient α value by taking the standard characteristic value as a reference, and calculating to obtain the wall thickness of the pipeline to be measured.
Preferably, the extracting the feature value in Step4 includes the steps of:
step4.1, carrying out noise reduction processing on the acquired data;
step4.2 adopts y ═ Ae for the data after noise reduction processingkxFitting is carried out;
and (5) performing optimal processing on the fitting result by Step4.3, and extracting a characteristic value k.
Preferably, in Step6, the method comprises the following steps:
step6.1 Standard test piece wall thickness (d) through pipelinem，km) And (d)n，kn) Using the formula
Calculate outCorrection factor α value;
step6.2 adopted a standard wall thickness dmAnd a standard characteristic value kmAs a calculation reference, a formula is used
Calculate the pipeline d to be measuredi。
A method for detecting the wall thickness of a metal pipeline by a transient electromagnetic method comprises the following steps: looking up information of a metal pipeline to be detected, determining the trend, the material and the size of the pipeline, manufacturing a standard pipeline test piece, optimizing a sensor according to the standard wall thickness, adopting a transient electromagnetic instrument to excite a step pulse as a transmitting signal, placing the selected sensor right above the standard pipeline test piece, collecting data of induced electromotive force attenuated along with time, and extracting a characteristic value called a standard characteristic value by utilizing an operation program; and detecting the position right above the pipeline to be detected by using a sensor, moving along the direction of the pipeline, continuously collecting induced electromotive force attenuation data, extracting a characteristic value, and calculating the metal loss of the corresponding pipeline by using the standard characteristic value and the characteristic value of the pipeline to be detected as a reference. The method disclosed by the invention is close to the actual detection working condition, the reliability of the reference datum data is high, the detection precision is high, the continuous data acquisition can be realized, the later-stage data imaging is facilitated, and the application range is wide.
Claims (3)
1. A method for detecting the wall thickness of a metal pipeline by a transient electromagnetic method is characterized by comprising the following steps;
step1, looking up information of the pipeline to be tested, and determining the trend, the material and the wall thickness d of the pipeline;
step2. making two walls of thickness dmAnd dnWherein dmThe wall thickness d of the pipeline to be detected is the same, and a transient electromagnetic instrument is used for detecting to obtain output signals of two pipeline standard test pieces;
and Step3, extracting standard characteristic values of the output signals by using a computer program, and respectively finding out the standard characteristic values k of the two pipeline standard test piecesmAnd kn；
Step4. determining measuring point of pipeline trend information to be measured (A)1A2……..An) Using a transient electromagnetic instrument for each measurement point (A)1,A2……..An) Detecting and processing the output signal to obtain the attenuation rate k of the characteristic valuei，i＝1，2，3…n；
Step5. Using the two standard wall thicknesses (d) described abovem，dn) And the eigenvalue decay Rate (k)m，kn) And determining a correction coefficient α value as a reference, and obtaining the wall thickness of the pipeline to be measured by taking a standard test piece with the same wall thickness as the pipeline to be measured as a calculation reference.
2. The method for detecting the wall thickness of the metal pipeline by the transient electromagnetic method as claimed in claim 1, wherein the Step3 for extracting the characteristic value comprises the following steps:
the Step3.1 output signal has 30 measurement data (a)1,a2……..a30) Composition is carried out; and carrying out noise reduction and filtering processing on the output signal.
Step3.2 groups the processed signals, and each data point is divided into 25 groups (Mj, j is 1, 2, 3 … 25) of 5 data points, and each data group includes Mj { aj, aj +1 … ….. aj +4 }; using y as AekxFitting was performed to extract the attenuation ratio (ki, i ═ 1, 2, 3 … 25), where y: output signal, a: data set signal amplitude, k: attenuation rate, x: and outputting the attenuation time of the signal.
Step3.3 vs. extracted decay Rate kiThe numerical value is subjected to difference processing to obtain the attenuation rate k with the maximum differencemaxAs the standard characteristic value of the pipeline.
3. The transient electromagnetic method for detecting the wall thickness of a metal pipeline according to claim 1, wherein in Step5, the method comprises the following steps:
step5.1 Standard test piece wall thickness (d) through pipelinem，dn) And (k)m，kn) Using the formula
Calculating a correction coefficient α value;
step5.2 use a standard wallThickness dmAnd a standard characteristic value kmAs a calculation reference, a formula is used
Calculate the pipeline d to be measuredi。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911338137.7A CN111288883A (en) | 2019-12-23 | 2019-12-23 | Method for detecting wall thickness of metal pipeline by transient electromagnetic method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911338137.7A CN111288883A (en) | 2019-12-23 | 2019-12-23 | Method for detecting wall thickness of metal pipeline by transient electromagnetic method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111288883A true CN111288883A (en) | 2020-06-16 |
Family
ID=71022286
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911338137.7A Pending CN111288883A (en) | 2019-12-23 | 2019-12-23 | Method for detecting wall thickness of metal pipeline by transient electromagnetic method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111288883A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106596715A (en) * | 2017-01-20 | 2017-04-26 | 西安石油大学 | Array type transient electromagnetic method multi-layer pipe column damage detection system and array type transient electromagnetic method multi-layer pipe column damage detection method |
| EP3055504B1 (en) * | 2013-10-07 | 2018-09-26 | Guardian Global Technologies Limited | Downhole detection tool |
| CN109211153A (en) * | 2018-11-16 | 2019-01-15 | 中冶建筑研究总院有限公司 | A kind of measurement method of body structure surface strain |
| CN109668505A (en) * | 2019-01-09 | 2019-04-23 | 中国石油大学(华东) | A kind of pulse ACFM ferromagnetic metal structure wall thickness measurement method |
| CN109764800A (en) * | 2019-01-15 | 2019-05-17 | 西南石油大学 | A kind of corrosive pipeline wall thickness detecting system based on vortex thermal imaging array |
| CN108415081B (en) * | 2018-02-27 | 2020-02-11 | 山东大学 | Method for transient electromagnetic detection of terrestrial Japanese heritage chemical warfare |
-
2019
- 2019-12-23 CN CN201911338137.7A patent/CN111288883A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3055504B1 (en) * | 2013-10-07 | 2018-09-26 | Guardian Global Technologies Limited | Downhole detection tool |
| CN106596715A (en) * | 2017-01-20 | 2017-04-26 | 西安石油大学 | Array type transient electromagnetic method multi-layer pipe column damage detection system and array type transient electromagnetic method multi-layer pipe column damage detection method |
| CN108415081B (en) * | 2018-02-27 | 2020-02-11 | 山东大学 | Method for transient electromagnetic detection of terrestrial Japanese heritage chemical warfare |
| CN109211153A (en) * | 2018-11-16 | 2019-01-15 | 中冶建筑研究总院有限公司 | A kind of measurement method of body structure surface strain |
| CN109668505A (en) * | 2019-01-09 | 2019-04-23 | 中国石油大学(华东) | A kind of pulse ACFM ferromagnetic metal structure wall thickness measurement method |
| CN109764800A (en) * | 2019-01-15 | 2019-05-17 | 西南石油大学 | A kind of corrosive pipeline wall thickness detecting system based on vortex thermal imaging array |
Non-Patent Citations (1)
| Title |
|---|
| 张涛: "基于脉冲涡流对埋地金属管道缺陷定量算法研究", 《电子测量技术》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108918660B (en) | Nondestructive detection method for sleeve grouting fullness of steel bar sleeve grouting connection joint | |
| CN103063737B (en) | Coiled tubing magnetic method detection method | |
| CN104990977A (en) | Three-dimensional magnetic flux leakage inspection and defect compound inversion imaging method | |
| CN206208832U (en) | A kind of coiled tubing on-line measuring device | |
| CN103268802A (en) | Magnetizing device and detecting method for detecting corrosion condition of underground metal pipelines | |
| CN110346454A (en) | Concrete superficial layer ultrasound surface wave detection method based on arranged type ultrasonic vibration source | |
| CN202420427U (en) | Signal detection system for electromagnetic thickness gauge | |
| CN104389586A (en) | Oil well working fluid level measuring device and method | |
| CN107850570A (en) | Defect testing method, defect testing device and inspection probe | |
| CN103196991B (en) | The all standing transient electromagnetic detection method of the metal erosion of continuous diagnosis body and defect | |
| Zhao et al. | A novel ACFM probe with flexible sensor array for pipe cracks inspection | |
| CN102537668B (en) | Method for determining ground mark time of inner detector of pipeline | |
| CN105092691A (en) | Quantitative detection method and detector for detecting accumulated oxide scales in pipelines | |
| CN108181377B (en) | Intelligent interpretation system and method for broken PCCP steel wire | |
| CN106526078A (en) | Radon gas-geogas combined measurement method for extracting deep uranium mineralization information | |
| CN111288883A (en) | Method for detecting wall thickness of metal pipeline by transient electromagnetic method | |
| CN102520064B (en) | Time reversal focusing method-based method for judging size of pipeline defect | |
| CN102518422A (en) | Method for detecting and identifying current stress state of downhole casing pipe of oil field | |
| CN106195648B (en) | A kind of experimental test procedures of the equivalent pipe range of reducer pipe | |
| CN115451800A (en) | Testing method of portable field testing imager for cement electric pole | |
| RU2586261C2 (en) | Device for magnetic flaw detector and method of reducing error in determining size of defects of pipeline magnetic flaw detectors | |
| RU143552U1 (en) | DEVICE FOR MEASURING THE DEBIT OF PRODUCTS OF GAS-CONDENSATE WELLS | |
| CN211348655U (en) | Automatic storage type underground electromagnetic detection device | |
| CN111197471B (en) | Transient electromagnetic detection calculation model and detection method for underground screen pipe | |
| CN112098306A (en) | Steel bar corrosion detection device based on spontaneous magnetic flux leakage |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200616 |
|
| RJ01 | Rejection of invention patent application after publication |