CN112281165A - A multifunctional polarization probe for cathodic protection oil and gas pipelines and using method thereof - Google Patents

A multifunctional polarization probe for cathodic protection oil and gas pipelines and using method thereof Download PDF

Info

Publication number
CN112281165A
CN112281165A CN202011380352.6A CN202011380352A CN112281165A CN 112281165 A CN112281165 A CN 112281165A CN 202011380352 A CN202011380352 A CN 202011380352A CN 112281165 A CN112281165 A CN 112281165A
Authority
CN
China
Prior art keywords
test piece
polarization
pipeline
test
cathodic protection
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
Application number
CN202011380352.6A
Other languages
Chinese (zh)
Inventor
闫茂成
林俊岭
马永超
范卫华
王彬彬
石薇
李欣
张倩
邱萌
杨永吉
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Institute of Corrosion Science and Technology
Original Assignee
Institute of Corrosion Science and Technology
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Institute of Corrosion Science and Technology filed Critical Institute of Corrosion Science and Technology
Priority to CN202011380352.6A priority Critical patent/CN112281165A/en
Publication of CN112281165A publication Critical patent/CN112281165A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
    • C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
    • C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
    • C23F13/08—Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
    • C23F13/22—Monitoring arrangements therefor
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F2213/00—Aspects of inhibiting corrosion of metals by anodic or cathodic protection
    • C23F2213/30—Anodic or cathodic protection specially adapted for a specific object
    • C23F2213/32—Pipes

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
  • Prevention Of Electric Corrosion (AREA)

Abstract

The invention belongs to the field of monitoring and detecting of cathode protection of buried pipelines, and relates to a multifunctional polarization probe for a cathode protection oil-gas pipeline and a using method thereof. The shell of the probe comprises a PVC shell, a PVC end socket and epoxy resin insulation filler, wherein the lower end of the cylindrical PVC shell is inserted into a groove-shaped protective cap, the upper end of the PVC shell is sealed by an annular PVC end socket, and a hole is formed in the center of the PVC end socket; the self-corrosion test piece, the first polarization test piece, the double-salt bridge reference electrode and the second polarization test piece are arranged on the upper surface of the protective cap in the PVC shell, the epoxy resin insulating filler is filled in the PVC shell, each polarization test piece and the double-salt bridge reference electrode are fixed inside the PVC shell, and the lower surfaces of each polarization test piece, the double-salt bridge reference electrode and the epoxy resin insulating filler are positioned on the same horizontal plane with the lower end surface and the inner bottom surface of the protective cap of the PVC shell. The invention is used for long-term on-line detection of the cathode protection effectiveness and the stray current interference level of the buried pipeline.

Description

Multifunctional polarization probe for cathodic protection oil and gas pipeline and use method thereof
Technical Field
The invention belongs to the field of monitoring and detecting of cathode protection of buried pipelines, and relates to a multifunctional polarization probe for a cathode protection oil-gas pipeline and a using method thereof.
Background
The polarization potential is the true protection potential of the buried cathodic protection pipeline and is an important index for evaluating the effectiveness of cathodic protection of the pipeline. In general, the potential difference between the pipe and the reference electrode, measured by placing the reference electrode in the soil near the pipe, i.e., the energizing potential, is not equal to the true polarization potential of the pipe due to the presence of the IR drop. Partial errors can be eliminated by adopting a power-off method for measurement, but in some cases, the power-off potential still has larger errors with the real polarization potential of the pipeline, and the errors are caused by IR drop. In addition, when dynamic stray current exists in the environment, the ground potential gradient is large, and particularly near the defect point of the anticorrosive coating, so that the position of the reference electrode has great influence on the test result; in some cases, even if the dc stray current interference is small, the on-site tested pipe-to-ground potential may contain a large IR drop, which makes the measurement of the pipe potential and the evaluation of the effectiveness of the cathodic protection difficult.
The traditional pipeline outage potential test needs to synchronously interrupt an impressed current power supply, and along with the increasing complexity of the pipeline service environment, for example, the external current cannot be completely disconnected under various conditions that a sacrificial anode is directly connected with a pipeline, a drainage device is arranged on the pipeline and the like, so that the pipeline outage method test cannot be implemented. Adopting a polarization probe to carry out potential measurement, burying the polarization probe near a pipeline, simulating a pipeline anticorrosive layer defect point by a polarization test piece in the polarization probe, connecting the test piece and the pipeline through a test pile, and fully polarizing the test piece and the pipeline as well; during measurement, the test piece is instantaneously disconnected from the pipeline, so that the power-off potential test is realized under the condition that all power supplies on the pipeline are not disconnected. The polarized probe method is the measurement technique which is most commonly used for eliminating IR drop and measuring the cathodic protection polarization potential of the pipeline which is closest to the true value.
The polarization test block is the most effective means for evaluating the effectiveness of the cathodic protection of the pipeline, but a plurality of problems still exist in the practical application process, and the influence of the test block area on the test result and the polarization state of the measured pipeline is not clear. In practical application, the area of the test piece is supposed to be the representative area of the defect of the anticorrosive layer on the surface of the pipeline. The area of the test piece is determined according to the type of the anticorrosive coating, the construction quality, the environment of the pipeline and the construction period, and the area of the test piece is generally 1cm2～50cm2In the meantime. The area of the test piece is too small, the difference between the contact resistance of the test piece and soil and the defect of the pipeline coating is too large, the corrosion characteristics are different, and the actual protection condition of the pipeline cannot be represented; if the area of the test strip is too large, the IR drop may cause the result to be distorted, or the protection current to be excessively lost, thereby changing the cathode protection state of the tube. The defect point of the polyethylene (3PE) anticorrosive coating for simulating the newly-built three-layer structure generally adopts 6.5cm2The area of the polarized test piece is 1.0cm when the polarized test piece is used for measuring the alternating current interference parameter2. Currently, on-off potential test is carried out on site, generally, only a polarization probe of a polarization test piece with a single size is embedded, if alternating current interference is detected on a site pipeline in the later stage, alternating current density and alternating current interference potential need to be collected, excavation needs to be carried out again, and then the polarization test piece is embedded with the area of 1.0cm2The polarization probe not only increases the excavation construction and monitoring cost, but also is not beneficial to later data acquisition.
When the traditional polarization probe is used, electrolyte in the reference electrode can gradually leak, so that the reference electrode and the polarization probe are failed; meanwhile, the leaked electrolyte can change the environment of the test piece, when the copper sulfate electrolyte is in contact with the test piece, a displacement reaction can occur, the surface of the test piece is covered by copper, the polarization characteristic of the test piece is changed, and the reference electrode is not easy to perceive when the potential of the reference electrode drifts. Therefore, there is a need to develop a multifunctional polarization probe and a using method thereof, which can select or replace the area of a polarization test piece according to the pipe interference condition and the coating condition in different periods, and the double-salt bridge reference electrode can effectively avoid the pollution of the test piece caused by the leakage of the traditional reference electrode, thereby ensuring the long-term stability of the probe test and being used for comprehensively evaluating the pipe interference level and the cathode protection effectiveness.
Disclosure of Invention
The invention aims to provide a multifunctional polarization probe for a cathodic protection oil and gas pipeline and a using method thereof, which are used for long-term online detection of the cathodic protection effectiveness and the stray current interference level of a buried pipeline.
The technical scheme of the invention is as follows:
the utility model provides a multi-functional polarization probe of cathodic protection oil gas pipeline, includes from corrosion test piece, first polarization test piece, double salt bridge reference electrode, second polarization test piece, protective cap, casing, and concrete structure is as follows:
the shell comprises a PVC shell, a PVC end socket and epoxy resin insulation filler, the lower end of the cylindrical PVC shell is inserted into the groove-shaped protective cap, the upper end of the PVC shell is sealed by the annular PVC end socket, and a hole is formed in the center of the PVC end socket; the self-corrosion test piece, the first polarization test piece, the double-salt bridge reference electrode and the second polarization test piece are arranged on the upper surface of the protective cap in the PVC shell, the epoxy resin insulating filler is filled in the PVC shell, each polarization test piece and the double-salt bridge reference electrode are fixed inside the PVC shell, and the lower surfaces of each polarization test piece, the double-salt bridge reference electrode and the epoxy resin insulating filler are positioned on the same horizontal plane with the lower end surface and the inner bottom surface of the protective cap of the PVC shell.
The multifunctional polarization probe for the cathodic protection oil and gas pipeline further comprises a test wire, the test wire is a four-core cable, the test wire penetrates out of the center hole of the annular PVC seal head at the upper end of the shell, the four-core cable comprises a green wire, a red wire, a light blue wire and a yellow wire, the green wire is connected with a self-corrosion test piece, the red wire is connected with a first polarization test piece, the light blue wire is connected with a second polarization test piece, and the yellow wire is connected with a double-salt-bridge reference electrode.
The multifunctional polarization probe for cathodic protection oil-gas pipeline has a self-corrosion test piece with an area of 1.0cm2The circular test piece is used for testing the self-corrosion potential of the pipeline near the buried point; the first polarization test piece has an area of 1.0cm2The round test piece is used for testing the alternating current potential and the alternating current interference density of the pipeline; the second polarization test piece has an area of 6.5cm2The square test piece is used for testing the on-off potential of the pipeline; the three polarization test pieces are made of the same material of the pipeline, and the surface roughness Ra of the three polarization test pieces is less than or equal to 0.1 mu m.
The multifunctional polarization probe of the cathodic protection oil-gas pipeline is characterized in that a double-salt bridge reference electrode is saturated Cu/CuSO4And an electrode.
The multifunctional polarization probe of the cathodic protection oil-gas pipeline is characterized in that the protective cap is made of silica gel.
The application method of the multifunctional polarization probe for the cathodic protection oil and gas pipeline is characterized in that the multifunctional polarization probe for the cathodic protection oil and gas pipeline is used for monitoring and detecting the cathodic protection effectiveness of a buried pipeline, and the installation, wiring and test processes are as follows:
1) mounting of
The multifunctional polarization probe for the cathodic protection oil and gas pipeline is vertically buried in soil, the distance between the multifunctional polarization probe for the cathodic protection oil and gas pipeline and the pipeline is 0.1-0.3 m, a protective cap is taken down, the buried depth and the backfill state of the multifunctional polarization probe for the cathodic protection oil and gas pipeline are the same as those of the pipeline, and the multifunctional polarization probe for the cathodic protection oil and gas pipeline is ensured to be in close contact with the soil and be polarized sufficiently;
2) wiring
Selecting one or two test lines of a red line led out by the first polarization test piece and a light blue line led out by the second polarization test piece according to requirements, and connecting the test lines to corresponding terminals in a test pile junction box of the test pile; the terminal of the polarization test block is connected with the terminal of the protected pipeline by a conductive copper sheet, so that the polarization test block is polarized as same as the pipeline; a green line led out from the corrosion test piece and a yellow line led out from the double-salt bridge reference electrode are respectively led into corresponding binding posts of the junction box of the test pile, and then the connection of the test lines is completed;
3) testing
Before measurement, the cathode protection operation is determined to be normal, each polarization test piece is communicated with the pipeline, and the pipeline and each polarization test piece are fully polarized;
and (3) testing the electrified potential: before testing, ensuring that the polarization test piece is sufficiently polarized, adopting a digital multimeter direct-current voltage range under the continuous application of cathodic protection current, connecting the positive pole of the multimeter with a polarization test piece wiring terminal, connecting the negative pole of the multimeter with a reference electrode wiring terminal in a test pile, and recording the electrified potential of the polarization test piece under cathodic protection;
power-off potential: the wiring mode of the digital multimeter is tested with the electrified potential, during the measurement, the conductive copper sheet is disconnected, the cathodic protection current of the polarization test piece is disconnected at the moment, and the potential test value is read within 0.5 s-1 s, namely the power-off potential of the polarization test piece relative to the reference electrode;
self-corrosion potential test: the positive electrode of the multimeter is connected with the self-corrosion test piece wiring terminal, the negative electrode of the multimeter is connected with the reference electrode wiring terminal in the test pile, and the self-corrosion potential is recorded;
and (3) testing alternating current interference parameters: the alternating voltage or alternating current gear of the digital multimeter is adopted, the synchronous test curve function is selected for long-time detection, the anode of the multimeter is connected with a polarization test piece wiring terminal, the cathode of the multimeter is connected with a reference electrode wiring terminal in the test pile, and a corresponding test value or a corresponding test curve is recorded.
The use method of the multifunctional polarization probe for the cathodic protection oil-gas pipeline is characterized in that 8 binding posts are arranged in the test pile junction box, wherein: the wiring terminal I is a wiring terminal of a protected pipeline B and is connected with the protected pipeline B through a circuit; the binding post II is a binding post of the protected pipeline B and is connected with the protected pipeline B through a circuit; the wiring terminal III is a wiring terminal of the protected pipeline B and is connected with the protected pipeline B through a circuit; binding post for standby; the binding post is a polarization test piece binding post and is connected with one or two test lines of a red line led out by the first polarization test piece 2 and a light blue line led out by the second polarization test piece 4; the binding post is connected with a yellow line led out from the double-salt bridge reference electrode 3; the binding post is connected with a green line led out from the corrosion test piece 1; the binding post (B) is ready for use.
The design idea of the invention is as follows:
considering that the traditional polarization probe has a single test piece area, and the influence of the polarization test piece area on the test result and the polarization state of the measured pipeline is unclear; the invention designs a polarization probe, which realizes the selection of the quantity and the area of a polarization test piece, and the double-salt bridge reference electrode can ensure the long-term effect and the stability of the reference electrode, so that the probe can be used for the cathodic protection multi-parameter measurement of an oil-gas pipeline.
The invention has the advantages and beneficial effects that:
1. the invention encapsulates two polarized test pieces with different sizes and one self-corrosion test piece, and can select three polarized test pieces with different sizes to realize different testing functions according to the field working condition, and the self-corrosion test piece can collect self-corrosion potential.
2. The double-salt bridge reference electrode ensures the stability and precision of the test, can effectively avoid the problem of pollution to a test piece caused by leakage of the traditional reference electrode, and ensures the long-term stability of the probe test.
3. The invention can measure the on-off potential and the self-corrosion potential of the cathode protection of the oil and gas pipeline, and can also measure the alternating current potential and the alternating current density under the environment with alternating current interference.
4. The structural design of the invention ensures that the multifunctional probe for the cathodic protection oil and gas pipeline can be used for measuring the electrified potential, the power-off potential and the self-corrosion potential of the cathodic protection of the oil and gas pipeline, can also be used for measuring the alternating current potential and the alternating current density of a test piece in an alternating current and direct current interference environment, and is used for comprehensively evaluating the interference level of the pipeline and the effectiveness of cathodic protection.
Drawings
FIG. 1 is a schematic structural view of a multifunctional polarization probe for cathodic protection of oil and gas pipelines.
FIG. 2 is a schematic view of the multi-functional polarized probe for cathodic protection of oil and gas pipelines in the present invention.
FIG. 3 is a schematic diagram of the connection of the multifunctional polarization probe installation test line of the cathodic protection oil-gas pipeline of the invention.
In the figure, 1, a self-etching test piece; 2. a first polarization test piece; 3. a double salt bridge reference electrode; 4. a second polarization test piece; 5. a protective cap; 6. a housing; 61. a PVC housing; 62. PVC end socket; 63. an epoxy insulating filler; 7. a test line; 8. a conductive copper sheet; A. a multifunctional polarization probe for cathodic protection oil and gas pipelines; B. a pipeline; C. testing the pile; D. and (5) testing the pile junction box.
Detailed Description
As shown in fig. 1-3, the multifunctional polarization probe for cathodic protection of oil and gas pipelines of the present invention mainly comprises a self-corrosion test piece 1, a first polarization test piece 2, a double salt bridge reference electrode 3, a second polarization test piece 4, a protective cap 5, a housing 6, a test line 7, etc., and has the following specific structure:
the shell 6 comprises a PVC shell 61, a PVC end socket 62 and an epoxy resin insulating filler 63, the PVC shell 61 is a PVC cylinder with the wall thickness of 6mm, the lower end of the PVC shell 61 is inserted into the groove-shaped protective cap 5, the upper end of the PVC shell 61 is sealed by the annular PVC end socket 62, and the center of the PVC end socket 62 is provided with a hole. The self-corrosion test piece 1, the first polarization test piece 2, the double-salt bridge reference electrode 3 and the second polarization test piece 4 are arranged on the upper surface of the protective cap 5 in the PVC shell 61, the epoxy resin insulating filler 63 is filled in a filling mode, each polarization test piece and the double-salt bridge reference electrode 3 are fixed inside the PVC shell 61, the lower surfaces of each polarization test piece, the double-salt bridge reference electrode 3 and the epoxy resin insulating filler 63 are positioned on the same horizontal plane with the lower end face of the PVC shell 61 and the inner bottom face of the protective cap 5, and the epoxy resin insulating filler 63 fixes the positions of each polarization test piece and the double-salt bridge reference electrode 3 and ensures insulation.
The test wire 7 is a four-core cable, and the test wire 7 penetrates out from the central hole of the annular PVC seal head 62 at the upper end of the shell 6, so that the test and connection functions are achieved. In the four-core cable, a green line is connected with a self-corrosion test piece 1, a red line is connected with a first polarization test piece 2, a light blue line is connected with a second polarization test piece 4, and a yellow line is connected with a double-salt bridge reference electrode 3.
The area of the self-corrosion test piece 1 is 1.0cm2The circular test piece is used for testing the self-corrosion potential of the pipeline near the buried point; the first polarization test piece 2 has an area of 1.0cm2The round test piece is used for testing the alternating current potential and the alternating current interference density of the pipeline; the second polarization test piece 4 has an area of 6.5cm2And the square test piece is used for testing the on-off potential of the pipeline. Tubes for all three polarization test piecesThe same material, the surface roughness Ra of the three polarization test pieces is less than or equal to 0.1 μm, and the size, the shape and the number of the polarization test pieces can be determined according to actual requirements.
The double-salt bridge reference electrode 3 is saturated Cu/CuSO4The electrode comprises an inner tube body and an outer tube body and is provided with two independent liquid junctions. On one hand, the problems of liquid leakage pollution and failure of the traditional polarization probe, or the problem that pollutants enter the reference electrode in a counter-current manner in the environment and the like to cause test data distortion can be effectively avoided; on the other hand, the service life of the reference electrode can be prolonged, and the long-term effect can be realized.
The protective cap 5 is made of silica gel, and can buffer the collision in the transportation and construction processes and protect the surfaces of the polarization test pieces and the reference electrode.
As shown in fig. 1-3, the multifunctional polarization probe for cathodic protection oil and gas pipelines of the invention is used for monitoring and detecting the cathodic protection effectiveness of buried pipelines, and the burying, wiring and testing processes comprise:
1) mounting of
The multifunctional polarization probe A for the cathodic protection oil-gas pipeline is vertically buried in soil, the distance between the multifunctional polarization probe A for the cathodic protection oil-gas pipeline and the pipeline B is 0.1-0.3 m, the protective cap 5 is taken down, the buried depth and the backfilling state of the multifunctional polarization probe A for the cathodic protection oil-gas pipeline are the same as those of the pipeline B, and the multifunctional polarization probe A for the cathodic protection oil-gas pipeline is ensured to be in close contact with the soil, so that the multifunctional polarization probe A for the cathodic protection oil-gas pipeline is polarized sufficiently.
2) Wiring
According to the requirement, one or two test lines of the red line led out by the first polarization test piece 2 and the light blue line led out by the second polarization test piece 4 can be selected to be connected on the corresponding terminal post in the test pile terminal box D of the test pile C. If a test line is connected, the area of the test piece is the area of the polarized test piece corresponding to the test line; if two test lines are connected, the area of the test strip is the sum of the areas of the two polarized test strips. This means that 1.0cm can be selected2、6.5cm2And 7.5cm2Three sizes polarize the test piece. The terminal of the polarization test block is connected with the terminal of the protected pipeline by a conductive copper sheet 8, so that the polarization test block is polarized as same as the pipeline. Green lines and pairs led out from the corrosion test piece 1And (3) respectively introducing yellow lines led out from the salt bridge reference electrode 3 into corresponding binding posts of the junction box D of the test pile, and completing the connection of the test lines.
Description of connection of terminal post in terminal box
As shown in fig. 3, in this embodiment, 8 binding posts are arranged in the test pile junction box D, wherein: the wiring terminal I is a wiring terminal of a protected pipeline B and can be connected with the protected pipeline B through a circuit; the binding post II is a binding post of the protected pipeline B and can be connected with the protected pipeline B through a circuit; the wiring terminal III is a wiring terminal of the protected pipeline B and can be connected with the protected pipeline B through a circuit; binding post for standby; the binding post is a polarization test piece binding post and can be connected with one or two test lines of a red line led out by the first polarization test piece 2 and a light blue line led out by the second polarization test piece 4; the binding post can be connected with a yellow line led out from the double-salt bridge reference electrode 3; the binding post is connected with the green line led out from the corrosion test piece 1; the binding post (B) is ready for use.
3) Testing
Before measurement, the cathode protection operation should be confirmed to be normal, each polarization test piece is communicated with the pipeline, and the pipeline and each polarization test piece are fully polarized.
And (3) testing the electrified potential: before testing, the polarization test piece is ensured to be fully polarized (generally, at least 24h must be buried), under the continuous application of cathodic protection current, a digital multimeter is adopted to realize direct-current voltage level, the positive pole (red meter pen) of the multimeter is connected with a polarization test piece wiring terminal, the negative pole (black meter pen) is connected with a reference electrode wiring terminal in a test pile, and the electrified potential of the polarization test piece under the cathodic protection is recorded.
Off potential (polarization potential): and (3) testing the wiring mode of the digital multimeter and the electrified potential, disconnecting the conductive copper sheet during measurement, disconnecting the cathodic protection current of the polarization test piece at the moment, and reading a potential test value within 0.5 s-1 s, namely the power-off potential of the polarization test piece relative to the reference electrode.
Self-corrosion potential test: the positive pole (red meter pen) of the multimeter is connected with the self-corrosion test piece wiring terminal, the negative pole (black meter pen) is connected with the reference electrode wiring terminal in the test pile, and the self-corrosion potential is recorded.
And (3) testing alternating current interference parameters: the alternating voltage or alternating current gear of the digital multimeter is adopted, the synchronous test curve function can be selected for long-time detection, the anode (red meter pen) of the multimeter is connected with a polarization test piece wiring terminal, the cathode (black meter pen) is connected with a reference electrode wiring terminal in a test pile, and a corresponding test value or a test curve is recorded.
4) If the area, shape and number of the polarized test pieces need to be changed according to the actual working conditions, the testing method is the same as the above.
The results of the examples show that the double-salt bridge reference electrode can effectively avoid the pollution to the test piece caused by the leakage of the traditional reference electrode, ensure the long-term stability of the probe test, and be used for comprehensively evaluating the interference level of the pipeline and the effectiveness of the cathodic protection.

Claims (7)

1. The utility model provides a multi-functional polarization probe of cathodic protection oil gas pipeline which characterized in that, includes from corrosion test piece, first polarization test piece, double salt bridge reference electrode, second polarization test piece, protective cap, casing, and concrete structure is as follows:
the shell comprises a PVC shell, a PVC end socket and epoxy resin insulation filler, the lower end of the cylindrical PVC shell is inserted into the groove-shaped protective cap, the upper end of the PVC shell is sealed by the annular PVC end socket, and a hole is formed in the center of the PVC end socket; the self-corrosion test piece, the first polarization test piece, the double-salt bridge reference electrode and the second polarization test piece are arranged on the upper surface of the protective cap in the PVC shell, the epoxy resin insulating filler is filled in the PVC shell, each polarization test piece and the double-salt bridge reference electrode are fixed inside the PVC shell, and the lower surfaces of each polarization test piece, the double-salt bridge reference electrode and the epoxy resin insulating filler are positioned on the same horizontal plane with the lower end surface and the inner bottom surface of the protective cap of the PVC shell.
2. The multifunctional polarization probe for the cathodic protection oil-gas pipeline as claimed in claim 1, further comprising a test wire, wherein the test wire is a four-core cable, the test wire penetrates out from the central hole of the annular PVC end socket at the upper end of the shell, the four-core cable comprises a green wire, a red wire, a light blue wire and a yellow wire, the green wire is connected with the self-corrosion test piece, the red wire is connected with the first polarization test piece, the light blue wire is connected with the second polarization test piece, and the yellow wire is connected with the double-salt bridge reference electrode.
3. The multi-functional polarization probe for cathodic protection of oil and gas pipelines as claimed in claim 1, wherein the self-corrosion coupon is 1.0cm in area2The circular test piece is used for testing the self-corrosion potential of the pipeline near the buried point; the first polarization test piece has an area of 1.0cm2The round test piece is used for testing the alternating current potential and the alternating current interference density of the pipeline; the second polarization test piece has an area of 6.5cm2The square test piece is used for testing the on-off potential of the pipeline; the three polarization test pieces are made of the same material of the pipeline, and the surface roughness Ra of the three polarization test pieces is less than or equal to 0.1 mu m.
4. The multi-functional polarized probe for cathodic protection of oil and gas pipelines as defined in claim 1 wherein the double salt bridge reference electrode is saturated Cu/CuSO4And an electrode.
5. The multifunctional polarization probe for cathodic protection of oil and gas pipelines as claimed in claim 1, wherein the protective cap is made of silica gel.
6. The use method of the multifunctional polarization probe for cathodic protection oil and gas pipelines as claimed in any one of claims 1 to 5, characterized in that the multifunctional polarization probe for cathodic protection oil and gas pipelines is used for monitoring and detecting the cathodic protection effectiveness of buried pipelines, and the installation, wiring and test processes are as follows:
1) mounting of
The multifunctional polarization probe for the cathodic protection oil and gas pipeline is vertically buried in soil, the distance between the multifunctional polarization probe for the cathodic protection oil and gas pipeline and the pipeline is 0.1-0.3 m, a protective cap is taken down, the buried depth and the backfill state of the multifunctional polarization probe for the cathodic protection oil and gas pipeline are the same as those of the pipeline, and the multifunctional polarization probe for the cathodic protection oil and gas pipeline is ensured to be in close contact with the soil and be polarized sufficiently;
2) wiring
Selecting one or two test lines of a red line led out by the first polarization test piece and a light blue line led out by the second polarization test piece according to requirements, and connecting the test lines to corresponding terminals in a test pile junction box of the test pile; the terminal of the polarization test block is connected with the terminal of the protected pipeline by a conductive copper sheet, so that the polarization test block is polarized as same as the pipeline; a green line led out from the corrosion test piece and a yellow line led out from the double-salt bridge reference electrode are respectively led into corresponding binding posts of the junction box of the test pile, and then the connection of the test lines is completed;
3) testing
Before measurement, the cathode protection operation is determined to be normal, each polarization test piece is communicated with the pipeline, and the pipeline and each polarization test piece are fully polarized;
and (3) testing the electrified potential: before testing, ensuring that the polarization test piece is sufficiently polarized, adopting a digital multimeter direct-current voltage range under the continuous application of cathodic protection current, connecting the positive pole of the multimeter with a polarization test piece wiring terminal, connecting the negative pole of the multimeter with a reference electrode wiring terminal in a test pile, and recording the electrified potential of the polarization test piece under cathodic protection;
power-off potential: the wiring mode of the digital multimeter is tested with the electrified potential, during the measurement, the conductive copper sheet is disconnected, the cathodic protection current of the polarization test piece is disconnected at the moment, and the potential test value is read within 0.5 s-1 s, namely the power-off potential of the polarization test piece relative to the reference electrode;
self-corrosion potential test: the positive electrode of the multimeter is connected with the self-corrosion test piece wiring terminal, the negative electrode of the multimeter is connected with the reference electrode wiring terminal in the test pile, and the self-corrosion potential is recorded;
and (3) testing alternating current interference parameters: the alternating voltage or alternating current gear of the digital multimeter is adopted, the synchronous test curve function is selected for long-time detection, the anode of the multimeter is connected with a polarization test piece wiring terminal, the cathode of the multimeter is connected with a reference electrode wiring terminal in the test pile, and a corresponding test value or a corresponding test curve is recorded.
7. The use method of the multifunctional polarization probe for the cathodic protection oil-gas pipeline according to claim 6, characterized in that 8 binding posts are arranged in the test pile junction box, wherein: the wiring terminal I is a wiring terminal of a protected pipeline B and is connected with the protected pipeline B through a circuit; the binding post II is a binding post of the protected pipeline B and is connected with the protected pipeline B through a circuit; the wiring terminal III is a wiring terminal of the protected pipeline B and is connected with the protected pipeline B through a circuit; binding post for standby; the binding post is a polarization test piece binding post and is connected with one or two test lines of a red line led out by the first polarization test piece 2 and a light blue line led out by the second polarization test piece 4; the binding post is connected with a yellow line led out from the double-salt bridge reference electrode 3; the binding post is connected with a green line led out from the corrosion test piece 1; the binding post (B) is ready for use.
CN202011380352.6A 2020-11-30 2020-11-30 A multifunctional polarization probe for cathodic protection oil and gas pipelines and using method thereof Pending CN112281165A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011380352.6A CN112281165A (en) 2020-11-30 2020-11-30 A multifunctional polarization probe for cathodic protection oil and gas pipelines and using method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011380352.6A CN112281165A (en) 2020-11-30 2020-11-30 A multifunctional polarization probe for cathodic protection oil and gas pipelines and using method thereof

Publications (1)

Publication Number Publication Date
CN112281165A true CN112281165A (en) 2021-01-29

Family

ID=74426508

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011380352.6A Pending CN112281165A (en) 2020-11-30 2020-11-30 A multifunctional polarization probe for cathodic protection oil and gas pipelines and using method thereof

Country Status (1)

Country Link
CN (1) CN112281165A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115248233A (en) * 2021-04-26 2022-10-28 中国石油天然气股份有限公司 Alternating current interference test probe and test method
CN116288371A (en) * 2023-02-14 2023-06-23 深圳中广核工程设计有限公司 Integrated Combination Probes for Cathodic Protection
CN117187819A (en) * 2023-06-25 2023-12-08 大庆荣安科技有限公司 Cathodic protection measurement polarization probe and its application
CN118067598A (en) * 2023-11-24 2024-05-24 国网电力科学研究院武汉南瑞有限责任公司 A transmission line tower grounding device corrosion online monitoring system and method

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201662525U (en) * 2010-04-12 2010-12-01 天津市水利科学研究院 Cathode protection monitoring probe and cathode protection monitoring probe monitoring system
CN202214419U (en) * 2011-08-05 2012-05-09 北京科技大学 Multifunctional cathode protection test probe
CN102912356A (en) * 2011-08-05 2013-02-06 北京科技大学 Multifunctional catholic protection test probe and test method
CN204649683U (en) * 2015-04-24 2015-09-16 上海水仪科技有限公司 Two salt bridge contrast electrode
CN109917720A (en) * 2019-04-04 2019-06-21 中国石油化工股份有限公司 In-service steel pipe stray electrical current prison detection and cathodic protection power control and method
CN211445906U (en) * 2020-02-25 2020-09-08 武汉材料保护研究所有限公司 A polarization probe for cathodic protection online monitoring system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201662525U (en) * 2010-04-12 2010-12-01 天津市水利科学研究院 Cathode protection monitoring probe and cathode protection monitoring probe monitoring system
CN202214419U (en) * 2011-08-05 2012-05-09 北京科技大学 Multifunctional cathode protection test probe
CN102912356A (en) * 2011-08-05 2013-02-06 北京科技大学 Multifunctional catholic protection test probe and test method
CN204649683U (en) * 2015-04-24 2015-09-16 上海水仪科技有限公司 Two salt bridge contrast electrode
CN109917720A (en) * 2019-04-04 2019-06-21 中国石油化工股份有限公司 In-service steel pipe stray electrical current prison detection and cathodic protection power control and method
CN211445906U (en) * 2020-02-25 2020-09-08 武汉材料保护研究所有限公司 A polarization probe for cathodic protection online monitoring system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115248233A (en) * 2021-04-26 2022-10-28 中国石油天然气股份有限公司 Alternating current interference test probe and test method
CN116288371A (en) * 2023-02-14 2023-06-23 深圳中广核工程设计有限公司 Integrated Combination Probes for Cathodic Protection
CN117187819A (en) * 2023-06-25 2023-12-08 大庆荣安科技有限公司 Cathodic protection measurement polarization probe and its application
CN118067598A (en) * 2023-11-24 2024-05-24 国网电力科学研究院武汉南瑞有限责任公司 A transmission line tower grounding device corrosion online monitoring system and method

Similar Documents

Publication Publication Date Title
CN112281165A (en) A multifunctional polarization probe for cathodic protection oil and gas pipelines and using method thereof
CN102912356B (en) Multifunctional catholic protection test probe and test method
CN112430817B (en) Buried metal pipeline corrosion parameter test probe split device and test method
US7508223B1 (en) Multihole and multiwire sensors for localized and general corrosion monitoring
CN105424293A (en) Water supply-drainage pipe leak detection system and detection method
CN113549918A (en) Contact type measuring device and method for sacrificial anode cathodic protection state of offshore submarine pipeline
CN108298216A (en) The monitoring system and method for oil storage tank leakage
CN106706029B (en) Soil body performance monitoring device for underground structure construction and working method thereof
US6060877A (en) Flat cathodic protection test probe
CN201662525U (en) Cathode protection monitoring probe and cathode protection monitoring probe monitoring system
JP4137058B2 (en) Corrosion / corrosion protection evaluation method
CN104726871A (en) Cathodic protection system test piece testing system and testing method
CN202214419U (en) Multifunctional cathode protection test probe
CN205175626U (en) Water supply and drainage pipe leak testing system
CN214060645U (en) Multifunctional polarization probe for cathodic protection oil and gas pipeline
CN216208480U (en) Buried pipeline stray current interference monitoring device and system
CN212103016U (en) Double-reference polarization probe with IR drop compensation function
CN218524557U (en) Pipe jacking pipeline corrosion risk detection device
CN113280888A (en) Double-resistance high-precision underground water level measuring instrument and water level calculation method thereof
CN202337827U (en) Buried anti-interference polarization probe
CN101710149B (en) System for measuring current density of oil gas pipeline
RU2471171C1 (en) Evaluation device of protection against corrosion as to value of deflection from natural potential
CN114086186A (en) Pipeline protection effect detection device and detection method
CN214407668U (en) Water level measuring device
CN209481802U (en) A kind of cathodic protection polarized probe

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: 20210129

RJ01 Rejection of invention patent application after publication