Device for simply testing insulation resistance of anticorrosive coating of directional drilling pipeline

Abstract

The utility model discloses a device for simply testing insulation resistance of an anticorrosive coating of a directional drilling pipeline. The device comprises a data recorder, a potentiostat and a magnet, the data recorders are arranged at the two ends of the pipeline; the anode of the potentiostat is connected with a temporary anode ground bed, and the cathode is connected with an ampere meter; the magnets are arranged at the two ends of the pipeline, one end of each magnet is connected with the pipeline, and the other end of each magnet is connected with the data recorder and the potentiostat through wires. The device provided by the utility model can accurately detect the insulation resistance of the anti-corrosion layer of the drilling pipeline, and is simple and convenient to install.

Description

TECHNICAL FIELD

[0001] The utility model relates to pipeline anticorrosion technical field more specifically relates to a simple and easy test directional drilling pipeline anticorrosion layer insulation resistance's device. BACKGROUND

[0002] Buried steel pipeline for conveying petroleum and natural gas usually uses outer anticorrosion insulation layer to prevent pipeline from being corroded, thereby ensuring its safe operation. The quality of anticorrosion layer is directly related to the service life and safety of pipeline. However, since directional drilling pipeline construction is in deep underground, geological conditions are complex and changeable, and construction quality is difficult to completely guarantee, therefore, after construction is completed, it is necessary to effectively evaluate pipeline anticorrosion quality.

[0003] At present, although the research on pipeline anticorrosion layer insulation resistance has achieved certain results, most of these researches are concentrated on shallow buried (mostly about 2 meters) or overhead pipeline. For directional drilling pipeline, since its burial depth is relatively deep (generally not less than 6 meters below flood scour line and planned dredging line), the existing technology has obvious deficiencies in measuring the insulation resistance of its anticorrosion layer, lacks a measuring method suitable for deep buried pipeline, and cannot comprehensively reflect the performance of deep buried pipeline anticorrosion layer in complex environment.

[0004] Therefore, it is an urgent problem for those skilled in the art to develop a simple and easy test directional drilling pipeline anticorrosion layer insulation resistance device which is easy to install and has accurate test results. CONTENT OF THE UTILITY MODEL

[0005] Therefore, the utility model provides a simple and easy test directional drilling pipeline anticorrosion layer insulation resistance device which is easy to install and has accurate test results.

[0006] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0007] A simple and easy test directional drilling pipeline anticorrosion layer insulation resistance device comprises:

[0008] A data recorder is arranged at both ends of the pipeline.

[0009] A constant potential instrument is connected with a temporary anode bed at the positive electrode and a current meter at the negative electrode.

[0010] Magnets are arranged at both ends of the pipeline, one end of the magnet is connected with the pipeline, and the other end is connected with the data recorder and the constant potential instrument through wires respectively.

[0011] The beneficial effect of the above technical scheme is that the data recorder has power-on and power-off test and GPS clock functions, can test and record the potential change of the power-on and power-off of the two ends of the pipeline, and can calculate the average value of the insulating resistance of the anticorrosive layer of the directional drilling pipeline according to the measured value and other data measured by the conventional method, and the detection result is accurate; meanwhile, the two ends of the pipeline are connected by the magnet, so that the installation process is more simple and convenient.

[0012] Preferably, the data recorder is connected with a reference electrode, and the reference electrode is located close to the pipeline.

[0013] Preferably, the data recorder is connected with a polarization test piece, and the polarization test piece is arranged adjacent to the reference electrode. The reference electrode is buried near the directional drilling pipeline and is adjacent to the polarization test piece, so that the pressure drop is effectively reduced and the test data is ensured to be true and reliable.

[0014] Preferably, the polarization test piece is made of the same material as the pipeline, so that the measurement error caused by different materials can be avoided.

[0015] Preferably, the temporary anode ground bed comprises a plurality of copper grounding spikes, and the plurality of grounding spikes are uniformly distributed.

[0016] According to the above technical scheme, compared with the prior art, the utility model discloses a kind of simple and easy test directional drilling pipeline anticorrosive layer insulating resistance device, and its beneficial effect is:

[0017] (1) in the utility model, by constant potential instrument, reference electrode, data recorder and polarization test piece cooperation, a certain protective current is applied to directional drilling pipeline, the average value of the insulating resistance of the anticorrosive layer of directional drilling pipeline can be accurately measured by simultaneously recording the potential change of the power-on and power-off of the two ends of directional drilling pipeline through the on-off function and GPS clock of data recorder itself;

[0018] (2) meanwhile, pipeline connection adopts magnet adsorption connection, and installation is simple and firm, and conductivity is good. DRAWINGS

[0019] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be simply introduced below, and obviously, the drawings in the following description are only embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creating labor.

[0020] Figure 1 The drawings are the structural schematic diagram of the device provided by the utility model.

[0021] In the drawings,

[0022] 1-data logger; 2-pipeline; 3-potentiostat; 4-temporary anode bed; 5-ammeter; 6-magnet; 7-reference electrode; 8-polarization coupon. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0024] Embodiment 1:

[0025] The embodiment of the present application discloses a device for simply testing the insulating resistance of the anticorrosive layer of a directional drilling pipeline, comprising:

[0026] The data logger 1 is arranged at both ends of the pipeline 2.

[0027] The positive electrode of the potentiostat 3 is connected with the temporary anode bed 4, and the negative electrode is connected with the ammeter 5.

[0028] The magnet 6 is arranged at both ends of the pipeline 2, one end of the magnet 6 is connected with the pipeline 2, and the other end is connected with the data logger 1 and the potentiostat 3 through wires respectively. The data logger 1 can store the potential data detected at both ends of the pipeline 2 into a document format, which is convenient for data processing in the later stage.

[0029] In order to further optimize the above technical solution, the potentiostat 3 has two modes of constant current output and constant potential output, which can meet the required protection current of all directional drilling pipelines, has a large output range, is widely applied, and can prevent electric shock injury by connecting the temporary anode bed 4.

[0030] In order to further optimize the above technical solution, the current of the ammeter includes three ranges of "microampere", "milliampere" and "ampere", the precision of the ammeter 5 is 1.3%+3, and the current change in the loop is accurately measured.

[0031] In order to further optimize the above technical solution, the magnet is a strong magnetic conductive material, has strong adsorption and good conductive performance.

[0032] In order to further optimize the above technical solution, the data logger 1 is connected with the reference electrode 7, and the reference electrode 7 is located close to the pipeline 2.

[0033] In order to further optimize the above technical solution, the data logger 1 is connected with the polarization coupon 8, and the polarization coupon 8 is arranged adjacent to the reference electrode 7.

[0034] In order to further optimize the above technical solutions, the polarization test piece 8 is made of the same material as the pipeline 2. The polarization test piece 8 is made of carbon steel, which is the same material as the pipeline 2, and is buried near the pipeline 2, so that the corrosion environment is basically the same, and the measurement error is reduced.

[0035] In order to further optimize the above technical solutions, the temporary anode ground bed 4 includes a plurality of copper grounding rods, and the plurality of grounding rods are uniformly distributed. The grounding rod is made of copper, which can effectively reduce the grounding resistance and ensure the maximum output of the constant potential instrument 3.

[0036] Example 2:

[0037] The following data is used to illustrate the test process of the insulating resistance of the anticorrosion layer of the directional drilling pipeline:

[0038] According to the above technical solutions, the insulating resistance of the anticorrosion layer of the directional drilling pipeline can be measured, and the corrosion state of the pipeline can be determined. Figure 1 After setting up various instruments and equipment, turn on the constant potential instrument 3, the ammeter 5 and the data logger 1 in turn. Adjust the output current of the constant potential instrument 3 to the data logger 1 on both ends to display the open circuit potential ≦-0.85V. After debugging, record the current value of the ammeter 5 at this time, and start the automatic acquisition and storage function of the data logger 1. After acquisition, test and record the soil resistivity near the directional drilling pipeline.

[0039] Table 1 Pipeline basic information

[0040] Pipe specification Length Type of anticorrosive coating D813 x 21 mm 866.7m 3PE reinforced level

[0041] Table 2 Change of potential at both ends of directional drilling pipeline

[0042]

[0043]

[0044] Table 3 Measurement data statistics

[0045]

[0046] Insulating resistance value calculation process of anticorrosion layer:

[0047] Potential difference at the soil entry point: ΔUa=1.5408V;

[0048] Potential difference at the soil exit point: Ub=1.7390V;

[0049] Anticorrosion layer resistance of the crossing section: R=ΔU(average) / ΔI=(ΔUa+Ub) / 2 / ΔI=24.96Ω

[0050] The resistance rate of the outer anticorrosion layer of the pipeline is r=R*π*d*L=24.96*3.14*0.813*866.7=55217.26 Ω·㎡

[0051] The nominal resistance rate of the outer anticorrosion layer of the pipeline is Rn=r*1000 Ω·cm / ρ=55217.26*1000 / 28.888 / 100=19114.26 Ω·㎡

[0052] ΔI refers to the average value of the current, d refers to the diameter of the pipeline, and L refers to the length of the pipeline.

[0053] According to the anticorrosion layer quality comparison table of the nominal insulation resistance rate of the anticorrosion layer stipulated in the GB50424-2015 "Oil and gas pipeline crossing engineering construction specification", the outer anticorrosion layer quality grade of the directional drilling crossing pipeline is evaluated as "excellent".

[0054] Table 4: Anticorrosion layer nominal insulation resistance rate and anticorrosion layer quality comparison table

[0055] Insulation resistance of anticorrosive coating R (0 Ω.m2) Evaluation of anticorrosive coating quality R≥10000 Excellent 10000＞R≥5000 Good 5000＞R≥1000 Fair R＜1000 Poor

[0056] In the embodiment 2 of the utility model, two end data recorders 1 acquire 20 groups of on-off potential data through GPS clock synchronization, take the average value of potential change, calculate the insulation resistance value according to the formula, avoid contingency, and can guarantee the repeatability and accuracy of test results; ammeters 5 are connected in series in the loop, accurately measure the current change value in the loop, and avoid external interference; a plurality of copper drill rods are used as temporary anode beds 4, which effectively reduce the grounding resistance of the anode bed; the wires are connected with the pipeline 2 through the magnet 6, which is easy to install and has good conductivity.

[0057] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0058] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the utility model. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the utility model. Therefore, the utility model will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for simply testing the insulation resistance of a directional drilling pipe anticorrosion layer, characterized in that, The utility model relates to a kind of electrochemical corrosion test device, including: Data logger, the data logger is set to the both ends of pipeline; Constant potential instrument, the positive pole of constant potential instrument is connected with temporary anode ground bed, negative pole connects ammeter; Magnet, the magnet is set to the both ends of pipeline, one end of the magnet is connected with the pipeline, the other end is connected with the data logger, constant potential instrument through wire respectively.

2. The device for simply testing the insulation resistance of the anticorrosive layer of the directional drilling pipe according to claim 1, characterized in that, The data logger is connected with reference electrode, and the reference electrode is located close to the pipeline.

3. The device for simply testing the insulation resistance of the anticorrosive layer of the directional drilling pipe according to claim 2, characterized in that, The data logger is connected with polarization test piece, and the polarization test piece is arranged adjacent to the reference electrode.

4. The device for simply testing the insulation resistance of the anticorrosive layer of the directional drilling pipe according to claim 3, characterized in that, The polarization test piece is same with the material of the pipeline.

5. The device for simply testing the insulation resistance of the anticorrosive layer of the directional drilling pipe according to claim 1, characterized in that, The temporary anode ground bed includes a plurality of copper grounding rods, and the plurality of grounding rods are uniformly distributed.

Images