CN112921323A - Indoor evaluation device and evaluation method for sacrificial anode material - Google Patents
Indoor evaluation device and evaluation method for sacrificial anode material Download PDFInfo
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- 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
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- 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
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Abstract
The invention discloses an indoor evaluation device and an evaluation method for a sacrificial anode material. The casing pipe short section, the oil pipe short section, the sacrificial anode, the test electrode and the reference electrode are sequentially arranged on the sealing fixed base, and the ammeter and the voltmeter are externally connected on the sacrificial anode to form the indoor evaluation device of the sacrificial anode. The device simulates the actual working conditions (such as temperature, mineralization degree and corrosion protection coating completeness) of a shaft of the oil and gas well through a full-size model, tests the change rule of the corresponding protection potential along with time by applying constant and continuous protection current to the system, draws a protection potential and protection distance relation curve to evaluate the protection effect of the sacrificial anode, and provides basic test data support for the application of the sacrificial anode in the oil and gas well.
Description
Technical Field
The invention relates to the technical field of corrosion and protection of oil and gas fields, in particular to an indoor evaluation device and an evaluation method for a sacrificial anode material.
Background
At present, oil well pipe columns of oil field production enterprises generally adopt common carbon steel pipes, and oil well produced liquid seriously corrodes carbon steel sleeves. In order to safely and efficiently develop oil fields, various sleeve corrosion prevention measures except corrosion-resistant pipes are generally adopted in each oil field, such as external current cathodic protection and external corrosion prevention with early application and mature technology, epoxy cold winding belt (epoxy coating) sacrificial anode corrosion prevention applied in China in large quantity, commonly-implemented corrosion inhibitor filling technology and the like.
The patent "a sacrificial anode protection device for inner coating cased well (MN 105154889B)" discloses a sacrificial anode device for corrosion protection inside casing by using oil pipe to bring sacrificial anode, and does not further describe how the sacrificial anode on the oil pipe should be distributed; the patent "a downhole evaluation device for sacrificial anode materials" (MN105401921B) discloses a device for downhole evaluation of the working condition of anodes, but does not provide a downhole distribution of the anodes; the document "a tool development for preventing corrosion of casing pipe with the oil pipe going into well" (xiaozhiying, li jonwei, order forever, oil industry technical supervision, vol.33no.3mar.2017) describes the field application condition and effect of the anticorrosion anode in the casing pipe, and does not relate to the anode protection potential or installation mode; the patent 'oil well casing cathode protection system based on pulse current and electrode placement method (MN 104562043B)' discloses a potential distribution detection method of casing impressed current cathode protection, which is to detect the distribution potential of different positions of the outer wall of a casing by wrapping and binding a reference electrode cloth on the outer wall of the casing through a heat insulating material. The prior patent documents do not discuss an anode installation and arrangement method of the sacrificial anode in the sleeve, the distribution and installation of the sacrificial anode in the sleeve cannot be determined in production, and the installation and arrangement of the sacrificial anode are mainly determined according to the design experience of the electrochemical parameters of the anode in a ground pipeline and a storage tank.
GB/T17848-1999 test method for electrochemical performance of sacrificial anode describes in detail the test device, sample preparation, test conditions and test procedure for testing electrochemical performance of sacrificial anode indoors. The evaluation method can obtain electrochemical performance data such as actual capacitance, theoretical capacitance, current efficiency and the like of the sacrificial anode. However, the method does not relate to the potential detection of the sacrificial anode in the sleeve, the calculation of the protection distance and the evaluation of the protection effect.
Because the electromagnetic action range of the sacrificial anode in the limited space of the oil well casing is limited, the depth of the oil well casing in the underground is more than kilometer, the protective potential of the sacrificial anode in the casing is naturally difficult to measure, the method for detecting the distribution potential of the outer wall of the casing is feasible by adopting the principle that the reference electrode is fixed on the oil pipe to measure the potentials at different positions of the inner wall of the casing, the direct detection is almost impossible to realize with great difficulty, and the reasonable distribution of the sacrificial anode in the casing can not be known from the verification, so that the distribution of the anode can not be reasonably determined.
Therefore, the technology of preventing the sleeve from being corroded by the sacrificial anode is scientifically and reasonably adopted, scientific protection of the sleeve by the sacrificial anode is realized, the cathode protection criterion specified by the national standard is met, underprotection or over-protection is prevented, the distribution method of the sacrificial anode in the sleeve under the corrosion environment with different temperatures, mineralization degrees and coating integrity rates must be mastered, the installation mode of the sacrificial anode in the longitudinal direction in the sleeve is determined, and the production problem of reasonable application of the sacrificial anode which troubles the corrosion prevention in the sleeve is solved.
Disclosure of Invention
In order to solve the problems in the prior art, the invention aims to provide an indoor evaluation device and an evaluation method for a sacrificial anode material.
The technical scheme of the invention is as follows:
an indoor evaluation device for a sacrificial anode material comprises a casing pipe nipple, an oil pipe nipple, a test electrode, a reference electrode, a sacrificial anode nipple, a voltmeter, an ammeter, a temperature controller, a heater and a multi-channel data recorder, wherein the oil pipe nipple is coaxially arranged in an inner cavity of the casing pipe nipple, the sacrificial anode nipple is sleeved at the lower end of the oil pipe nipple, the sacrificial anode nipple is insulated from the oil pipe nipple, the lower ends of the oil pipe nipple and the casing pipe nipple are sealed, and the casing pipe nipple and the sacrificial anode nipple are in insulated connection by a conducting wire; a plurality of pairs of electrode pairs are arranged on the sacrificial anode short section and the sleeve short section along the length direction, each pair of electrode comprises a test electrode and a reference electrode, the sacrificial anode short section is insulated from the test electrodes and the reference electrodes, and the sleeve short section is insulated from the test electrodes and the reference electrodes; in each pair of electrodes, the test electrode and the reference electrode are correspondingly connected with a voltmeter, and the test electrode and the reference electrode are respectively connected with two ends of the voltmeter; the sleeve pipe nipple is connected with an ammeter at the upper end of the oil pipe nipple and a position above the oil pipe nipple by a preset distance, the anode of the ammeter is connected with the upper end of the sleeve pipe nipple, and a temperature sensor probe of a temperature controller is fixed on the sleeve pipe nipple; the voltmeter, the ammeter and the temperature controller are connected to the multi-channel data recorder through wires, and the heater is arranged in the oil pipe nipple.
Preferably, the electrodes on the sacrificial anode short section and the casing short section are aligned, the test electrode and the reference electrode are arranged along the circumferential direction of the sacrificial anode short section and the casing short section, and the distance between the test electrode and the reference electrode is 1-2cm in each pair of electrodes.
Preferably, the lower ends of the oil pipe nipple and the casing nipple are hermetically mounted on a sealing and fixing base, and an annular groove for embedding the oil supply pipe nipple and the casing nipple is formed in the sealing and fixing base.
Preferably, the material of the sealing and fixing base is polytetrafluoroethylene, PVC or nylon.
Preferably, the length of the casing nipple is 2-3 m, and the specification is 41/2″、51/2"or 7" sleeves; the length of the oil pipe nipple is the same as that of the casing pipe nipple, and the specification is 23/8″、27/8"or 31/2"tubing; the sacrificial anode has a length of 0.3-0.5 m and a wall thickness of 8-15 mm.
Preferably, 2-4 pairs of test electrodes and reference electrodes are arranged on the outer surface of the sacrificial anode short section at intervals along the length direction; 5-7 pairs of test electrodes and reference electrodes are arranged on the inner surface of the casing pipe nipple at intervals along the length direction.
Preferably, the inner wall of the casing nipple is provided with an anti-corrosion coating.
Preferably, the sacrificial anode short section and the oil pipe short section are insulated through an insulating tape, and the sacrificial anode short section and the oil pipe short section are in tight fit.
Preferably, a resistor R is connected in parallel on the ammeter; the casing nipple is made of J55, N80 or P110, and the oil pipe nipple is made of J55, N80 or P110.
The invention also provides an indoor evaluation method of the sacrificial anode material, which is carried out by the indoor evaluation device of the sacrificial anode material, and comprises the following steps:
filling an annular space between the inner cavity oil pipe nipple of the oil pipe nipple and the sleeve nipple with a corrosive medium, and starting a heater to heat the corrosive medium to a target temperature; according to the cathodic protection principle, the sacrificial anode continuously supplies a protection current to the bushing, thereby generating a corresponding protection potential.
Recording the sleeve pipe nipple and the sacrificial anode nipple potential of each reference position by using a multi-channel data recorder; and drawing a curve of the change of the protection potential along with time, a curve of the relation between the protection potential and the protection distance according to the test data on the multi-channel data recorder, and obtaining the change rule of the protection distance of the sacrificial anode short section along with the simulation working condition through numerical value fitting.
Preferably, the corrosive medium is taken from a formation water fluid medium of an actual oil well shaft or is configured with a simulation water sample; the lowest mineralization value of the corrosive medium is more than or equal to 10g/l, the highest temperature value is less than or equal to 80 ℃, and the damage rate of the coating is 0-100%.
The invention has the following beneficial effects:
according to the indoor evaluation device for the sacrificial anode material, the oil pipe short section is coaxially arranged in the inner cavity of the casing short section, the sacrificial anode short section is sleeved at the lower end of the oil pipe short section, and the lower ends of the oil pipe short section and the casing short section are sealed, so that a corrosive medium can be added into the oil pipe short section to simulate the working condition of the oil pipe short section; the sacrificial anode pup joint and the sleeve pup joint are provided with a plurality of pairs of test electrodes and reference electrodes along the length direction, point positions of different positions can be obtained by utilizing the test electrodes and the reference electrodes, a channel data recorder can record corresponding data, a protection potential variation curve along time, a protection potential and protection distance relation curve are drawn according to test data on the channel data recorder, and the variation rule of the sacrificial anode protection distance along with simulation working conditions (such as temperature, mineralization degree and corrosion protection coating completeness rate) is obtained through numerical fitting. Therefore, the indoor evaluation device for the sacrificial anode material provided by the invention can determine the protection distance and the protection potential distribution rule of the sacrificial anode in the casing by means of an indoor simulation experiment, and solves the problems that the sacrificial anode for the oil-gas well casing cannot carry out daily potential detection and the cathode protection effect lacks an accurate and reliable evaluation method.
Furthermore, the sealing and fixing base is provided with an annular groove for embedding the oil supply pipe nipple and the sleeve nipple, the relative positions of the sleeve nipple and the oil pipe nipple can be ensured through the groove, and then the relative positions of the sleeve nipple and the sacrificial anode nipple are ensured, so that the measured potential is accurate.
Drawings
Fig. 1 is a schematic view showing the overall structure of an apparatus for evaluating a sacrificial anode material in a chamber according to the present invention.
Figure 2 is a schematic end view of the seal mount of the present invention.
Fig. 3 is a sectional view a-a of fig. 2.
Description of reference numerals: 1. a casing nipple; 2. an oil pipe nipple; 3. a test electrode, 4, a reference electrode; 5. a sacrificial anode; 6. a voltmeter; 7. an ammeter; 8. a temperature sensor probe; 9. sealing and fixing the base; 9-1-annular groove.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and examples.
Referring to fig. 1, the indoor evaluation device for the sacrificial anode material comprises a casing pipe nipple 1, an oil pipe nipple 2, a test electrode 3, a reference electrode 4, a sacrificial anode nipple 5, a voltmeter 6, an ammeter 7, a temperature controller, a heater and a multi-channel data recorder 10, wherein the oil pipe nipple 2 is coaxially arranged in an inner cavity of the casing pipe nipple 1, the sacrificial anode nipple 5 is sleeved at the lower end of the oil pipe nipple 2, the sacrificial anode nipple 5 is insulated from the oil pipe nipple 2, the oil pipe nipple 2 is sealed from the lower end of the casing pipe nipple 1, and the casing pipe nipple 1 is in insulated connection with the sacrificial anode nipple 5 through a lead; a plurality of pairs of electrode pairs are arranged on the sacrificial anode short section 5 and the sleeve short section 1 along the length direction, each pair of electrode comprises a test electrode 3 and a reference electrode 4, the sacrificial anode short section 5 is insulated from the test electrode 3 and the reference electrode 4, and the sleeve short section 1 is insulated from the test electrode 3 and the reference electrode 4; in each pair of electrodes, the test electrode 3 and the reference electrode 4 are correspondingly connected with a voltmeter 6, and the test electrode 3 and the reference electrode 4 are respectively connected with two ends of the voltmeter 6; the sleeve pipe nipple 1 is connected with an ammeter 7 (the connection point is the negative pole of the ammeter 7) at the upper end of the oil pipe nipple 2 and a position above the oil pipe nipple 2 by a preset distance, and the positive pole of the ammeter 7 is connected with the upper end of the sleeve pipe nipple 1; the connection points of the two ammeters 7 are both arranged on the inner wall of the sleeve, one of the ammeters tests the current near the sacrificial anode short section (at the near end position), and the other ammeter tests the current at the far end position of the sacrificial anode short section. Since the current will consume attenuation during transmission, the corresponding potential will change accordingly. A temperature sensor probe 8 of the temperature controller is fixed on the casing pipe nipple 1; the voltmeter 6, the ammeter 7 and the temperature controller are connected to the multi-channel data recorder 10 through leads, and the heater is arranged in the oil pipe nipple 2.
As a preferred embodiment of the invention, in the electrode pairs on the sacrificial anode short section 5 and the casing short section 1, the test electrode 3 and the reference electrode 4 are arranged along the circumferential direction of the sacrificial anode short section 5 and the casing short section 1, and in each electrode pair, the distance between the test electrode 3 and the reference electrode 4 is 1-2 cm.
As a preferred embodiment of the present invention, with reference to fig. 2 and 3, the lower ends of the oil pipe nipple 2 and the casing nipple 1 are hermetically mounted on a sealing and fixing base 9, the sealing and fixing base 9 is provided with annular grooves into which the oil pipe nipple 2 and the casing nipple 1 are inserted, the oil pipe nipple 2 and the casing nipple 1 are inserted into the corresponding annular grooves, and are sealed without a gap by using an insulating adhesive.
In a preferred embodiment of the present invention, the sealing and fixing base 9 is made of teflon, PVC or nylon.
As a preferred embodiment of the invention, the casing nipple 1 has the length of 2-3 m and the specification of 41/2″、51/2"or 7" sleeves; the length of the oil pipe nipple 2 is the same as that of the casing pipe nipple 1, and the specification is 23/8″、27/8"or 31/2"tubing; the sacrificial anode 5 has a length of 0.3-0.5 m and a wall thickness of 8-15 mm.
As a preferred embodiment of the invention, 2-4 pairs of test electrodes 3 and reference electrodes 4 are arranged on the outer surface of the sacrificial anode short section 5 at intervals along the length direction; 5-7 pairs of test electrodes 3 and reference electrodes 4 are arranged on the inner surface of the casing pipe nipple 1 at intervals along the length direction.
As the preferred embodiment of the invention, whether the inner wall of the casing nipple 1 is coated with the anticorrosive coating or not can be selected according to the requirements of simulated working conditions.
As the preferred embodiment of the invention, the sacrificial anode short section 5 is insulated from the oil pipe short section 2 by the insulating tape, and the sacrificial anode short section 5 is tightly matched with the oil pipe short section 2.
As a preferred embodiment of the present invention, a resistor R is connected in parallel to the ammeter 7; the material of the casing nipple 1 is J55, N80 or P110, and the material of the oil pipe nipple 2 is J55, N80 or P110.
The invention also provides an indoor evaluation method of the sacrificial anode material, which is carried out by the indoor evaluation device of the sacrificial anode material, and comprises the following steps:
and filling the inner cavity of the oil pipe nipple 2 and the annular space between the oil pipe nipple 2 and the casing nipple 1 with corrosive medium. And turning on a heater to raise the temperature of the corrosion medium to a target temperature. Because the self-corrosion potential of the sacrificial anode is more negative than the self-corrosion potential of the sleeve, the sacrificial anode will continue to provide a protection current to the sleeve according to the cathodic protection principle, thereby generating a corresponding protection potential until the sacrificial anode is completely consumed.
Recording the potentials of the casing pipe nipple 1 and the sacrificial anode nipple 5 at each reference position by using a multi-channel data recorder 10; according to the test data on the multi-channel data recorder 10, a curve of the change of the protection potential along with time, a curve of the relation between the protection potential and the protection distance are drawn, and the change rule of the protection distance of the sacrificial anode short section 5 along with the simulation working condition (temperature, mineralization degree and corrosion-resistant coating integrity) is obtained through numerical fitting.
The corrosive medium is taken from a stratum water fluid medium of an actual oil well shaft or is configured with a simulation water sample; the lowest mineralization value of the corrosive medium is more than or equal to 10g/l, the highest temperature value is less than or equal to 80 ℃, and the damage rate of the coating is 0-100%.
Example 1
A certain oilfield city 27-wells, well depth 1860m, casing gauge 139.7mm (outside diameter) x 7.72mm (wall thickness), tubing gauge 73.0mm (outside diameter) x 5.50mm (wall thickness). MIT + MTT engineering logging shows that the well is seriously corroded near 1420 m-1725 m, and in order to prolong the production period of an oil well and slow down the corrosion damage of a casing, the sacrificial anode short section protection is determined to be implemented at the position of 1420 m-1725 m of the well. In order to improve the economy and ensure the effectiveness, the best protection effect is achieved by using the minimum quantity of the sacrificial anode short sections, and the maximum protection distance L and the corresponding protection potential V of a single sacrificial anode short section need to be determined. The number of sacrificial anode pups required for the well is [ (1725m-1420m)/L ].
This embodiment provides a sacrificial anode in-chamber evaluation apparatus as shown in fig. 1. The device comprises a casing pipe nipple 1, an oil pipe nipple 2, a test electrode 3, a reference electrode 4, a sacrificial anode nipple 5, a voltmeter 6, an ammeter 7, a temperature controller, a sealing fixed base 9 and a multi-channel data recorder 10. The specific implementation steps are as follows:
step 1: and (3) processing the disc-shaped sealing fixed base 9, and processing the prepared polytetrafluoroethylene bar material by using a lathe according to the figures 2 and 3. The sizes of the two circular grooves are respectively matched with the cross section sizes of the casing pipe nipple 1 and the oil pipe nipple 2.
Step 2: and (3) preparing a casing nipple 1 which is made of J55 material, and has the length of 2.5m, the outer diameter of 139.7mm and the wall thickness of 7.72 mm. 6 reference electrodes 4 are uniformly arranged on the inner wall of the casing nipple from top to bottom, and insulation is realized between the reference electrodes 4 and a fixed point by using an insulating tape.
And step 3: preparing an oil pipe nipple 2, wherein the oil pipe nipple 2 is made of J55 material, and has the length of 2.5m, the outer diameter of 73mm and the wall thickness of 5.5 mm.
And 4, step 4: and (3) preparing a sacrificial anode short section 5, wherein the length of the sacrificial anode short section 5 is 0.3m, the outer diameter is 98mm, and the wall thickness is 9.5 mm. 2 reference electrodes 4 are uniformly arranged on the outer wall of the sacrificial anode, and insulation between the reference electrodes 4 and a fixed point is realized by using an insulating tape.
And 5: and sleeving the sacrificial anode short section 5 on the oil pipe short section 2, and insulating the sacrificial anode short section 5 and the oil pipe short section 2 through an insulating tape.
Step 6: and (3) placing the sacrificial anode short section 5 and the oil pipe assembly assembled in the step (5) on a sealing fixed base 9, and sealing without gaps by using insulating glue.
And 7: and (4) carrying out insulation connection on the casing pipe nipple 1 assembled in the step (2) and the sacrificial anode nipple 5 assembled in the step (4) by using a wire, and confirming that the insulation performance is good by using a universal meter after the connection is finished. And the casing sub 1 is placed on the sealing and fixing base 9.
And 8: connect the test wire, it is 6 to need test casing nipple joint electric potential altogether, and sacrificial anode nipple joint electric potential is 2, and electric current is 2 between casing nipple joint and the sacrificial anode nipple joint, and the temperature is 1, carries out the test wire according to table 1 and connects according to the test demand to it is firm effective to ensure to connect. 1601, 16 denotes a 16-channel data recorder, and 01 denotes a first channel. The materials and equipment required for the test are shown in Table 2.
TABLE 1
TABLE 2
And step 9: the multichannel data recorder 10 is used for recording the sleeve pipe nipple and the sacrificial anode nipple potential of each reference position, data are recorded every 10min, and the temperature controller is used for temperature control. According to the position of the sacrificial anode short section between 1420m and 1725m, the temperature range of the position is calculated to be 57 ℃ to 67 ℃, and the heating temperature is controlled to be 67 +/-1 ℃ by using a temperature controller in the test process.
Step 10: and drawing a protection potential variation curve along with time, a protection potential and protection distance relation curve according to test data on the multi-channel data recorder 10, and obtaining a variation rule of the protection distance of the sacrificial anode along with the simulation working conditions (temperature, mineralization degree and integrity rate of an anti-corrosion coating) through numerical fitting.
Example 2
Example 1 only one sacrificial anode sample can be evaluated at a time, and to improve the evaluation efficiency, 4 of examples 1 can be evaluated simultaneously in parallel. The specific test protocol is shown in table 3, the arrangement of the test line connection ports is shown in table 4, the test materials and equipment are shown in table 5, and the rest is the same as example 1.
TABLE 3
TABLE 4
TABLE 5
The indoor evaluation device of the sacrificial anode material simulates the actual working conditions (temperature, mineralization degree and corrosion-resistant coating integrity rate) of a shaft of an oil and gas well through a full-size model, tests the change rule of the corresponding protection potential along with time by applying constant and continuous protection current to a system, draws a protection potential and protection distance relation curve to evaluate the protection effect of the sacrificial anode, and provides basic test data support for the application of the sacrificial anode in the oil and gas well. The experiment is fast and easy to implement, the technology is reliable, and the economy is good.
The indoor evaluation device for the sacrificial anode material can simulate performance evaluation tests of the sacrificial anode under various working conditions (the mineralization is more than or equal to 10g/l, the temperature is less than or equal to 80 ℃, and the damage rate of the coating is 0-100%), and is wide in applicability.
As described above, although the embodiments of the present invention have been described in detail, it will be apparent to those skilled in the art that many modifications are possible without substantially departing from the spirit and scope of the present invention. Therefore, such modifications are also all included in the scope of protection of the present invention.
Claims (10)
1. An indoor evaluation device for a sacrificial anode material is characterized by comprising a casing pipe nipple (1), an oil pipe nipple (2), a test electrode (3), a reference electrode (4), a sacrificial anode nipple (5), a voltmeter (6), an ammeter (7), a temperature controller, a heater and a multi-channel data recorder (10), wherein the oil pipe nipple (2) is coaxially arranged in an inner cavity of the casing pipe nipple (1), the sacrificial anode nipple (5) is sleeved at the lower end of the oil pipe nipple (2), the sacrificial anode nipple (5) is insulated from the oil pipe nipple (2), the lower ends of the oil pipe nipple (2) and the casing pipe nipple (1) are sealed, and the casing pipe nipple (1) and the sacrificial anode nipple (5) are in insulated connection through a conducting wire; a plurality of pairs of electrode pairs are arranged on the sacrificial anode short section (5) and the sleeve pipe short section (1) along the length direction, the electrode pairs comprise a test electrode (3) and a reference electrode (4), the sacrificial anode short section (5) is insulated from the test electrode (3) and the reference electrode (4), and the sleeve pipe short section (1) is insulated from the test electrode (3) and the reference electrode (4); in each pair of electrodes, the test electrode (3) and the reference electrode (4) are correspondingly connected with a voltmeter (6), and the test electrode (3) and the reference electrode (4) are respectively connected with two ends of the voltmeter (6); the sleeve pipe nipple (1) is connected with an ammeter (7) at the upper end of the oil pipe nipple (2) and at a position above the oil pipe nipple by a preset distance, the anode of the ammeter is connected with the upper end of the sleeve pipe nipple (1), and a temperature sensor probe (8) of a temperature controller is fixed on the sleeve pipe nipple (1); the voltmeter (6), the ammeter (7) and the temperature controller are connected to the multi-channel data recorder (10) through leads, and the heater is arranged in the oil pipe nipple (2).
2. The indoor evaluation device of the sacrificial anode material, according to claim 1, is characterized in that, in the pair of electrodes on the sacrificial anode short section (5) and the casing short section (1), the test electrode (3) and the reference electrode (4) are arranged along the circumferential direction of the sacrificial anode short section (5) and the casing short section (1), and in each pair of electrodes, the distance between the test electrode (3) and the reference electrode (4) is 1-2 cm.
3. The indoor evaluation device of the sacrificial anode material as claimed in claim 1, wherein the lower ends of the oil pipe nipple (2) and the casing nipple (1) are hermetically mounted on a sealing fixing base (9), the sealing fixing base (9) is provided with a circular groove in which the oil supply pipe nipple (2) and the casing nipple (1) are embedded, and the sealing fixing base (9) is made of polytetrafluoroethylene, PVC or nylon.
4. The indoor evaluation device of the sacrificial anode material as claimed in claim 1, wherein the length of the casing nipple (1) is 2-3 m, and the specification is 41/2″、51/2"or 7" sleeves; the length of the oil pipe nipple (2) is the same as that of the casing pipe nipple (1), and the specification is 23/8″、27/8"or 31/2"tubing; the length of the sacrificial anode (5) is 0.3-0.5 m, and the wall thickness is 8-15 mm.
5. The indoor evaluation device of the sacrificial anode material as claimed in claim 4, wherein the sacrificial anode short section (5) is provided with 2-4 pairs of test electrodes (3) and reference electrodes (4) on the outer surface at intervals along the length direction; 5-7 pairs of test electrodes (3) and reference electrodes (4) are arranged on the inner surface of the casing pipe nipple (1) at intervals along the length direction.
6. The indoor evaluation device of the sacrificial anode material as claimed in claim 1, wherein the inner wall of the casing nipple (1) is provided with an anti-corrosion coating.
7. The indoor evaluation device of the sacrificial anode material as claimed in claim 1, wherein the sacrificial anode nipple (5) and the oil pipe nipple (2) are insulated by an insulating tape, and the sacrificial anode nipple (5) and the oil pipe nipple (2) are in tight fit.
8. The apparatus for the indoor evaluation of sacrificial anode materials according to claim 1, characterized in that the ammeter (7) is connected in parallel with a resistance R; the casing nipple (1) is made of J55, N80 or P110, and the oil pipe nipple (2) is made of J55, N80 or P110.
9. A method for evaluating a sacrificial anode material indoors, which is performed by the indoor evaluation apparatus for a sacrificial anode material claimed in any one of claims 1 to 8, comprising the steps of:
filling the inner cavity of the oil pipe nipple (2) and the annular space between the oil pipe nipple (2) and the casing pipe nipple (1) with a corrosive medium, and starting a heater to heat the corrosive medium to a target temperature; recording the potentials of the casing pipe nipple (1) and the sacrificial anode nipple (5) at each reference position by using a multi-channel data recorder (10); and drawing a curve of the change of the protection potential along with time, a curve of the relation between the protection potential and the protection distance according to the test data on the multi-channel data recorder (10), and obtaining the change rule of the protection distance of the sacrificial anode short section (5) along with the simulation working condition through numerical value fitting.
10. The indoor evaluation method of the sacrificial anode material as claimed in claim 9, wherein the corrosion medium is taken from a formation water fluid medium of a real oil well shaft or is configured to simulate a water sample; the lowest mineralization value of the corrosive medium is more than or equal to 10g/l, the highest temperature value is less than or equal to 80 ℃, and the damage rate of the coating is 0-100%.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117214076A (en) * | 2023-09-14 | 2023-12-12 | 大连理工大学 | Comprehensive analysis device and monitoring method for corrosion state of marine structure |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204401107U (en) * | 2014-12-22 | 2015-06-17 | 盘锦辽河油田金宇集团有限公司 | Oil well sacrificial anode protection device |
| CN105154889A (en) * | 2015-09-08 | 2015-12-16 | 中国石油天然气股份有限公司 | Sacrificial anode protection device of inner coating cased well |
| JP2020012189A (en) * | 2018-07-20 | 2020-01-23 | 日本防蝕工業株式会社 | Sacrificial anode structure, apparatus for determining consumed state of sacrificial anode, and determination method |
| CN210287529U (en) * | 2019-06-04 | 2020-04-10 | 中国石油天然气股份有限公司 | Anticorrosive sacrificial anode short circuit device in sleeve pipe |
| CN211142182U (en) * | 2019-11-28 | 2020-07-31 | 西安山川石油科技有限责任公司 | Oil pipe brings sleeve pipe anode protection device into |
-
2021
- 2021-01-14 CN CN202110049491.9A patent/CN112921323B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204401107U (en) * | 2014-12-22 | 2015-06-17 | 盘锦辽河油田金宇集团有限公司 | Oil well sacrificial anode protection device |
| CN105154889A (en) * | 2015-09-08 | 2015-12-16 | 中国石油天然气股份有限公司 | Sacrificial anode protection device of inner coating cased well |
| JP2020012189A (en) * | 2018-07-20 | 2020-01-23 | 日本防蝕工業株式会社 | Sacrificial anode structure, apparatus for determining consumed state of sacrificial anode, and determination method |
| CN210287529U (en) * | 2019-06-04 | 2020-04-10 | 中国石油天然气股份有限公司 | Anticorrosive sacrificial anode short circuit device in sleeve pipe |
| CN211142182U (en) * | 2019-11-28 | 2020-07-31 | 西安山川石油科技有限责任公司 | Oil pipe brings sleeve pipe anode protection device into |
Non-Patent Citations (1)
| Title |
|---|
| 刘学勤: "应用牺牲阳极保护注水井油套管技术", 《腐蚀与防护》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117214076A (en) * | 2023-09-14 | 2023-12-12 | 大连理工大学 | Comprehensive analysis device and monitoring method for corrosion state of marine structure |
| CN117214076B (en) * | 2023-09-14 | 2024-05-14 | 大连理工大学 | Comprehensive analysis device and monitoring method for corrosion state of marine structure |
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| CN112921323B (en) | 2023-01-10 |
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