A system and method for on-line monitoring of corrosion and evaluation of cathodic protection of oilfield pipelines

Abstract

This invention provides a system and method for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines, belonging to the technical field of online monitoring and cathodic protection for oil pipeline corrosion. The system includes an online corrosion monitoring system for well site oil pipelines, a cathodic protection potential assessment system, a corrosion and cathodic protection data acquisition unit, a local online corrosion and cathodic protection monitoring unit, a well site oil pipeline, and a remote monitoring center unit. The corrosion and cathodic protection data acquisition unit is electrically connected to the remote monitoring center unit via the local online corrosion and cathodic protection monitoring unit. The corrosion and cathodic protection data acquisition unit is also electrically connected to the online corrosion monitoring system and the cathodic protection potential assessment system located on the well site oil pipeline via corresponding network cables. This invention, through the combined use of multiple corrosion detection methods, ensures the reliability of the detection results and reduces the limitations of single-method detection results.

Description

Technical Field

[0001] This invention belongs to the field of online monitoring and cathodic protection technology for oil pipeline corrosion, specifically relating to a system and method for online monitoring and cathodic protection assessment of oil pipeline corrosion at well sites. Background Technology

[0002] Oil pipelines at well sites are constantly corroded under natural or man-made conditions. Corrosion damage severely reduces the structural strength, load-bearing capacity, and reliability of the pipelines, shortens their service life, increases operational risks, significantly increases maintenance costs, shortens maintenance and replacement cycles, and threatens the safety of the entire transportation system. Therefore, corrosion monitoring of oil pipelines at well sites is crucial. Paying attention to corrosion and protecting oil pipelines at well sites not only has significant economic benefits but also substantial social benefits.

[0003] Publication No. CN116815189A discloses a fault diagnosis method, device, and electronic equipment for an oil and gas pipeline cathodic protection system. The method includes: determining the weight ratio among the de-energization potential, protection potential, and current resistance IR drop of each test pile based on a preset hierarchical model of system health; calculating the health of each test pile based on its de-energization potential, protection potential, and IR drop, and the weight ratio among these factors; obtaining the health of the oil and gas pipeline cathodic protection system based on the health of each test pile; and obtaining the fault diagnosis result of the oil and gas pipeline cathodic protection system based on its health. This solves the problems in related technologies where pipeline cathodic protection systems lack objective, accurate, and universal health assessment methods, leading to inaccurate identification, high false alarm rates, and high missed alarm rates during practical use.

[0004] Due to variations in location, soil corrosion environment, corrosion layer condition, cathodic protection effectiveness, transported crude oil medium, and operating conditions, buried oil pipelines exhibit different corrosion damage states. These differences necessitate different focuses in corrosion monitoring and the adoption of different monitoring methods. Therefore, developing an online corrosion monitoring system for well site oil pipelines, along with a cathodic protection assessment and monitoring method, holds significant market potential. Summary of the Invention

[0005] To overcome the limitations of existing conventional manual inspections in meeting on-site requirements, and the limitations of current online corrosion and cathodic protection monitoring technologies that cannot assess the effectiveness of corrosion inhibitor application and impressed current cathodic protection, this invention provides a system and method for online corrosion monitoring and cathodic protection assessment of well site oil pipelines. This invention, through the combined use of multiple corrosion detection methods, ensures the reliability of the detection results and reduces the limitations of single-method detection. It can determine the corrosion damage state of buried well site oil pipelines, locate corrosion layer breakage points, assess the aging state of the anti-corrosion layer, and form the basis for developing maintenance plans. It can determine the corrosion status and rate of well site oil pipelines, predict the safe service life of well site oil pipelines, and avoid potential hazards caused by corrosion leaks.

[0006] The technical solution adopted in this invention is as follows: A system for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines includes an online corrosion monitoring system, a cathodic protection potential assessment system, a corrosion and cathodic protection data acquisition unit, a local online corrosion and cathodic protection monitoring unit, a well site oil pipeline, and a remote monitoring center unit. The corrosion and cathodic protection data acquisition unit is electrically connected to the remote monitoring center unit via the local online corrosion and cathodic protection monitoring unit. The corrosion and cathodic protection data acquisition unit is electrically connected to the online corrosion monitoring system and the cathodic protection potential assessment system located on the well site oil pipeline via corresponding network cables.

[0007] The online corrosion monitoring system for well site oil pipelines includes an array ultrasonic thickness measurement unit, a hydrogen flux probe corrosion monitoring unit, and a resistance probe corrosion monitoring unit. The array ultrasonic thickness measurement unit, the hydrogen flux probe corrosion monitoring unit, and the resistance probe corrosion monitoring unit are sequentially installed on the well site oil pipeline. The resistance probe corrosion monitoring unit is equipped with a metal corrosion test piece.

[0008] The array ultrasonic thickness measurement unit, hydrogen flux probe corrosion monitoring unit, and resistance probe corrosion monitoring unit are all equipped with probes. Each probe is installed on the well site oil pipeline. The resistance probe corrosion monitoring unit has a window on its probe with a metal corrosion test piece installed on it.

[0009] The outer shells of the array ultrasonic thickness measurement unit, the hydrogen flux probe corrosion monitoring unit, and the resistance probe corrosion monitoring unit are respectively connected to grounding electrodes.

[0010] The grounding electrode is made of stainless steel grounding rod.

[0011] The cathodic protection potential assessment system includes a natural potential test piece unit, a reference electrode unit, a protection potential test point unit, and a power-off potential test piece unit. The natural potential test piece unit, the reference electrode unit, the protection potential test point unit, and the power-off potential test piece unit are sequentially arranged in the middle of the well site oil pipeline, and are located between the array ultrasonic thickness measurement unit and the resistance probe corrosion monitoring unit of the well site oil pipeline corrosion online monitoring system.

[0012] The on-site online corrosion and cathodic protection monitoring unit is connected to the corrosion and cathodic protection data acquisition unit via a transmission optical fiber; the on-site online corrosion and cathodic protection monitoring unit includes an on-site online corrosion monitoring unit and an on-site online cathodic protection monitoring unit; the corrosion and cathodic protection data acquisition unit includes a corrosion data acquisition unit and a cathodic protection data acquisition unit.

[0013] The probe of the hydrogen flux probe corrosion monitoring unit is a non-invasive bronze probe; the probe of the resistance probe corrosion monitoring unit is a precision resistance probe.

[0014] The probe of the array ultrasonic thickness measurement unit is a piezoelectric ceramic ultrasonic probe, which is used to monitor the wall thickness of the oil pipeline body in the well site and the corrosion rate of the monitoring point.

[0015] A method for online monitoring of corrosion and cathodic protection potential assessment of well site oil pipelines, comprising the following steps: Step 1: Configure monitoring equipment and install control system in the remote monitoring center unit, and connect the remote monitoring center unit to the local online corrosion and cathodic protection monitoring unit via optical cable; Step 2: Install the corrosion prevention online monitoring unit sensor. Step 3: Install the corrosion and cathodic protection data acquisition unit and lay the transmission fiber optic cable. Keep the corrosion and cathodic protection data acquisition unit away from the field and install it indoors in an explosion-proof manner. Use the transmission fiber optic cable to connect the corrosion and cathodic protection data acquisition unit to the local online corrosion and cathodic protection monitoring unit. Step 4: Transmit the data signals collected by the sensors in Step 2 to the remote monitoring center unit in Step 1 through the corrosion and cathodic protection data acquisition unit and the on-site online corrosion and cathodic protection monitoring unit connected in Step 3, and debug the online monitoring system for corrosion protection effect of well site oil pipeline and the cathodic protection potential evaluation system. Step 5: The inspection of the well site oil pipeline corrosion online monitoring system and cathodic protection potential assessment system begins. The well site oil pipeline corrosion prevention effect online monitoring system and cathodic protection potential assessment system are started on the computer of the local online corrosion and cathodic protection monitoring unit.

[0016] In step 2, the installation of the corrosion monitoring unit sensor specifically involves: installing an array ultrasonic thickness sensor, a hydrogen flux probe corrosion monitoring sensor, a resistance probe corrosion monitoring sensor, a natural potential test piece, a reference electrode, a protection potential test point, and a power-off potential test piece on the well site oil pipeline. The outer shells of the array ultrasonic thickness sensor, the hydrogen flux probe corrosion monitoring sensor, and the resistance probe corrosion monitoring sensor are respectively connected to the grounding electrode.

[0017] In step 4, the data detected by the array ultrasonic thickness measurement unit, the hydrogen flux probe corrosion monitoring unit, and the resistance probe corrosion monitoring unit are uploaded to the remote monitoring center unit. The online monitoring system for the corrosion protection effect of the well site oil pipeline is debugged in the control system configuration screen of the remote monitoring center, and the response time of various sensors is compared when the corrosion rate is 0.2 mm / a. The cathodic protection parameter data of the spontaneous potential test piece unit, the reference electrode unit, the protection potential test point unit, and the power failure potential test piece unit are uploaded to the remote monitoring center unit. The cathodic protection potential evaluation system is debugged in the control system configuration screen of the remote monitoring center unit.

[0018] In step 5, the online corrosion monitoring system and cathodic protection potential assessment system for the well site oil pipeline begin their inspection. Simultaneously, the array ultrasonic thickness measurement unit, hydrogen flux probe corrosion monitoring unit, and resistance probe corrosion monitoring unit begin operation. The corrosion data acquisition unit collects and converts various corrosion signals from the well site oil pipeline and transmits them via optical fiber to the local online corrosion and cathodic protection monitoring unit for storage. The data is then uploaded to the remote monitoring center unit. After processing by the monitoring system, accurate corrosion data is obtained, and the corrosion status is calculated to determine the corrosion and leakage state of the well site oil pipeline, locate the anti-corrosion layer, assess the aging state of the anti-corrosion layer, and identify pipeline operating parameters. The system guides the selection and concentration of corrosion inhibitors, adjusts the injection of corrosion inhibitors, and guides the implementation plan for forced external current cathodic protection of oil pipelines at the well site. It also provides online parameter warnings through a monitoring system. On the other hand, the cathodic protection parameters of the natural potential test piece unit, reference electrode unit, protection potential test point unit, and power-off potential test piece unit are analyzed and processed by the corrosion and cathodic protection data acquisition unit. These signals are then transmitted via optical fiber to the local online cathodic protection monitoring unit for storage of cathodic protection potential data for the oil pipelines at the well site. The data is then uploaded to the remote monitoring center unit, where it is processed by the monitoring system to obtain accurate cathodic protection potential data and calculate the cathodic protection status.

[0019] The beneficial effects of this invention are: This invention, through the combined use of multiple corrosion detection methods, ensures the reliability of the detection results and reduces the limitations of single-method detection results. It can determine the corrosion damage status of buried well site oil pipelines, locate corrosion layer damage points, assess the aging status of anti-corrosion layers, and form the basis for developing maintenance plans. It can also determine the corrosion status and rate of well site oil pipelines, predict the safe service life of well site oil pipelines, and avoid potential hazards caused by corrosion leaks.

[0020] This invention, through data accumulation, grasps the patterns of corrosion occurrence, understands the corrosion inhibition effects of corrosion inhibitors, guides the selection and optimal concentration of corrosion inhibitors, and adjusts the injection of corrosion inhibitors. This not only slows down corrosion occurrence but also avoids waste of corrosion inhibitors, providing a scientific basis for process corrosion prevention. Furthermore, this invention guides the optimal implementation scheme for forced current cathodic protection of well site oil pipelines by remotely monitoring cathodic protection potential data. Forced current cathodic protection is an effective technology for controlling external corrosion and can effectively extend the service life of well site oil pipelines.

[0021] This invention establishes an online monitoring system for corrosion of well site oil pipelines, providing a scientific basis for the replacement, repair, and maintenance of oil pipelines. It is of great significance for ensuring the safe, efficient, and stable operation of well site oil pipelines, environmental protection, and sustainable development of oil fields. This invention ensures the reliability, stability, and accuracy of the well site oil pipeline corrosion prevention effect monitoring system and the cathodic protection potential assessment system in terms of functionality, safety, environmental protection, and ease of operation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the well site oil pipeline corrosion online monitoring and cathodic protection potential assessment system of the present invention.

[0023] The present invention will now be described in further detail with reference to the accompanying drawings.

[0024] In the figure, the attached figures are labeled as follows: 1. Array ultrasonic thickness measurement unit; 2. Hydrogen flux probe corrosion monitoring unit; 3. Spontaneous potential test piece unit; 4. Reference electrode unit; 5. Protection potential test point unit; 6. Power-off potential test piece unit; 7. Metal corrosion test piece; 8. Resistance probe corrosion monitoring unit; 9. Well site oil pipeline; 10. Corrosion and cathodic protection data acquisition unit; 11. On-site online corrosion and cathodic protection monitoring unit; 12. Remote monitoring center unit. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0027] Example 1: To overcome the limitations of existing conventional manual inspections in meeting on-site requirements, and the limitations of current online corrosion and cathodic protection monitoring technologies that cannot assess the effectiveness of corrosion inhibitor application and impressed current cathodic protection, this invention provides a system and method for online corrosion monitoring and cathodic protection assessment of well site oil pipelines. This invention, through the combined use of multiple corrosion detection methods, ensures the reliability of the detection results and reduces the limitations of single-method detection. It can determine the corrosion damage state of buried well site oil pipelines, locate corrosion layer breakage points, assess the aging state of the anti-corrosion layer, and form the basis for developing maintenance plans. It can determine the corrosion status and rate of well site oil pipelines, predict the safe service life of well site oil pipelines, and avoid potential hazards caused by corrosion leaks.

[0028] A system for online monitoring of corrosion and cathodic protection assessment of well site oil pipelines includes an online corrosion monitoring system for well site oil pipelines, a cathodic protection potential assessment system, a corrosion and cathodic protection data acquisition unit 10, a local online corrosion and cathodic protection monitoring unit 11, a well site oil pipeline 9, and a remote monitoring center unit 12. The corrosion and cathodic protection data acquisition unit 10 is electrically connected to the remote monitoring center unit 12 via the local online corrosion and cathodic protection monitoring unit 11. The corrosion and cathodic protection data acquisition unit 10 is electrically connected to the online corrosion monitoring system and the cathodic protection potential assessment system installed on the well site oil pipeline 9 via corresponding network cables.

[0029] like Figure 1As shown, in this invention, the remote monitoring center unit 12 includes a monitoring unit and a control system. The control system is preferably a SCADA control system. The monitoring unit is a computer, and the SCADA control system is installed on the computer to perform corrosion data analysis. The remote monitoring center unit 12 has functions such as corrosion data acquisition, monitoring of parameters including well site oil pipeline corrosion residue, corrosion rate, temperature and humidity, and cathodic protection potential, accident replay, event sequence recording, and online parameter early warning. The on-site online corrosion and cathodic protection monitoring unit 11 is equipped with a computer and an information storage module. The computer is used to display corrosion data and cathodic protection data for convenient on-site monitoring. The information storage module stores the signals from the corrosion and cathodic protection data acquisition unit 10 and reports them to the remote monitoring center unit 12.

[0030] This invention, through the combined use of multiple corrosion detection methods, ensures the reliability of detection results and reduces the limitations of single-method detection. It can determine the corrosion damage state of buried well site oil pipelines, locate corrosion layer breakpoints, assess the aging state of anti-corrosion layers, and form the basis for developing maintenance plans. It can determine the corrosion status and rate of well site oil pipelines, predict their safe service life, and avoid potential leaks due to corrosion. This invention establishes an online corrosion monitoring system for well site oil pipelines, providing a scientific basis for pipeline replacement, repair, and maintenance. It is of great significance for ensuring the safe, efficient, and stable operation of well site oil pipelines, environmental protection, and sustainable oilfield development. This invention guides the optimal implementation scheme for forced impressed current cathodic protection of well site oil pipelines by remotely monitoring cathodic protection potential data. Forced current cathodic protection is an effective technology for controlling external corrosion and can effectively extend the service life of well site oil pipelines. This invention, in terms of functionality, safety, environmental protection, and ease of operation, ensures the reliability, stability, and accuracy of the well site oil pipeline corrosion prevention effect monitoring system and cathodic protection assessment system.

[0031] Example 2: Based on Embodiment 1, in this embodiment, preferably, the online corrosion monitoring system for well site oil pipelines includes an array ultrasonic thickness measurement unit 1, a hydrogen flux probe corrosion monitoring unit 2, and a resistance probe corrosion monitoring unit 8. The array ultrasonic thickness measurement unit 1, the hydrogen flux probe corrosion monitoring unit 2, and the resistance probe corrosion monitoring unit 8 are sequentially arranged on the well site oil pipeline 9, and the resistance probe corrosion monitoring unit 8 is provided with a metal corrosion test piece 7.

[0032] In this invention, the array ultrasonic thickness measurement unit 1 employs a piezoelectric ceramic ultrasonic probe, utilizing innovative piezoelectric ultrasonic technology. It incorporates a built-in quartz crystal oscillator and a high-frequency oscillation signal generation circuit, offering high resolution. This unit is used to monitor parameters such as the wall thickness of the well site oil pipeline and the corrosion rate at monitoring points. It performs annular array thickness measurement of the well site oil pipeline, enabling online corrosion monitoring without production shutdowns or drilling into the pipeline. By analyzing the thickness variation trend at various points along the well site oil pipeline over time, the growth rate of internal corrosion defects can be calculated, facilitating the early detection of high-risk corrosion defects. This provides a basis for preventative maintenance and replacement of the well site oil pipeline 9, resulting in significant economic benefits. It is primarily used for monitoring corrosion in oil pipelines with high pressure and H2S concentrations where drilling is not required.

[0033] In specific applications, a CSB-type array ultrasonic thickness measurement unit is used, employing an 8-column, 2-position probe array with a total of 16 channels. The array ultrasonic probes measure corrosion thinning and corrosion rate over a large area of ​​the pipe's inner wall, and the results are visualized in 3D. The probes utilize non-invasive, flexible array ultrasonic sensors, precision time measurement circuits, and temperature compensation circuits. This overcomes the limitations and difficulties of commonly used ultrasonic sensors when measuring curved surfaces, accurately monitoring the internal corrosion thickness and corrosion rate of the curved surfaces in the well site oil pipeline, providing a basis for the rapid diagnosis of internal corrosion defects in the well site oil pipeline.

[0034] The CSB-type array ultrasonic thickness gauge unit measures material thickness using the pulse-echo time difference of ultrasonic waves. When ultrasonic waves propagate through a workpiece, some waves are reflected when they encounter the interface between different materials, while the remaining waves continue to propagate through the interface. The circuit design utilizes the reflection characteristics of ultrasonic waves by fixing an ultrasonic composite probe (including a transmitter and receiver) to the surface of the material being measured. A high-precision time-resolved circuit measures the time difference between the reflections of the ultrasonic transmitted signal on the inner and outer surfaces, thereby calculating the thickness of the material. This is suitable for determining the internal corrosion thickness and corrosion rate of curved surfaces such as pipes or storage tanks.

[0035] The main technical specifications are: thickness measurement range: 1~50mm; Thickness measurement resolution: 0.01mm; Thickness measurement accuracy: 1% × total thickness ± 0.01 mm; Ultrasonic frequency: 5MHz; Acoustic probe diameter: Ø.8mm; Measurement channels: 1, 4, 8, 16 or 32 channels (optional); Communication method: RS485, standard Modbus protocol; Explosion-proof marking: ExiaⅡBT4.

[0036] Preferably, the array ultrasonic thickness measurement unit 1, the hydrogen flux probe corrosion monitoring unit 2, and the resistance probe corrosion monitoring unit 8 are all equipped with probes, and each probe is respectively installed on the well site oil pipeline 9. The probe of the resistance probe corrosion monitoring unit 8 has a window on its outside and is equipped with a metal corrosion test piece 7.

[0037] Preferably, the outer shells of the array ultrasonic thickness measurement unit 1, the hydrogen flux probe corrosion monitoring unit 2, and the resistance probe corrosion monitoring unit 8 are respectively connected to grounding electrodes.

[0038] Preferably, the grounding electrode is a stainless steel grounding rod.

[0039] In this invention, the hydrogen flux probe corrosion monitoring unit 2 employs non-invasive bronze probe monitoring technology to monitor the hydrogen concentration and internal wall corrosion rate of pipelines without drilling, avoiding secondary hazards caused by pipeline perforation and ensuring higher safety. The probe consists of a specially designed thin-film electrolytic cell, which is closely attached to the outer surface of the pipeline being tested and fixed by a locking mechanism. It uses a fully solid alkaline gel electrolyte with a long service life. Employing constant potential polarization and potential square wave excitation modes, it features a high-precision analog-to-digital conversion circuit, automatic current range selection, automatic calculation and storage of test data, and a low-power design, making it suitable for use in situations without a power source. Its primary application is monitoring the hydrogen concentration and internal wall corrosion rate of well site oil pipelines 9 without drilling.

[0040] In specific applications, the hydrogen flux probe corrosion monitoring unit 2 employs a QTL-type hydrogen flux probe corrosion monitoring unit. Based on constant potential polarization and using a potential square wave excitation mode, it measures the residual hydrogen concentration and diffusion rate in metals. It mainly consists of a constant potential control circuit, a microcontroller system, a high-precision analog-to-digital converter circuit, a clock circuit, and a communication interface circuit. The entire measurement process is controlled by the microcontroller, and the current range is automatically selected via an electronic switch. Test data is automatically calculated and stored. It features a low-power design, allowing operation without a power supply in the field. The QTL-type hydrogen flux probe corrosion monitoring unit can store approximately 100,000 sets of results. Measurement results can be uploaded to corrosion monitoring unit 10 via an RS485 communication line for post-processing and display of the data.

[0041] Its main technical parameters are: Corrosion potential measurement range: -2.5V to 2.5V; Hydrogen current measurement range: 1×10⁻¹⁰~1×10⁻³A; Explosion-proof rating: ExibⅡCT4Gb.

[0042] In this invention, the resistance probe corrosion monitoring unit 8 employs precision resistance probe technology, incorporating a high-sensitivity converter and temperature compensation circuit. Both the high-sensitivity converter and temperature compensation circuit are existing technologies and will not be further described in this invention. The resistance probe corrosion monitoring unit 8 has high resolution, monitoring the corrosion rate of the well site oil pipeline 9, and monitoring parameters such as the remaining thickness of the sensor, corrosion rate, and temperature. It uses a high-pressure carrier and a pressurized pick-and-place device, allowing for probe replacement under pressure. The resistance probe corrosion monitoring unit 8 has two weightlessness plates and one ohmic resistance corrosion sensing plate arranged at 120° on its bottom side. This allows for comparison of the corrosion rate of protected and self-corroding test pieces with ohmic resistance measurements. By measuring the resistance increment of the metal test piece electrically connected to the main structure, the total corrosion amount and corrosion rate of the test piece are calculated, avoiding the significant drawback of not being able to measure the corrosion rate using electrochemical polarization under cathodic protection. Its main application is monitoring the corrosion of the high-pressure well site oil pipeline 9.

[0043] For specific applications, the DZTZ type resistance probe corrosion monitoring unit is preferred. It is suitable for continuous corrosion monitoring of multiphase systems containing oil, water, and gas in oil pipelines, acquiring data such as corrosion rate, amount of corrosion, and remaining corrosion. It employs a high-speed, low-power MCU unit and a high-precision, low-power 24-bit AD converter, achieving a resolution of 0.06 / 1,000,000. Utilizing AC excitation source technology and the AV bridge principle, it achieves high micro-resistance measurement resolution, with corrosion resolution reaching the lifespan of the sensing element. A built-in temperature compensation circuit minimizes the impact of temperature on the measurement data.

[0044] Its main technical specifications are: AD conversion resolution: 24bit (0.06 / 1,000,000); Etching resolution: Sensing element lifetime @ 0.01%; Communication method: RS485, standard Modbus protocol; Explosion-proof marking: ExibⅡCT4Gb.

[0045] Preferably, the cathodic protection potential assessment system includes a natural potential test piece unit 3, a reference electrode unit 4, a protection potential test point unit 5, and a power-off potential test piece unit 6. The natural potential test piece unit 3, the reference electrode unit 4, the protection potential test point unit 5, and the power-off potential test piece unit 6 are sequentially arranged in the middle of the well site oil pipeline 9, and are located between the array ultrasonic thickness measurement unit 1 and the resistance probe corrosion monitoring unit 8 of the well site oil pipeline corrosion online monitoring system.

[0046] Preferably, the on-site online corrosion and cathodic protection monitoring unit 11 is connected to the corrosion and cathodic protection data acquisition unit 10 via a transmission optical fiber; the on-site online corrosion and cathodic protection monitoring unit 11 includes an on-site online corrosion monitoring unit and an on-site online cathodic protection monitoring unit; the corrosion and cathodic protection data acquisition unit 10 includes a corrosion data acquisition unit and a cathodic protection data acquisition unit.

[0047] In this invention, the cathodic protection data acquisition unit adopts a high-precision, low-power 24-bit AD converter and utilizes the patented AC excitation source technology and AV bridge principle to achieve high-resolution micro-resistance measurement.

[0048] The cathodic protection data acquisition unit incorporates a cathodic protection potential measurement module with four differential voltage and one current acquisition channels. It can measure the protection potential of buried steel pipes under cathodic protection conditions, as well as the natural corrosion potential and protection current of the test piece. The unit also features a built-in relay control circuit, which can instantaneously disconnect the electrical connection between the buried test piece and the steel pipe under timed control, delaying the measurement of the steel piece's de-energization potential. This cathodic protection potential data acquisition unit is primarily used for multi-parameter monitoring of cathodic protection parameters such as AC interference potential, natural corrosion potential, energized potential, and de-energized potential in buried oil pipelines. The effectiveness of cathodic protection can be determined by measuring the potential between the protected object, the polarized test piece, the self-corroding test piece, and the reference electrode.

[0049] In practical applications, the preferred cathodic protection data acquisition unit is the YJBH type cathodic protection potential data acquisition unit. The YJBH type cathodic protection potential data acquisition unit has three built-in differential voltage acquisition channels, which can measure the protection potential (V1) of the buried oil pipeline relative to the reference electrode under cathodic protection, and the natural corrosion potential (V2) of the exposed steel sheet relative to the reference electrode. The monitoring unit has a built-in relay, which can instantly disconnect the buried steel sheet electrically connected to the buried steel pipeline under the control of a microcontroller. Then, it synchronously monitors the de-energization potential-time curve (V3) of the steel sheet, and extracts the potential value 10ms to 100ms after the de-energization as the de-energization potential of the buried oil pipeline according to set parameters. This de-energization potential is generally considered to eliminate IR drop and reflect the true protection potential of the buried oil pipeline.

[0050] The YJBH type cathodic protection potential data acquisition unit can effectively eliminate power frequency interference. The instantaneous interruption potential is tested according to the GB / T21246 power-off potential test method, that is, the relay is turned on for 4 seconds and turned off for 1 second. The instantaneous protection potential of the test piece relative to the reference electrode is collected within 100ms after the power is turned off. This potential value eliminates the IR drop in the cathodic protection potential and can accurately reflect the real protection status of buried pipelines.

[0051] The YJBH-type cathodic protection potential data acquisition unit can be installed in conventional test piles to achieve intelligent potential acquisition. Upon initial use, measurement parameters, including potential sampling interval, number of channels, and data upload time window, can be configured via a data downloader. The on-site online corrosion and cathodic protection monitoring unit can upload all newly added historical data to the remote monitoring center 12 within a specified time period. Users can check parameters such as protection potential, de-energization potential, and self-corrosion potential of each test pile at any time by accessing a password-protected website.

[0052] Its main technical specifications are Potential measurement channels: 4 (protection potential, self-corrosion potential, power-off potential, interference potential). Potential measurement range: -2.5V to +2.5V; Potential measurement accuracy: 0.1% ± 10mV at full scale; Current measurement range: −20mA to +20mA; Power-off sampling time: 1 to 100 seconds, configurable; Communication method: RS485, standard Modbus protocol; Explosion-proof marking: ExibⅡCT4Gb.

[0053] Preferably, the probe of the hydrogen flux probe corrosion monitoring unit 2 is a non-invasive bronze probe; the probe of the resistance probe corrosion monitoring unit 8 is a precision resistance probe.

[0054] Preferably, the probe of the array ultrasonic thickness measurement unit 1 is a piezoelectric ceramic ultrasonic probe, used to monitor the wall thickness of the well site oil pipeline 9 and the corrosion rate of the monitoring point.

[0055] The specific detection and evaluation methods of this invention are as follows: The first step is to configure the remote monitoring center unit 12, the local online corrosion and cathodic protection monitoring unit 11, and the corrosion and cathodic protection data acquisition unit. The monitoring equipment is configured in the remote monitoring center unit 12, and the SCADA control system is installed. The remote monitoring center unit 12 and the local online corrosion monitoring unit 11 are connected by optical fiber. The second step is to install the corrosion online monitoring unit sensor, including array ultrasonic thickness sensor, hydrogen flux probe corrosion monitoring sensor, resistance probe corrosion monitoring sensor, natural potential test piece, reference electrode, protection potential test point, and power-off potential test piece on the well site oil pipeline. The outer shells of the array ultrasonic thickness sensor, hydrogen flux probe corrosion monitoring sensor, and resistance probe corrosion monitoring sensor are respectively connected to the grounding electrode. The third step is to install the corrosion and cathodic protection data acquisition unit 10 and lay the transmission optical fiber. Keep the corrosion and cathodic protection data acquisition unit 10 away from the site, pay attention to explosion protection and install it indoors. Use the transmission optical fiber to connect the corrosion and cathodic protection data acquisition unit 10 and the local online corrosion and cathodic protection monitoring unit 11. The fourth step involves debugging the online corrosion monitoring system and cathodic protection potential assessment system for the well site oil pipeline. Data from the array ultrasonic thickness measurement unit 1, hydrogen flux probe corrosion monitoring unit 2, and resistance probe corrosion monitoring unit 8 are uploaded to the remote monitoring center unit 12. The online corrosion monitoring system for the well site oil pipeline is debugged in the SCADA control system configuration screen of the remote monitoring center unit 12, comparing the response times of various sensors when the corrosion rate is 0.2 mm / a. The cathodic protection multi-parameter data from the AC interference potential unit, natural corrosion potential unit, energized potential unit, and de-energized potential unit (i.e., natural potential test piece unit 3, reference electrode unit 4, protection potential test point unit 5, and de-energized potential test piece unit 6) of the oil pipeline cathodic protection potential assessment system are uploaded to the remote monitoring center unit 12. The cathodic protection potential assessment system is debugged in the SCADA control system configuration screen of the remote monitoring center unit 12. The fifth step involves the commencement of the inspection of the online corrosion monitoring system and cathodic protection potential assessment system for the well site oil pipeline. The system is activated on the computer of the on-site online corrosion and cathodic protection monitoring unit 11. Simultaneously, the array ultrasonic thickness measurement unit 1, hydrogen flux probe corrosion monitoring unit 2, and resistance probe corrosion monitoring unit 8 begin operation. The corrosion data acquisition unit analyzes and processes various corrosion signals from the well site oil pipeline, converting them into 4-20mA signals and RS-485 signals. The signal is transmitted via optical fiber to the local online corrosion and cathodic protection monitoring unit 10 for storage of corrosion data of the well site oil pipeline 9, and then uploaded to the remote monitoring center unit 12. After processing by the SCADA monitoring system, accurate corrosion data is obtained and the corrosion situation is calculated to determine the corrosion and leakage status of the well site oil pipeline 9, locate the anti-corrosion layer, assess the aging status of the anti-corrosion layer, identify pipeline operating parameters, guide the selection and concentration of corrosion inhibitors, adjust the injection of corrosion inhibitors, guide the implementation plan of forced impressed current cathodic protection for the well site oil pipeline, and provide online parameter early warning through the SCADA monitoring system. On the other hand, the cathodic protection parameters of the buried oil pipeline's AC interference potential unit, natural corrosion potential unit, energized potential unit, and de-energized potential unit (i.e., natural potential test piece unit 3, reference electrode unit 4, protection potential test point unit 5, and de-energized potential test piece unit 6) are analyzed and processed by the corrosion and cathodic protection potential data acquisition unit 10 and converted into 4-20mA signals and RS-485 signals. The signals are transmitted through the transmission optical fiber to the local cathodic protection potential monitoring unit 11 for storage of cathodic protection potential data of the well site oil pipeline, and then uploaded to the remote monitoring center unit 12. After processing by the SCADA monitoring system, accurate data of the cathodic protection potential is obtained and the cathodic protection status is calculated.

[0056] This invention establishes an online monitoring system for corrosion of well site oil pipelines, providing a scientific basis for the replacement, repair, and maintenance of oil pipelines. It is of great significance for ensuring the safe, efficient, and stable operation of well site oil pipelines, environmental protection, and sustainable development of oil fields. This invention ensures the reliability, stability, and accuracy of the well site oil pipeline corrosion prevention monitoring system and cathodic protection assessment system in terms of functionality, safety, environmental protection, and ease of operation.

[0057] Example 3: Based on Embodiment 1 or 2, this embodiment provides a method for online monitoring of corrosion and cathodic protection potential assessment of well site oil pipelines, the specific steps of which are as follows: Step 1: Configure monitoring equipment and install control system in remote monitoring center unit 12, and connect remote monitoring center unit 12 to local online corrosion and cathodic protection monitoring unit 11 via optical cable; Step 2: Install the corrosion prevention online monitoring unit sensor. Step 3: Install the corrosion and cathodic protection data acquisition unit 10 and lay the transmission optical fiber. Install the corrosion and cathodic protection data acquisition unit 10 indoors away from the field and in an explosion-proof manner. Connect the corrosion and cathodic protection data acquisition unit 10 to the local online corrosion and cathodic protection monitoring unit 11 using the transmission optical fiber. Step 4: Transmit the data signals collected by the sensors in Step 2 to the remote monitoring center unit 12 in Step 1 through the corrosion and cathodic protection data acquisition unit 10 and the on-site online corrosion and cathodic protection monitoring unit 11 connected in Step 3, and debug the online monitoring system for corrosion protection effect of well site oil pipeline and the cathodic protection potential evaluation system. Step 5: The inspection of the well site oil pipeline corrosion online monitoring system and cathodic protection potential assessment system begins. The well site oil pipeline corrosion prevention effect online monitoring system and cathodic protection potential assessment system are started on the computer of the local online corrosion and cathodic protection monitoring unit 11.

[0058] Preferably, in step 2, the installation of the corrosion monitoring unit sensor specifically involves: installing an array ultrasonic thickness sensor, a hydrogen flux probe corrosion monitoring sensor, a resistance probe corrosion monitoring sensor, a natural potential test piece, a reference electrode, a protection potential test point, and a power-off potential test piece on the well site oil pipeline 9. The outer shells of the array ultrasonic thickness sensor, the hydrogen flux probe corrosion monitoring sensor, and the resistance probe corrosion monitoring sensor are respectively connected to grounding electrodes.

[0059] Preferably, in step 4, the data detected by the array ultrasonic thickness measurement unit 1, the hydrogen flux probe corrosion monitoring unit 2, and the resistance probe corrosion monitoring unit 8 are uploaded to the remote monitoring center unit 12. The online monitoring system for the corrosion protection effect of the well site oil pipeline is debugged in the control system configuration screen of the remote monitoring center unit 12, and the response time of various sensors is compared when the corrosion rate is 0.2 mm / a. The cathodic protection parameter data of the natural potential test piece unit 3, the reference electrode unit 4, the protection potential test point unit 5, and the power failure potential test piece unit 6 are uploaded to the remote monitoring center unit 12. The cathodic protection potential evaluation system is debugged in the control system configuration screen of the remote monitoring center unit 12.

[0060] Preferably, in step 5, when the inspection of the well site oil pipeline corrosion online monitoring system and the cathodic protection potential assessment system begins, the array ultrasonic thickness measurement unit 1, the hydrogen flux probe corrosion monitoring unit 2, and the resistance probe corrosion monitoring unit 8 start working. The corrosion data acquisition unit collects and converts various well site oil pipeline corrosion signals and transmits them through optical fiber to the local online corrosion and cathodic protection monitoring unit 10 for storage. Then, it uploads the data to the remote monitoring center unit 12. After processing by the monitoring system, accurate corrosion data is obtained, and the corrosion status is calculated to determine the corrosion and leakage status of the well site oil pipeline, locate the anti-corrosion layer, assess the aging status of the anti-corrosion layer, and determine the pipeline operation. The parameters guide the selection and concentration of corrosion inhibitors, adjust the injection of corrosion inhibitors, and guide the implementation plan for forced external current cathodic protection of oil pipelines in the well site. Online parameter warnings are provided through the monitoring system. On the other hand, the cathodic protection parameters of the natural potential test piece unit 3, reference electrode unit 4, protection potential test point unit 5, and power failure potential test piece unit 6 are transmitted to the local online cathodic protection monitoring unit via optical fiber after the signals are analyzed and processed by the corrosion and cathodic protection data acquisition unit 10. The data are stored for cathodic protection potential data of the oil pipeline in the well site, and then uploaded to the remote monitoring center unit 12. After processing by the monitoring system, accurate cathodic protection potential data is obtained and the cathodic protection status is calculated.

[0061] In this invention, an array ultrasonic thickness measurement unit 1, a hydrogen flux corrosion monitoring unit 2, a resistance probe corrosion monitoring unit 8, a spontaneous potential test piece unit 3, a reference electrode unit 4, a protection potential test point unit 5, and a power-off potential test piece unit 6 are connected to the well site oil pipeline 9. The array ultrasonic thickness measurement unit 1, hydrogen flux corrosion monitoring unit 2, spontaneous potential test piece unit 3, reference electrode unit 4, protection potential test point unit 5, power-off potential test piece unit 6, and resistance probe corrosion monitoring unit 8 are sequentially arranged on the well site oil pipeline 9; the resistance probe corrosion monitoring unit 8 is equipped with a metal corrosion test piece 7.

[0062] This invention establishes an online monitoring system for corrosion of well site oil pipelines, providing a scientific basis for the replacement, repair, and maintenance of oil pipelines. It is of great significance for ensuring the safe, efficient, and stable operation of well site oil pipelines, environmental protection, and sustainable development of oil fields. This invention ensures the reliability, stability, and accuracy of the well site oil pipeline corrosion prevention monitoring system and cathodic protection assessment system in terms of functionality, safety, environmental protection, and ease of operation.

[0063] This invention, through data accumulation, grasps the patterns of corrosion occurrence, understands the corrosion inhibition effects of corrosion inhibitors, guides the selection and optimal concentration of corrosion inhibitors, and adjusts the injection of corrosion inhibitors. This not only slows down corrosion but also avoids waste of corrosion inhibitors, providing a scientific basis for process corrosion prevention. Furthermore, this invention guides the optimal implementation of forced current cathodic protection for well site oil pipelines by remotely monitoring cathodic protection potential data. Forced current cathodic protection is an effective technology for controlling external corrosion and can effectively extend the service life of well site oil pipelines. This invention, through the combined use of multiple corrosion detection methods, ensures the reliability of detection results, reduces the limitations of single-method detection results, and can determine the corrosion damage state of buried well site oil pipelines, locate corrosion layer damage points, assess the aging state of anti-corrosion layers, and provide a basis for developing maintenance plans. It can determine the corrosion status and rate of well site oil pipelines, predict the safe service life of well site oil pipelines, and avoid potential risks of corrosion-induced leaks.

[0064] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0065] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0066] The examples above are merely illustrative of the present invention and do not constitute a limitation on the scope of protection of the present invention. All designs that are the same as or similar to the present invention fall within the scope of protection of the present invention. Device structures and method steps not described in detail in this invention are prior art and will not be further described in this invention.

Claims

1. A system for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines, characterized in that: It includes an online corrosion monitoring system for well site oil pipelines, a cathodic protection potential assessment system, a corrosion and cathodic protection data acquisition unit (10), an on-site online corrosion and cathodic protection monitoring unit (11), a well site oil pipeline (9), and a remote monitoring center unit (12); the corrosion and cathodic protection data acquisition unit (10) is electrically connected to the remote monitoring center unit (12) through the on-site online corrosion and cathodic protection monitoring unit (11); the corrosion and cathodic protection data acquisition unit (10) is electrically connected to the online corrosion monitoring system for well site oil pipelines and the cathodic protection potential assessment system installed on the well site oil pipeline (9) through corresponding network cables.

2. The system for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines according to claim 1, characterized in that: The well site oil pipeline corrosion online monitoring system includes an array ultrasonic thickness measurement unit (1), a hydrogen flux probe corrosion monitoring unit (2) and a resistance probe corrosion monitoring unit (8). The array ultrasonic thickness measurement unit (1), the hydrogen flux probe corrosion monitoring unit (2) and the resistance probe corrosion monitoring unit (8) are sequentially installed on the well site oil pipeline (9). The resistance probe corrosion monitoring unit (8) is equipped with a metal corrosion test piece (7).

3. The system for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines according to claim 2, characterized in that: The array ultrasonic thickness measurement unit (1), hydrogen flux probe corrosion monitoring unit (2) and resistance probe corrosion monitoring unit (8) are all equipped with probes. Each probe is set on the well site oil pipeline (9). The probe of the resistance probe corrosion monitoring unit (8) has a window on the outside and is equipped with a metal corrosion test piece (7).

4. The system for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines according to claim 2, characterized in that: The outer shells of the array ultrasonic thickness measurement unit (1), the hydrogen flux probe corrosion monitoring unit (2), and the resistance probe corrosion monitoring unit (8) are respectively connected to grounding electrodes.

5. The system for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines according to claim 4, characterized in that: The grounding electrode is made of stainless steel grounding rod.

6. The system for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines according to claim 1, characterized in that: The cathodic protection potential assessment system includes a natural potential test piece unit (3), a reference electrode unit (4), a protection potential test point unit (5), and a power-off potential test piece unit (6). The natural potential test piece unit (3), the reference electrode unit (4), the protection potential test point unit (5), and the power-off potential test piece unit (6) are sequentially located in the middle of the well site oil pipeline (9) and between the array ultrasonic thickness measurement unit (1) and the resistance probe corrosion monitoring unit (8) of the well site oil pipeline corrosion online monitoring system.

7. The system for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines according to claim 1, characterized in that: The on-site online corrosion and cathodic protection monitoring unit (11) is connected to the corrosion and cathodic protection data acquisition unit (10) via a transmission optical fiber; the on-site online corrosion and cathodic protection monitoring unit (11) includes an on-site online corrosion monitoring unit and an on-site online cathodic protection monitoring unit; the corrosion and cathodic protection data acquisition unit (10) includes a corrosion data acquisition unit and a cathodic protection data acquisition unit.

8. The system for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines according to claim 2, characterized in that: The probe of the hydrogen flux probe corrosion monitoring unit (2) is a non-invasive bronze probe; The probe of the resistance probe corrosion monitoring unit (8) is a precision resistance probe.

9. The system for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines according to claim 2, characterized in that: The probe of the array ultrasonic thickness measurement unit (1) is a piezoelectric ceramic ultrasonic probe, which is used to monitor the wall thickness of the well site oil pipeline (9) and the corrosion rate of the monitoring point.

10. A monitoring and evaluation method for a system of online monitoring and cathodic protection assessment of corrosion in well site oil pipelines according to any one of claims 1-9, characterized in that: The specific steps are as follows: Step 1: Configure monitoring equipment in the remote monitoring center unit (12), install the control system, and connect the remote monitoring center unit (12) to the local online corrosion and cathodic protection monitoring unit (11) via optical fiber; Step 2: Install the corrosion prevention online monitoring unit sensor. Step 3: Install the corrosion and cathodic protection data acquisition unit (10) and lay the transmission optical fiber. Install the corrosion and cathodic protection data acquisition unit (10) indoors away from the site and in an explosion-proof manner. Use the transmission optical fiber to connect the corrosion and cathodic protection data acquisition unit (10) to the local online corrosion and cathodic protection monitoring unit (11). Step 4: Transmit the data signals collected by the sensors in Step 2 to the remote monitoring center unit (12) in Step 1 through the corrosion and cathodic protection data acquisition unit (10) and the on-site online corrosion and cathodic protection monitoring unit (11) connected in Step 3, and debug the online monitoring system for corrosion protection effect of well site oil pipeline and the cathodic protection potential evaluation system. Step 5: The inspection of the well site oil pipeline corrosion online monitoring system and cathodic protection potential assessment system begins. The well site oil pipeline corrosion prevention effect online monitoring system and cathodic protection potential assessment system are started on the computer of the local online corrosion and cathodic protection monitoring unit (11).

11. The method for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines according to claim 10, characterized in that: In step 2, the installation of the corrosion online monitoring unit sensor specifically involves: installing an array ultrasonic thickness sensor, a hydrogen flux probe corrosion monitoring sensor, a resistance probe corrosion monitoring sensor, a natural potential test piece, a reference electrode, a protection potential test point, and a power-off potential test piece on the well site oil pipeline (9). The outer shells of the array ultrasonic thickness sensor, the hydrogen flux probe corrosion monitoring sensor, and the resistance probe corrosion monitoring sensor are respectively connected to the grounding electrode.

12. The method for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines according to claim 10, characterized in that: In step 4, the data detected by the array ultrasonic thickness measurement unit (1), hydrogen flux probe corrosion monitoring unit (2), and resistance probe corrosion monitoring unit (8) are uploaded to the remote monitoring center unit (12). The online monitoring system for the corrosion protection effect of the well site oil pipeline is debugged in the control system configuration screen of the remote monitoring center (12), and the response time of various sensors is compared when the corrosion rate is 0.2 mm / a. The cathodic protection parameter data of the natural potential test piece unit (3), reference electrode unit (4), protection potential test point unit (5) and power failure potential test piece unit (6) are uploaded to the remote monitoring center unit (12), and the cathodic protection potential evaluation system is debugged in the control system configuration screen of the remote monitoring center unit (12).

13. The method for online monitoring and cathodic protection assessment of corrosion in well site oil pipelines according to claim 10, characterized in that: In step 5, the inspection of the well site oil pipeline corrosion online monitoring system and the cathodic protection potential assessment system begins. On the one hand, the array ultrasonic thickness measurement unit (1), the hydrogen flux probe corrosion monitoring unit (2), and the resistance probe corrosion monitoring unit (8) start working. The corrosion data acquisition unit collects and converts various well site oil pipeline corrosion signals and transmits them through the transmission optical fiber to the local online corrosion and cathodic protection monitoring unit (10) for storage of well site oil pipeline corrosion data. Then, it is uploaded to the remote monitoring center unit (12). After processing by the monitoring system, accurate corrosion data is obtained and the corrosion situation is calculated to determine the corrosion leakage status of the well site oil pipeline, locate the anti-corrosion layer, assess the aging status of the anti-corrosion layer, and identify the pipeline operating parameters. The system guides the selection and concentration of corrosion inhibitors, adjusts the injection of corrosion inhibitors, guides the implementation of forced external current cathodic protection for well site oil pipelines, and provides online parameter warnings through the monitoring system. On the other hand, the cathodic protection parameters of the natural potential test piece unit (3), reference electrode unit (4), protection potential test point unit (5) and power failure potential test piece unit (6) are transmitted to the local online cathodic protection monitoring unit via optical fiber through the signal analysis and processing of the corrosion and cathodic protection data acquisition unit (10) for storage of cathodic protection potential data of well site oil pipelines, and then uploaded to the remote monitoring center unit (12). After processing by the monitoring system, accurate data of cathodic protection potential is obtained and the cathodic protection status is calculated.

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