Oil and gas pipeline corrosion monitoring device and method

Abstract

The application discloses an oil and gas pipeline corrosion condition monitoring device and method. The oil and gas pipeline corrosion condition monitoring device comprises a plurality of metal bases, which are suitable for being fixed on the outer wall of an oil and gas pipeline and are arranged at intervals along the length extension direction of the oil and gas pipeline; a plurality of flexible strips, which are arranged in one-to-one position correspondence with the plurality of metal bases, the two ends of the flexible strips being connected to the position-corresponding metal bases, the plurality of flexible strips being in a stress state under the action force of the metal bases; a plurality of fiber Bragg grating sensors, which are installed in a one-to-one correspondence on preset positions on the flexible strips, the plurality of fiber Bragg grating sensors being connected to a demodulator through optical fibers; and the demodulator being suitable for receiving optical signals fed back from the plurality of fiber Bragg grating sensors and generating a fault signal containing position information of the corresponding fiber Bragg grating sensor when the optical signal fed back by any one of the fiber Bragg grating sensors is abnormal. The oil and gas pipeline corrosion condition monitoring device disclosed by the embodiment is high in efficiency and low in cost.

Description

Technical Field

[0001] This application relates to the field of oil and gas pipeline monitoring technology, specifically to a device and method for monitoring corrosion in oil and gas pipelines. Background Technology

[0002] In the existing technology, there are four main methods for detecting external corrosion of oil and gas pipelines and assessing whether corroded oil and gas pipelines are operating safely: visual inspection, ultrasonic thickness measurement, online inspection, and hydrostatic pressure testing.

[0003] Visual inspection is the simplest method, but also the most expensive and time-consuming. Specifically, oil and gas pipeline inspectors carry portable visual scanners (laser scanners) and walk along the pipelines to examine their surface condition, looking for dents, pitting, metal loss, cracks, and other defects. It allows for precise and traceable measurements of surface corrosion on the outer diameter of the pipeline. However, when insulation or thermal insulation layers are involved, these layers must be removed before visual inspection, which is extremely time-consuming, labor-intensive, and inefficient.

[0004] Ultrasonic thickness measurement is a very effective tool for determining the local wall thickness of oil and gas pipelines. This method can detect the depth of corrosion using ultrasound, and it can also detect whether internal corrosion has occurred at the same location where external corrosion has occurred. However, this method is limited to small areas, and it is time-consuming and inefficient to use this method to inspect large areas of oil and gas pipelines.

[0005] Online inspection methods use magnetic flux leakage or ultrasonic waves to scan, measure, and record the wall thickness in oil and gas pipelines. The results are then analyzed to look for dents, corrosion, deformation, cracks, or other defects. Most oil and gas companies use online inspection technology every 3-5 years, which is a long interval and generally requires production shutdowns, resulting in high inspection costs.

[0006] Hydrostatic pressure testing is a technique for testing the strength and leak detection of oil and gas pipelines. It is commonly used to detect leaks in newly laid oil and gas pipelines and can also be applied to detect defects and corrosion damage in existing pipelines. The oil and gas pipeline is pressurized to a specified test pressure, and a section of corroded pipeline is filled with a dye-containing liquid (usually water). This allows for direct identification of leak locations, and if leaks or severe corrosion are found, repairs can be carried out. However, hydrostatic pressure testing also involves production shutdowns, resulting in high maintenance costs.

[0007] Given the shortcomings of existing technologies, it is necessary to design a new device and method for monitoring corrosion in oil and gas pipelines. Summary of the Invention

[0008] Therefore, the technical problem to be solved by this application is to overcome the shortcomings of the existing technology, such as the low detection efficiency of visual inspection method and ultrasonic thickness measurement method, and the high detection cost of online detection method and hydrostatic pressure test method, so as to provide a method and device for monitoring the corrosion of oil and gas pipelines.

[0009] To solve the above-mentioned technical problems, the technical solution of this application is as follows:

[0010] A device for monitoring corrosion of oil and gas pipelines, comprising:

[0011] Multiple metal bases are suitable for being fixed to the outer wall of the oil and gas pipeline and are spaced apart along the length of the oil and gas pipeline.

[0012] Multiple flexible strips are arranged in a corresponding position to multiple metal bases. The two ends of each flexible strip are connected to the corresponding metal base. The multiple flexible strips are under stress under the force of the metal bases.

[0013] Multiple fiber Bragg grating sensors are installed at preset positions on the flexible strip, one for each of them, to detect the stress of the flexible strip. The multiple fiber Bragg grating sensors are connected to the demodulator via optical fibers.

[0014] The demodulator is adapted to receive optical signals fed back from multiple fiber Bragg grating sensors and generate a fault signal containing the position information of the corresponding fiber Bragg grating sensor when any optical signal fed back from any fiber Bragg grating sensor is abnormal.

[0015] Furthermore, the metal base is made of the same material as the oil and gas pipeline.

[0016] Furthermore, the thickness of the metal base is 0.4-0.6 times the wall thickness of the oil and gas pipeline.

[0017] Furthermore, the metal base is provided with two insertion holes, and the two ends of the flexible strip are respectively inserted into the corresponding insertion holes; the distance between the two ends of the flexible strip in the non-stressed state is greater than the distance between the two insertion holes, so that the two ends of the flexible strip are in a stressed state after being inserted into the insertion holes.

[0018] Furthermore, the length extension direction of the metal base is parallel to the length extension direction of the oil and gas pipeline, and the two insertion holes are located at both ends of the length direction of the metal base.

[0019] Furthermore, the flexible strip is a corrosion-resistant plastic strip.

[0020] Furthermore, the fiber Bragg grating sensor is attached to the middle of the flexible strip.

[0021] The technical solution of this application has the following advantages:

[0022] 1. The oil and gas pipeline corrosion monitoring device provided in this application has a metal base fixed to the outer wall of the oil and gas pipeline, and two ends of a flexible strip connected to the metal base. Fiber Bragg grating sensors are installed at preset positions on the flexible strip. Since the flexible strip is under stress under the force of the metal base, when the metal base is corroded, the flexible strip will strain, and the stress state of the flexible strip will change accordingly. The fiber Bragg grating sensor can detect the stress signal of the flexible strip and transmit the stress signal to the demodulator via optical fiber in the form of an optical signal. When the optical signal fed back by the fiber Bragg grating sensor is abnormal, the demodulator generates a fault signal containing the corresponding fiber Bragg grating sensor position information. Based on the fault signal containing position information, the location of corrosion in the oil and gas pipeline can be determined, thereby realizing remote online efficient monitoring of oil and gas pipeline corrosion. Moreover, the monitoring process does not require the oil and gas pipeline to be shut down, which greatly reduces the monitoring cost of oil and gas pipeline corrosion.

[0023] 2. The oil and gas pipeline corrosion monitoring device provided in this application uses a metal base made of the same material as the oil and gas pipeline. Since the metal base and the pipeline are in the same environment, the corrosion status of the metal base can reflect the corrosion status of the oil and gas pipeline, achieving non-invasive detection of pipeline corrosion. Compared with invasive detection methods such as laser scanning, ultrasound, and hydrostatic testing in existing technologies, this avoids damage to the pipeline structure during the detection process, thus improving the service life of the pipeline. Furthermore, the thickness of the metal base is 0.4 to 0.6 times the thickness of the pipeline wall. This means that even if the metal base is severely corroded or even broken, the pipeline will not rupture. However, severe corrosion or even breakage of the metal base can serve as an early warning of severe corrosion in the pipeline, allowing for timely inspection and repair, and preventing leaks.

[0024] A method for monitoring corrosion in oil and gas pipelines, based on the aforementioned oil and gas pipeline corrosion monitoring device, includes the following steps:

[0025] Acquire stress signals of flexible strips located at various positions along the length of the oil and gas pipeline;

[0026] Determine whether the difference between the stress signal obtained from the flexible strip at each position and the preset stress value exceeds a set value;

[0027] If the judgment result is yes, then a fault signal containing the corresponding flexible strip position information is generated;

[0028] The location of corrosion in the oil and gas pipeline is obtained based on the fault signal containing the position information corresponding to the flexible strip.

[0029] Furthermore, the preset stress value is the stress value detected by the fiber Bragg grating sensor when the flexible strip is in its initial stress state, and the initial stress state of the flexible strip is the stress state when the flexible strip is just installed on the metal base.

[0030] The oil and gas pipeline corrosion monitoring method provided in this application acquires stress signals from flexible strips located at various positions along the length of the oil and gas pipeline. When the difference between the stress signal acquired at a certain position and the preset stress value exceeds a set value, a fault signal containing the corresponding flexible strip position information is automatically generated. Based on the position information indicated by the fault signal, the location of the corroded metal base can be determined. Furthermore, the location of the corrosion in the oil and gas pipeline can be determined based on the location of the corroded metal base, thereby achieving remote online monitoring of the corrosion location of the oil and gas pipeline. Moreover, the monitoring process does not require the oil and gas pipeline to be shut down, greatly reducing the monitoring cost of oil and gas pipeline corrosion.

[0031] A method for monitoring corrosion in oil and gas pipelines, based on the aforementioned oil and gas pipeline corrosion monitoring device, includes the following steps:

[0032] Acquire stress signals of flexible strips located at various positions along the length of the oil and gas pipeline;

[0033] The stress signal of the flexible strip is input into the stress-strain solution model to calculate the strain of the flexible strip; wherein, the stress-strain solution model is established based on the relationship between the stress on the flexible strip on the metal base and the strain of the flexible strip;

[0034] The corrosion amount of the metal base is obtained based on the calculated strain of the flexible strip;

[0035] The corrosion level at the corresponding location of the oil and gas pipeline is obtained based on the corrosion level of the metal base.

[0036] The corrosion monitoring method for oil and gas pipelines provided in this application acquires stress signals from flexible strips located at various positions along the length of the oil and gas pipeline. These stress signals are then input into a stress-strain calculation model to calculate the strain of the flexible strips. Based on the strain of the flexible strips, the corrosion amount of the metal base can be determined, thereby revealing the corrosion amount at the corresponding location on the oil and gas pipeline. This method not only enables remote online monitoring of corrosion locations on oil and gas pipelines but also allows for the determination of the corrosion amount at the corresponding location based on the feedback stress signals. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 This is a top view of the metal base in this embodiment;

[0039] Figure 2 This is a three-dimensional schematic diagram of the metal base in this embodiment;

[0040] Figure 3 This is a front view of the flexible strip in this embodiment;

[0041] Figure 4 This is a schematic diagram of the flexible strip, fiber optic grating sensor, and metal base assembled in this embodiment;

[0042] Figure 5 This is a force analysis diagram of the flexible strip in this embodiment;

[0043] Figure 6 This is a diagram showing the internal forces and bending moments of the flexible strip in this embodiment.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1. Metal base; 11. Socket; 2. Flexible strip; 3. Fiber Bragg grating sensor; 4. Fiber. Detailed Implementation

[0046] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0048] In the description of this application, it should be noted that, unless otherwise expressly 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 between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0049] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0050] Example 1

[0051] like Figures 1 to 6 As shown, this embodiment provides a device for monitoring the corrosion of oil and gas pipelines, which is particularly suitable for monitoring the corrosion of metal oil and gas pipelines. Of course, it can also monitor the corrosion of non-metallic oil and gas pipelines. In this case, there needs to be a clear comparison between the corrosion of the metal base 1 and the corrosion of the non-metallic oil and gas pipeline, so that the corrosion of the non-metallic oil and gas pipeline can be deduced from the corrosion of the metal base 1.

[0052] The oil and gas pipeline corrosion monitoring device includes multiple metal bases 1, multiple flexible strips 2, multiple fiber Bragg grating sensors 3 (FBG sensors), and a demodulator. Multiple optical fibers 4 equipped with fiber Bragg grating sensors 3 will be placed on each oil and gas pipeline. The optical fibers 4 are fixed to the oil and gas pipeline using simple cable ties or binding tape. The metal bases 1 can be fixed to the oil and gas pipeline using cable ties or adhesive tape.

[0053] Multiple metal bases 1 are adapted to be fixed to the outer wall of the oil and gas pipeline and are arranged at intervals along the length of the oil and gas pipeline. In this embodiment, the material of the metal bases 1 is the same as that of the oil and gas pipeline, and the thickness of the metal bases 1 is 0.4-0.6 times the thickness of the oil and gas pipeline wall. Preferably, the thickness of the metal bases 1 is 0.5 times the thickness of the oil and gas pipeline wall. The metal bases 1 are elongated, and their length extension direction is parallel to the length extension direction of the oil and gas pipeline. Preferably, the bottom surface of the metal bases 1 is designed with a certain curvature, rather than being straight, so that the metal bases 1 can better adapt to the outer wall of the oil and gas pipeline. Two insertion holes 11 are symmetrically provided on the metal bases 1. In an alternative embodiment, the length extension direction of the metal bases 1 can also be perpendicular to the length extension direction of the oil and gas pipeline.

[0054] Multiple flexible strips 2 are positioned correspondingly to multiple metal bases 1, with both ends of the flexible strip 2 connected to the corresponding metal base 1. Specifically, the two ends of the flexible strip 2 are respectively inserted into two insertion holes 11 of the metal base 1. The multiple flexible strips 2 are under stress under the force of the corresponding metal base 1. In this embodiment, the flexible strips 2 are corrosion-resistant plastic strips. To ensure that the plastic strips are under stress after being connected to the metal base 1, the distance D between the two ends of the plastic strip needs to be greater than the distance L between the two insertion holes 11 in the non-stressed state.

[0055] Multiple fiber Bragg grating sensors are installed at predetermined positions on the flexible strip 2, corresponding one-to-one, to detect the stress level of the flexible strip 2. Specifically, the fiber Bragg grating sensor 3 is attached to the middle of the flexible strip 2, preferably, the fiber Bragg grating sensor 3 is located at the top of the flexible strip 2. The multiple fiber Bragg grating sensors are connected to the demodulator through a single optical fiber. One, two, or even more parallel optical fibers can be installed on the same section of the oil and gas pipeline.

[0056] The demodulator is adapted to receive optical signals fed back from multiple fiber Bragg grating sensors 3 and generate a fault signal containing the position information of the corresponding fiber Bragg grating sensor 3 when an abnormality occurs in the optical signal fed back by any one of the fiber Bragg grating sensors 3.

[0057] Because fiber Bragg gratings can be embedded with different specific reflection wavelengths, they can be used to achieve excellent wavelength division multiplexing (WDM) technology. This characteristic allows multiple different sensors with specific Bragg wavelengths to be connected on a single, long-distance optical fiber. WDM technology assigns a specific wavelength range to each fiber Bragg grating sensor 3 within the available optical spectrum. For example, for an optical fiber with a wavelength range of 160 nm and 16 channels, assuming each fiber Bragg grating sensor 3 operates at a wavelength range of 4 nm, at least 40 fiber Bragg grating sensors 3 can be implemented in one fiber. Using a 16-channel demodulator, at least 640 fiber Bragg grating sensors 3 can transmit optical signals through the channels in each fiber without using any optical switches. Thus, assuming a 4-kilometer-long oil or gas pipeline, corrosion of the pipeline can be monitored every 6.25 meters without using any optical switches, thereby achieving relatively dense monitoring of the oil and gas pipeline. Of course, when the oil and gas pipeline is very long, multiple demodulators need to be installed to adapt to the fiber Bragg grating sensors on the oil and gas pipeline within the corresponding length range.

[0058] In this embodiment, since the distance D between the two ends of the flexible strip 2 is greater than the distance L between the two insertion holes 11 on the metal base 1 when the two ends of the flexible strip 2 are inserted into the two insertion holes 11, the flexible strip 2, which is in an arch shape, needs to be compressed inward in the direction of the inner diameter. The following describes the stress situation of the flexible strip 2 during the insertion process, taking the right end B of the flexible strip 2 as an example. Figure 5 As shown, a force F along the negative x-direction acts on point B on the flexible strip 2, imparting a radial displacement to point B in the negative x-direction. Force F not only causes point B and surface BC to move in the negative x-direction but also in the negative y-direction, causing surface BC to rotate clockwise. To make the slope of surface BC zero and its movement in the y-direction zero, a counterclockwise torque M needs to be applied to the right end of the curved beam.

[0059] Of course, when the angle between the line connecting the point where force F acts on the flexible strip and the center of the flexible strip and the horizontal direction is θ, the internal force and bending moment of the flexible strip 2 are as follows: Figure 6 As shown, the calculation and analysis of internal forces and moments are as follows:

[0060] F θ =Fsinθ (1)

[0061] F r =Fcosθ (2)

[0062] M F =FRcosθ (3)

[0063] Under arbitrary angle θ and arbitrary radius r, the stress at the corresponding point on flexible strip 2 is equal to:

[0064]

[0065] In the formula, M t =M F -M, where A is the contact area.

[0066] Under arbitrary angle θ and arbitrary radius r, the strain at the corresponding point on flexible strip 2 is equal to:

[0067]

[0068] In the formula, E is Young's modulus.

[0069] The strain limit detectable by the fiber Bragg grating sensor 3 determines the maximum deflection that can be applied to point B. A closed-form equation is established based on Karl von Krones' second theorem. For a bent beam with a rectangular cross-section, let the width be W and the outer radius be r. o The inner radius is r i The position of the neutral axis is as follows:

[0070]

[0071] like Figure 6 As shown, the plastic strip will have two forces F. r and F θ And a torque M t The angle between the line connecting the point where force F acts on the flexible strip and the center of the flexible strip and the horizontal direction is θ. The total strain energy from 0 < θ < π can be calculated by adding four terms:

[0072]

[0073] The first strain energy is determined by the torque M. t The second strain energy is generated by the axial force F. θ The third strain energy is generated by M. t With axial force F θ The coupling energy is generated, and the fourth strain energy is generated by the radial force F. r Transverse shear energy is generated. Parameter C in the fourth term is the strain energy correction factor for transverse shear, which is 1.2 when the cross-section is rectangular.

[0074] After simplified decomposition, the X and Y axis directions are obtained as follows:

[0075]

[0076]

[0077] against Figure 6 The monitoring device design scheme, because force F is horizontal, therefore U y =0, U x The data detected by the fiber Bragg grating sensor 3 (which is attached to the flexible strip and connected to the analysis and calculation system via a circuit) is directly calculated by the analysis and calculation system, and is known. Knowing U... x and U y Force F and torque M can be calculated using formulas (9) and (10). Knowing F and M, stress and strain can be calculated using formulas (4) and (5) respectively. From the calculation formulas, the maximum strain occurs at θ = 90 degrees and r = r o Therefore, the fiber Bragg grating sensor 3 is positioned at point A on the top of the flexible strip 2. As long as the strain is below the strain limit detectable by the fiber Bragg grating sensor 3, and the strain is large enough to be detected by the fiber Bragg grating sensor 3, the corrosion status around the oil and gas pipeline can be obtained by analyzing the changes in stress and strain at point A.

[0078] Assuming the thickness of the metal base 1 is 1 mm, at a corrosion rate of 0.4 mm / year, it would take 2.5 years for the metal base 1 to completely corrode to a thickness of 1 mm. Two and a half years is the midpoint of a 5-year inspection interval. If, after 2.5 years, no corrosion signal is displayed on the remote demodulator from the fiber Bragg grating sensor 3, it can be concluded that the corrosion rate of the oil and gas pipeline is less than 0.4 mm / year. If the fiber Bragg grating sensor 3 fails after 2.5 years, it means that severe corrosion has occurred at certain locations on the oil and gas pipeline. These specific locations can be quickly accessed to determine why the corrosion rate is higher at these locations. In these areas with high corrosion rates, measures can be taken to reduce the corrosion rate to 0.4 mm / year or lower.

[0079] If an oil leak occurs, the heat from the hot crude oil will exert additional stress on the flexible strip 2. Therefore, the demodulator in the control room can receive a signal from the fiber Bragg grating sensor 3 on the corresponding flexible strip 2, which is different from the signal from oil and gas pipeline corrosion, informing the control room that a leak has occurred. Thus, the oil and gas pipeline corrosion monitoring device provided in this embodiment can not only monitor the occurrence of oil and gas pipeline corrosion but also detect leaks of fluids within the pipeline.

[0080] In this embodiment, corrosion of the metal base 1 will cause a change in the stress state on the flexible strip 2. If the stress change exceeds a certain value or the metal base 1 breaks and fails, relieving the stress at point A, the fiber Bragg grating sensor 3 sends a fault signal containing the position information of the flexible strip 2 to the demodulator. Based on the fault signal containing the position information, the location of corrosion in the oil and gas pipeline can be determined, thereby achieving remote online efficient monitoring of oil and gas pipeline corrosion. Moreover, the monitoring process does not require the oil and gas pipeline to be shut down, greatly reducing the monitoring cost of oil and gas pipeline corrosion. After receiving the fault signal, the oil and gas pipeline inspector can first conduct a visual inspection at the corresponding location of the flexible strip 2. If corrosion is observed on the oil and gas pipeline, inspection techniques such as ultrasonic technology or eddy current probes will be used to further assess the severity of the corrosion. If repair is required, production will be stopped and the corresponding oil and gas pipeline will be repaired. If no corrosion is observed in the pipeline, only the metal base 1, flexible strip 2, and fiber Bragg grating sensor 3 need to be reinstalled, or the metal base 1 needs to be replaced, until the next fault signal occurs.

[0081] Furthermore, since the metal base 1 is made of the same material as the oil and gas pipeline, and both are in the same environment, the corrosion status of the metal base 1 can reflect the corrosion status of the oil and gas pipeline. This allows for non-invasive detection of pipeline corrosion, which, compared to invasive methods such as laser scanning, ultrasound, and hydrostatic testing, avoids damage to the pipeline structure during the inspection process and helps extend the pipeline's service life. Additionally, the thickness of the metal base 1 is 0.4 to 0.6 times the thickness of the oil and gas pipeline wall. This means that even if the metal base 1 is severely corroded or even broken, the oil and gas pipeline will not rupture. However, the severe corrosion or breakage of the metal base 1 can serve as an early warning of severe corrosion in the oil and gas pipeline, allowing for timely inspection and repair to prevent leaks.

[0082] In summary, the fiber Bragg grating sensor 3 detects the stress state of the semi-circular flexible strip 2 fixed on the metal base 1 outside the oil and gas pipeline. When the difference between the stress of the flexible strip 2 and the preset stress exceeds the predetermined value, the fiber Bragg grating sensor 3 will send a fault signal containing the position information of the flexible strip 2 to the demodulator. This is qualitative monitoring.

[0083] Of course, the stress state of the semi-circular flexible strip 2 fixed on the metal base 1 outside the oil and gas pipeline can be detected by the fiber Bragg grating sensor 3, and a stress and strain solution model can be established. By using the signal detected by the fiber Bragg grating sensor 3 on the flexible strip 2 and the stress and strain solution model, the stress and strain changes at point A can be calculated quantitatively remotely, and the corrosion and leakage of the oil and gas pipeline can be judged remotely online. It has the advantages of low cost, high reliability and remote monitoring.

[0084] In this embodiment, based on wavelength division multiplexing (WDM) technology, large-scale deployment can be achieved at a low cost; the stress and strain results can be mutually verified, improving the reliability of the result analysis; remote automated monitoring can be achieved, saving time in locating corrosion and leakage points, improving handling efficiency, and ensuring the safety of personnel; the oil and gas pipeline corrosion monitoring device is a non-invasive monitoring method and will not affect the structure of the oil and gas pipeline.

[0085] Example 2

[0086] This embodiment provides a method for monitoring corrosion of oil and gas pipelines, based on the aforementioned oil and gas pipeline corrosion monitoring device, and includes the following steps:

[0087] Acquire stress signals of flexible strips located at various positions along the length of the oil and gas pipeline;

[0088] Determine whether the difference between the stress signal obtained from the flexible strip at each position and the preset stress value exceeds the set value;

[0089] If the judgment result is yes, a fault signal containing the corresponding flexible strip position information is generated;

[0090] The location of corrosion in the oil and gas pipeline is obtained based on the fault signal containing the corresponding flexible strip position information.

[0091] Furthermore, the preset stress value is the stress value detected by the fiber Bragg grating sensor when the flexible strip is in its initial stress state, which is the stress state when the flexible strip is just installed on the metal base.

[0092] The oil and gas pipeline corrosion monitoring method provided in this embodiment acquires stress signals from flexible strips located at various positions along the length of the oil and gas pipeline. When the difference between the stress signal acquired at a certain position and the preset stress value exceeds a set value, a fault signal containing the corresponding flexible strip position information is automatically generated. Based on the position information indicated by the fault signal, the location of the corroded metal base can be determined. Furthermore, the location of the corrosion in the oil and gas pipeline can be determined based on the location of the corroded metal base, thereby achieving remote and efficient online monitoring of the corrosion location of the oil and gas pipeline. Moreover, the monitoring process does not require the oil and gas pipeline to be shut down, greatly reducing the monitoring cost of oil and gas pipeline corrosion.

[0093] Example 3

[0094] This embodiment provides a method for monitoring corrosion of oil and gas pipelines, based on the aforementioned oil and gas pipeline corrosion monitoring device, and includes the following steps:

[0095] Acquire stress signals of flexible strips located at various positions along the length of the oil and gas pipeline;

[0096] The stress signal of the flexible strip is input into the stress-strain solution model to calculate the strain of the flexible strip; the stress-strain solution model is established based on the relationship between the stress on the flexible strip on the metal base and the strain of the flexible strip.

[0097] The corrosion amount of the metal base is obtained based on the calculated strain of the flexible strip;

[0098] The corrosion level at the corresponding location on the oil and gas pipeline is determined based on the corrosion level of the metal base.

[0099] The oil and gas pipeline corrosion monitoring method provided in this embodiment acquires stress signals from flexible strips located at various positions along the length of the oil and gas pipeline. These stress signals are then input into a stress-strain calculation model to calculate the strain of the flexible strips. Based on the strain of the flexible strips, the corrosion amount of the metal base can be determined, thereby revealing the corrosion amount at the corresponding location on the oil and gas pipeline. This method not only enables remote and efficient online monitoring of oil and gas pipeline corrosion locations but also allows for the determination of the corrosion amount at the corresponding location based on the feedback stress signals.

[0100] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A device for monitoring corrosion of oil and gas pipelines, characterized in that, The application relates to a pipeline corrosion monitoring system, which comprises the following components: a plurality of metal bases (1) adapted to be fixed on the outer wall of an oil and gas pipeline and arranged at intervals along the length extension direction of the oil and gas pipeline; a plurality of flexible strips (2) arranged in one-to-one correspondence with the plurality of metal bases (1), the two ends of the flexible strips (2) being connected to the position-corresponding metal bases (1), and the plurality of flexible strips (2) being in a stress state under the action of the metal bases (1); a plurality of fiber Bragg grating sensors (3) installed in one-to-one correspondence with the flexible strips (2) at preset positions on the flexible strips (2) and adapted to detect the stress of the flexible strips (2), the plurality of fiber Bragg grating sensors (3) being connected to a demodulator through optical fibers; the demodulator being adapted to receive optical signals fed back from the plurality of fiber Bragg grating sensors (3) and generate a fault signal containing the position information of the corresponding fiber Bragg grating sensor (3) when the optical signal fed back by any one of the fiber Bragg grating sensors (3) is abnormal; the material of the metal base (1) being the same as that of the oil and gas pipeline; and the flexible strip (2) being a corrosion-resistant plastic strip. The thickness of the metal base (1) is 0.4-0.6 times the wall thickness of the oil and gas pipeline. The metal base (1) is provided with two insertion holes (11), and the two ends of the flexible strip (2) are respectively inserted into the corresponding insertion holes (11); the distance between the two ends of the flexible strip (2) in a non-stress state is greater than the distance between the two insertion holes (11), so that the two ends of the flexible strip (2) are in a stress state after being inserted into the insertion holes (11). The length extension direction of the metal base (1) is parallel to the length extension direction of the oil and gas pipeline, and the two insertion holes (11) are arranged at the two ends of the metal base (1) in the length direction. The fiber Bragg grating sensor (3) is pasted in the middle of the flexible strip (2). The application further relates to a pipeline corrosion monitoring method, which comprises the following steps: acquiring the stress signals of the flexible strips located at various positions along the length direction of the oil and gas pipeline; judging whether the difference between the stress signals acquired from the flexible strips at various positions and a preset stress value exceeds a set value; generating a fault signal containing the position information of the corresponding flexible strip if the judgment result is yes; and acquiring the position where the oil and gas pipeline is corroded according to the fault signal containing the position information of the corresponding flexible strip. The preset stress value is the stress value of the flexible strip in an initial stress state detected by the fiber Bragg grating sensor, and the initial stress state of the flexible strip is the stress state of the flexible strip immediately after being installed on the metal base.

2. The apparatus of claim 1, wherein, The application further relates to a pipeline corrosion monitoring method, which comprises the following steps: acquiring the stress signals of the flexible strips located at various positions along the length direction of the oil and gas pipeline; inputting the acquired stress signals of the flexible strips into a stress-strain solving model to calculate the strain amount of the flexible strip, wherein the stress-strain solving model is established according to the relationship between the stress of the flexible strip on the metal base and the strain amount of the flexible strip; and acquiring the corrosion amount of the metal base according to the calculated strain amount of the flexible strip.

3. The apparatus of claim 1, wherein, ​ 4. The apparatus of claim 3, wherein, ​ 5. The apparatus of claim 1, wherein, ​ 6. A method of monitoring corrosion conditions in a hydrocarbon pipeline based on the corrosion condition monitoring device according to any one of claims 1 to 5, characterized in that, ​ ​ ​ ​ ​ 7. The method of claim 6, wherein, ​ 8. A method of monitoring corrosion conditions in a hydrocarbon pipeline based on the corrosion condition monitoring device according to any one of claims 1 to 5, characterized in that, ​ ​ ​ ​ According to the corrosion amount of the metal base, the corrosion amount of the corresponding position of the oil and gas pipeline is obtained.

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