Oil and gas pipeline safety status monitoring method and system

Abstract

The present invention provides a method and system for monitoring the safety status of an oil and gas pipeline, comprising: first, obtaining pipeline information, on-site operating condition information, and initial stress values ​​of a target oil and gas pipeline. Then, determining a test pipeline and setting a pipeline water pressure-far-field magnetic signal testing device; applying multiple preset water pressures to the test pipeline through the pipeline water pressure-far-field magnetic signal testing device; and obtaining multiple test magnetic field gradient moduli and multiple test stress values ​​corresponding to the test pipeline under the multiple preset water pressures. Next, performing a matching correction to determine a corrected first pipeline stress value change calculation model and a corrected second pipeline stress value change calculation model for determining the monitored stress value of the target oil and gas pipeline. Finally, performing a safety status assessment on the target oil and gas pipeline based on the monitored stress value. In this way, the accuracy of monitoring the stress status of the oil and gas pipeline can be improved by using the corrected pipeline stress value change calculation model, thereby improving the accuracy of monitoring the safety status of the oil and gas pipeline.

Description

Technical Field

[0001] The present invention relates to the technical field of nondestructive testing of oil and gas pipelines, and in particular to a method and system for monitoring the safety status of oil and gas pipelines. Background Art

[0002] Currently, numerous oil and gas pipelines traverse mountainous areas, posing a significant threat to the construction and safe operation of long-distance oil and gas pipelines. Landslides are the most common type of geological disaster threatening the safe operation of buried pipelines. Once a landslide occurs, it can easily cause pipeline deformation and rupture, leading to oil and gas leaks and serious threats to life and property. Therefore, real-time monitoring of pipeline safety is essential.

[0003] Non-contact magnetic monitoring technology is an effective real-time monitoring method. Its principle is to understand the safety status of oil and gas pipelines by monitoring abnormal magnetic signals generated by defects, deformation, and stress concentration in the pipeline. Specifically, based on the pipeline complex load-non-contact magnetic signal forward model, the quantitative relationship between the pipeline's true stress and magnetic signal under complex loads can be clarified, thus enabling the use of non-contact magnetic stress detection to characterize and assess the pipeline's safety status (such as stress state).

[0004] However, due to the influence of magnetic hysteresis, the relationship between magnetic signals and pipeline stress is still unclear, making it impossible to accurately determine the stress of oil and gas pipelines. This has led to a decrease in the ability to monitor the safety status of pipelines, making it impossible to accurately monitor the safety status of oil and gas pipelines. Summary of the Invention

[0005] The technical problem to be solved by the present invention is the inability to accurately monitor the safety status of oil and gas pipelines.

[0006] To solve the above technical problems, the present invention provides a method and system for monitoring the safety status of oil and gas pipelines, which specifically adopt the following technical solutions:

[0007] In a first aspect, the present invention provides a method for monitoring the safety status of an oil and gas pipeline, comprising: first, obtaining pipeline information, field operating condition information, and initial stress values ​​of a target oil and gas pipeline, wherein the field operating condition information is used to characterize the environmental conditions of the target oil and gas pipeline. Then, a test pipeline is determined based on the pipeline information, and a pipeline water pressure-remote-field magnetic signal testing device is set up based on the field operating condition information. The test pipeline is placed in the pipeline water pressure-remote-field magnetic signal testing device, and the pipeline water pressure-remote-field magnetic signal testing device is used to perform a water pressure loading simulation test on the test pipeline. Next, the pipeline water pressure-remote-field magnetic signal testing device applies multiple preset water pressures to the test pipeline, obtaining multiple test magnetic field gradient moduli and multiple test stress values ​​corresponding to the test pipeline at the multiple preset water pressures. Next, matching and correcting the multiple test magnetic field gradient moduli and multiple test stress values ​​are performed to determine a corrected first pipeline stress value change calculation model and a second pipeline stress value change calculation model. The first pipeline stress value change calculation model is used to determine the stress value change of the pipeline during the rising phase of the magnetic field gradient modulus, and the second pipeline stress value change calculation model is used to determine the stress value change of the pipeline during the falling phase of the magnetic field gradient modulus. Based on the monitored magnetic field gradient modulus and initial stress value, the monitored stress value of the target oil and gas pipeline is determined using a first pipeline stress value change calculation model or a second pipeline stress value change calculation model. Finally, a safety status assessment of the target oil and gas pipeline is performed based on the monitored stress value.

[0008] In this method, a test pipeline can be identified based on different on-site operating conditions and pipeline information for oil and gas pipelines, and a pipeline water pressure-remote-field magnetic signal testing device can be set up. A hydraulic loading simulation test is performed on the test pipeline using the pipeline water pressure-remote-field magnetic signal testing device. The established forward model of pipeline stress and magnetic signals is modified based on the test magnetic field gradient modulus and test stress values ​​to correct for the effects of hysteresis, improve the correspondence between magnetic signals and pipeline stress, and obtain a modified pipeline stress value variation calculation model. This pipeline stress value variation calculation model can thus improve the accuracy of monitored oil and gas pipeline stress states, thereby improving the accuracy of monitoring oil and gas pipeline safety status.

[0009] In conjunction with the first aspect, in an optional implementation, the expression of the above-mentioned first pipeline stress value change calculation model is:

[0010]

[0011] Among them, Δσ1 represents the stress value change of the pipeline during the magnetic field gradient modulus rising stage, ΔG1 represents the magnetic field gradient modulus change value of the pipeline during the magnetic field gradient modulus rising stage, a represents the first correction coefficient, and b represents the second correction coefficient. The first correction coefficient and the second correction coefficient are determined by fitting analysis based on multiple test magnetic field gradient moduli and multiple test stress values.

[0012] In combination with the first aspect, in an optional implementation, the expression of the above-mentioned second pipeline stress value change calculation model is:

[0013] Δσ2=cΔG2+d;

[0014] Among them, Δσ2 represents the stress value change of the pipeline during the magnetic field gradient modulus decrease stage, ΔG2 represents the magnetic field gradient modulus change value of the pipeline during the magnetic field gradient modulus decrease stage, c represents the third correction coefficient, d represents the fourth correction coefficient, and the third correction coefficient and the fourth correction coefficient are determined by fitting analysis based on multiple test magnetic field gradient moduli and multiple test stress values.

[0015] In conjunction with the first aspect, in one optional implementation, the pipeline information includes the yield strength of the pipe. A safety status assessment of the target oil and gas pipeline is performed based on the monitored stress value. Specifically, the assessment includes: first, determining a failure probability value based on the monitored stress value and the yield strength. The failure probability value is the ratio of the monitored stress value to the yield strength. Then, determining a failure probability level based on the failure probability value. The failure probability level is used to assess the safety status of the target oil and gas pipeline.

[0016] In combination with the first aspect, in an optional implementation, the above-mentioned pipeline information includes one or more of the following parameters: pipe diameter, wall thickness, pipeline material, pipeline design pressure and pipeline operating pressure.

[0017] In combination with the first aspect, in an optional implementation, the above-mentioned on-site working condition information includes: pipeline burial depth.

[0018] In a second aspect, the present invention provides an oil and gas pipeline safety status monitoring system, comprising: an acquisition device, a construction device, a pipeline water pressure-far-field magnetic signal testing device, and a monitoring device. The acquisition device is used to acquire pipeline information, field operating condition information, and initial stress values ​​of a target oil and gas pipeline, wherein the field operating condition information is used to characterize the environmental conditions of the target oil and gas pipeline. The construction device is used to determine a test pipeline based on the pipeline information and to set up a pipeline water pressure-far-field magnetic signal testing device based on the field operating condition information. The test pipeline is set in the pipeline water pressure-far-field magnetic signal testing device, and the pipeline water pressure-far-field magnetic signal testing device is used to perform a water pressure loading simulation test on the test pipeline. The pipeline water pressure-far-field magnetic signal testing device is used to load a plurality of preset water pressures on the test pipeline and acquire a plurality of test magnetic field gradient moduli and a plurality of test stress values ​​corresponding to the test pipeline under the plurality of preset water pressures. The pipeline water pressure-far-field magnetic signal testing device is further configured to perform matching corrections based on multiple test magnetic field gradient moduli and multiple test stress values ​​to determine a corrected first pipeline stress value change calculation model and a corrected second pipeline stress value change calculation model. The first pipeline stress value change calculation model is configured to determine the pipeline stress value change during the rising phase of the magnetic field gradient modulus, while the second pipeline stress value change calculation model is configured to determine the pipeline stress value change during the falling phase of the magnetic field gradient modulus. The monitoring device is configured to determine the monitored stress value of the target oil and gas pipeline using the first pipeline stress value change calculation model or the second pipeline stress value change calculation model based on the monitored magnetic field gradient modulus and initial stress value. The monitoring device is further configured to perform a safety status assessment of the target oil and gas pipeline based on the monitored stress value.

[0019] In conjunction with the second aspect, in an optional implementation, the pipeline water pressure-remote-field magnetic signal testing device includes: a magnetic gradient detector, a strain gauge, a water pump, a data acquisition device, an engineering host computer, a remote numerical control device, a water reservoir, and an aluminum truss. The aluminum truss is positioned above the test pipeline, the magnetic gradient detector is mounted on the aluminum truss, the magnetic gradient detector is connected to the data acquisition device, the strain gauge is mounted on the test pipeline, the strain gauge is connected to the data acquisition device, the data acquisition device is connected to the engineering host computer, the water pump's water inlet is connected to the water reservoir, the water pump's water outlet is connected to the test pipeline, and the water pump is connected to the remote numerical control device. The remote numerical control device is configured to control the water pump to apply multiple preset water pressures to the test pipeline. The data acquisition device is configured to collect multiple test magnetic field gradient moduli using the magnetic gradient detector and multiple test stress values ​​using the strain gauge. The engineering host computer is configured to perform matching corrections based on the multiple test magnetic field gradient moduli and multiple test stress values ​​collected by the data acquisition device to determine a first pipeline stress value change calculation model and a second pipeline stress value change calculation model.

[0020] In conjunction with the second aspect, in an optional implementation, the expression of the above-mentioned first pipeline stress value change calculation model is:

[0021]

[0022] Among them, Δσ1 represents the stress value change of the pipeline during the magnetic field gradient modulus rising stage, ΔG1 represents the magnetic field gradient modulus change value of the pipeline during the magnetic field gradient modulus rising stage, a represents the first correction coefficient, and b represents the second correction coefficient. The first correction coefficient and the second correction coefficient are determined by fitting analysis based on multiple test magnetic field gradient moduli and multiple test stress values.

[0023] In conjunction with the second aspect, in an optional implementation, the expression of the above-mentioned second pipeline stress value change calculation model is:

[0024] Δσ2=cΔG2+d;

[0025] Among them, Δσ2 represents the stress value change of the pipeline during the magnetic field gradient modulus decrease stage, ΔG2 represents the magnetic field gradient modulus change value of the pipeline during the magnetic field gradient modulus decrease stage, c represents the third correction coefficient, d represents the fourth correction coefficient, and the third correction coefficient and the fourth correction coefficient are determined by fitting analysis based on multiple test magnetic field gradient moduli and multiple test stress values.

[0026] It can be understood that the beneficial effects that can be achieved by the oil and gas pipeline safety status monitoring system provided by the second aspect mentioned above can refer to the beneficial effects in the first aspect and any possible design method thereof, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic flow chart of a method for monitoring the safety status of an oil and gas pipeline provided in an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of the structure of an oil and gas pipeline safety status monitoring system provided by an embodiment of the present invention;

[0029] Figure 3 A schematic structural diagram of a pipeline water pressure-far-field magnetic signal testing device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following embodiments are described in detail, with examples illustrated in the accompanying drawings. When the following description refers to the drawings, identical numbers in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following embodiments are not intended to represent all possible implementations consistent with the present application. They are merely examples of systems and methods consistent with certain aspects of the present application, as detailed in the claims.

[0031] Non-contact magnetic monitoring technology is an effective real-time monitoring method. Its principle is to understand the safety status of oil and gas pipelines by monitoring abnormal magnetic signals generated by defects, deformation, and stress concentration in the pipeline. Specifically, based on the pipeline complex load-non-contact magnetic signal forward model, the quantitative relationship between the pipeline's true stress and magnetic signal under complex loads can be clarified, thus enabling the use of non-contact magnetic stress detection to characterize and assess the pipeline's safety status (such as stress state).

[0032] However, due to the influence of magnetic hysteresis, the relationship between magnetic signals and pipeline stress is still unclear, making it impossible to accurately determine the stress of oil and gas pipelines. This has led to a decrease in the ability to monitor the safety status of pipelines, making it impossible to accurately monitor the safety status of oil and gas pipelines.

[0033] To address the aforementioned issues, embodiments of the present invention provide a method and system for monitoring the safety status of oil and gas pipelines. This method establishes a forward model of pipeline stress and magnetic signals based on different field conditions and oil and gas pipeline materials. This model corrects for the effects of hysteresis, improves the correspondence between magnetic signals and pipeline stress, and generates a revised pipeline stress value variation calculation model. This revised pipeline stress value variation calculation model improves the accuracy of determining the stress state of the oil and gas pipeline, thereby improving the accuracy of monitoring the safety status of the oil and gas pipeline.

[0034] The following describes the solution provided by the embodiments of the present application in conjunction with the accompanying drawings.

[0035] For details, see Figure 1 , which is a flow chart of the oil and gas pipeline safety status monitoring method provided by an embodiment of the present invention, such as Figure 1 As shown, the oil and gas pipeline safety status monitoring method provided by the present invention includes the following steps S101-S106:

[0036] S101. Obtain pipeline information, on-site working condition information, and initial stress value of a target oil and gas pipeline.

[0037] In this embodiment of the present application, the target oil and gas pipeline is the oil and gas pipeline to be monitored. First, basic and on-site information of the target oil and gas pipeline is obtained. This includes pipeline information, on-site operating conditions, and initial stress values. The on-site operating conditions information characterizes the environmental conditions of the target oil and gas pipeline.

[0038] In some embodiments, pipeline information may include one or more of the following parameters: pipe diameter, wall thickness, pipe material, pipeline design pressure, and pipeline operating pressure. On-site working condition information may include: pipeline burial depth.

[0039] S102: Determine the test pipeline according to the pipeline information, and set up the pipeline water pressure-far-field magnetic signal testing device according to the on-site working condition information.

[0040] Then, based on the pipeline information and on-site working condition information obtained in S101, the test pipeline can be determined and a pipeline water pressure-far-field magnetic signal testing device can be constructed. The test pipeline is set in the pipeline water pressure-far-field magnetic signal testing device, which can be used to perform a water pressure loading simulation test on the test pipeline.

[0041] In one implementation, the test pipe is sealed, that is, in a sealed state. A strain gauge is also provided in the test pipe, and a test stress value of the test pipe can be collected through the strain gauge.

[0042] S103 , applying multiple preset water pressures to the test pipeline through the pipeline water pressure-far-field magnetic signal testing device, and obtaining multiple test magnetic field gradient moduli and multiple test stress values ​​corresponding to the test pipeline under the multiple preset water pressures.

[0043] Furthermore, the pipeline water pressure-remote-field magnetic signal testing device can be used to simulate water pressure loading on the test pipeline, applying multiple preset water pressures to the test pipeline. For example, a pump can be used to establish on-site flow conditions to apply water pressure to the test pipeline. The multiple preset water pressures can be determined based on the historical operating conditions of the target oil and gas pipeline and actual monitoring requirements, and this application does not impose specific limitations on this.

[0044] Then, a plurality of test magnetic field gradient moduli and a plurality of test stress values ​​corresponding to the test pipeline under a plurality of preset water pressures may be obtained.

[0045] For example, a magnetic gradiometer can be used to collect the test magnetic field gradient modulus of the test pipeline under different water pressure loading modes, and a strain gauge can be used to obtain the test stress value under different water pressure loading modes.

[0046] S104 , performing matching correction according to the multiple test magnetic field gradient moduli and the multiple test stress values, and determining a corrected first pipeline stress value change calculation model and a corrected second pipeline stress value change calculation model.

[0047] Specifically, stress calibration can be performed on the multiple test stress values ​​obtained in S104 according to the initial stress value of the target oil and gas pipeline. Then, statistical analysis can be performed based on the calibrated multiple test stress values ​​and multiple test magnetic field gradient moduli to quantitatively study the variation law of stress and pipeline spatial magnetic field gradient modulus, and analyze the mismatch between pipeline stress and magnetic field gradient modulus caused by hysteresis, thereby achieving matching correction of the multiple test magnetic field gradient moduli and the multiple test stress values, and obtaining the corrected first pipeline stress value change calculation model and second pipeline stress value change calculation model.

[0048] Among them, the first pipeline stress value change calculation model is used to determine the stress value change of the pipeline during the rising stage of the magnetic field gradient modulus, and the second pipeline stress value change calculation model is used to determine the stress value change of the pipeline during the falling stage of the magnetic field gradient modulus.

[0049] In some embodiments, the expression of the first pipeline stress value change calculation model can be:

[0050]

[0051] Among them, Δv1 represents the stress value change of the pipeline during the magnetic field gradient modulus rising stage, ΔG1 represents the magnetic field gradient modulus change value of the pipeline during the magnetic field gradient modulus rising stage, a represents the first correction coefficient, and b represents the second correction coefficient. The first correction coefficient and the second correction coefficient are determined by fitting analysis based on multiple test magnetic field gradient moduli and multiple test stress values.

[0052] In some embodiments, the expression of the second pipeline stress value change calculation model can be:

[0053] Δσ2=cΔG2+d;

[0054] Among them, Δσ2 represents the stress value change of the pipeline during the magnetic field gradient modulus decrease stage, ΔG2 represents the magnetic field gradient modulus change value of the pipeline during the magnetic field gradient modulus decrease stage, c represents the third correction coefficient, d represents the fourth correction coefficient, and the third correction coefficient and the fourth correction coefficient are determined by fitting analysis based on multiple test magnetic field gradient moduli and multiple test stress values.

[0055] S105 , determining the monitoring stress value of the target oil and gas pipeline according to the monitoring magnetic field gradient modulus and the initial stress value through the first pipeline stress value change calculation model or the second pipeline stress value change calculation model.

[0056] Specifically, when the monitoring magnetic field gradient modulus is in an ascending phase, the monitoring stress value of the target oil and gas pipeline can be determined using the first pipeline stress value change calculation model. When the monitoring magnetic field gradient modulus is in a descending phase, the monitoring stress value of the target oil and gas pipeline can be determined using the second pipeline stress value change calculation model.

[0057] S106. Evaluate the safety status of the target oil and gas pipeline based on the monitored stress value.

[0058] In some embodiments, when the pipeline information includes the yield strength of the pipe, S106 may specifically include:

[0059] First, the failure probability value (WSR) is determined based on the monitored stress value and the yield strength. The failure probability value is the ratio of the monitored stress value to the yield strength.

[0060] Then, the failure probability level is determined according to the failure probability value, and the failure probability level is used to evaluate the safety status of the target oil and gas pipeline.

[0061] For example, as shown in Table 1, the failure probability levels can be divided into: level 1, level 2, and level 3. When the failure probability value is within the range of [0, 0.4), the failure probability level is level 1; when the failure probability value is within the range of [0.4, 0.6), the failure probability level is level 2; and when the failure probability value is within the range of [0.6, 1), the failure probability level is level 3.

[0062] Table 1 Correspondence between failure probability values ​​and failure probability levels

[0063]

[0064] The higher the failure possibility level, the greater the failure possibility of the target oil and gas pipeline, the more dangerous the target oil and gas pipeline is, that is, the lower the safety.

[0065] By using the oil and gas pipeline safety status monitoring method provided in the embodiment of the present application, a test pipeline can be determined based on the oil and gas pipelines with different field conditions and different pipeline information, and a pipeline water pressure-far-field magnetic signal testing device can be set. A water pressure loading simulation test is performed on the test pipeline using the pipeline water pressure-far-field magnetic signal testing device. The established pipeline stress and magnetic signal forward model is corrected based on the test magnetic field gradient modulus and the test stress value to correct the influence of hysteresis, improve the correspondence between the magnetic signal and the pipeline stress, and obtain a corrected pipeline stress value change calculation model. In this way, the pipeline stress value change calculation model can improve the accuracy of the monitored oil and gas pipeline stress state, thereby improving the accuracy of monitoring the oil and gas pipeline safety state.

[0066] In some embodiments, a monitoring experiment is conducted to verify the feasibility and effectiveness of the oil and gas pipeline safety status monitoring method provided by the embodiments of the present invention.

[0067] For example, consider the target pipeline's pipeline information, which includes pipe diameter, pipe material, design pressure, and operating pressure. The pipe diameter is 1016 mm, the pipe material is X80, the design pressure is 8 MPa, and the operating pressure is 6 MPa. For example, consider the field operating conditions, which include the burial depth. Specifically, the burial depth is 1.5 m. The initial stress value obtained is 223 MPa.

[0068] Through the above S102-S104, the expression of the calculation model of the stress value change of the first pipeline can be determined as follows:

[0069]

[0070] The expression of the calculation model of the stress value change of the second pipeline can be:

[0071] Δσ2=0.2107ΔG2+21.607.

[0072] Then, the safety status of the target pipeline is evaluated by the first pipeline stress value change calculation model and the second pipeline stress value change calculation model according to the above expression.

[0073] For example, when the magnetic field gradient modulus increases by 298 nT / m, the stress change value of the target pipeline is 62 MPa. When the magnetic field gradient modulus decreases by 226 nT / m, the stress change value of the target pipeline is 69 MPa.

[0074] Furthermore, based on the initial stress value of 223 MPa, the corresponding stress values ​​of the magnetic field gradient modulus during the ascending and descending phases are 285 MPa and 292 MPa, respectively. In one implementation, ultrasonic stress testing can also be performed on the target pipeline, and it can be determined that the stress values ​​calculated using the first and second pipeline stress value change calculation models, respectively, have errors of 12 MPa and 11 MPa compared to the ultrasonic stress test results. Based on the yield strength of X80 steel of 555 MPa, the failure probability values ​​are 0.51 and 0.53, respectively, corresponding to a failure probability level of 2.

[0075] It can be seen that the oil and gas pipeline safety status monitoring method provided by the embodiment of the present application can effectively and accurately determine the stress state of the oil and gas pipeline, thereby improving the accuracy of monitoring the safety status of the oil and gas pipeline.

[0076] The embodiment of the present invention also provides an oil and gas pipeline safety status monitoring system, Figure 2 A schematic diagram of the structure of the oil and gas pipeline safety status monitoring system provided by the embodiment of the present invention is shown in FIG. Figure 2 As shown, the oil and gas pipeline safety status monitoring system 200 includes: an acquisition device 210, a construction device 220, a pipeline water pressure-far-field magnetic signal testing device 230 and a monitoring device 240.

[0077] The acquisition device 210 may be used to acquire pipeline information, field operating condition information, and initial stress value of the target oil and gas pipeline. The field operating condition information is used to characterize the environmental conditions of the target oil and gas pipeline.

[0078] The construction device 220 can be used to determine the test pipeline 250 based on the pipeline information, and set the pipeline water pressure-far-field magnetic signal testing device 230 based on the on-site working conditions information; the test pipeline 250 is set in the pipeline water pressure-far-field magnetic signal testing device 230, and the pipeline water pressure-far-field magnetic signal testing device 230 is used to perform a water pressure loading simulation test on the test pipeline 250.

[0079] The pipeline water pressure-far-field magnetic signal testing device 230 can be used to load multiple preset water pressures on the test pipeline 250 to obtain multiple test magnetic field gradient moduli and multiple test stress values ​​corresponding to the test pipeline 250 under the multiple preset water pressures.

[0080] The pipeline water pressure-far-field magnetic signal testing device 230 can also be used to perform matching corrections based on multiple test magnetic field gradient moduli and multiple test stress values ​​to determine the corrected first pipeline stress value change calculation model and second pipeline stress value change calculation model; wherein the first pipeline stress value change calculation model is used to determine the stress value change of the pipeline during the rising stage of the magnetic field gradient modulus, and the second pipeline stress value change calculation model is used to determine the stress value change of the pipeline during the falling stage of the magnetic field gradient modulus.

[0081] In some embodiments, the expression of the first pipeline stress value change calculation model is:

[0082]

[0083] Among them, Δσ1 represents the stress value change of the pipeline during the magnetic field gradient modulus rising stage, ΔG1 represents the magnetic field gradient modulus change value of the pipeline during the magnetic field gradient modulus rising stage, a represents the first correction coefficient, and b represents the second correction coefficient. The first correction coefficient and the second correction coefficient are determined by fitting analysis based on multiple test magnetic field gradient moduli and multiple test stress values.

[0084] In some embodiments, the expression of the second pipeline stress value change calculation model is:

[0085] Δσ2=cΔG2+d;

[0086] Among them, Δσ2 represents the stress value change of the pipeline during the magnetic field gradient modulus decrease stage, ΔG2 represents the magnetic field gradient modulus change value of the pipeline during the magnetic field gradient modulus decrease stage, c represents the third correction coefficient, d represents the fourth correction coefficient, and the third correction coefficient and the fourth correction coefficient are determined by fitting analysis based on multiple test magnetic field gradient moduli and multiple test stress values.

[0087] The monitoring device 240 can be used to determine the monitoring stress value of the target oil and gas pipeline based on the monitoring magnetic field gradient modulus and the initial stress value through the first pipeline stress value change calculation model or the second pipeline stress value change calculation model.

[0088] The monitoring device 240 can also be used to evaluate the safety status of the target oil and gas pipeline based on the monitored stress value.

[0089] In some embodiments, Figure 3 A schematic diagram of the structure of a pipeline water pressure-far-field magnetic signal testing device provided by an embodiment of the present invention is shown in FIG. Figure 3 As shown, the pipeline water pressure-far-field magnetic signal testing device 230 includes: a magnetic gradient detector 231, a strain gauge 232, a water pump 233, a data acquisition device 234, an engineering host computer 235, a remote numerical control device 236, a water reservoir 237 and an aluminum truss 238.

[0090] Among them, the aluminum truss 238 is arranged above the test pipe 250, the magnetic gradient detector 231 is arranged on the aluminum truss 238, the magnetic gradient detector 231 is connected to the data acquisition device 234, the strain gauge 232 is arranged on the test pipe 250, the strain gauge 232 is connected to the data acquisition device 234, the data acquisition device 234 is connected to the engineering host computer 235, the water inlet of the water pump 233 is connected to the water reservoir 237, the water outlet of the water pump 233 is connected to the test pipe 250, and the water pump 233 is connected to the remote numerical control device 236.

[0091] The remote numerical control device 236 can be used to control the water pump 233 to load a plurality of preset water pressures into the test pipe 250 .

[0092] The data acquisition device 234 can be used to acquire multiple test magnetic field gradient moduli through the magnetic gradient detector 231 , and to acquire multiple test stress values ​​through the strain gauge 232 .

[0093] The engineering host computer 235 can be used to perform matching correction based on multiple test magnetic field gradient moduli and multiple test stress values ​​collected by the data acquisition device 234 to determine the first pipeline stress value change calculation model and the second pipeline stress value change calculation model.

[0094] Using the oil and gas pipeline safety status monitoring system provided in the embodiments of the present application, a test pipeline can be determined based on oil and gas pipelines with different field conditions and different pipeline information, and a pipeline water pressure-far-field magnetic signal testing device can be set. A water pressure loading simulation test is performed on the test pipeline using the pipeline water pressure-far-field magnetic signal testing device. The established forward model of pipeline stress and magnetic signal is corrected based on the test magnetic field gradient modulus and test stress value to correct the influence of hysteresis, improve the correspondence between magnetic signal and pipeline stress, and obtain a corrected pipeline stress value change calculation model. In this way, the pipeline stress value change calculation model can improve the accuracy of the monitored oil and gas pipeline stress state, thereby improving the accuracy of monitoring the oil and gas pipeline safety state.

[0095] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0096] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0097] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0098] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0099] Similar parts between the embodiments provided in this application can be referenced to each other. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods expanded based on the scheme of this application without expending creative work shall fall within the scope of protection of this application.

Claims

1. A method for monitoring the safety status of an oil and gas pipeline, characterized in that: include: Obtaining pipeline information, on-site operating condition information, and initial stress value of a target oil and gas pipeline, wherein the on-site operating condition information is used to characterize the environmental conditions of the target oil and gas pipeline; Determine a test pipeline based on the pipeline information, and set a pipeline water pressure-far-field magnetic signal testing device based on the on-site working condition information; the test pipeline is set in the pipeline water pressure-far-field magnetic signal testing device, and the pipeline water pressure-far-field magnetic signal testing device is used to perform a water pressure loading simulation test on the test pipeline; Applying multiple preset water pressures to the test pipeline using the pipeline water pressure-far-field magnetic signal testing device to obtain multiple test magnetic field gradient moduli and multiple test stress values ​​corresponding to the test pipeline under the multiple preset water pressures; Matching and correcting the multiple test magnetic field gradient moduli and the multiple test stress values ​​are performed to determine a corrected first pipeline stress value change calculation model and a corrected second pipeline stress value change calculation model; wherein the first pipeline stress value change calculation model is used to determine the stress value change of the pipeline during the rising stage of the magnetic field gradient modulus, and the second pipeline stress value change calculation model is used to determine the stress value change of the pipeline during the falling stage of the magnetic field gradient modulus; Determining a monitoring stress value of the target oil and gas pipeline using the first pipeline stress value change calculation model or the second pipeline stress value change calculation model according to the monitoring magnetic field gradient modulus and the initial stress value; Performing a safety status assessment on the target oil and gas pipeline according to the monitored stress value; The expression of the calculation model of the first pipeline stress value change is: ; in, Indicates the change in the stress value of the pipeline during the rising stage of the magnetic field gradient modulus, Indicates the change in the magnetic field gradient modulus of the pipeline during the rising stage of the magnetic field gradient modulus. represents the first correction coefficient, represents a second correction coefficient, wherein the first correction coefficient and the second correction coefficient are determined by fitting analysis according to the multiple test magnetic field gradient moduli and the multiple test stress values; The expression of the calculation model of the second pipeline stress value change is: ; in, Indicates the change in the stress value of the pipeline during the stage of magnetic field gradient modulus decrease, Indicates the change in the magnetic field gradient modulus of the pipeline during the magnetic field gradient modulus decrease stage. represents the third correction coefficient, represents a fourth correction coefficient, and the third correction coefficient and the fourth correction coefficient are determined by fitting analysis according to the multiple test magnetic field gradient moduli and the multiple test stress values.

2. The method according to claim 1, characterized in that The pipeline information includes: yield strength of the pipe; The safety status assessment of the target oil and gas pipeline according to the monitored stress value includes: determining a failure probability value according to the monitored stress value and the yield strength, wherein the failure probability value is a ratio of the monitored stress value to the yield strength; A failure probability level is determined according to the failure probability value, and the failure probability level is used to evaluate the safety status of the target oil and gas pipeline.

3. The method according to claim 1, characterized in that The pipeline information includes one or more of the following parameters: pipe diameter, wall thickness, pipeline material, pipeline design pressure, and pipeline operating pressure.

4. The method according to claim 1, wherein The on-site working condition information includes: pipeline burial depth.

5. An oil and gas pipeline safety status monitoring system, characterized in that: include: Acquisition device, construction device, pipeline water pressure-remote field magnetic signal testing device and monitoring device; The acquisition device is used to acquire pipeline information, on-site working condition information and initial stress value of the target oil and gas pipeline, wherein the on-site working condition information is used to characterize the environmental conditions of the target oil and gas pipeline; The construction device is used to determine the test pipeline based on the pipeline information and set the pipeline water pressure-far-field magnetic signal testing device based on the on-site working condition information; the test pipeline is set in the pipeline water pressure-far-field magnetic signal testing device, and the pipeline water pressure-far-field magnetic signal testing device is used to perform a water pressure loading simulation test on the test pipeline; The pipeline water pressure-far-field magnetic signal testing device is used to apply multiple preset water pressures to the test pipeline and obtain multiple test magnetic field gradient moduli and multiple test stress values ​​corresponding to the test pipeline under the multiple preset water pressures; The pipeline water pressure-far-field magnetic signal testing device is further configured to perform matching corrections based on the multiple test magnetic field gradient moduli and the multiple test stress values ​​to determine a corrected first pipeline stress value change calculation model and a corrected second pipeline stress value change calculation model; wherein the first pipeline stress value change calculation model is configured to determine the stress value change of the pipeline during an increasing phase of the magnetic field gradient modulus, and the second pipeline stress value change calculation model is configured to determine the stress value change of the pipeline during a decreasing phase of the magnetic field gradient modulus. The monitoring device is configured to determine a monitoring stress value of the target oil and gas pipeline based on the monitoring magnetic field gradient modulus and the initial stress value and using the first pipeline stress value change calculation model or the second pipeline stress value change calculation model; The monitoring device is further configured to perform a safety status assessment on the target oil and gas pipeline based on the monitored stress value; The expression of the calculation model of the first pipeline stress value change is: ; in, Indicates the change in the stress value of the pipeline during the rising stage of the magnetic field gradient modulus, Indicates the change in the magnetic field gradient modulus of the pipeline during the rising stage of the magnetic field gradient modulus. represents the first correction coefficient, represents a second correction coefficient, wherein the first correction coefficient and the second correction coefficient are determined by fitting analysis according to the multiple test magnetic field gradient moduli and the multiple test stress values; The expression of the calculation model of the second pipeline stress value change is: ; in, Indicates the change in the stress value of the pipeline during the stage of magnetic field gradient modulus decrease, Indicates the change in the magnetic field gradient modulus of the pipeline during the magnetic field gradient modulus decrease stage. represents the third correction coefficient, represents a fourth correction coefficient, and the third correction coefficient and the fourth correction coefficient are determined by fitting analysis according to the multiple test magnetic field gradient moduli and the multiple test stress values.

6. The system according to claim 5, characterized in that The pipeline water pressure-far-field magnetic signal testing device includes: a magnetic gradient detector, a strain gauge, a water pump, a data acquisition device, an engineering host computer, a remote numerical control device, a water reservoir and an aluminum truss; The aluminum truss is arranged above the test pipe, the magnetic gradient detector is arranged on the aluminum truss, the magnetic gradient detector is connected to the data acquisition device, the strain gauge is arranged on the test pipe, the strain gauge is connected to the data acquisition device, the data acquisition device is connected to the engineering host computer, the water inlet of the water pump is connected to the water reservoir, the water outlet of the water pump is connected to the test pipe, and the water pump is connected to the remote numerical control device; The remote numerical control device is used to control the water pump to load the test pipe with the multiple preset water pressures; The data acquisition device is configured to acquire the plurality of test magnetic field gradient moduli through the magnetic gradient detector, and to acquire the plurality of test stress values ​​through the strain gauge; The engineering host computer is used to perform matching correction based on the multiple test magnetic field gradient moduli and the multiple test stress values ​​collected by the data acquisition device, and determine the first pipeline stress value change calculation model and the second pipeline stress value change calculation model.

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