Oil and gas pipeline safety state monitoring method and system

Abstract

The invention provides an oil and gas pipeline safety state monitoring method and system, and the method comprises the steps: firstly, obtaining the pipeline information, field working condition information and an initial stress value of a target oil and gas pipeline; then, a test pipeline is determined, a pipeline water pressure-far field magnetic signal test device is arranged, a plurality of preset water pressures are loaded to the test pipeline through the pipeline water pressure-far field magnetic signal test device, and 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 are obtained; next, matching correction is carried out, and a corrected first pipeline stress value variable quantity calculation model and a corrected second pipeline stress value variable quantity calculation model are determined so as to be used for determining the monitoring stress value of the target oil and gas pipeline. And finally, performing safety state evaluation on the target oil and gas pipeline according to the monitored stress value. In this way, the accuracy of monitoring the stress state of the oil and gas pipeline can be improved through the corrected pipeline stress value variation calculation model, and therefore the accuracy of monitoring the safety state of the oil and gas pipeline is improved.

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] At present, there are many oil and gas pipelines passing through mountainous areas, and potential geological disasters will directly threaten the construction and safe operation of long-distance oil and gas pipelines. Among them, landslides are the most common type of geological disasters that threaten the safe operation of buried pipelines. Once a landslide natural disaster occurs, it is very easy to cause deformation and rupture of oil and gas pipelines, resulting in oil and gas leakage, which seriously threatens the safety of people's lives and property. Therefore, it is necessary to monitor the safety status of pipelines in real time.

[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 of oil and gas pipelines. Specifically, based on the pipeline complex load-non-contact magnetic signal forward model, the quantitative relationship between the real stress and magnetic signal of the pipeline under complex loads can be clarified, so as to realize the use of non-contact magnetic stress detection to characterize and evaluate the safety status (such as stress status) of the pipeline.

[0004] However, due to the influence of hysteresis, the relationship between magnetic signals and pipeline stress is still unclear, and the stress of oil and gas pipelines cannot be accurately determined. This leads to a decrease in the monitoring ability of pipeline safety status, 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 that the safety status of the oil and gas pipeline cannot be accurately monitored.

[0006] In order 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 adopts the following technical solutions:

[0007] In the 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 value 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, determining a test pipeline according to the pipeline information, setting a pipeline water pressure-remote field magnetic signal test device according to the field operating condition information; the test pipeline is set in the pipeline water pressure-remote field magnetic signal test device, and the pipeline water pressure-remote field magnetic signal test device is used to perform a water pressure loading simulation test on the test pipeline. Secondly, multiple preset water pressures are loaded on the test pipeline by the pipeline water pressure-remote field magnetic signal test device, and multiple test magnetic field gradient moduli and multiple test stress values ​​corresponding to the test pipeline under multiple preset water pressures are obtained. Next, matching correction is performed according to multiple test magnetic field gradient moduli and multiple test stress values, and a corrected first pipeline stress value change calculation model and a second pipeline stress value change calculation model are determined. Among them, the first pipeline stress value change calculation model is used to determine the stress value change of the pipeline in 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 in the falling stage of the magnetic field gradient modulus. According to the monitoring magnetic field gradient modulus and the initial stress value, the monitoring stress value of the target oil and gas pipeline is determined through the first pipeline stress value change calculation model or the second pipeline stress value change calculation model. Finally, the safety status of the target oil and gas pipeline is evaluated according to the monitoring stress value.

[0008] In this method, the test pipeline can be determined according to the oil and gas pipelines with different on-site working conditions and different pipeline information, and a pipeline water pressure-remote field magnetic signal test device can be set. The test pipeline is subjected to a water pressure loading simulation test by the pipeline water pressure-remote field magnetic signal test device, and the established pipeline stress and magnetic signal forward model is corrected according to the test magnetic field gradient modulus and the test stress value to correct the influence of the hysteresis phenomenon, improve the correspondence between the magnetic signal and the pipeline stress, and obtain the 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 safety state of the oil and gas pipeline.

[0009] In combination with the first aspect, in an optional implementation, the expression of the calculation model of the change amount of the first pipeline stress value is:

[0010]

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

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

[0013] Δσ2=cΔG2+d;

[0014] Among them, Δσ2 represents the change in stress value of the pipeline during the stage of magnetic field gradient modulus decrease, ΔG2 represents the change in magnetic field gradient modulus of the pipeline during the stage of magnetic field gradient modulus decrease, 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 combination with the first aspect, in an optional implementation, the above pipeline information includes: the yield strength of the pipe. Then, the safety status of the target oil and gas pipeline is evaluated according to the monitored stress value, specifically including: first, determining the failure possibility value according to the monitored stress value and the yield strength, and the failure possibility value is the ratio of the monitored stress value to the yield strength. Then, determining the failure possibility level according to the failure possibility value, and the failure possibility level is used to evaluate 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 the second aspect, the present invention provides an oil and gas pipeline safety status monitoring system, including: an acquisition device, a construction device, a pipeline water pressure-far-field magnetic signal testing device and a monitoring device. Among them, the acquisition device is used to obtain the pipeline information, field working condition information and initial stress value of the target oil and gas pipeline, and the field 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 according to the pipeline information, and set the pipeline water pressure-far-field magnetic signal testing device according to the field 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 load a plurality of preset water pressures on the test pipeline, and obtain 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. The pipeline water pressure-far-field magnetic signal testing device is also used to match and correct multiple test magnetic field gradient moduli and multiple test stress values ​​to determine the corrected first pipeline stress value change calculation model and the 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 in 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 in the falling stage of the magnetic field gradient modulus. The monitoring device is used to determine the monitoring stress value of the target oil and gas pipeline through 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. The monitoring device is also used to evaluate the safety status of the target oil and gas pipeline according to the monitoring stress value.

[0019] In combination with the second aspect, in an optional implementation, the pipeline water pressure-remote field magnetic signal test 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. Among them, the aluminum truss is arranged above the test pipeline, 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 pipeline, 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 pipeline, 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 multiple preset water pressures to the test pipeline. The data acquisition device is used to collect multiple test magnetic field gradient moduli through the magnetic gradient detector, and collect multiple test stress values ​​through the strain gauge. The engineering host computer is used to match and correct the multiple test magnetic field gradient moduli and 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.

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

[0021]

[0022] Among them, Δσ1 represents the change in stress value of the pipeline during the rising stage of magnetic field gradient modulus, ΔG1 represents the change in magnetic field gradient modulus of the pipeline during the rising stage of magnetic field gradient modulus, a represents the first correction coefficient, b represents the second correction coefficient, and the first correction coefficient and the second correction coefficient are determined by fitting analysis based on multiple tested magnetic field gradient moduli and multiple tested 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 change in stress value of the pipeline during the stage of magnetic field gradient modulus decrease, ΔG2 represents the change in magnetic field gradient modulus of the pipeline during the stage of magnetic field gradient modulus decrease, 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 diagram of a flow chart of a method for monitoring the safety status of an oil and gas pipeline provided by 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 diagram of the structure 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, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following embodiments do not represent all implementations consistent with the present application. They are only examples of systems and methods consistent with some 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 of oil and gas pipelines. Specifically, based on the pipeline complex load-non-contact magnetic signal forward model, the quantitative relationship between the real stress and magnetic signal of the pipeline under complex loads can be clarified, so as to realize the use of non-contact magnetic stress detection to characterize and evaluate the safety status (such as stress status) of the pipeline.

[0032] However, due to the influence of hysteresis, the relationship between magnetic signals and pipeline stress is still unclear, and the stress of oil and gas pipelines cannot be accurately determined. This leads to a decrease in the monitoring ability of pipeline safety status, making it impossible to accurately monitor the safety status of oil and gas pipelines.

[0033] In order to solve the above problems, an embodiment of the present invention provides a method and system for monitoring the safety status of an oil and gas pipeline. The method can establish a forward model of pipeline stress and magnetic signals according to different on-site working conditions and oil and gas pipelines of different materials, and correct the influence of hysteresis, improve the correspondence between magnetic signals and pipeline stress, and obtain a corrected pipeline stress value change calculation model. In this way, the accuracy of the determined oil and gas pipeline stress state can be improved through the corrected pipeline stress value change calculation model, thereby improving the accuracy of monitoring the safety status of the oil and gas pipeline.

[0034] The solution provided by the embodiment of the present application is introduced below in conjunction with the accompanying drawings.

[0035] For details, see Figure 1 , which is a flow chart of a method for monitoring the safety status of an oil and gas pipeline 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 the embodiment of the present application, the target oil and gas pipeline is the oil and gas pipeline to be monitored. First, basic information and field information of the target oil and gas pipeline are obtained. Specifically, it includes: pipeline information, field working condition information and initial stress value. Among them, the field working condition information is used to characterize the environmental conditions of the target oil and gas pipeline.

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

[0039] S102, determining a test pipeline according to pipeline information, and setting a pipeline water pressure-far-field magnetic signal test device according to on-site working condition information.

[0040] Then, according to the pipeline information and field working condition information obtained in S101, the test pipeline can be determined, and the pipeline water pressure-far-field magnetic signal test device can be built. The test pipeline is set in the pipeline water pressure-far-field magnetic signal test device, and the pipeline water pressure-far-field magnetic signal test device 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, loading a plurality of preset water pressures on the test pipeline through a pipeline water pressure-far-field magnetic signal testing device, and obtaining 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.

[0043] Furthermore, the pipeline water pressure-remote field magnetic signal test device can be used to perform a water pressure loading simulation test on the test pipeline, and multiple preset water pressures can be loaded on the test pipeline. For example, a pump can be used to establish on-site flow conditions to load water pressure on the test pipeline. Among them, multiple preset water pressures can be preset according to the historical operating conditions of the target oil and gas pipeline and the actual monitoring requirements, and this application does not make 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, the test magnetic field gradient modulus of the test pipeline under different water pressure loading modes can be collected by a magnetic gradiometer, and the test stress value under different water pressure loading modes can also be obtained by a strain gauge.

[0046] S104, performing matching correction according to a plurality of test magnetic field gradient moduli and a plurality of test stress values, and determining a corrected first pipeline stress value change calculation model and a 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, and 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 mismatching behavior of pipeline stress and magnetic field gradient modulus caused by hysteresis, so as to achieve matching correction of multiple test magnetic field gradient moduli and multiple test stress values, and obtain 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 in the magnetic field gradient modulus rising stage, and the second pipeline stress value change calculation model is used to determine the stress value change of the pipeline in the magnetic field gradient modulus decreasing stage.

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

[0050]

[0051] Among them, Δv1 represents the change in stress value of the pipeline during the rising stage of magnetic field gradient modulus, ΔG1 represents the change in magnetic field gradient modulus of the pipeline during the rising stage of magnetic field gradient modulus, a represents the first correction coefficient, b represents the second correction coefficient, and the first correction coefficient and the second correction coefficient are determined by fitting analysis based on multiple tested magnetic field gradient moduli and multiple tested 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 change in stress value of the pipeline during the stage of magnetic field gradient modulus decrease, ΔG2 represents the change in magnetic field gradient modulus of the pipeline during the stage of magnetic field gradient modulus decrease, 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. Determine 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 stage, the monitoring stress value of the target oil and gas pipeline can be determined by the first pipeline stress value change calculation model. When the monitoring magnetic field gradient modulus is in a descending stage, the monitoring stress value of the target oil and gas pipeline can be determined by the second pipeline stress value change calculation model.

[0057] S106. Evaluate the safety status of the target oil and gas pipeline according to 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 possibility level is determined according to the failure possibility value, and the failure possibility level is used to evaluate the safety status of the target oil and gas pipeline.

[0061] Exemplarily, as shown in Table 1, the failure probability level 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] Among them, the higher the level of 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 adopting the oil and gas pipeline safety status monitoring method provided in the embodiment of the present application, the test pipeline can be determined according to the oil and gas pipelines with different on-site working conditions and different pipeline information, and a pipeline water pressure-far-field magnetic signal testing device can be set. The test pipeline is subjected to a water pressure loading simulation test by the pipeline water pressure-far-field magnetic signal testing device, and the established pipeline stress and magnetic signal forward model is corrected according to the test magnetic field gradient modulus and the test stress value to correct the influence of the hysteresis phenomenon, improve the correspondence between the magnetic signal and the pipeline stress, and obtain the corrected pipeline stress value change calculation model. In this way, the accuracy of the monitored oil and gas pipeline stress state can be improved by the pipeline stress value change calculation model, thereby improving the accuracy of monitoring the safety state of the oil and gas pipeline.

[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, the pipeline information of the target pipeline includes: pipe diameter, pipe material, pipe design pressure and operating pressure. Among them, the pipe diameter is 1016mm, the pipe material is X80, the pipe design pressure is 8MPa, and the operating pressure is 6MP. The field working condition information includes: burial depth. Specifically, the burial depth is: 1.5m. The initial stress value obtained is 223Mpa.

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

[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 of 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] Further, according to the initial stress value of 223 MPa, it can be determined that the magnetic field gradient modulus in the rising stage and the falling stage have corresponding stress values ​​of 285 MPa and 292 MPa, respectively. In one implementation, ultrasonic stress detection can also be performed on the target pipeline to determine that the stress value calculated by the first pipeline stress value change calculation model and the second pipeline stress value change calculation model has an error of 12 MPa and 11 MPa with the ultrasonic stress test result, respectively. Calculated with the yield strength of X80 steel of 555 MPa, the failure probability values ​​are 0.51 and 0.53, respectively, and the corresponding failure probability level is level 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-remote 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 according to the pipeline information, and set the pipeline water pressure-far-field magnetic signal testing device 230 according to 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 a plurality of preset water pressures on the test pipeline 250 to obtain a plurality of test magnetic field gradient moduli and a plurality of test stress values ​​corresponding to the test pipeline 250 under the plurality of 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 the 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 in 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 in 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 change in stress value of the pipeline during the rising stage of magnetic field gradient modulus, ΔG1 represents the change in magnetic field gradient modulus of the pipeline during the rising stage of magnetic field gradient modulus, a represents the first correction coefficient, b represents the second correction coefficient, and the first correction coefficient and the second correction coefficient are determined by fitting analysis based on multiple tested magnetic field gradient moduli and multiple tested 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 change in stress value of the pipeline during the stage of magnetic field gradient modulus decrease, ΔG2 represents the change in magnetic field gradient modulus of the pipeline during the stage of magnetic field gradient modulus decrease, 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 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.

[0088] The monitoring device 240 may also be used to evaluate the safety status of the target oil and gas pipeline according to 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-remote 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 according to multiple test magnetic field gradient moduli and multiple test stress values ​​collected by the data acquisition device 234, and determine the first pipeline stress value change calculation model and the second pipeline stress value change calculation model.

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

[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 as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0097] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0098] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means 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 may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the 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 general concept of this application and do not constitute a limitation on the protection scope of this application. For those skilled in the art, any other implementation methods expanded based on the scheme of this application without creative work belong to the protection scope 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, field operating condition information, and initial stress value 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; Determine a test pipeline according to the pipeline information, and set a pipeline water pressure-remote field magnetic signal test device according to the on-site working condition information; the test pipeline is set in the pipeline water pressure-remote field magnetic signal test device, and the pipeline water pressure-remote field magnetic signal test device is used to perform a water pressure loading simulation test on the test pipeline; Loading a plurality of preset water pressures on the test pipeline by the pipeline water pressure-far-field magnetic signal testing device to obtain 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; Matching and correcting are performed according to the multiple test magnetic field gradient moduli and the multiple test stress values, and a corrected first pipeline stress value change calculation model and a second pipeline stress value change calculation model are determined; wherein the first pipeline stress value change calculation model is used to determine the stress value change of the pipeline in the magnetic field gradient modulus rising stage, and the second pipeline stress value change calculation model is used to determine the stress value change of the pipeline in the magnetic field gradient modulus falling stage; Determine 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; A safety status assessment is performed on the target oil and gas pipeline according to the monitored stress value.

2. The method according to claim 1, characterized in that The expression of the calculation model of the first pipeline stress value change is: Among them, Δσ1 represents the change in stress value of the pipeline during the rising stage of magnetic field gradient modulus, ΔG1 represents the change in magnetic field gradient modulus of the pipeline during the rising stage of magnetic field gradient modulus, a represents the first correction coefficient, b represents the second correction coefficient, and the first correction coefficient and the second correction coefficient are determined by fitting analysis based on the multiple test magnetic field gradient moduli and the multiple test stress values.

3. The method according to claim 1 or 2, characterized in that: The expression of the calculation model of the stress value change of the second pipeline is: Δσ2=cΔG2+d; Among them, Δσ2 represents the change in the stress value of the pipeline in the stage where the magnetic field gradient modulus decreases, ΔG2 represents the change in the magnetic field gradient modulus of the pipeline in the stage where the magnetic field gradient modulus decreases, c represents the third correction coefficient, and d represents the fourth correction coefficient. The third correction coefficient and the fourth correction coefficient are determined by fitting analysis based on the multiple test magnetic field gradient moduli and the multiple test stress values.

4. The method according to claim 1, characterized in that The pipeline information includes: the 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 possibility level is determined according to the failure possibility value, and the failure possibility level is used to evaluate the safety status of the target oil and gas pipeline.

5. 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.

6. The method according to claim 1, characterized in that The on-site working condition information includes: pipeline burial depth.

7. 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, field operating condition information and initial stress value of the 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 the test pipeline according to the pipeline information, and to set the pipeline water pressure-far-field magnetic signal test device according to the on-site working condition information; the test pipeline is set in the pipeline water pressure-far-field magnetic signal test device, and the pipeline water pressure-far-field magnetic signal test 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 obtain 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 used to perform matching correction according to the multiple test magnetic field gradient moduli and the multiple test stress values, and determine the corrected first pipeline stress value change calculation model and the 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 in the magnetic field gradient modulus rising stage, and the second pipeline stress value change calculation model is used to determine the stress value change of the pipeline in the magnetic field gradient modulus falling stage; The monitoring device is used to determine 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; The monitoring device is also used to evaluate the safety status of the target oil and gas pipeline according to the monitored stress value.

8. The system according to claim 7, characterized in that 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; Wherein, the aluminum truss is arranged above the test pipeline, 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 pipeline, 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 pipeline, 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 multiple preset water pressures to the test pipe; The data acquisition device is used to acquire the multiple test magnetic field gradient moduli through the magnetic gradient detector, and to acquire the multiple test stress values ​​through the strain gauge; The engineering host computer is used to perform matching correction according to 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.

9. The system according to claim 7 or 8, characterized in that: The expression of the calculation model of the first pipeline stress value change is: Among them, Δσ1 represents the change in stress value of the pipeline during the rising stage of magnetic field gradient modulus, ΔG1 represents the change in magnetic field gradient modulus of the pipeline during the rising stage of magnetic field gradient modulus, a represents the first correction coefficient, b represents the second correction coefficient, and the first correction coefficient and the second correction coefficient are determined by fitting analysis based on the multiple test magnetic field gradient moduli and the multiple test stress values.

10. The system according to claim 7 or 8, characterized in that: The expression of the calculation model of the stress value change of the second pipeline is: Δσ2=cΔG2+d; Among them, Δσ2 represents the change in the stress value of the pipeline in the stage where the magnetic field gradient modulus decreases, ΔG2 represents the change in the magnetic field gradient modulus of the pipeline in the stage where the magnetic field gradient modulus decreases, c represents the third correction coefficient, and d represents the fourth correction coefficient. The third correction coefficient and the fourth correction coefficient are determined by fitting analysis based on the multiple test magnetic field gradient moduli and the multiple test stress values.

Images