Risk assessment method and system for buried pipeline in geological disaster area

Abstract

The invention discloses a risk assessment method and system for a buried pipeline in a geological disaster area, and the method comprises the steps: obtaining the corrosion rate of a to-be-assessed pipeline, and carrying out the assessment of a first leakage risk caused by the corrosion in the pipeline according to the corrosion rate; obtaining a pipeline damage risk index under a ground disaster occurrence condition by using a ground disaster occurrence risk index representing the severity of a ground disaster faced by the area where the pipeline is located and a vulnerability risk index representing the pipeline damage difficulty, and evaluating a second leakage risk caused by the ground disaster according to the pipeline damage risk index; and obtaining the actual leakage risk of the pipeline according to the first leakage risk assessment result and the second leakage risk assessment result. According to the method, the pertinence of risk assessment is enhanced, quantitative risk assessment of the buried pipeline in the ground disaster area is realized, the safe and stable operation guarantee level of the buried pipeline in the ground disaster area is greatly improved, and technical support is provided for improving the safe operation management and technical level of the buried pipeline.

Description

Technical Field

[0001] The invention belongs to the field of quantitative assessment of safety risks of gathering and transportation pipelines in geological disaster areas, and in particular relates to a risk assessment method and system for buried pipelines in geological disaster areas. Background Art

[0002] With the continuous development of the national economy and the continuous optimization of the energy structure, natural gas, as a clean, environmentally friendly and high-quality energy, has gradually occupied an important position in the energy structure. In order to ensure the supply of natural gas, the exploration and development of natural gas has also been continuously strengthened. In today's large-scale natural gas pipeline network, gas field gathering and transportation pipelines, natural gas long-distance pipelines and urban natural gas pipelines have jointly formed a "trunk interconnection and local network" pattern, with a total mileage of more than 1 million kilometers. Among them, although the gas field gathering and transportation pipelines account for a small proportion, the complex external environment in which they are located and the harsh internal working conditions they have have led to the frequent occurrence of natural gas leakage accidents. If they are not discovered and properly handled in time, they are very likely to cause fires or explosions, posing a great threat to the safety of production of enterprises and the safety of people's lives and property.

[0003] The prior art discloses a method for evaluating the internal corrosion of buried pipelines, including: a pre-evaluation step for detecting the internal corrosion of buried pipelines; an indirect detection and evaluation step for detecting the internal corrosion of buried pipelines; a direct detection and evaluation step for detecting the internal corrosion of buried pipelines; an effectiveness evaluation step and a re-evaluation time determination step for the direct evaluation ICDA of the internal corrosion of buried pipelines. The method for evaluating the internal corrosion of buried pipelines improves the level of safe operation management and technology of buried pipelines, can reduce personal injury and economic losses of facilities caused by sudden accidents, and ensure safe production. The prior art also discloses a method for evaluating geological hazards of oil and gas pipelines based on information volume-neural network, including the following steps: determining the study area and dividing the grid units; conducting a geological hazard susceptibility evaluation; conducting a pipeline vulnerability evaluation; determining the level of failure consequences according to the failure consequence classification standard; and determining the risk level of pipeline geological hazards using the pipeline failure probability and the level of failure consequences. In addition, the prior art also discloses a natural gas pipeline risk assessment method, which first analyzes the service status of the service pipeline and determines the coupling model required for the pipeline risk assessment failure analysis characterization model; then, based on the coupling model required for the analysis, a pipeline risk assessment failure analysis characterization model is established; then, according to the service status of the service pipeline, the corresponding parameter values ​​are screened with reference to "GB / T34346-2017" to calculate the oil pipeline risk assessment failure risk; finally, in order to judge the dangerous condition of the natural gas pipeline in advance, preventive measures can be taken in advance and by understanding the hazard factors faced by the natural gas pipeline, risks can be identified and ranked, thereby formulating the optimal maintenance plan and avoiding the waste of manpower and material resources.

[0004] With reference to the aforementioned prior art, in the process of realizing the present invention, the inventors found that most of the prior art is a risk assessment method established by considering only one kind of risk, and less in-depth consideration is given to the dual coupling risk of corrosion / geological disasters actually faced by buried pipelines in geological disaster areas. The risk assessment coverage is insufficient, and the currently used pipeline risk quantitative assessment methods are mostly based on complex formulas, which are not suitable for rapid and accurate assessment of buried pipeline risks. The Sichuan-Chongqing region is one of the main battlefields for oil and gas production. It is located in a mountainous area with high continuous precipitation and is a severely affected area by geological disasters. According to statistics, geological disasters such as landslides and mudslides in the Sichuan-Chongqing region account for about 14% of the same type of geological disasters in the country. Buried pipelines built in geological disaster areas within the Sichuan-Chongqing region not only face the widespread risk of corrosion perforation, but also face the risk of pipe section cracking caused by geological disasters. Both of the above-mentioned risks can lead to natural gas leakage. Therefore, in order to ensure the safe and smooth operation of buried oil and gas pipelines in geological disaster areas with high sulfur gas fields, it is necessary to establish a new method for rapid quantitative assessment and classification of corrosion and geological disaster risks in buried pipelines in geological disaster areas, so as to achieve effective assessment, monitoring and early warning of the dual risks of corrosion / geological disasters. Summary of the invention

[0005] In order to solve the above problems, an embodiment of the present invention provides a risk assessment method for buried pipelines in geological disaster areas, including: obtaining the corrosion rate of the pipeline to be assessed, thereby assessing the first leakage risk caused by corrosion in the pipeline according to the corrosion rate; using a geological disaster risk index that characterizes the severity of the geological disaster faced by the area where the pipeline is located, and a vulnerability risk index that characterizes the difficulty of pipeline damage, to obtain a pipeline damage risk index under geological disaster conditions, thereby assessing the second leakage risk caused by the geological disaster according to the pipeline damage risk index; obtaining the actual leakage risk of the pipeline according to the first leakage risk assessment result and the second leakage risk assessment result.

[0006] Preferably, the step of obtaining the corrosion rate of the pipeline to be evaluated includes: obtaining multiple corrosion rate data using different corrosion rate acquisition methods, and taking the maximum corrosion rate as the corrosion rate of the pipeline to be evaluated, wherein the multiple corrosion rate data include but are not limited to: a first corrosion rate calculated based on the oxygen content in the pipeline, the pH property of the conveying medium and the flow rate of the conveying medium, and a second corrosion rate measured using the electric field fingerprint corrosion monitoring technology.

[0007] Preferably, the first corrosion rate is calculated using the following expression:

[0008] CR1=CR PH ×F O ×F V

[0009] Among them, CR1 represents the first corrosion rate, CR PH Indicates the pH property coefficient of the conveying medium, F O Indicates the oxygen content coefficient, F V Indicates the flow rate coefficient of the conveying medium.

[0010] Preferably, in the step of evaluating the first leakage risk caused by corrosion in the pipeline according to the corrosion rate, it includes: if the corrosion rate is greater than or equal to 0.091 mm / a, the first leakage risk assessment result is a significant risk; if the corrosion rate is greater than or equal to 0.076 and less than 0.091 mm / a, the first leakage risk assessment result is a greater risk; if the corrosion rate is greater than or equal to 0.061 and less than 0.076 mm / a, the first leakage risk assessment result is a general risk; if the corrosion rate is less than 0.061 mm / a, the first leakage risk assessment result is a low risk.

[0011] Preferably, the pipeline damage risk index is calculated using the following expression:

[0012] PR=PH×PV

[0013] Among them, PR represents the pipeline damage risk index, PH represents the geological disaster risk index, and PV represents the vulnerability risk index.

[0014] Preferably, the geological disaster risk index is the geological disaster risk index of the pipeline area after engineering management, wherein the geological disaster risk index is calculated based on the geological disaster risk index of the pipeline area before engineering management, the landslide risk index characterizing the severity of the landslide faced by the pipeline area after engineering management, and the weight of the landslide risk prevention and control effect faced by the pipeline area after engineering management in the overall geological disaster risk prevention and control effect.

[0015] Preferably, the geological disaster risk index is calculated using the following expression:

[0016] PH = PH1 × PI + PH2 × (1-PI)

[0017] Among them, PH represents the geological disaster risk index, PH1 represents the geological disaster risk index before the implementation of engineering control, PI represents the coefficient of the weight of landslide risk prevention and control effect in the overall geological disaster risk prevention and control effect, and PH2 represents the landslide risk index.

[0018] Preferably, the risk assessment method further comprises: calculating a risk index for geological disasters in the area where the pipeline is located before implementing engineering control, based on the correlation between the severity of geological disasters faced by the area where the pipeline is located before implementing engineering control and different types of geological conditions, and the weight of each type of geological condition in the occurrence of geological disasters.

[0019] Preferably, the following expression is used to calculate the risk index of geological disasters before the implementation of engineering control in the area where the pipeline is located:

[0020]

[0021] Among them, PH1 represents the risk index of geological disasters before the implementation of engineering control, y i represents the score value of the i-th type of geological state, ω i represents the weight of the i-th type of geological state in the occurrence of geological disasters, n represents the number of geological state types, and a represents the normalization factor.

[0022] Preferably, the different types of geological conditions include but are not limited to: slope, soil type, landslide warning level, sliding body thickness, earthquake intensity, slope morphology, historical landslides, soil state and 24h maximum rainfall, wherein the weight of the slope is 0.16, the weight of the soil type is 0.14, the weight of the landslide warning level is 0.10, the weight of the sliding body thickness is 0.06, the weight of the earthquake intensity is 0.12, the weight of the slope morphology is 0.08, the weight of the historical landslides is 0.08, the weight of the soil state is 0.10, and the weight of the 24h maximum rainfall is 0.16.

[0023] Preferably, the risk assessment method further comprises: evaluating the landslide disaster prevention and control effect according to the weight of the landslide risk prevention and control effect faced by the pipeline area after the implementation of engineering management in the overall geological disaster risk prevention and control effect, and scoring the current landslide disaster prevention and control effect according to the evaluation result, so as to obtain a landslide occurrence risk index characterizing the severity of the landslide faced by the pipeline area after the implementation of engineering management, wherein the landslide occurrence risk index is calculated using the following expression:

[0024] PH2=0.44-x

[0025] Among them, PH2 represents the landslide risk index, and x represents the landslide disaster prevention and control effect score.

[0026] Preferably, the risk assessment method further comprises: evaluating the degree of damage to the pipeline according to the pipeline position and pipeline laying method of the pipeline to be assessed, and scoring the degree of damage to the current pipeline according to the evaluation result to obtain the vulnerability risk index, wherein the vulnerability risk index is calculated using the following expression:

[0027]

[0028] Among them, PV represents the vulnerability risk index, f represents the pipeline damage difficulty score, and a represents the normalization factor.

[0029] Preferably, in the step of evaluating the second leakage risk caused by the geological disaster according to the pipeline damage risk index, it includes: if the pipeline damage risk index is greater than or equal to 0.56 and less than or equal to 1, the second leakage risk assessment result is a major risk; if the pipeline damage risk index is greater than or equal to 0.33 and less than 0.56, the second leakage risk assessment result is a greater risk; if the pipeline damage risk index is greater than or equal to 0.25 and less than 0.33, the second leakage risk assessment result is a general risk; if the pipeline damage risk index is greater than or equal to 0 and less than 0.25, the second leakage risk assessment result is a low risk.

[0030] Preferably, the pipeline to be evaluated is a buried portion of the pipeline located between adjacent cut-off valve chambers.

[0031] In addition, the present invention also proposes a risk assessment system for buried pipelines in geological disaster areas, the risk assessment system comprising the following modules: a first leakage risk assessment module, which is used to obtain the corrosion rate of the pipeline to be assessed, thereby assessing the first leakage risk caused by corrosion in the pipeline according to the corrosion rate; a second leakage risk assessment module, which is used to obtain the pipeline damage risk index under the conditions of geological disasters using a geological disaster risk index that characterizes the severity of the geological disasters faced by the area where the pipeline is located, and a vulnerability risk index that characterizes the difficulty of pipeline damage, thereby assessing the second leakage risk caused by the geological disaster according to the pipeline damage risk index; an actual leakage risk assessment module, which is used to obtain the actual leakage risk of the pipeline according to the first leakage risk assessment result and the second leakage risk assessment result.

[0032] Compared with the prior art, one or more embodiments of the above scheme may have the following advantages or beneficial effects:

[0033] The present invention proposes a risk assessment method and system for buried pipelines in geological disaster areas. The risk assessment method first selects some pipelines suitable for risk assessment as pipelines to be assessed, and based on the actual risks faced by buried pipelines in geological disaster areas, the selected pipelines to be assessed are quantitatively assessed and graded for internal corrosion risks, and quantitatively assessed and graded for geological disaster risks; finally, the two types of risk quantitative assessment results are coupled to obtain the actual leakage risk of the pipeline. The present invention enhances the pertinence of risk assessment, realizes the quantitative risk assessment of buried pipelines in geological disaster areas, greatly improves the level of safe and stable operation of buried pipelines in geological disaster areas, and provides technical support for improving the safe operation management and technical level of buried pipelines.

[0034] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0036] Figure 1 This is a step diagram of a risk assessment method for buried pipelines in disaster-stricken areas according to an embodiment of the present application.

[0037] Figure 2 An example diagram of pipeline segmentation for a risk assessment method for buried pipelines in disaster-stricken areas according to an embodiment of the present application.

[0038] Figure 3 This is a module block diagram of a risk assessment system for buried pipelines in disaster-stricken areas according to an embodiment of the present application. DETAILED DESCRIPTION

[0039] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that as long as there is no conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

[0040] In addition, the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be performed in an order different from that shown here.

[0041] With the continuous development of the national economy and the continuous optimization of the energy structure, natural gas, as a clean, environmentally friendly and high-quality energy, has gradually occupied an important position in the energy structure. In order to ensure the supply of natural gas, the exploration and development of natural gas has also been continuously strengthened. In today's large-scale natural gas pipeline network, gas field gathering and transportation pipelines, natural gas long-distance pipelines and urban natural gas pipelines have jointly formed a "trunk interconnection and local network" pattern, with a total mileage of more than 1 million kilometers. Among them, although the gas field gathering and transportation pipelines account for a small proportion, the complex external environment in which they are located and the harsh internal working conditions they have have led to the frequent occurrence of natural gas leakage accidents. If they are not discovered and properly handled in time, they are very likely to cause fires or explosions, posing a great threat to the safety of production of enterprises and the safety of people's lives and property.

[0042] The prior art discloses a method for evaluating the internal corrosion of buried pipelines, including: a pre-evaluation step for detecting the internal corrosion of buried pipelines; an indirect detection and evaluation step for detecting the internal corrosion of buried pipelines; a direct detection and evaluation step for detecting the internal corrosion of buried pipelines; an effectiveness evaluation step and a re-evaluation time determination step for the direct evaluation ICDA of the internal corrosion of buried pipelines. The method for evaluating the internal corrosion of buried pipelines improves the level of safe operation management and technology of buried pipelines, can reduce personal injury and economic losses of facilities caused by sudden accidents, and ensure safe production. The prior art also discloses a method for evaluating geological hazards of oil and gas pipelines based on information volume-neural network, including the following steps: determining the study area and dividing the grid units; conducting a geological hazard susceptibility evaluation; conducting a pipeline vulnerability evaluation; determining the level of failure consequences according to the failure consequence classification standard; and determining the risk level of pipeline geological hazards using the pipeline failure probability and the level of failure consequences. In addition, the prior art also discloses a natural gas pipeline risk assessment method, which first analyzes the service status of the service pipeline and determines the coupling model required for the pipeline risk assessment failure analysis characterization model; then, based on the coupling model required for the analysis, a pipeline risk assessment failure analysis characterization model is established; then, according to the service status of the service pipeline, the corresponding parameter values ​​are screened with reference to "GB / T34346-2017" to calculate the oil pipeline risk assessment failure risk; finally, in order to judge the dangerous condition of the natural gas pipeline in advance, preventive measures can be taken in advance and by understanding the hazard factors faced by the natural gas pipeline, risks can be identified and ranked, thereby formulating the optimal maintenance plan and avoiding the waste of manpower and material resources.

[0043] With reference to the aforementioned prior art, in the process of realizing the present invention, the inventors found that most of the prior art is a risk assessment method established by considering only one kind of risk, and less in-depth consideration is given to the dual coupling risk of corrosion / geological disasters actually faced by buried pipelines in geological disaster areas. The risk assessment coverage is insufficient, and the currently used pipeline risk quantitative assessment methods are mostly based on complex formulas, which are not suitable for rapid and accurate assessment of buried pipeline risks. The Sichuan-Chongqing region is one of the main battlefields for oil and gas production. It is located in a mountainous area with high continuous precipitation and is a severely affected area by geological disasters. According to statistics, geological disasters such as landslides and mudslides in the Sichuan-Chongqing region account for about 14% of the same type of geological disasters in the country. Buried pipelines built in geological disaster areas within the Sichuan-Chongqing region not only face the widespread risk of corrosion perforation, but also face the risk of pipe section cracking caused by geological disasters. Both of the above-mentioned risks can lead to natural gas leakage. Therefore, in order to ensure the safe and smooth operation of buried oil and gas pipelines in geological disaster areas with high sulfur gas fields, it is necessary to establish a new method for rapid quantitative assessment and classification of corrosion and geological disaster risks in buried pipelines in geological disaster areas, so as to achieve effective assessment, monitoring and early warning of the dual risks of corrosion / geological disasters.

[0044] Therefore, in order to solve the above problems, the embodiment of the present invention proposes a risk assessment method and system for buried pipelines in geological disaster areas. The risk assessment method first selects some pipelines suitable for risk assessment as pipelines to be assessed, and based on the actual risks faced by buried pipelines in geological disaster areas, the selected pipelines to be assessed are quantitatively assessed and graded for internal corrosion risks, and quantitatively assessed and graded for geological disaster risks; finally, the two types of risk quantitative assessment results are coupled to obtain the actual leakage risk of the pipeline. The present invention enhances the pertinence of risk assessment, realizes the quantitative risk assessment of buried pipelines in geological disaster areas, greatly improves the level of safe and stable operation guarantee of buried pipelines in geological disaster areas, and provides technical support for improving the safe operation management and technical level of buried pipelines.

[0045] Embodiment 1

[0046] In an embodiment of the present application, the pipeline to be evaluated is a buried portion of the pipeline located between adjacent cut-off valve chambers. In the process of route design for buried pipelines in disaster-stricken areas, in order to ensure a balance between safety, construction volume and laying difficulty, the pipelines are generally laid in three ways: buried, crossing (tunnel) and spanning (truss, cable bridge). Therefore, in this embodiment, for the gathering and transportation pipeline network in the disaster-stricken area where the pipeline to be evaluated is located, first, the gathering and transportation pipeline network is divided into n sections with the cut-off valve chamber as the dividing point, and the oil and gas pipeline between two adjacent cut-off valve chambers is taken as a unit; then, the pipelines laid in the form of crossing and spanning between the current adjacent cut-off valve chambers are removed, leaving only the buried portion, and the buried portion of the pipeline is used as the pipeline to be evaluated for risk assessment. In other words, the pipeline to be evaluated in this embodiment is a buried pipeline located between two adjacent cut-off valve chambers (one unit).

[0047] Figure 2 This is an example diagram of pipeline segmentation in the risk assessment method for buried pipelines in disaster areas according to an embodiment of the present application. Figure 2 In a specific embodiment of the present application, there is an unconnected tunnel section and a river-crossing truss section between two adjacent cut-off valve chambers, and there are three sections of buried pipelines (n-1 section, n-2 section, and n-3 section) between the two adjacent cut-off valve chambers. At this time, any section of the buried pipeline can be used as a pipeline to be evaluated for risk assessment.

[0048] Figure 1 This is a step diagram of the risk assessment method for buried pipelines in disaster areas according to an embodiment of the present application. Figure 1 To illustrate the various steps of this method.

[0049] like Figure 1 As shown, in step S110, the corrosion rate of the pipeline to be evaluated is obtained, so as to evaluate the first leakage risk caused by the internal corrosion of the pipeline according to the corrosion rate. Internal corrosion is the most common form of failure of buried oil and gas pipelines, which will cause a large amount of natural gas / oil leakage, and then cause serious casualties or environmental pollution. Therefore, this embodiment first obtains the corrosion rate of the pipeline to be evaluated based on the actual operating conditions and monitoring data of the pipeline to be evaluated, so as to quantitatively evaluate the first leakage risk caused by the internal corrosion of the pipeline using the obtained corrosion rate as the core parameter. Among them, in the process of quantitatively evaluating the first leakage risk, the first leakage risk is divided into multiple levels according to the severity of the consequences caused by the first leakage risk, and the current first leakage risk level of the pipeline to be evaluated is used as the first leakage risk evaluation result.

[0050] In the step of obtaining the corrosion rate of the pipeline to be evaluated, different corrosion rate acquisition methods are used to obtain multiple corrosion rate data, and the maximum corrosion rate is used as the corrosion rate of the pipeline to be evaluated. Specifically, this embodiment adopts different corrosion rate acquisition methods to obtain multiple corrosion rate data (that is, each corrosion rate acquisition method corresponds to one corrosion rate data). The source of each corrosion rate data is different, which causes the deviation between different data. Therefore, this embodiment selects the maximum corrosion rate among multiple corrosion rate data as the corrosion rate of the pipeline to be evaluated, which effectively reduces the negative impact of data errors on the first leakage risk assessment result, thereby avoiding the first leakage risk being underestimated and causing serious consequences. In a specific embodiment of the present application, multiple corrosion rate data include but are not limited to: a first corrosion rate calculated based on the oxygen content in the pipeline, the pH property of the conveying medium and the flow rate of the conveying medium, and a second corrosion rate measured by the electric field fingerprint corrosion monitoring technology. It should be noted that the present invention does not specifically limit the corrosion rate acquisition method, and those skilled in the art can choose according to actual needs.

[0051] Next, this embodiment is based on the real-time detection and continuous calculation of the oxygen content in the pipeline, the pH property of the transport medium and the flow rate of the transport medium by measuring instruments such as temperature, flow rate and oxygen content tester installed on the gathering pipeline or valve chamber. And the corresponding item parameters used to calculate the first corrosion rate are valued to obtain the coefficients corresponding to the corresponding item parameters, so as to obtain the first corrosion rate according to the assignment results, which can effectively simplify the calculation process.

[0052] In the embodiment of the present application, the first corrosion rate is calculated using the following expression:

[0053] CR1=CR PH ×F O ×F V (1)

[0054] Among them, CR1 represents the first corrosion rate, CR PH Indicates the pH property coefficient of the conveying medium, F O Indicates the oxygen content coefficient, F V Indicates the flow rate coefficient of the conveying medium.

[0055] In a specific embodiment of the present application, the values ​​of the pH property coefficient of the transport medium are shown in Table 1:

[0056] Table 1 Values ​​of pH property coefficients of transport media

[0057]

[0058] In a specific embodiment of the present application, the value of the oxygen content coefficient is shown in Table 2:

[0059] Table 2 Values ​​of oxygen content coefficient

[0060] Oxygen content / ppb <![CDATA[Oxygen content coefficient (F O )]]> ≤50 1.0 ＞50 2.0

[0061] In a specific embodiment of the present application, the value of the flow rate coefficient of the conveying medium is shown in Table 3:

[0062] Table 3 Values ​​of flow rate coefficient of conveying medium

[0063] Pipe flow velocity (v) / m / s <![CDATA[Pipeline flow velocity coefficient (F V )]]> ＜1.83 1.0 1.83≤v≤6.10 0.82*v-0.5 ＞6.10 5.0

[0064] Further, in the step of evaluating the first leakage risk caused by corrosion in the pipeline according to the corrosion rate, if the corrosion rate is greater than or equal to 0.091 mm / a, the first leakage risk assessment result is a significant risk; if the corrosion rate is greater than or equal to 0.076 and less than 0.091 mm / a, the first leakage risk assessment result is a greater risk; if the corrosion rate is greater than or equal to 0.061 and less than 0.076 mm / a, the first leakage risk assessment result is a general risk; if the corrosion rate is less than 0.061 mm / a, the first leakage risk assessment result is a low risk.

[0065] In the embodiment of the present application, the internal corrosion risk (first leakage risk) level of the pipeline is determined according to the obtained corrosion rate. The corresponding relationship between the corrosion rate and the internal corrosion risk (first leakage risk) level is shown in Table 4:

[0066] Table 4 Correspondence between corrosion rate and internal corrosion risk (first leakage risk) level

[0067]

[0068]

[0069] In step S120, the geological disaster risk index characterizing the severity of the geological disaster faced by the pipeline area and the vulnerability risk index characterizing the difficulty of pipeline damage are used to obtain the pipeline damage risk index under the condition of geological disasters, so as to evaluate the second leakage risk caused by geological disasters according to the pipeline damage risk index. Landslides, debris flows, and rockfalls are the main forms of geological disasters that cause damage and failure of buried pipelines in geological disaster areas. The pipeline failure caused by geological disasters is generally in the form of fracture, and the amount of natural gas / oil leakage is large and covers a wide area. Therefore, this embodiment first calculates the geological disaster risk index characterizing the severity of the geological disaster faced by the pipeline area and the vulnerability risk index characterizing the difficulty of pipeline damage according to the actual operating conditions and monitoring data of the pipeline to be evaluated. Afterwards, the geological disaster risk index and the vulnerability risk index are used to obtain the pipeline damage risk index under the condition of geological disasters, so as to evaluate the second leakage risk caused by geological disasters with the pipeline damage risk index as the core parameter. In the process of quantitatively evaluating the second leakage risk, the second leakage risk is divided into multiple levels according to the severity of the consequences caused by the second leakage risk, and the current second leakage risk level of the pipeline to be evaluated is used as the second leakage risk assessment result.

[0070] In the embodiment of the present application, the pipeline damage risk index is calculated using the following expression:

[0071] PR=PH×PV (2)

[0072] Among them, PR represents the pipeline damage risk index, PH represents the geological disaster risk index, and PV represents the vulnerability risk index.

[0073] Furthermore, the geological disaster risk index is the geological disaster risk index of the pipeline area after engineering control, wherein the geological disaster risk index is calculated based on the geological disaster risk index of the pipeline area before engineering control, the landslide risk index representing the severity of the landslide faced by the pipeline area after engineering control, and the weight of the landslide risk prevention and control effect faced by the pipeline area after engineering control in the overall geological disaster risk prevention and control effect.

[0074] Specifically, since the pipeline to be evaluated is in a geological disaster area, and the area where the pipeline is located usually conducts engineering treatment in advance before the pipeline is set up to ensure the safety of subsequent pipeline operation. Therefore, this embodiment needs to first obtain a geological disaster risk index that matches the current actual engineering treatment results (i.e., the geological disaster risk index of the area where the pipeline is located after engineering treatment), so as to use the geological disaster risk index as the geological disaster risk index for evaluating the second leakage risk. Further, combined with the fact that landslide is a decisive factor affecting the degree of pipeline damage, this embodiment uses the geological disaster risk index before the implementation of engineering treatment in the area where the pipeline is located, the landslide risk index that characterizes the severity of the landslide faced by the area where the pipeline is located after the implementation of engineering treatment, and the coefficient of the weight of the landslide risk prevention and control effect faced by the area where the pipeline is located after the implementation of engineering treatment in the overall geological disaster risk prevention and control effect to calculate the geological disaster risk index.

[0075] In the embodiment of the present application, the following expression is used to calculate the risk index of geological disasters:

[0076] PH=PH1×PI+PH2×(1-PI) (3)

[0077] Among them, PH1 represents the geological disaster risk index before the implementation of engineering control, PI represents the coefficient of the weight of landslide risk prevention and control effect in the overall geological disaster risk prevention and control effect, and PH2 represents the landslide risk index.

[0078] Furthermore, the risk assessment method described in this embodiment also calculates the risk index of geological disasters in the area where the pipeline is located before the implementation of engineering governance, based on the correlation between the severity of geological disasters faced by the area where the pipeline is located before the implementation of engineering governance and different types of geological states, as well as the weight of each type of geological state in the occurrence of geological disasters. Specifically, this embodiment considers the correlation between the severity of geological disasters faced by the area where the pipeline is located before the implementation of engineering governance and different types of geological states, as well as the weight of each type of geological state in the occurrence of geological disasters, and assigns a value to the influence of each specific geological state of the same type on the severity. Then, based on the actual geological state of the area where the pipeline is located before the implementation of engineering governance, combined with the weight of each type of geological state in the occurrence of geological disasters, the risk index of geological disasters in the area where the pipeline is located before the implementation of engineering governance is obtained.

[0079] Further, different types of geological conditions include, but are not limited to: slope, soil type, landslide warning level, sliding body thickness, earthquake intensity, slope morphology, historical landslides, soil state and 24h maximum rainfall, wherein the weight of the slope is 0.16, the weight of the soil type is 0.14, the weight of the landslide warning level is 0.10, the weight of the sliding body thickness is 0.06, the weight of the earthquake intensity is 0.12, the weight of the slope morphology is 0.08, the weight of the historical landslide is 0.08, the weight of the soil state is 0.10, and the weight of the 24h maximum rainfall is 0.16. In a specific embodiment of the present application, the correlation, weight and assignment results are shown in Table 5:

[0080] Table 5 Correlation, weights and assignment results

[0081]

[0082]

[0083] In the embodiment of the present application, except for the "maximum rainfall in 24 hours" which is dynamic data, other types of geological conditions are static data determined based on the results of each geological disaster investigation.

[0084] In the embodiment of the present application, the following expression is used to calculate the risk index of geological disasters before the implementation of engineering control in the area where the pipeline is located:

[0085]

[0086] Among them, y i represents the score value of the i-th type of geological state, ω i represents the weight of the i-th type of geological state in the occurrence of geological disasters, n represents the number of geological state types, and a represents the normalization factor.

[0087] In a specific embodiment of the present application, the value of the number of geological state types is 9, and the value of the normalization factor is 10.

[0088] Further, the risk assessment method described in this embodiment also evaluates the landslide disaster prevention and control effect according to the weight of the landslide risk prevention and control effect faced by the pipeline area after the implementation of engineering governance in the overall geological disaster risk prevention and control effect, and scores the current landslide disaster prevention and control effect according to the evaluation result, so as to obtain a landslide occurrence risk index that characterizes the severity of the landslide faced by the pipeline area after the implementation of engineering governance. Specifically, this embodiment divides the evaluation results into multiple levels according to the degree of good or bad according to the correlation between the weight of the landslide risk prevention and control effect faced by the pipeline area after the implementation of engineering governance in the overall geological disaster risk prevention and control effect and the landslide disaster prevention and control effect, and formulates a scoring standard for the landslide disaster prevention and control effect corresponding to each level. Then, the current landslide disaster prevention and control effect is scored according to the formulated scoring standard, so as to obtain the landslide disaster prevention and control effect score value, and then the landslide disaster prevention and control effect score value is used to obtain the landslide occurrence risk index that characterizes the severity of the landslide faced by the pipeline area after the implementation of engineering governance.

[0089] Furthermore, this embodiment assigns a weight range of the landslide risk prevention and control effect in the overall geological disaster risk prevention and control effect after the implementation of engineering management in the pipeline area corresponding to each level of evaluation result, so that the numerical values ​​corresponding to different weight ranges are used as the aforementioned coefficient PI representing the weight of the landslide risk prevention and control effect in the overall geological disaster risk prevention and control effect, to calculate the geological disaster risk index before the implementation of engineering management.

[0090] In the embodiment of the present application, the landslide risk index is calculated using the following expression:

[0091] PH2=0.44-x (5)

[0092] Among them, x represents the score value of landslide disaster prevention and control effect.

[0093] In a specific embodiment of the present application, the landslide disaster prevention and control effect score and coefficient PI corresponding to each level of evaluation results are shown in Table 6:

[0094] Table 6 Landslide disaster prevention and control effect score and coefficient

[0095] Grading of control effect Landslide disaster prevention and control effect score Coefficient PI No treatment or poor treatment effect 0～0.05 1～0.9 Poor governance effect 0.1～0.15 0.8～0.7 Moderate governance effect 0.2～0.25 0.6～0.5 Good governance effect 0.3～0.35 0.4～0.3 Good governance effect 0.4～0.44 0.2～0.1

[0096] Furthermore, the risk assessment method described in this embodiment also evaluates the difficulty of pipeline damage according to the pipeline laying conditions (a combination of pipeline position and pipeline laying method) of the pipeline to be evaluated, and scores the difficulty of damage of the current pipeline according to the evaluation result to obtain a vulnerability risk index. Specifically, pipeline vulnerability is determined by the pipeline position and laying method, so this embodiment evaluates the difficulty of pipeline damage according to the pipeline position and pipeline laying method of the pipeline to be evaluated, and scores the difficulty of damage in the manner shown in Table 7, thereby obtaining a vulnerability risk index using the pipeline damage difficulty score value:

[0097] Table 7 Damage difficulty rating results

[0098] Vulnerability classification Pipeline laying Pipeline damage severity rating Low Fragility Outside the landslide affected area (1,2) Lower vulnerability Landslide peripheral impact area (3,4) Moderately vulnerable Inside the landslide and through (5,6) Higher vulnerability Inside the landslide body and obliquely through (7,8) High Fragility Inside the landslide and across (9,10)

[0099] In the embodiment of the present application, the vulnerability risk index is calculated using the following expression:

[0100]

[0101] Wherein, f represents the damage difficulty score of the pipeline.

[0102] Furthermore, in the step of evaluating the second leakage risk caused by the geological disaster according to the pipeline damage risk index, if the pipeline damage risk index is greater than or equal to 0.56 and less than or equal to 1, the second leakage risk assessment result is a major risk; if the pipeline damage risk index is greater than or equal to 0.33 and less than 0.56, the second leakage risk assessment result is a large risk; if the pipeline damage risk index is greater than or equal to 0.25 and less than 0.33, the second leakage risk assessment result is a general risk; if the pipeline damage risk index is greater than or equal to 0 and less than 0.25, the second leakage risk assessment result is a low risk.

[0103] In the embodiment of the present application, the pipeline geological disaster risk (second leakage risk) level is determined according to the obtained pipeline damage risk index. The corresponding relationship between the pipeline damage risk index and the pipeline geological disaster risk (second leakage risk) level is shown in Table 8:

[0104] Table 8 Correspondence between pipeline damage risk index and pipeline geological disaster risk (second leakage risk) level

[0105] Pipeline leakage risk index caused by geological disasters Pipeline geological disaster risk (secondary leakage risk) level 0.56≤PR≤1 Red (significant risk) 0.33≤PR<0.56 Orange (greater risk) 0.25≤PR<0.33 Yellow (average risk) 0≤PR<0.25 Blue (low risk)

[0106] In step S130, the actual leakage risk of the pipeline is obtained according to the first leakage risk assessment result and the second leakage risk assessment result. In practical applications, the core risks faced by buried pipelines in disaster-stricken areas are mainly internal corrosion and geological disasters. Therefore, this embodiment can obtain the actual leakage risk of the pipeline by integrating the first leakage risk assessment result and the second leakage risk assessment result.

[0107] Embodiment 2

[0108] The pipeline to be evaluated in this embodiment is a buried pipeline on the pipeline section A in the northeastern Sichuan region, where the pipeline section A is located between valve chambers 1 and 2, with a total length of 5 km. There is a truss in the middle of the pipeline section, and the pipeline section A is divided into two sections, A-1 and A-2, with lengths of 2.0 km and 1.8 km respectively. The A-1 section is now used as the pipeline to be evaluated for risk assessment. According to the actual operating conditions and monitoring data of the A-1 section, the basic situation of the A-1 section is shown in Table 9:

[0109] Table 9A-1 Basic Information

[0110]

[0111] After calculation, the first corrosion rate is CR1 = CR PH *F O *F V =0.08*2*(0.82*2-0.5)=0.1824mm / a, and the first corrosion rate is greater than the second corrosion rate. At this time, the corrosion rate of the pipeline to be evaluated is 0.1824mm / a, and the internal corrosion risk (first leakage risk) level is red (major risk).

[0112] According to the geological disaster investigation, the basic situation of geological disasters in the area where the pipeline to be assessed is currently located is shown in Table 10:

[0113] Table 10 Basic situation of geological disasters in Example 2

[0114] Geological conditions <![CDATA[Weight ω i > Specific geological conditions Assignment result slope 0.16 30° 6 Soil type 0.14 Clay soil 10 Warning level 0.10 Warning level 8 Sliding body thickness 0.06 Shallow landslide 2 earthquake intensity 0.12 7 degrees 4 Slope shape 0.08 Stepped 7 Historical collapse 0.08 medium 5 Soil state 0.10 Medium density / plastic 6 Maximum rainfall in 24 hours 0.16 150～200 8

[0115] After calculation, the geological disaster risk index (PH1) before the implementation of engineering control was 0.66, and it was confirmed that the geological disaster prevention and control effect was "poor control effect". Therefore, the landslide disaster prevention and control effect score is 0.14, and the coefficient PI is 0.7. At this time, the landslide risk index PH2 = 0.44-0.14 = 0.3, and the geological disaster risk index PH = PH1*PI+PH2*(1-PI) = 0.552. Further, combined with the laying of the A-1 section of the pipeline, which is inside the landslide body and obliquely passes through, the pipeline damage difficulty score is taken as 8, and the pipeline damage difficulty score (PV) is calculated to be 0.8.

[0116] In summary, the pipeline damage risk index PR=PH*PV=0.4416, and the pipeline geological disaster risk (second leakage risk) level is orange (higher risk).

[0117] Embodiment 3

[0118] The pipeline to be evaluated in this embodiment is a buried pipeline on the gathering and transportation pipeline section B in the northeastern Sichuan region, where the B section is located between valve chambers 5 and 6, with a total length of 4.3 km. There is a truss and a tunnel in the middle of the section. The B section is divided into three sections: B-1, B-2 and B-3, with lengths of 1.0 km, 0.6 km and 1.8 km respectively. The B-1 section is now used as the pipeline to be evaluated for risk assessment. According to the actual operating conditions and monitoring data of the B-1 section, the basic situation of the B-1 section is shown in Table 11:

[0119] Table 11 Basic information of Section B-1

[0120]

[0121] After calculation, the first corrosion rate is CR1 = CR PH *F O *F V =0.02*1*1=0.02mm / a, and the first corrosion rate is less than the second corrosion rate. At this time, the corrosion rate of the pipeline to be evaluated is 0.05mm / a, and the internal corrosion risk (first leakage risk) level is blue (low risk).

[0122] According to the geological disaster investigation, the basic situation of geological disasters in the area where the pipeline to be assessed is currently located is shown in Table 12:

[0123] Table 12 Basic information of geological disasters in Example 3

[0124] Geological conditions <![CDATA[Weight ω i > Specific geological conditions Assignment result slope 0.16 10° 3 Soil type 0.14 Silt 5 Warning level 0.10 Attention 4 Sliding body thickness 0.06 Middle layer landslide 6 earthquake intensity 0.12 8 degrees 6 Slope shape 0.08 Straight Line 3 Historical collapse 0.08 none 1 Soil state 0.10 Dense / hard plastic 4 Maximum rainfall in 24 hours 0.16 50～100 4

[0125] After calculation, the geological disaster risk index (PH1) before the implementation of engineering control was 0.402, and it was confirmed that the geological disaster prevention and control effect was "good control effect". Therefore, the landslide disaster prevention and control effect score is 0.3, and the coefficient PI is 0.4. At this time, the landslide risk index PH2 = 0.44-0.3 = 0.14, and the geological disaster risk index PH = PH1*PI+PH2*(1-PI) = 0.2448. Further, combined with the laying of the B-1 section of the pipeline, which is the outer impact area of ​​the landslide body and is buried, the pipeline damage difficulty score is taken as 3, and the pipeline damage difficulty score (PV) is calculated to be 0.3.

[0126] In summary, the pipeline damage risk index PR=PH*PV=0.07344, and the pipeline geological disaster risk (second leakage risk) level is blue (low risk).

[0127] Embodiment 4

[0128] The pipeline to be evaluated in this embodiment is a buried pipeline on the gathering and transportation pipeline section C in the northeastern Sichuan region, where the C section is located between valve chambers 6 and 7, with a total length of 9 km. There is a truss and 2 tunnels in the middle of the section. The C section is divided into four sections: C-1, C-2, C-3 and C-4, with lengths of 1.0 km, 0.6 km, 4.5 km and 1.8 km respectively. The C-3 section is now used as the pipeline to be evaluated for risk assessment. According to the actual operating conditions and monitoring data of the C-3 section, the basic situation of the C-3 section is shown in Table 13:

[0129] Table 13 Basic information of C-3 segment

[0130]

[0131] After calculation, the first corrosion rate is CR1 = CR PH *F O *F V =0.05*1*1.96=0.0775mm / a, and the first corrosion rate is greater than the second corrosion rate. At this time, the corrosion rate of the pipeline to be evaluated is 0.0775mm / a, and the internal corrosion risk (first leakage risk) level is orange (higher risk).

[0132] According to the geological disaster investigation, the basic situation of geological disasters in the area where the pipeline to be assessed is currently located is shown in Table 14:

[0133] Table 14 Basic information of geological disasters in Example 4

[0134] Geological conditions <![CDATA[Weight ω i > Specific geological conditions Assignment result slope 0.16 50° 9 Soil type 0.14 Crushed soil and stone 2 Warning level 0.10 Alert Level 8 Sliding body thickness 0.06 Middle layer landslide 6 earthquake intensity 0.12 9 degrees 8 Slope shape 0.08 Straight Line 3 Historical collapse 0.08 slight 3 Soil state 0.10 Dense / hard plastic 3 Maximum rainfall in 24 hours 0.16 150～200 8

[0135] After calculation, the geological disaster risk index (PH1) before the implementation of engineering control was 0.59, and it was confirmed that the geological disaster prevention and control effect was "good control effect". Therefore, the landslide disaster prevention and control effect score is 0.4, and the coefficient PI is 0.15. At this time, the landslide risk index PH2 = 0.44-0.4 = 0.04, and the geological disaster risk index PH = PH1*PI+PH2*(1-PI) = 0.1225. Further, combined with the laying of the C-3 section pipeline, which is outside the outer influence area of ​​the landslide body and buried, the pipeline damage difficulty score value is taken as 1, and the pipeline damage difficulty score value (PV) is calculated to be 0.1.

[0136] In summary, the pipeline damage risk index PR=PH*PV=0.01225, and the pipeline geological disaster risk (second leakage risk) level is blue (low risk).

[0137] Embodiment 5

[0138] The pipeline to be evaluated in this embodiment is a buried pipeline on the pipeline section D in the northeastern Sichuan region, where the D section is located between valve chambers 7 and 8, with a total length of 2 km. There is a tunnel in the middle of the section, and the D section is divided into two sections, D-1 and D-2, with lengths of 0.5 km and 0.8 km respectively. The D-2 section is now used as the pipeline to be evaluated for risk assessment. According to the actual operating conditions and monitoring data of the D-2 section, the basic situation of the D-2 section is shown in Table 15:

[0139] Table 15 Basic information of D-2 segment

[0140]

[0141] After calculation, the first corrosion rate is CR1 = CR PH *F O *F V =0.13*2*1=0.26mm / a, and the first corrosion rate is greater than the second corrosion rate. At this time, the corrosion rate of the pipeline to be evaluated is 0.26mm / a, and the internal corrosion risk (first leakage risk) level is red (major risk).

[0142] According to the geological disaster investigation, the basic situation of geological disasters in the area where the pipeline to be assessed is currently located is shown in Table 16:

[0143] Table 16 Basic situation of geological disasters in Example 5

[0144]

[0145]

[0146] After calculation, the geological disaster risk index (PH1) before the implementation of engineering control was 0.802, and it was confirmed that the geological disaster prevention and control effect was "poor control effect". Therefore, the landslide disaster prevention and control effect score is 0.1, and the coefficient PI is 0.8. At this time, the landslide risk index PH2 = 0.44-0.1 = 0.34, and the geological disaster risk index PH = PH1*PI+PH2*(1-PI) = 0.7096. Further, combined with the laying of the D-2 section of the pipeline, which is inside and across the landslide body, the pipeline damage difficulty score is taken as 9, and the pipeline damage difficulty score (PV) is calculated to be 0.9.

[0147] In summary, the pipeline damage risk index PR=PH*PV=0.63864, and the pipeline geological disaster risk (second leakage risk) level is red (major risk).

[0148] Embodiment 6

[0149] The pipeline to be evaluated in this embodiment is a buried pipeline on the gathering and transportation pipeline section a in the western Sichuan region, where section a is located between valve chamber a1 and valve chamber a2, with a total length of 3.9 km. There is a truss and a tunnel in the middle of the section. Section a is divided into three sections, a-1, a-2 and a-3, with lengths of 1.0 km, 0.6 km and 1.8 km respectively. Section a-3 is now used as the pipeline to be evaluated for risk assessment. According to the actual operating conditions and monitoring data of section a-3, the basic situation of section a-3 is shown in Table 17:

[0150] Table 17 Basic information of a-3 segment

[0151]

[0152] After calculation, the first corrosion rate is CR1 = CR PH *F O *F V =0.03*2*1=0.06mm / a, and the first corrosion rate is less than the second corrosion rate. At this time, the corrosion rate of the pipeline to be evaluated is 0.07mm / a, and the internal corrosion risk (first leakage risk) level is yellow (general risk).

[0153] According to the geological disaster investigation, the basic situation of geological disasters in the area where the pipeline to be assessed is currently located is shown in Table 18:

[0154] Table 18 Basic information of geological disasters in Example 6

[0155]

[0156]

[0157] After calculation, the geological disaster risk index (PH1) before the implementation of engineering control was 0.618, and it was confirmed that the geological disaster prevention and control effect was "medium control effect". Therefore, the landslide disaster prevention and control effect score is 0.2, and the coefficient PI is 0.6. At this time, the landslide risk index PH2 = 0.44-0.2 = 0.24, and the geological disaster risk index PH = PH1*PI+PH2*(1-PI) = 0.4668. Further, combined with the laying of the a-3 section of the pipeline, which is inside the landslide body and vertically penetrates, the pipeline damage difficulty score is taken as 6, and the pipeline damage difficulty score (PV) is calculated to be 0.5.

[0158] In summary, the pipeline damage risk index PR=PH*PV=0.28, and the pipeline geological disaster risk (second leakage risk) level is yellow (general risk).

[0159] Embodiment 7

[0160] The pipeline to be evaluated in this embodiment is a buried pipeline on the gathering and transportation pipeline section b in the western Sichuan region, where the b section is located between the b3 valve chamber and the b4 valve chamber, with a total length of 2.3 km. There are no trusses or tunnels in the section, and the b section is directly used as the pipeline to be evaluated for risk assessment. According to the actual operating conditions and monitoring data of the b section, the basic situation of the b section is shown in Table 19:

[0161] Table 19 Basic information of pipe section b

[0162]

[0163] After calculation, the first corrosion rate is CR1 = CR PH *F O *F V =0.04*1*3.6=0.144mm / a, and the first corrosion rate is greater than the second corrosion rate. At this time, the corrosion rate of the pipeline to be evaluated is 0.144mm / a, and the internal corrosion risk (first leakage risk) level is red (major risk).

[0164] According to the geological disaster investigation, the basic situation of geological disasters in the area where the pipeline to be assessed is currently located is shown in Table 20:

[0165] Table 20 Basic information of geological disasters in Example 7

[0166] Geological conditions Weight ωi Specific geological conditions Assignment result slope 0.16 15° 3 Soil type 0.14 Clay soil 10 Warning level 0.10 Attention 4 Sliding body thickness 0.06 Shallow landslide 2 earthquake intensity 0.12 6 degrees 2 Slope shape 0.08 Composite 5 Historical collapse 0.08 slight 3 Soil state 0.10 Slightly dense / soft plastic 8 Maximum rainfall in 24 hours 0.16 100～150 6

[0167] After calculation, the geological disaster risk index (PH1) before the implementation of engineering control was 0.504, and it was confirmed that the geological disaster prevention and control effect was "good control effect". Therefore, the landslide disaster prevention and control effect score is 0.35, and the coefficient PI is 0.3. At this time, the landslide risk index PH2 = 0.44-0.35 = 0.09, and the geological disaster risk index PH = PH1*PI+PH2*(1-PI) = 0.2142. Further, combined with the laying of pipe section b, which is inside the landslide body and obliquely penetrates, the pipeline damage difficulty score value is taken as 7, and the pipeline damage difficulty score value (PV) is calculated to be 0.7.

[0168] In summary, the pipeline damage risk index PR=PH*PV=0.15, and the pipeline geological disaster risk (second leakage risk) level is blue (low risk).

[0169] Embodiment 8

[0170] The pipeline to be evaluated in this embodiment is a buried pipeline on the pipeline section I of the North China gathering and transportation pipeline, wherein the pipeline section I is located between the valve chamber H2 and the valve chamber H3, the total length of the pipeline section is 7.7 km, there is a truss and a tunnel in the middle of the pipeline section, and the pipeline section I is divided into three sections: I-1, I-2 and I-3, with lengths of 2.0 km, 2.5 km and 1.8 km respectively. The I-1 section is now used as the pipeline to be evaluated for risk assessment. According to the actual operating conditions and monitoring data of the I-1 section, the basic situation of the I-1 section is shown in Table 21:

[0171] Table 21 Basic information of section I-1

[0172]

[0173] After calculation, the first corrosion rate is CR1 = CR PH *F O *F V =0.01*1*1=0.01mm / a, and the first corrosion rate is less than the second corrosion rate. At this time, the corrosion rate of the pipeline to be evaluated is 0.08mm / a, and the internal corrosion risk (first leakage risk) level is orange (higher risk).

[0174] According to the geological disaster investigation, the basic situation of geological disasters in the area where the pipeline to be assessed is currently located is shown in Table 22:

[0175] Table 22 Basic information of geological disasters in Example 8

[0176] Geological conditions Weight ωi Specific geological conditions Assignment result slope 0.16 45° 10 Soil type 0.14 Crushed soil and stone 1 Warning level 0.10 Warning level 6 Sliding body thickness 0.06 Shallow landslide 2 earthquake intensity 0.12 10 degrees 10 Slope shape 0.08 Concave 2 Historical collapse 0.08 More serious 7 Soil state 0.10 Very dense / hard 2 Maximum rainfall in 24 hours 0.16 100～150 5

[0177] After calculation, the geological disaster risk index (PH1) before the implementation of engineering control was 0.538, and it was confirmed that the geological disaster prevention and control effect was "good control effect". Therefore, the landslide disaster prevention and control effect score is 0.41, and the coefficient PI is 0.18. At this time, the landslide risk index PH2 = 0.44-0.41 = 0.03, and the geological disaster risk index PH = PH1*PI+PH2*(1-PI) = 0.12144. Further, combined with the laying of section I-1, which is outside the landslide influence area and buried, the pipeline damage difficulty score is taken as 2, and the pipeline damage difficulty score (PV) is calculated to be 0.2.

[0178] In summary, the pipeline damage risk index PR=PH*PV=0.024288, and the pipeline geological disaster risk (second leakage risk) level is blue (low risk).

[0179] Embodiment 9

[0180] Based on the risk assessment method for buried pipelines in disaster-stricken areas described in the first embodiment, an embodiment of the present invention further provides a risk assessment system for buried pipelines in disaster-stricken areas (hereinafter referred to as "risk assessment system"). Figure 3 This is a module block diagram of a risk assessment system for buried pipelines in disaster-stricken areas according to an embodiment of the present application.

[0181] like Figure 3 As shown, the risk assessment system in the embodiment of the present invention includes: a first leakage risk assessment module 31, a second leakage risk assessment module 32 and an actual leakage risk assessment module 33. Specifically, the first leakage risk assessment module 31 is implemented according to the method described in step S110 above, and is configured to obtain the corrosion rate of the pipeline to be assessed, so as to assess the first leakage risk caused by the corrosion in the pipeline according to the corrosion rate; the second leakage risk assessment module 32 is implemented according to the method described in step S120 above, and is configured to obtain the pipeline damage risk index under the condition of the occurrence of the geological disaster by using the geological disaster risk index that characterizes the severity of the geological disaster faced by the area where the pipeline is located, and the vulnerability risk index that characterizes the difficulty of pipeline damage, so as to assess the second leakage risk caused by the geological disaster according to the pipeline damage risk index; the actual leakage risk assessment module 33 is implemented according to the method described in step S130 above, and is configured to obtain the actual leakage risk of the pipeline according to the first leakage risk assessment result and the second leakage risk assessment result.

[0182] The present invention proposes a risk assessment method and system for buried pipelines in geological disaster areas. The risk assessment method first selects part of the pipelines suitable for risk assessment as pipelines to be assessed, and based on the actual risks faced by the buried pipelines in the geological disaster areas, the selected pipelines to be assessed are quantitatively assessed and graded for internal corrosion risks, and quantitatively assessed and graded for geological disaster risks; finally, the two types of risk quantitative assessment results are coupled to obtain the actual leakage risk of the pipeline. The new method for rapid quantitative assessment and grading of internal corrosion and geological disaster risks of buried pipelines in geological disaster areas provided by the present invention enriches and improves the failure probability calculation and quantitative assessment means of upstream gathering and transportation pipelines in oil development (especially buried pipelines in geological disaster-prone areas such as Sichuan and Chongqing), can be promoted and applied in long-distance pipelines, and has high economic and technical value. At the same time, the present invention enhances the pertinence of risk assessment, realizes the risk quantitative assessment of buried pipelines in geological disaster areas, greatly improves the level of safe and stable operation guarantee of buried pipelines in geological disaster areas, and provides technical support for improving the safe operation management and technical level of buried pipelines.

[0183] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person familiar with the technology within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0184] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0185] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" appearing in various places throughout the specification do not necessarily refer to the same embodiment.

[0186] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A risk assessment method for buried pipelines in disaster-stricken areas, characterized in that: include: Obtaining a corrosion rate of the pipeline to be evaluated, thereby evaluating a first leakage risk caused by corrosion in the pipeline according to the corrosion rate; Using the geological disaster risk index that characterizes the severity of geological disasters faced by the pipeline area and the vulnerability risk index that characterizes the ease of pipeline damage, the pipeline damage risk index under the condition of geological disasters is obtained, so as to evaluate the second leakage risk caused by geological disasters according to the pipeline damage risk index; The actual leakage risk of the pipeline is obtained according to the first leakage risk assessment result and the second leakage risk assessment result.

2. The risk assessment method according to claim 1, characterized in that: The steps to obtain the corrosion rate of the pipeline to be evaluated include: Multiple corrosion rate data are obtained by using different corrosion rate acquisition methods, and the maximum corrosion rate is used as the corrosion rate of the pipeline to be evaluated. The multiple corrosion rate data include but are not limited to: a first corrosion rate calculated based on the oxygen content in the pipeline, the pH property of the transported medium and the flow rate of the transported medium, and a second corrosion rate measured using the electric field fingerprint corrosion monitoring technology.

3. The risk assessment method according to claim 2, characterized in that: The first corrosion rate is calculated using the following expression: CR1=CR PH ×F O ×F V Among them, CR1 represents the first corrosion rate, CR PH Indicates the pH property coefficient of the conveying medium, F O Indicates the oxygen content coefficient, F V Indicates the flow rate coefficient of the conveying medium.

4. The risk assessment method according to any one of claims 1 to 3, characterized in that: The step of evaluating the first leakage risk caused by the corrosion in the pipeline according to the corrosion rate includes: If the corrosion rate is greater than or equal to 0.091 mm / a, the first leakage risk assessment result is a significant risk; If the corrosion rate is greater than or equal to 0.076 and less than 0.091 mm / a, the first leakage risk assessment result is a greater risk; If the corrosion rate is greater than or equal to 0.061 and less than 0.076 mm / a, the first leakage risk assessment result is a general risk; If the corrosion rate is less than 0.061 mm / a, the first leakage risk assessment result is low risk.

5. The risk assessment method according to any one of claims 1 to 4, characterized in that: The pipeline damage risk index is calculated using the following expression: PR=PH×PV Among them, PR represents the pipeline damage risk index, PH represents the geological disaster risk index, and PV represents the vulnerability risk index.

6. The risk assessment method according to any one of claims 1 to 5, characterized in that: The geological disaster risk index is the geological disaster risk index of the pipeline area after engineering treatment, where: The geological disaster risk index is calculated based on the geological disaster risk index before the implementation of engineering control in the pipeline area, the landslide risk index that represents the severity of the landslide faced by the pipeline area after the implementation of engineering control, and the weight of the landslide risk prevention and control effect faced by the pipeline area after the implementation of engineering control in the overall geological disaster risk prevention and control effect.

7. The risk assessment method according to claim 6, characterized in that: The geological disaster risk index is calculated using the following expression: PH = PH1 × PI + PH2 × (1-PI) Among them, PH represents the geological disaster risk index, PH1 represents the geological disaster risk index before the implementation of engineering control, PI represents the coefficient of the weight of landslide risk prevention and control effect in the overall geological disaster risk prevention and control effect, and PH2 represents the landslide risk index.

8. The risk assessment method according to claim 6 or 7, characterized in that: The risk assessment method further comprises: Based on the correlation between the severity of geological disasters faced by the pipeline area before the implementation of engineering control and different types of geological conditions, as well as the weight of each type of geological condition in the occurrence of geological disasters, the geological disaster risk index before the implementation of engineering control in the pipeline area is calculated.

9. The risk assessment method according to claim 8, characterized in that: The following expression is used to calculate the risk index of geological disasters before the implementation of engineering control in the pipeline area: Among them, PH1 represents the risk index of geological disasters before the implementation of engineering control, y i represents the score value of the i-th type of geological state, ω i represents the weight of the i-th type of geological state in the occurrence of geological disasters, n represents the number of geological state types, and a represents the normalization factor.

10. The risk assessment method according to claim 9, characterized in that: The different types of geological conditions include, but are not limited to: slope, soil type, landslide warning level, landslide thickness, earthquake intensity, slope morphology, historical landslides, soil state and 24h maximum rainfall, among which: The weight of the slope is 0.16, the weight of the soil type is 0.14, the weight of the landslide warning level is 0.10, the weight of the sliding body thickness is 0.06, the weight of the earthquake intensity is 0.12, the weight of the slope morphology is 0.08, the weight of the historical landslide is 0.08, the weight of the soil state is 0.10, and the weight of the maximum rainfall in 24 hours is 0.

16.

11. The risk assessment method according to any one of claims 6 to 10, characterized in that: The risk assessment method further comprises: According to the weight of the landslide risk prevention and control effect faced by the pipeline area after the implementation of engineering control in the overall geological disaster risk prevention and control effect, the landslide disaster prevention and control effect is evaluated, and according to the evaluation result, the current landslide disaster prevention and control effect is scored to obtain the landslide occurrence risk index that characterizes the severity of the landslide faced by the pipeline area after the implementation of engineering control. The landslide occurrence risk index is calculated using the following expression: PH2=0.44-x Among them, PH2 represents the landslide risk index, and x represents the landslide disaster prevention and control effect score.

12. The risk assessment method according to any one of claims 1 to 11, characterized in that: The risk assessment method further comprises: The damage difficulty of the pipeline is evaluated according to the pipeline position and pipeline laying method of the pipeline to be evaluated, and the damage difficulty of the current pipeline is scored according to the evaluation result to obtain the vulnerability risk index, wherein the vulnerability risk index is calculated using the following expression: Among them, PV represents the vulnerability risk index, f represents the pipeline damage difficulty score, and a represents the normalization factor.

13. The risk assessment method according to any one of claims 1 to 12, characterized in that: The step of evaluating the second leakage risk caused by the geological disaster according to the pipeline damage risk index includes: If the pipeline damage risk index is greater than or equal to 0.56 and less than or equal to 1, the second leakage risk assessment result is a significant risk; If the pipeline damage risk index is greater than or equal to 0.33 and less than 0.56, the second leakage risk assessment result is a greater risk; If the pipeline damage risk index is greater than or equal to 0.25 and less than 0.33, the second leakage risk assessment result is a general risk; If the pipeline damage risk index is greater than or equal to 0 and less than 0.25, the second leakage risk assessment result is low risk.

14. The risk assessment method according to any one of claims 1 to 13, characterized in that: The pipeline to be evaluated is a buried portion of the pipeline located between adjacent cut-off valve chambers.

15. A risk assessment system for buried pipelines in disaster-stricken areas, characterized in that: The risk assessment system includes the following modules: A first leakage risk assessment module, which is used to obtain the corrosion rate of the pipeline to be assessed, so as to assess the first leakage risk caused by the corrosion in the pipeline according to the corrosion rate; A second leakage risk assessment module is used to obtain a pipeline damage risk index under the condition of a geological disaster, using a geological disaster risk index representing the severity of the geological disaster faced by the area where the pipeline is located and a vulnerability risk index representing the ease of pipeline damage, so as to assess the second leakage risk caused by the geological disaster according to the pipeline damage risk index; The actual leakage risk assessment module is used to obtain the actual leakage risk of the pipeline according to the first leakage risk assessment result and the second leakage risk assessment result.

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