A risk assessment method and system for buried pipelines in geohazard areas

Abstract

The application discloses a kind of risk assessment method and system for ground disaster area buried pipeline, comprising: the corrosion rate of the pipeline to be evaluated is obtained, so as to evaluate the first leakage risk caused by corrosion in the pipeline according to the corrosion rate;Using the ground disaster occurrence risk index representing the severity of the ground disaster faced by the area where the pipeline is located, and the vulnerability risk index representing the difficulty of pipeline damage, obtain the pipeline damage risk index under the condition of ground disaster occurrence, so as to evaluate the second leakage risk caused by ground disaster according to the pipeline damage risk index;According to the first leakage risk evaluation result and the second leakage risk evaluation result, obtain the actual leakage risk of the pipeline.The application enhances the pertinence of risk assessment, realizes the risk quantitative evaluation of buried pipeline in ground disaster area, greatly improves the safety and stability operation guarantee level of buried pipeline in ground disaster area, and provides technical support for improving the safety operation management and technical level of buried pipeline.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of quantitative risk assessment of buried pipelines in disaster areas, and particularly relates to a risk assessment method and system for buried pipelines in disaster areas. BACKGROUND

[0002] With the continuous development of the national economy and the continuous optimization of the energy structure, natural gas, as a clean and environmentally friendly 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 is also continuously increasing. In today's large-scale natural gas pipeline network, gas field gathering pipelines, long-distance natural gas pipelines and urban natural gas pipelines together form a pattern of "main trunk interconnection and local network". The total mileage exceeds 1 million kilometers. Among them, although the proportion of gas field gathering pipelines is small, the complex external environment and the harsh internal working conditions lead to the occurrence of natural gas leakage accidents from time to time. If not discovered and properly handled in time, it is easy to cause fire or explosion accidents, which poses a great threat to the safety of production, life and property.

[0003] The prior art discloses a buried pipeline internal corrosion evaluation method, which comprises the following steps: buried pipeline internal corrosion detection pre-evaluation step; buried pipeline internal corrosion indirect detection and evaluation step; buried pipeline internal corrosion direct detection and evaluation step; buried pipeline internal corrosion direct evaluation ICDA effectiveness evaluation and re-evaluation time determination step. The buried pipeline internal corrosion evaluation method improves the level of buried pipeline safety operation management and technology, can reduce the personnel injury and economic loss of facilities caused by sudden accidents, and ensures safe production. The prior art also discloses an oil and gas pipeline geological disaster evaluation method based on information amount-neural network, which comprises the following steps: determining a research area and dividing a grid unit; performing geological disaster susceptibility evaluation; performing pipeline vulnerability evaluation; dividing the level of failure consequences according to the division standard of failure consequences and determining the level of failure consequences; and determining the risk level of pipeline geological disasters by using pipeline failure probability and the level of failure consequences. In addition, the prior art also discloses a natural gas pipeline risk evaluation method. The natural gas pipeline risk evaluation method first analyzes the service state of the service pipeline, determines the coupling model required for the pipeline risk evaluation failure analysis characterization model; then, based on the coupling model required for analysis, the pipeline risk evaluation failure analysis characterization model is established; then, according to the service state of the service pipeline, the corresponding parameter value is selected according to GB / T 34346-2017, and the oil pipeline risk evaluation failure risk is calculated; finally, for early judgment of the dangerous condition of the natural gas pipeline, preventive measures can be taken in advance, and by grasping the hazard factors faced by the natural gas pipeline, risk identification and sorting are performed, so that the optimal maintenance plan is formulated, and the waste of human and material resources is avoided.

[0004] With reference to the foregoing prior art, in the process of implementing the present application, the inventors have found that the prior art is mostly risk assessment methods that only consider a certain risk, and less in-depth consideration is given to the corrosion / geological disaster double coupling risk actually faced by buried pipelines in geological disaster areas, and the risk assessment coverage is insufficient, and the currently used pipeline risk quantification assessment means are mostly based on complex formulas and are not suitable for rapid and accurate assessment of buried pipeline risks. The Sichuan-Chongqing region is one of the main battlegrounds for oil and gas production, and it is located in a mountainous area with a large amount of continuous rainfall, and is a heavy disaster area. According to statistics, landslides, mudslides and other geological disasters in the Sichuan-Chongqing region account for about 14% of the same type of geological disasters in the country. Buried pipelines constructed in the geological disaster area within the Sichuan-Chongqing region not only face the risk of corrosion perforation that exists universally, but also face the risk of pipe section cracking caused by geological disasters. Both of the aforementioned risks will cause natural gas leakage, so in order to ensure the safe and stable operation of buried oil and gas pipelines in high-sulfur gas fields in geological disaster areas, it is necessary to establish a new method for rapid quantification and classification of corrosion and geological disaster risks in buried pipelines in geological disaster areas, so as to effectively evaluate, monitor and warn the corrosion / geological disaster double risk. SUMMARY

[0005] In order to solve the above problems, the embodiments of the present application provide a risk assessment method for buried pipelines in geological disaster areas, comprising: obtaining the corrosion rate of the pipeline to be evaluated, thereby evaluating the first leakage risk caused by the corrosion in the pipeline according to the corrosion rate; obtaining a pipeline damage risk index under the condition of geological disasters by using a geological disaster occurrence risk index representing the severity of the geological disasters faced by the area where the pipeline is located, and a vulnerability risk index representing the difficulty of pipeline damage, thereby evaluating the second leakage risk caused by the geological disasters according to the pipeline damage risk index, the geological disaster occurrence risk index being a geological disaster occurrence risk index after engineering treatment of the area where the pipeline is located, wherein the geological disaster occurrence risk index is calculated according to the geological disaster occurrence risk index before the engineering treatment of the area where the pipeline is located, a landslide occurrence risk index representing the severity of the landslides faced by the area where the pipeline is located after the engineering treatment, and the weight of the landslide risk prevention effect in the overall geological disaster risk prevention effect after the engineering treatment of the area where the pipeline is located, and the geological disaster occurrence risk index is calculated by using the following expression:

[0006]

[0007] wherein, GR represents the geological disaster occurrence risk index, GR 1 represents the geological disaster occurrence risk index before the engineering treatment, PI represents the coefficient of the weight of the landslide risk prevention effect in the overall geological disaster risk prevention effect, GR2 represents a landslide risk index; and the actual leakage risk of the pipeline is obtained according to the first leakage risk assessment result and the second leakage risk assessment result.

[0008] Preferably, in the step of obtaining the corrosion rate of the pipeline to be evaluated, the following is included: obtaining multiple corrosion rate data by using different corrosion rate obtaining 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 obtained according to the oxygen content in the pipeline, the PH attribute of the conveying medium and the flow rate of the conveying medium, and a second corrosion rate obtained by using an electric field fingerprint method corrosion monitoring technology.

[0009] Preferably, the first corrosion rate is calculated by using the following expression:

[0010]

[0011] wherein, CR 1 represents the first corrosion rate, CR pH represents a pH attribute coefficient of the conveying medium, F O represents an oxygen content coefficient, F V represents a flow rate coefficient of the conveying medium.

[0012] Preferably, in the step of evaluating the first leakage risk caused by the corrosion in the pipeline according to the corrosion rate, the following is included: if the corrosion rate is greater than or equal to 0.091 mm / a, the first leakage risk assessment result is a major risk; if the corrosion rate is greater than or equal to 0.076 mm / a and less than 0.091 mm / a, the first leakage risk assessment result is a relatively major risk; if the corrosion rate is greater than or equal to 0.061 mm / a and less than 0.076 mm / a, the first leakage risk assessment result is a general risk; and if the corrosion rate is less than 0.061 mm / a, the first leakage risk assessment result is a low risk.

[0013] Preferably, the pipeline damage risk index is calculated by using the following expression:

[0014]

[0015] wherein, PR represents the pipeline damage risk index, GR represents a geohazard risk index, PV represents a vulnerability risk index.

[0016] Preferably, the risk assessment method further comprises: calculating a landslide risk index of the region where the pipeline is located before the engineering management is implemented according to the correlation between the severity of the geological disasters faced by the region where the pipeline is located before the engineering management is implemented and different types of geological states, and the weight of each type of geological state in the occurrence of geological disasters.

[0017] Preferably, the landslide risk index of the region where the pipeline is located before the engineering management is implemented is calculated by using the following expression:

[0018]

[0019] wherein, GR 1 represents the landslide risk index before the engineering management is implemented, y i represents the score value of the geological state of the i th type, ω i represents the weight of the geological state of the i th type in the occurrence of geological disasters, n represents the number of geological state types, a represents a normalization factor.

[0020] Preferably, the different types of geological states include but are not limited to: slope, soil type, landslide warning level, landslide thickness, seismic intensity, slope surface form, historical landslide, 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 landslide thickness is 0.06, the weight of the seismic intensity is 0.12, the weight of the slope surface form 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.

[0021] Preferably, the risk assessment method further comprises: evaluating the landslide disaster prevention effect according to the weight of the landslide risk prevention effect of the region where the pipeline is located after the engineering management is implemented in the overall geological disaster risk prevention effect, and scoring the current landslide disaster prevention effect according to the evaluation result, to obtain a landslide risk index representing the severity of the landslide faced by the region where the pipeline is located after the engineering management is implemented, wherein the landslide risk index is calculated by using the following expression:

[0022]

[0023] wherein, GR 2 represents the landslide risk index, x represents the score value of the landslide disaster prevention effect.

[0024] Preferably, the risk assessment method further comprises: evaluating the difficulty of pipeline damage according to the pipeline location and pipeline laying mode of the pipeline to be evaluated, and scoring the difficulty of current pipeline damage according to the evaluation result to obtain the vulnerability risk index, wherein the vulnerability risk index is calculated by using the following expression:

[0025]

[0026] wherein, PV represents the vulnerability risk index, f represents the score value of the difficulty of pipeline damage, a represents a normalization factor.

[0027] Preferably, in the step of evaluating the second leakage risk caused by the ground 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 evaluation result of the second leakage risk is a major risk; if the pipeline damage risk index is greater than or equal to 0.33 and less than 0.56, the evaluation result of the second leakage risk is a relatively major risk; if the pipeline damage risk index is greater than or equal to 0.25 and less than 0.33, the evaluation result of the second leakage risk is a general risk; if the pipeline damage risk index is greater than or equal to 0 and less than 0.25, the evaluation result of the second leakage risk is a low risk.

[0028] Preferably, the pipeline to be evaluated is a buried portion of the pipeline located between adjacent shut-off valve chambers.

[0029] In addition, the present application also provides a risk assessment system for a buried pipeline in a ground disaster area, which comprises the following modules: a first leakage risk assessment module for obtaining the corrosion rate of a pipeline to be evaluated, thereby evaluating the first leakage risk caused by internal corrosion of the pipeline according to the corrosion rate; a second leakage risk assessment module for obtaining a pipeline damage risk index under the condition of ground disaster occurrence by using a ground disaster occurrence risk index representing the severity of the ground disaster faced by the pipeline and a vulnerability risk index representing the difficulty of pipeline damage, thereby evaluating the second leakage risk caused by the ground disaster according to the pipeline damage risk index, wherein the ground disaster occurrence risk index is a ground disaster occurrence risk index after engineering treatment of the area where the pipeline is located, wherein the ground disaster occurrence risk index is calculated according to the ground disaster occurrence risk index before the engineering treatment of the area where the pipeline is located, a landslide occurrence risk index representing the severity of the landslide faced by the area where the pipeline is located after the engineering treatment, and the weight of the landslide risk prevention effect of the area where the pipeline is located in the overall ground disaster risk prevention effect after the engineering treatment, and the pipeline damage risk index is calculated by using the following expression:

[0030]

[0031] wherein, GR represents a landslide risk index, GR 1 represents a landslide risk index before implementing engineering governance, PI represents a landslide risk index before implementing engineering governance, GR 2 represents a landslide risk index; an actual leakage risk assessment module, which is used to obtain an 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 in the above scheme can have the following advantages or beneficial effects.

[0033] The present application provides a risk assessment method and system for buried pipelines in a landslide area. The risk assessment method first selects part of the pipeline suitable for risk assessment as the pipeline to be evaluated, and based on the actual risks faced by the buried pipelines in the landslide area, the selected pipeline to be evaluated is subjected to internal corrosion risk quantitative assessment and grading, and landslide risk quantitative assessment and grading, respectively. Finally, the two types of risk quantitative assessment results are coupled to obtain the actual leakage risk of the pipeline. The present application enhances the pertinence of risk assessment, realizes the risk quantitative assessment of buried pipelines in the landslide area, greatly improves the safety and stable operation guarantee level of buried pipelines in the landslide area, and provides technical support for improving the safety operation management and technical level of buried pipelines.

[0034] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and achieved by the structures specifically pointed out in the specification, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0035] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, which together with the application embodiments, serve to explain the present application, and do not constitute a limitation on the present application.

[0036] Figure 1 A flowchart of the risk assessment method for buried pipelines in a landslide area of an embodiment of the present application.

[0037] Figure 2 An example diagram of pipeline segmentation of the risk assessment method for buried pipelines in a landslide area of an embodiment of the present application.

[0038] Figure 3A module block diagram of a risk assessment system for a buried pipeline in a geohazard area according to an embodiment of the present application. DETAILED DESCRIPTION

[0039] The embodiments of the present application will be described in detail with reference to the drawings and embodiments, so that how the present application applies technical means to solve technical problems and achieves technical effects can be fully understood and implemented. It should be noted that, as long as there is no conflict, each embodiment in the present application and each feature in each embodiment can be combined with each other, and the technical solutions formed thereby are all within the protection scope of the present application.

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

[0041] With the continuous development of the national economy and the continuous optimization of the energy structure, natural gas, as a clean and environmentally friendly 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 is also continuously increasing. In today's large-scale natural gas pipeline network, gas field gathering pipelines, natural gas long-distance pipelines and urban natural gas pipelines together form a pattern of "main trunk interconnection and local network". The total mileage exceeds 1 million kilometers. Among them, although the proportion of gas field gathering pipelines is small, the complex external environment and the harsh internal working conditions make natural gas leakage accidents occur from time to time. If not discovered and properly handled in time, it is easy to cause fire or explosion accidents, which poses a great threat to the safety of production, life and property.

[0042] The prior art discloses a buried pipeline internal corrosion evaluation method, which comprises the following steps: buried pipeline internal corrosion detection pre-evaluation; buried pipeline internal corrosion indirect detection and evaluation; buried pipeline internal corrosion direct detection and evaluation; buried pipeline internal corrosion direct evaluation ICDA effectiveness evaluation and re-evaluation time determination. The buried pipeline internal corrosion evaluation method improves the level of buried pipeline safe operation management and technology, can reduce personnel injury and economic loss of facilities caused by sudden accidents, and ensures safe production. The prior art also discloses an oil and gas pipeline geological disaster evaluation method based on information amount-neural network, which comprises the following steps: determining a research area, dividing a grid unit; performing geological disaster proneness evaluation; performing pipeline vulnerability evaluation; dividing the level of failure consequences according to the division standard of failure consequences and determining the level of failure consequences; and determining the risk level of pipeline geological disasters by using pipeline failure probability and the level of failure consequences. In addition, the prior art also discloses a natural gas pipeline risk evaluation method. The natural gas pipeline risk evaluation method first analyzes the service state of a service pipeline, determines the coupling model required by a pipeline risk evaluation failure analysis characterization model, then establishes the pipeline risk evaluation failure analysis characterization model based on the coupling model required by the analysis, then calculates the oil pipeline risk evaluation failure risk by referring to the corresponding parameter value in GB / T 34346-2017 according to the service state of the service pipeline, and finally, for early judgment of the dangerous condition of the natural gas pipeline, preventive measures can be taken in advance, and by mastering the hazard factors faced by the natural gas pipeline, risk identification and sorting are performed, so that the optimal maintenance plan is formulated, and the waste of human and material resources is avoided.

[0043] With reference to the foregoing prior art, in the process of implementing the present application, the inventors found that the prior art is mostly a risk assessment method considering only one kind of risk, and less considering the corrosion / geological disaster double coupling risk actually faced by the buried pipeline in the geological disaster area, the risk assessment coverage is insufficient, and the pipeline risk quantification evaluation means currently adopted is mostly based on complex formulas, which is not suitable for rapid and accurate evaluation of the buried pipeline risk. The Sichuan-Chongqing region is one of the main battlefields of oil and gas production, which is located in the mountainous area and has large continuous rainfall, and is a heavy disaster area of geological disasters. According to statistics, the landslides, mudslides and other geological disasters occurring in the Sichuan-Chongqing region account for about 14% of the same type of geological disasters in the country. The buried pipeline constructed in the geological disaster area in the Sichuan-Chongqing region not only faces the risk of corrosion perforation, but also faces the risk of pipe section cracking caused by geological disasters. The foregoing two types of risks will both cause natural gas leakage, so in order to ensure the safe and stable operation of the buried oil and gas pipeline in the geological disaster area of the high-sulfur gas field, it is necessary to establish a new method for rapid quantification evaluation and grading of the internal corrosion and geological disaster risk of the buried pipeline in the geological disaster area, so as to realize effective evaluation, monitoring and early warning of the corrosion / geological disaster double risk.

[0044] Therefore, in order to solve the above problems, the embodiment of the present application proposes a risk assessment method and system for buried pipelines in a disaster area. The risk assessment method first selects part of the pipeline suitable for risk assessment as the pipeline to be evaluated, and based on the actual risks faced by the buried pipeline in the disaster area, respectively quantitatively evaluates and classifies the internal corrosion risk and the disaster risk of the selected pipeline to be evaluated. Finally, the two types of risk quantitative evaluation results are coupled to obtain the actual leakage risk of the pipeline. The present application enhances the pertinence of risk assessment, realizes the quantitative risk assessment of buried pipelines in a disaster area, greatly improves the safety and stable operation guarantee level of buried pipelines in a disaster area, and provides technical support for improving the safety operation management and technical level of buried pipelines.

[0045] Example 1

[0046] In the embodiment of the present application, the pipeline to be evaluated is the buried pipeline between adjacent shut-off valve chambers. In the routing design process, in order to balance safety, construction quantity and laying difficulty, the pipeline is generally laid in three ways: buried, crossing (tunnel) and crossing (truss, cable bridge). Therefore, for the gathering pipeline network in the disaster area where the pipeline to be evaluated is located, first, the gathering pipeline network is divided into n sections with the shut-off valve chamber as the boundary point, and the oil and gas pipeline between two adjacent shut-off valve chambers is taken as a unit. Then, the pipeline laid in the form of crossing and crossing between the current adjacent shut-off valve chambers is removed, only the buried part is left, and the buried pipeline is taken as the pipeline to be evaluated for risk assessment. In other words, the pipeline to be evaluated in the embodiment is the buried pipeline between two adjacent shut-off valve chambers (a unit).

[0047] Figure 2 An example diagram of pipeline segmentation for the risk assessment method for buried pipelines in a disaster area of the present application. Referring to Figure 2 In a specific embodiment of the present application, there is a section of tunnel pipe segment and a section of river-crossing truss pipe segment that are not connected between two adjacent shut-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 shut-off valve chambers. At this time, any section of buried pipeline can be taken as the pipeline to be evaluated for risk assessment.

[0048] Figure 1 A step diagram of the risk assessment method for buried pipelines in a disaster area of the present application. The following refers to Figure 1 to explain each step of the method.

[0049] As Figure 1As 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 internal corrosion of the pipeline according to the corrosion rate. Internal corrosion is the most common failure form of buried oil and gas pipelines, which can cause large leakage of natural gas / oil, and further cause serious personnel casualty accidents or environmental pollution. Therefore, the embodiment first obtains the corrosion rate of the pipeline to be evaluated according to the actual operating conditions and monitoring data of the pipeline to be evaluated, so as to quantitatively evaluate the first leakage risk caused by internal corrosion of the pipeline by taking the obtained corrosion rate as a core parameter. 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 taken as the first leakage risk evaluation result.

[0050] In the step of obtaining the corrosion rate of the pipeline to be evaluated, multiple corrosion rate data are obtained by using different corrosion rate obtaining methods, and the maximum corrosion rate is taken as the corrosion rate of the pipeline to be evaluated. Specifically, the embodiment uses different corrosion rate obtaining methods to obtain multiple corrosion rate data (i.e., each corrosion rate obtaining method corresponds to one corrosion rate data). The sources of each corrosion rate data are different, which causes the deviation between different data. Therefore, the embodiment selects the maximum corrosion rate in the multiple corrosion rate data as the corrosion rate of the pipeline to be evaluated, which effectively reduces the negative influence of data errors on the first leakage risk evaluation result, thereby avoiding the first leakage risk being underestimated and causing serious consequences. In a specific embodiment of the present application, the multiple corrosion rate data include but are not limited to a first corrosion rate obtained by calculating the oxygen content in the pipeline, the PH attribute of the conveying medium and the flow rate of the conveying medium, and a second corrosion rate obtained by measuring by using an electric field fingerprint method corrosion monitoring technology. It should be noted that the present application does not specifically limit the corrosion rate obtaining method, and a person skilled in the art can select according to actual needs.

[0051] Next, the embodiment obtains the oxygen content in the pipeline, the PH attribute of the conveying medium and the flow rate of the conveying medium based on real-time detection and continuous calculation of the temperature, flow rate, oxygen content tester and other metering instruments installed on the gathering pipeline or valve chamber. The corresponding parameters for calculating the first corrosion rate are valued, the coefficients corresponding to the corresponding parameters are obtained, and the first corrosion rate is obtained according to the valuation result, which can effectively simplify the calculation process.

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

[0053] (1)

[0054] wherein, CR 1 represents the first corrosion rate,CR pH a pH attribute coefficient of the conveying medium, F O an oxygen content coefficient, F V a flow rate coefficient of the conveying medium.

[0055] In one embodiment of the present application, the pH attribute coefficient of the conveying medium has the values shown in Table 1.

[0056] Table 1 Values of the pH attribute coefficient of the conveying medium

[0057]

[0058] In one embodiment of the present application, the oxygen content coefficient has the values shown in Table 2.

[0059] Table 2 Values of the oxygen content coefficient

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

[0061] In one embodiment of the present application, the flow rate coefficient of the conveying medium has the values shown in Table 3.

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

[0063] Pipe flow velocity (v) / m / s Pipe flow 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 the internal corrosion of the pipeline according to the corrosion rate, if the corrosion rate is greater than or equal to 0.091 mm / a, the evaluation result of the first leakage risk is a major risk; if the corrosion rate is greater than or equal to 0.076 mm / a and less than 0.091 mm / a, the evaluation result of the first leakage risk is a greater risk; if the corrosion rate is greater than or equal to 0.061 mm / a and less than 0.076 mm / a, the evaluation result of the first leakage risk is a general risk; and if the corrosion rate is less than 0.061 mm / a, the evaluation result of the first leakage risk is a low risk.

[0065] In the embodiment of the present application, the internal corrosion risk (first leakage risk) level 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 Corresponding relationship between the corrosion rate and the internal corrosion risk (first leakage risk) level

[0067] Corrosion rate (mm / a) Internal corrosion risk (first leakage risk) level CR≥0.091 Red (major risk) 0.091>CR≥0.076 Orange (greater risk) 0.076>CR≥0.061 Yellow (general risk) 0.061>CR Blue (low risk)

[0068] In step S120, the pipeline damage risk index under the condition of the geological disaster is obtained by using the geological disaster occurrence risk index representing the severity of the geological disaster faced by the region where the pipeline is located and the vulnerability risk index representing the difficulty of pipeline damage, so as to evaluate the second leakage risk caused by the geological disaster according to the pipeline damage risk index. Landslide, debris flow and rockfall are the main geological disaster forms causing damage and failure of the buried pipeline in the geological disaster area. The pipeline failure caused by the geological disaster is generally in the form of fracture, and the natural gas / oil leakage amount is large and the coverage area is wide. Therefore, in this embodiment, the geological disaster occurrence risk index representing the severity of the geological disaster faced by the region where the pipeline is located and the vulnerability risk index representing the difficulty of pipeline damage are calculated according to the actual operation condition and monitoring data of the pipeline to be evaluated. Then, the pipeline damage risk index under the condition of the geological disaster is obtained by using the geological disaster occurrence risk index and the vulnerability risk index, so as to evaluate the second leakage risk caused by the geological disaster by taking the pipeline damage risk index as the core parameter. In the process of quantitative evaluation of 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 taken as the second leakage risk evaluation result.

[0069] In the embodiment of the present application, the pipeline damage risk index is calculated by using the following expression:

[0070] (2)

[0071] wherein, PR represents the pipeline damage risk index, GR represents the geological disaster occurrence risk index, PV represents the vulnerability risk index.

[0072] Further, the geological disaster occurrence risk index is the geological disaster occurrence risk index of the region where the pipeline is located after the engineering treatment, wherein the geological disaster occurrence risk index is calculated according to the geological disaster occurrence risk index before the engineering treatment of the region where the pipeline is located, the landslide occurrence risk index representing the severity of the landslide faced by the region where the pipeline is located after the engineering treatment, and the weight of the landslide risk prevention effect of the region where the pipeline is located after the engineering treatment in the overall geological disaster risk prevention effect.

[0073] Specifically, since the pipeline to be evaluated is located in a geohazard area, the area where the pipeline is located is usually pre-engineered before the pipeline is set to ensure the safety of subsequent pipeline operation. Therefore, the embodiment needs to obtain a geohazard occurrence risk index (i.e., a geohazard occurrence risk index of the area where the pipeline is located after the engineering treatment) matched with the actual engineering treatment result, so as to take the geohazard occurrence risk index as the geohazard occurrence risk index for evaluating the second leakage risk. Further, in combination with the fact that landslide is a decisive factor affecting the damage degree of the pipeline, the embodiment utilizes the geohazard occurrence risk index before the engineering treatment of the area where the pipeline is located, the landslide occurrence risk index representing the severity of the landslide faced by the area where the pipeline is located after the engineering treatment, and the coefficient of the weight of the landslide risk prevention effect in the overall geohazard risk prevention effect, to calculate the geohazard occurrence risk index.

[0074] In the embodiment of the present application, the geohazard occurrence risk index is calculated by using the following expression:

[0075] (3)

[0076] wherein, GR 1 represents the geohazard occurrence risk index before the engineering treatment, PI represents the coefficient of the weight of the landslide risk prevention effect in the overall geohazard risk prevention effect, GR 2 represents the landslide occurrence risk index.

[0077] Further, the risk evaluation method described in the embodiment calculates the geohazard occurrence risk index of the area where the pipeline is located before the engineering treatment according to the correlation between the severity of the geohazard faced by the area where the pipeline is located before the engineering treatment and different types of geological states, and the weight of each type of geological state in the occurrence of the geohazard. Specifically, the embodiment considers the correlation between the severity of the geohazard faced by the area where the pipeline is located before the engineering treatment and different types of geological states, and the weight of each type of geological state in the occurrence of the geohazard, and values the influence of each specific geological state belonging to the same type on the severity. Then, according to the actual geological state of the area where the pipeline is located before the engineering treatment, in combination with the weight of each type of geological state in the occurrence of the geohazard, the geohazard occurrence risk index of the area where the pipeline is located before the engineering treatment is obtained.

[0078] Furthermore, 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 24-hour maximum rainfall. The slope has a weight of 0.16, the soil type has a weight of 0.14, the landslide warning level has a weight of 0.10, the landslide thickness has a weight of 0.06, the earthquake intensity has a weight of 0.12, the slope morphology has a weight of 0.08, the historical landslides have a weight of 0.08, the soil state has a weight of 0.10, and the 24-hour maximum rainfall has a weight of 0.16. In a specific embodiment of the present application, the correlation, weights, and assignment results are shown in Table 5.

[0079] Table 5 Correlation, weight and assignment results

[0080]

[0081] 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.

[0082] In the embodiment of the present application, the following expression is used to calculate the geological disaster risk index before the implementation of engineering control in the pipeline area:

[0083] (4)

[0084] in, y i Indicates the i The scoring value of each type of geological state, ω i Indicates the i The weight of each type of geological state in the occurrence of geological disasters, n Indicates the number of geological state types, a represents the normalization factor.

[0085] 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.

[0086] Further, the risk assessment method described in the embodiment further evaluates the landslide disaster prevention effect according to the weight of the landslide risk prevention and control effect of the pipeline region after the implementation of the engineering governance in the overall geological disaster risk prevention and control effect, and scores the current landslide disaster prevention effect according to the evaluation result to obtain the landslide occurrence risk index representing the severity of the landslide faced by the pipeline region after the implementation of the engineering governance. Specifically, the embodiment divides the evaluation result into multiple grades according to the correlation between the weight of the landslide risk prevention and control effect of the pipeline region after the implementation of the engineering governance in the overall geological disaster risk prevention and control effect and the landslide disaster prevention effect, and formulates a scoring standard for the landslide disaster prevention effect corresponding to each grade. Then, the current landslide disaster prevention effect is scored according to the formulated scoring standard, so as to obtain the landslide disaster prevention effect score value, and then the landslide occurrence risk index representing the severity of the landslide faced by the pipeline region after the implementation of the engineering governance is obtained by using the landslide disaster prevention effect score value.

[0087] Further, the embodiment assigns a weight range to the landslide risk prevention and control effect of the pipeline region after the implementation of the engineering governance corresponding to the evaluation result of each grade in the overall geological disaster risk prevention and control effect, so that the values corresponding to different weight ranges are used as the coefficient PI for calculating the geological disaster occurrence risk index before the implementation of the engineering governance.

[0088] In the embodiment of the present application, the landslide occurrence risk index is calculated by using the following expression:

[0089] (5)

[0090] wherein, x represents the landslide disaster prevention effect score value.

[0091] In one specific embodiment of the present application, the landslide disaster prevention effect score value and the coefficient PI corresponding to the evaluation result of each grade are as shown in Table 6.

[0092] Table 6: landslide disaster prevention effect score value and coefficient

[0093] Prevention effect classification Landslide disaster prevention effect score Coefficient No governance or extremely poor governance effect 0~0.05 1~0.9 Poor governance effect 0.1~0.15 0.8~0.7 Medium governance effect 0.2~0.25 0.6~0.5 Better governance effect 0.3~0.35 0.4~0.3 Good governance effect 0.4~0.44 0.2~0.1

[0094] Further, the risk assessment method described in the embodiment further evaluates the damage difficulty degree of the pipeline according to the pipeline laying condition (combination of pipeline position and pipeline laying mode) of the pipeline to be evaluated, and scores the damage difficulty degree of the current pipeline according to the evaluation result to obtain the vulnerability risk index. Specifically, the pipeline vulnerability is determined by the pipeline position and the laying mode, so the embodiment evaluates the damage difficulty degree of the pipeline according to the pipeline position and the laying mode of the pipeline to be evaluated, and scores the damage difficulty degree according to the manner shown in Table 7, so as to obtain the vulnerability risk index by using the damage difficulty degree score value of the pipeline.

[0095] Table 7 Damage difficulty degree score result

[0096] Vulnerability classification Pipe laying condition Pipe damage difficulty score Low vulnerability Outside the landslide body affected area (1,2) Lower vulnerability Outside the landslide body affected area (3,4) Medium vulnerability Inside the landslide body and longitudinal (5,6) Higher vulnerability Inside the landslide body and oblique (7,8) High vulnerability Inside the landslide body and transverse (9,10)

[0097] In the embodiment of the present application, the vulnerability risk index is calculated by using the following expression:

[0098] (6)

[0099] wherein, f represents the damage difficulty degree score value of the pipeline.

[0100] Further, 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 evaluation 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 evaluation result is a larger risk; if the pipeline damage risk index is greater than or equal to 0.25 and less than 0.33, the second leakage risk evaluation 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 evaluation result is a low risk.

[0101] 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.

[0102] Table 8 Corresponding relationship between pipeline damage risk index and pipeline geological disaster risk (second leakage risk) level

[0103] Geological disaster leading to pipeline leakage risk index Pipeline geological disaster risk (second leakage risk) level 0.56≤PR≤1 Red (major risk) 0.33 < PR < 0.56 Orange (greater risk) 0.25 < PR < 0.33 Yellow (general risk) 0 < PR < 0.25 Blue (low risk)

[0104] In step S130, the actual leakage risk of the pipeline is obtained based on the first and second leakage risk assessment results. In practice, the core risks faced by buried pipelines in disaster-stricken areas are primarily internal corrosion and geological hazards. Therefore, this embodiment integrates the first and second leakage risk assessment results to determine the actual leakage risk of the pipeline.

[0105] Example 2

[0106] The pipeline under assessment in this example is a buried pipeline on Section A of the gathering and transportation pipeline in northeastern Sichuan. Section A is located between valve chambers 1 and 2, has a total length of 5 km, and features a truss in the middle. Section A is divided into two sections, A-1 and A-2, with lengths of 2.0 km and 1.8 km, respectively. Section A-1 is selected for risk assessment. Based on the actual operating conditions and monitoring data of Section A-1, its basic performance is shown in Table 9.

[0107] Table 9 Basic information of section A-1

[0108] Item Value Item Value pH value 3 Pipe flow velocity 2m / s Temperature 50℃ Electric fingerprint corrosion monitoring rate 0.08 mm / a Oxygen content 60ppb

[0109] After calculation, the first corrosion rate is CR 1= 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 assessed is 0.1824mm / a, and the internal corrosion risk (first leakage risk) level is red (major risk).

[0110] According to the geological disaster investigation, the basic situation of geological disasters in the area where the pipeline to be assessed is located is shown in Table 10.

[0111] Table 10 Basic situation of geological disasters in Example 2

[0112] Geological state weight ω i ]]> Specific geological state Assignment result Slope 0.16 30° 6 Soil type 0.14 Clay 10 Early warning level 0.10 Warning level 8 Slip thickness 0.06 Shallow landslide 2 Seismic intensity 0.12 7 degrees 4 Slope form 0.08 Step shape 7 History of landslides 0.08 Moderate 5 Soil state 0.10 Medium dense / plastic 6 24h maximum rainfall 0.16 150~200 8

[0113] After calculation, the geological disaster risk index before the implementation of engineering control was obtained ( GR 1) is 0.66, and it has been confirmed that the landslide disaster prevention effect is "poor control effect". Therefore, the landslide disaster prevention effect score is 0.14, and the coefficient PI At this time, the landslide risk index is 0.7. GR 2=0.44-0.14=0.3, geological disaster risk indexGR = GR 1* PI + GR 2*(1- PI ) = 0.552. Furthermore, considering that the pipeline in section A-1 is laid inside the landslide and crosses obliquely, the pipeline damage difficulty score is set to 8, and the pipeline damage difficulty score is calculated to be ( PV ) is 0.8.

[0114] In summary, pipeline damage risk index PR = GR * PV =0.4416, the pipeline geological disaster risk (second leakage risk) level is orange (higher risk).

[0115] Example 3

[0116] The pipeline under assessment in this example is a buried pipeline on Section B of the gathering and transportation pipeline in northeastern Sichuan. Section B is located between valve chambers 5 and 6, with a total length of 4.3 km. A truss and a tunnel are located in the middle of the section. Section B 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. Section B-1 is selected for risk assessment. Based on the actual operating conditions and monitoring data of Section B-1, the basic characteristics of Section B-1 are shown in Table 11.

[0117] Table 11 Basic information of Section B-1

[0118] Item Value Item Value pH value 5.25 Pipe flow velocity 1.5m / s Temperature 35℃ Electric fingerprint corrosion monitoring rate 0.05mm / a Oxygen content 30ppb

[0119] After calculation, the first corrosion rate is CR 1= 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 assessed is 0.05mm / a, and the internal corrosion risk (first leakage risk) level is blue (low risk).

[0120] According to the geological disaster investigation, the basic situation of geological disasters in the area where the pipeline to be assessed is located is shown in Table 12.

[0121] Table 12 Basic information on geological disasters in Example 3

[0122] Geological state weight ω i ]]> Specific geological state Assignment result Slope 0.16 10° 3 Soil type 0.14 Silt 5 Early warning level 0.10 Attention level 4 Slip thickness 0.06 Medium layer landslide 6 Seismic intensity 0.12 8 degrees 6 Slope form 0.08 Straight line shape 3 History of landslides 0.08 None 1 Soil state 0.10 Compact / hard plastic 4 24h maximum rainfall 0.16 50~100 4

[0123] After calculation, the geological disaster risk index before the implementation of engineering control was obtained (GR 1) is 0.402, and it is confirmed that the effect of disaster prevention is "better treatment effect". Therefore, the effect score of landslide disaster prevention is 0.3, and the coefficient PI is 0.4. At this time, the landslide risk index GR 2=0.44-0.3=0.14, and the landslide risk index GR = GR 1* PI + GR 2*(1- PI )=0.2448. Further, combined with the laying condition of the pipeline in section B-1, which is the peripheral influence area of the landslide body and is buried, the damage difficulty score of the pipeline is taken as 3, and the damage difficulty score of the pipeline is calculated to be 0.3. PV

[0124] In summary, the pipeline damage risk index PR = GR * PV =0.07344, and the pipeline geological disaster risk (second leakage risk) level is blue (low risk).

[0125] Example 4

[0126] The pipeline to be evaluated in this embodiment is a buried pipeline on pipeline section C in the northeastern Sichuan area, wherein the C section is located between the 6th valve chamber and the 7th valve chamber, the total length of the section is 9 km, there is one truss and two tunnels in the middle position of the section, which divides the C section 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, and now the C-3 section is taken as the pipeline to be evaluated for risk assessment. According to the actual operation conditions and monitoring data of the C-3 section, the basic conditions of the C-3 section are shown in Table 13.

[0127] Table 13 Basic conditions of C-3 section

[0128] Item Value Item Value pH value 5.75 Pipe flow velocity 2.5m / s Temperature 80℃ Electric fingerprint corrosion monitoring rate 0.04mm / a Oxygen content 40ppb

[0129] After calculation, the first corrosion rate is CR 1= 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 (greater risk).

[0130] ​According to the geological disaster investigation, the basic situation of geological disasters in the area where the pipeline to be assessed is located is shown in Table 14.

[0131] Table 14 Basic information on geological disasters in Example 4

[0132] Geological state weight ω i ]] Specific geological state Assignment result Slope 0.16 50° 9 Soil type 0.14 Broken stone 2 Early warning level 0.10 Warning level 8 Slip thickness 0.06 Medium layer landslide 6 Seismic intensity 0.12 9 degrees 8 Slope form 0.08 Straight line shape 3 History of landslides 0.08 Mild 3 Soil state 0.10 Compact / hard plastic 3 24h maximum rainfall 0.16 150~200 8

[0133] After calculation, the geological disaster risk index before the implementation of engineering control was obtained ( GR 1) is 0.59, and it has been confirmed that the landslide disaster prevention effect is "good". Therefore, the landslide disaster prevention effect score is 0.4, and the coefficient PI is 0.15. At this time, the landslide risk index GR 2=0.44-0.4=0.04, geological disaster risk index GR = GR 1* PI + GR 2*(1- PI ) = 0.1225. Furthermore, considering that the pipeline in section C-3 is laid outside the landslide area and buried, the pipeline damage difficulty score is set to 1, and the pipeline damage difficulty score is calculated ( PV ) is 0.1.

[0134] In summary, pipeline damage risk index PR = GR * PV =0.01225, the pipeline geological disaster risk (second leakage risk) level is blue (low risk).

[0135] Example 5

[0136] The pipeline under assessment in this example is a buried pipeline on Section D of the gathering and transportation pipeline in northeastern Sichuan. Section D is located between valve chambers 7 and 8, with a total length of 2 km and a tunnel located in the middle. Section D is divided into two sections, D-1 and D-2, with lengths of 0.5 km and 0.8 km, respectively. Section D-2 is selected for risk assessment. Based on the actual operating conditions and monitoring data of Section D-2, its basic characteristics are shown in Table 15.

[0137] Table 15 Basic information of D-2 section

[0138] Item Value Item Value pH value 2 Pipe flow velocity 1m / s Temperature 80℃ Electric fingerprint corrosion monitoring rate 0.07mm / a Oxygen content 70ppb

[0139] After calculation, the first corrosion rate is CR 1= CR pH * F O *F V = 0.13 * 2 * 1 = 0.26 mm / 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 0.26 mm / a, and the internal corrosion risk (first leakage risk) level is red (major risk).

[0140] According to the geological disaster investigation, the basic situation of the geological disaster in the area where the pipeline to be evaluated is located is shown in Table 16.

[0141] Table 16 Basic situation of geological disasters in Example Five

[0142] Geological state weight ω i ]] Specific geological state Assignment result Slope 0.16 40° 8 Soil type 0.14 Clay 9 Early warning level 0.10 Warning level 8 Slip thickness 0.06 Medium layer landslide 6 Seismic intensity 0.12 7 degrees 4 Slope form 0.08 Convex shape 9 History of landslides 0.08 Severe 9 Soil state 0.10 Slightly dense / soft plastic 8 24h maximum rainfall 0.16 200~250 10

[0143] After calculation, the geological disaster occurrence risk index (R) of the pipeline to be evaluated before the implementation of the engineering governance is obtained. GR 1) is 0.802, and it is confirmed that the geological disaster prevention effect is "poor governance effect". Therefore, the landslide disaster prevention effect score value is 0.1, and the coefficient PI is 0.8. At this time, the landslide occurrence risk index GR 2 = 0.44 - 0.1 = 0.34, and the geological disaster occurrence risk index GR = GR 1* PI + GR 2* (1- PI ) = 0.7096. Further, combined with the laying condition of the D-2 section pipeline in the landslide body and crossing, the pipeline damage difficulty degree score value is taken as 9, and the pipeline damage difficulty degree score value (D) is calculated to be 0.9. PV

[0144] Therefore, the pipeline damage risk index (R*D) PR = GR * PV = 0.63864, and the pipeline geological disaster risk (second leakage risk) level is red (major risk).

[0145] Example 6

[0146] The pipeline to be evaluated in this embodiment is a buried pipeline on the gathering pipeline pipe section a in the western Sichuan region, wherein the a pipe section is located between a1 valve chamber and a2 valve chamber, the total length of the pipe section is 3.9 km, there is 1 truss and 1 tunnel in the middle position of the pipe section, which divides the a pipe section into three sections a-1, a-2 and a-3, the lengths are 1.0 km, 0.6 km and 1.8 km respectively, and the a-3 section is taken as the pipeline to be evaluated for risk assessment. According to the actual operation condition and monitoring data of the a-3 section, the basic situation of the a-3 section is shown in Table 17.

[0147] Table 17 Basic situation of a-3 section ​

[0148] Item Value Item Value pH value 6.75 Pipe flow velocity 1.5 m / s Temperature 90℃ Electro-fingerprint corrosion monitoring rate 0.07 mm / a Oxygen content 80 ppb

[0149] After calculation, the first corrosion rate is CR 1= 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 assessed is 0.07mm / a, and the internal corrosion risk (first leakage risk) level is yellow (general risk).

[0150] According to the geological disaster investigation, the basic situation of geological disasters in the area where the pipeline to be assessed is located is shown in Table 18.

[0151] Table 18 Basic information on geological disasters in Example 6

[0152] Geological state Weight ωi Specific geological state Assignment result Slope gradient 0.16 35° 7 Soil type 0.14 Silt 6 Early warning level 0.10 Warning level 8 Slip thickness 0.06 Deep landslide 9 Seismic intensity 0.12 8 degrees 6 Slope surface shape 0.08 Convex 10 History of landslides 0.08 Mild 3 Soil state 0.10 Slightly dense / soft plastic 8 24 h maximum rainfall 0.16 ≦50 2

[0153] After calculation, the geological disaster risk index before the implementation of engineering control was obtained ( GR 1) is 0.618, and it has been confirmed that the landslide disaster prevention effect is "medium control effect". Therefore, the landslide disaster prevention effect score is 0.2, and the coefficient PI At this time, the landslide risk index is 0.6. GR 2=0.44-0.2=0.24, geological disaster risk index GR = GR 1* PI + GR 2*(1- PI ) = 0.4668. Furthermore, considering that the pipeline in section a-3 is laid inside the landslide and passes through it vertically, the pipeline damage difficulty score is set to 6, and the pipeline damage difficulty score is calculated to be ( PV ) is 0.5.

[0154] In summary, pipeline damage risk index PR = GR * PV 0.28, the pipeline geological disaster risk (second leakage risk) level is yellow (general risk).

[0155] Example 7

[0156] The pipeline under assessment in this example is a buried pipeline on section b of the gathering and transportation pipeline in western Sichuan. Section b is located between valve chambers b3 and b4, with a total length of 2.3 km. It contains no trusses or tunnels, and is therefore used directly as the pipeline under assessment for risk assessment. Based on the actual operating conditions and monitoring data of section b, its basic characteristics are shown in Table 19.

[0157] Table 19 Basic information of pipe section b

[0158] Item Value Item Value pH value 5.75 Pipe flow velocity 5 m / s Temperature 50℃ Electro-fingerprint corrosion monitoring rate 0.05 mm / a Oxygen content 35 ppb

[0159] After calculation, the first corrosion rate is CR 1= 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 assessed is 0.144mm / a, and the internal corrosion risk (first leakage risk) level is red (major risk).

[0160] According to the geological disaster investigation, the basic situation of geological disasters in the area where the pipeline to be assessed is located is shown in Table 20.

[0161] Table 20 Basic information on geological disasters in Example 7

[0162] Geological state Weight ωi Specific geological state Assignment result Slope gradient 0.16 15° 3 Soil type 0.14 Clay 10 Early warning level 0.10 Attention level 4 Slip thickness 0.06 Shallow landslide 2 Seismic intensity 0.12 6 degrees 2 Slope surface shape 0.08 Compound 5 History of landslides 0.08 Mild 3 Soil state 0.10 Slightly dense / soft plastic 8 24 h maximum rainfall 0.16 100~150 6

[0163] After calculation, the geological disaster risk index before the implementation of engineering control was obtained ( GR 1) is 0.504, and it has been confirmed that the landslide disaster prevention effect is "good". Therefore, the landslide disaster prevention effect score is 0.35, and the coefficient PI is 0.3. At this time, the landslide risk index GR 2=0.44-0.35=0.09, geological disaster risk index GR = GR 1* PI + GR 2*(1- PI ) = 0.2142. Furthermore, considering that the laying condition of pipe section b is inside the landslide body and obliquely crosses it, the pipeline damage difficulty score is set to 7, and the pipeline damage difficulty score is calculated to be ( PV ) is 0.7.

[0164] In summary, pipeline damage risk index PR = GR * PV= 0.15, the pipeline geological disaster risk (second leakage risk) level is blue (low risk).

[0165] Example 8

[0166] The pipeline to be evaluated in this embodiment is a buried pipeline on pipeline section I in the Huabei area gathering pipeline, wherein the I pipeline section is located between the H2 valve chamber and the H3 valve chamber, the total length of the pipeline section is 7.7 km, there is one truss and one tunnel at the middle position of the pipeline section, which divides the I pipeline section into three sections I-1, I-2 and I-3, with lengths of 2.0 km, 2.5 km and 1.8 km respectively, and the I-1 section is taken as the pipeline to be evaluated for risk evaluation. According to the actual operation conditions and monitoring data of the I-1 section, the basic conditions of the I-1 section are shown in Table 21.

[0167] Table 21 Basic conditions of I-1 section

[0168] Item Value Item Value pH value 6.25 Pipe flow velocity 1.3 m / s Temperature 35℃ Electro-fingerprint corrosion monitoring rate 0.08 mm / a Oxygen content 10 ppb

[0169] After calculation, the first corrosion rate is CR 1= CR pH * F O * F V = 0.01 * 1 * 1 = 0.01 mm / 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 0.08 mm / a, and the internal corrosion risk (first leakage risk) level is orange (greater risk).

[0170] According to the geological disaster investigation, the basic conditions of the geological disaster in the area where the pipeline to be evaluated is located are shown in Table 22.

[0171] Table 22 Basic conditions of geological disasters in Example Eight

[0172] Geological state Weight ωi Specific geological state Assignment result Slope gradient 0.16 45° 10 Soil type 0.14 Broken stone 1 Early warning level 0.10 Warning level 6 Slip thickness 0.06 Shallow landslide 2 Seismic intensity 0.12 10 degrees 10 Slope surface shape 0.08 Concave 2 History of landslides 0.08 More serious 7 Soil state 0.10 Very dense / hard 2 24 h maximum rainfall 0.16 100~150 5

[0173] After calculation, the geological disaster occurrence risk index (R1) before the implementation of engineering management is 0.538, and it is confirmed that the geological disaster prevention effect is "better management effect". Therefore, the landslide disaster prevention effect score value is 0.41, and the coefficient (C1) is 0.18. At this time, the landslide occurrence risk index (R2) is 0.03, the geological disaster occurrence risk index (R) is GR 1 PI + GR 2 GR = GR 1 PI + GR 2* (1- PI) = 0.12144. Furthermore, considering that the laying situation of section I-1 is outside the landslide affected area and buried, the pipeline damage difficulty score is set to 2, and the pipeline damage difficulty score is calculated ( PV ) is 0.2.

[0174] In summary, pipeline damage risk index PR = GR * PV =0.024288, the pipeline geological disaster risk (second leakage risk) level is blue (low risk).

[0175] Example 9

[0176] 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 the "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.

[0177] 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, thereby assessing the first leakage risk caused by corrosion in the pipeline based on 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 use a geological disaster risk index that represents the severity of geological disasters faced by the pipeline area and a vulnerability risk index that represents the ease 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 based on 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 based on the first leakage risk assessment results and the second leakage risk assessment results.

[0178] The application provides a risk assessment method and system for a buried pipeline in a geohazard area.

[0179] The above merely describes preferred specific embodiments of the application, but the protection scope of the application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the application, which should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

[0180] It should be understood that the disclosed embodiments are not limited to the specific structure, processing steps or materials disclosed herein, but extend to equivalent alternatives that are obvious to those skilled in the relevant art. It should also be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting.

[0181] The phrase "one embodiment" or "an embodiment" appearing in the specification does not necessarily refer to the same embodiment, and the different instances of the phrase "one embodiment" or "an embodiment" refer to one or more but not necessarily all embodiments of the application. Thus, descriptions and examples of the phrase "one embodiment" or "an embodiment" are not necessarily mutually inclusive and are not necessarily referred to multiple times in this specification.

[0182] Although the embodiments disclosed by the application are as above, the content described is only the embodiments adopted for the purpose of facilitating the understanding of the application, and is not intended to limit the application. Any person skilled in the art of the application can make any modification and change in the implementation form and details without departing from the spirit and scope of the application, but the patent protection scope of the application should be subject to the scope defined by the attached claims.

Claims

1. A method for risk assessment of a buried pipeline in a geohazard area, characterized by, The method comprises the following steps: obtaining a corrosion rate of a pipeline to be evaluated, and evaluating a first leakage risk caused by internal corrosion of the pipeline according to the corrosion rate; obtaining a pipeline damage risk index under a geological disaster condition by using a geological disaster occurrence risk index representing a severity of a geological disaster faced by a region where the pipeline is located and a vulnerability risk index representing a difficulty of pipeline damage, and evaluating a second leakage risk caused by the geological disaster according to the pipeline damage risk index, wherein the geological disaster occurrence risk index is a geological disaster occurrence risk index of the region where the pipeline is located after engineering treatment, and the geological disaster occurrence risk index is calculated according to a geological disaster occurrence risk index of the region where the pipeline is located before the engineering treatment, a landslide occurrence risk index representing a severity of a landslide faced by the region where the pipeline is located after the engineering treatment, and a weight of a landslide risk prevention effect of the region where the pipeline is located in a whole geological disaster risk prevention effect after the engineering treatment, wherein the geological disaster occurrence risk index is calculated by using the following expression: wherein, GR represents a landslide risk index, GR 1 represents a landslide risk index before implementing the engineering governance, PI represents a coefficient of the weight of the landslide risk prevention effect in the overall landslide risk prevention effect, GR 2 represents a landslide risk index; an actual leakage risk of the pipeline is obtained according to the first leakage risk evaluation result and the second leakage risk evaluation result.

2. The risk assessment method of claim 1, wherein, In the step of obtaining the corrosion rate of the pipeline to be evaluated, the following steps are further included: a plurality of corrosion rate data are obtained by using different corrosion rate obtaining methods, and a maximum corrosion rate is taken as the corrosion rate of the pipeline to be evaluated, wherein the plurality of corrosion rate data include but are not limited to a first corrosion rate calculated according to an oxygen content in the pipeline, a PH attribute of a conveying medium and a flow rate of the conveying medium, and a second corrosion rate measured by using an electric field fingerprint method corrosion monitoring technology.

3. The risk assessment method of claim 2, wherein, the first corrosion rate is calculated by using the following expression: wherein, CR 1 represents the first corrosion rate, CR PH represents the pH property coefficient of the transport medium, F O represents the oxygen content coefficient, F V represents the flow rate coefficient of the transport medium.

4. The risk assessment method according to any one of claims 1 to 3, characterized in that, In the step of evaluating the first leakage risk caused by internal corrosion of the pipeline according to the corrosion rate, the following steps are further included: if the corrosion rate is greater than or equal to 0.091 mm / a, the first leakage risk evaluation result is a major risk; if the corrosion rate is greater than or equal to 0.076 mm / a and less than 0.091 mm / a, the first leakage risk evaluation result is a relatively major risk; if the corrosion rate is greater than or equal to 0.061 mm / a and less than 0.076 mm / a, the first leakage risk evaluation result is a general risk; if the corrosion rate is less than 0.061 mm / a, the first leakage risk evaluation result is a low risk.

5. The risk assessment method of claim 4, wherein, the pipeline damage risk index is calculated by using the following expression: wherein, PR represents a pipe damage risk index, GR represents a ground disaster occurrence risk index, PV represents a vulnerability risk index.

6. The risk assessment method of claim 5, wherein, The method further comprises the following steps: the geological disaster occurrence risk index of the region where the pipeline is located before the engineering treatment is calculated according to a correlation between a severity of a geological disaster faced by the region where the pipeline is located before the engineering treatment and different types of geological states, and a weight of each type of geological state in the geological disaster occurrence.

7. The risk assessment method of claim 6, wherein, the geological disaster occurrence risk index of the region where the pipeline is located before the engineering treatment is calculated by using the following expression: wherein, GR 1 represents the risk index of a geo-hazard before the implementation of engineering governance, y i represents the score value of the i type of geological state, ω i represents the weight of the i type of geological state in the occurrence of a geo-hazard, n represents the number of types of geological states, a represents a normalization factor.

8. The risk evaluation method according to claim 7, wherein The different types of geological conditions include, but are not limited to, slope, soil type, landslide warning level, landslide thickness, seismic intensity, slope surface shape, historical landslide, soil condition, and 24-hour 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 landslide thickness is 0.06, the weight of the seismic intensity is 0.12, the weight of the slope surface shape is 0.08, the weight of the historical landslide is 0.08, the weight of the soil condition is 0.10, and the weight of the 24-hour maximum rainfall is 0.

16.

9. The risk assessment method according to any one of claims 6 to 8, characterized in that, The risk assessment method further comprises: According to the weight of the landslide risk prevention and control effect faced by the region where the pipeline is located after the implementation of the engineering governance in the overall geohazard 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 a landslide occurrence risk index representing the severity of the landslide faced by the region where the pipeline is located after the implementation of the engineering governance, wherein the landslide occurrence risk index is calculated by using the following expression: wherein, GR 2 represents the landslide risk index, x represents the landslide disaster prevention effect score.

10. The risk assessment method of claim 9, wherein, The risk assessment method further comprises: According to the pipeline position and pipeline laying mode of the pipeline to be evaluated, the damage difficulty of the pipeline is evaluated, and according to the evaluation result, the damage difficulty of the current pipeline is scored to obtain the vulnerability risk index, wherein the vulnerability risk index is calculated by using the following expression: wherein, PV represents a vulnerability risk index, f represents a score value of the difficulty of damage to the pipeline, a represents a normalization factor.

11. The risk assessment method of claim 10, wherein, In the step of evaluating the second leakage risk caused by the geohazard according to the pipeline damage risk index, the following is included: 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 evaluation 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 evaluation result is a larger risk; If the pipeline damage risk index is greater than or equal to 0.25 and less than 0.33, the second leakage risk evaluation 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 evaluation result is a low risk.

12. The risk assessment method according to claim 10 or 11, characterized in that, The pipeline to be evaluated is a buried part of the pipeline located between adjacent shut-off valve chambers.

13. A risk assessment system for buried pipelines in geohazard areas, characterized by, The risk assessment system comprises the following modules: A first leakage risk assessment module for obtaining the corrosion rate of the pipeline to be evaluated, thereby evaluating the first leakage risk caused by internal corrosion of the pipeline according to the corrosion rate; A second leakage risk assessment module for obtaining a pipeline damage risk index under the condition of geohazard occurrence by using a geohazard occurrence risk index representing the severity of the geohazard faced by the region where the pipeline is located after the implementation of the engineering governance, and a vulnerability risk index representing the damage difficulty of the pipeline, thereby evaluating the second leakage risk caused by the geohazard according to the pipeline damage risk index, wherein the geohazard occurrence risk index is the geohazard occurrence risk index of the region where the pipeline is located after the implementation of the engineering governance, and According to the ground disaster occurrence risk index of the pipeline area before the implementation of the engineering governance, the landslide occurrence risk index representing the severity of the landslide faced by the pipeline area after the implementation of the engineering governance, and the weight of the landslide risk prevention and control effect faced by the pipeline area after the implementation of the engineering governance in the overall ground disaster risk prevention and control effect, the ground disaster occurrence risk index is calculated, wherein The ground disaster occurrence risk index is calculated by using the following expression: wherein, GR represents a landslide risk index, GR 1 represents a landslide risk index before implementing the engineering governance, PI represents a coefficient of the weight of the landslide risk prevention effect in the overall landslide risk prevention effect, GR 2 represents a landslide risk index; An actual leakage risk assessment module is configured to obtain an 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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