Assessment method and control method for comprehensive risks of oil and gas pipelines

Abstract

The present invention provides a method for evaluating and controlling the comprehensive risk of oil and gas pipelines. The evaluation method includes: for each major factor affecting pipeline risk, determining n-level basic indicators respectively, where n≥2; determining the score of each basic indicator and the weight value corresponding to each basic indicator; for a single major factor, determining the score of each level of negative indicator and the score of each level of positive indicator step by step in ascending order; according to the score P Ni of the first-level negative indicator and the score P Si of the first-level positive indicator of a single major factor, determining the failure probability indicator P x of the single major factor; establishing a coupling action matrix of failure factors, and determining the correction value P' of the coupling action of different types of negative factors on the failure probability; determining the pipeline risk indicator score R. The evaluation method of the present invention fully considers the mutual relationship between risk influencing factors, can objectively evaluate the comprehensive risk of the pipeline, and reflects the true risk situation of the pipeline.

Description

Technical Field

[0001] The present invention relates to the technical field of risk assessment for oil and gas pipelines. Specifically, it relates to a method for evaluating the comprehensive risk of oil and gas pipelines and a method for controlling the comprehensive risk of oil and gas pipelines. Background Art

[0002] As one of the five major transportation modes, pipeline transportation occupies an extremely important position in the development of the petroleum and petrochemical industries. Due to the particularity of the transported medium, once an accident occurs in the pipeline, the consequences are often very serious. In the past decade or so, pipeline accidents have occurred frequently, and the safety situation has become increasingly severe. Therefore, a reasonable and effective risk technical assessment of pipelines is particularly important in pipeline safety management.

[0003] There are many factors affecting pipeline risk. By comparison, it can be seen that the index assessment method is an effective method to evaluate the combined effects of these factors. At present, domestic index methods mostly adopt the ideas of the "Risk Management Handbook" by Kentel from abroad and the risk assessment method (Risk Score) developed by the National Pipeline Network Corporation. These methods uniformly assign values to each influencing factor and then sum them according to weights, without considering the mutual relationships between factors. The determination of the scoring rules for underlying factors is also relatively subjective. Therefore, the assessment results can only roughly indicate the relative risk levels of each pipeline section, and have little practical guiding significance for risk control.

[0004] For example, the patent document with the invention name "Method for Evaluating the Risk of Buried Pipelines Using the Improved Kent Method" and the publication number CN104866977A, which was published on August 26, 2015, records a method for evaluating the risk of buried pipelines using the improved Kent method. This method determines the factor set based on the engineering data of the pipeline, uses the analytic hierarchy process to determine the weight matrix of each level of factor indicators, uses the fuzzy comprehensive evaluation method to obtain the single-factor risk assessment result, uses the membership degree fuzzy median principle to calculate the relative state characteristic value, and combines the leakage influence coefficient to calculate the relative risk value.

[0005] The patent document with the invention name of "A Quantitative Evaluation Method for the Control and Management Efficiency of Long-distance Pipeline Transportation Based on the Index Method" and the publication number of CN112348307A, which was published on February 9, 2021, records a quantitative evaluation method for the control and management efficiency of long-distance pipeline transportation based on the index method, including constructing a risk control and management efficiency model for long-distance pipelines; the calculation result of the risk control and management efficiency model for long-distance pipelines is the risk control and management efficiency value of long-distance pipelines; the evaluation indicators of the risk control and management efficiency model for long-distance pipelines include the line risk control and management efficiency value, the station risk control and management efficiency value, the operation risk control and management efficiency value, and the management risk control and management efficiency value; calculate the efficiency value of risk control and management according to the constructed risk control and management efficiency model for long-distance pipelines. Although these methods can comprehensively evaluate the index weights of accident factors, thereby reflecting the risk situation of pipelines, they do not consider the coupling effect between various factors and cannot evaluate and obtain the true risk situation of pipelines.

[0006] Therefore, it is necessary to establish an improved index method for evaluating the comprehensive risk of oil and gas pipelines, fully considering the mutual relationship between risk influencing factors, so as to objectively evaluate the comprehensive risk of pipelines, provide a direction for risk mitigation decision-making, accordingly propose targeted risk avoidance measures, avoid the occurrence of pipelines or adverse intermediate events, and effectively reduce the probability of pipeline accidents. Summary of the Invention

[0007] The purpose of the present invention is to solve at least one of the above-mentioned deficiencies existing in the prior art. For example, one of the purposes of the present invention is to provide a method that can fully consider the mutual relationship between risk influencing factors to objectively evaluate the comprehensive risk of pipelines.

[0008] To achieve the above purpose, on the one hand, the present invention provides an evaluation method for the comprehensive risk of oil and gas pipelines, and the evaluation method includes the following steps: S1. For each major category of factors affecting pipeline risk, determine the n-level basic indicators respectively, where n≥2; S2. Determine the score of each basic indicator and the weight value corresponding to each basic indicator; S3. For a single major category of factors, determine the negative indicator scores and positive indicator scores at each level in ascending order from low to high; S4. According to the first-level negative indicator score P Ni and the first-level positive indicator score P Si , determine the failure probability indicator P x of a single major category of factors; S5. Establish a coupling action matrix of failure factors and determine the correction value P' of the coupling action of different types of negative factors on the failure probability; S6. Determine the pipeline risk indicator score R according to formula (1), and formula (1) is as follows:

[0009]

[0010] Wherein, R is the pipeline risk index score, M is the total number of major factors affecting pipeline risk, x is the serial number of the major factor, and λ x is the index weight of a single major factor, P x is the failure probability index of a single major factor, P' is the correction value of the failure probability due to the coupling effect of different types of negative factors, and C is the pipeline failure consequence value.

[0011] In an exemplary embodiment of the present invention, step S3 may specifically include the following sub-steps: S31. For a single major factor, select at least one n-level negative index and at least one n-level positive index to conduct a risk analysis on the pipeline situation, and determine the n-level negative index score and the n-level positive index score; S32. According to the n-level negative index score and the n-level positive index score, respectively determine the n-1 level negative index score and the n-1 level positive index score; S33. Repeat step S32 until the first-level negative index score P Ni and the first-level positive index score P Si are determined.

[0012] In an exemplary embodiment of the method for evaluating the comprehensive risk of an oil and gas pipeline in the present invention, the n-level negative index score can be calculated based on the sum of the total score of the negative factor index and the weight value corresponding to at least one selected n-level negative index; the n-level positive index score can be calculated based on the sum of the total score of the positive factor index and the weight value corresponding to at least one selected n-level positive index.

[0013] In an exemplary embodiment of the method for evaluating the comprehensive risk of an oil and gas pipeline in the present invention, the n-1 level negative index score can be calculated based on the number of n-1 level negative indexes and the n-level negative index score; the n-1 level positive index score can be calculated based on the number of n-1 level positive indexes and the n-level positive index score.

[0014] In an exemplary embodiment of the method for evaluating the comprehensive risk of an oil and gas pipeline in the present invention, the failure probability index P of a single major factor can be determined according to formula (2) x , and formula (2) is as follows:

[0015]

[0016] Wherein, P x is the failure probability index of a single major factor, P Ni is the first-level negative index score, P Si is the first-level positive index score, and D is the total score of the first-level indexes of a single major factor.

[0017] In an exemplary embodiment of the method for evaluating the comprehensive risk of an oil and gas pipeline in the present invention, D can be 100-200.

[0018] In an exemplary embodiment of the method for evaluating the comprehensive risk of an oil and gas pipeline of the present invention, the correction value code with the largest coupling effect in the coupling effect matrix of failure factors can be determined as the correction value P' of the coupling effect of different types of negative factors on the failure probability.

[0019] In an exemplary embodiment of the method for evaluating the comprehensive risk of an oil and gas pipeline of the present invention, the major factors affecting the pipeline risk may include third-party damage, manufacturing defects, natural disasters, and corrosion.

[0020] In an exemplary embodiment of the method for evaluating the comprehensive risk of an oil and gas pipeline of the present invention, n can be 2 to 5.

[0021] On the other hand, the present invention provides a method for controlling the comprehensive risk of an oil and gas pipeline, which calculates the pipeline risk index score by using the above-mentioned method for evaluating the comprehensive risk of an oil and gas pipeline, and takes corresponding measures for control according to the pipeline risk index score.

[0022] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0023] (1) The evaluation method of the present invention fully considers the mutual relationship between risk influencing factors, can objectively evaluate the comprehensive risk of the pipeline, and reflects the true risk situation of the pipeline;

[0024] (2) The present invention has high calculation efficiency and can greatly improve the scientificity and feasibility of the comprehensive risk assessment of oil and gas pipelines;

[0025] (3) The present invention can indicate the direction for risk mitigation decision-making, and accordingly propose targeted risk avoidance measures, which can avoid the occurrence of pipelines or adverse intermediate events, and effectively reduce the probability of pipeline accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Through the following description in conjunction with the drawings, the above and other objects and / or features of the present invention will become clearer, wherein:

[0027] Figure 1 Shows a schematic flow chart of an exemplary embodiment of the method for evaluating the comprehensive risk of an oil and gas pipeline of the present invention.

[0028] Figure 2 Shows a basic index structure diagram of an exemplary embodiment of the method for evaluating the comprehensive risk of an oil and gas pipeline of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Hereinafter, the method for evaluating the comprehensive risk of an oil and gas pipeline and the method for control of the present invention will be described in detail in conjunction with exemplary embodiments.

[0030] In the prior art, the evaluation methods for pipeline risks uniformly assign values to each influencing factor and then sum them according to weights, without considering the mutual relationships among the factors. The determination of the scoring rules for underlying factors is also highly subjective. Therefore, the evaluation results can only roughly indicate the relative risk levels of each pipeline section and have little practical guiding significance for risk control.

[0031] In fact, the occurrence of pipeline failures is often the result of the combined action of several adverse factors. Among them, some adverse events are negative factors, which are objective factors that increase the risk of pipeline failure; while some other events are originally positive factors. In order to avoid the occurrence of pipelines or adverse intermediate events, some preventive control measures have been taken in the design, construction, operation and other stages. However, if the positive events are not properly carried out, it will provide conditions for the occurrence of negative factor events. Negative factors are the objective reasons for high risks, while positive factors are the subjective reasons for reducing risks and are the focus of pipeline safety management.

[0032] Based on this, by considering the logical relationships among the factors and the coupling effect on pipeline failure, the present invention proposes an improved index method to evaluate the comprehensive risk of oil and gas pipelines. This method fully considers the logical relationships among the influencing factors and the coupling effect on pipeline failure, and can greatly improve the scientificity and feasibility of the comprehensive risk assessment of oil and gas pipelines.

[0033] To achieve the above object, on the one hand, the present invention provides an evaluation method for the comprehensive risk of oil and gas pipelines.

[0034] In an exemplary embodiment of the present invention, by considering the logical relationships among the factors and the coupling effect on pipeline failure, an improved index method is established to evaluate the comprehensive risk of oil and gas pipelines. This method can avoid the occurrence of pipelines or adverse intermediate events, reduce the increase in pipeline failure risk, and improve the scientificity and feasibility of the method.

[0035] Among them, the logical relationship among the factors is: based on the understanding of engineering risks in China, it is considered that "high risk" is a more adverse situation than "low risk". The contribution of negative factors to risk is set to "positive", while positive factors are the reduction of the effect of negative factors and the contribution to risk is "negative".

[0036] The coupling effect of each factor on pipeline failure is: when two or more negative factors act on the pipeline jointly, each factor affects each other through mutual interaction, and thus combines to produce a greater destructive force than direct superposition. When the actions of multiple negative factors all exceed a certain limit, the coupling effect occurs; and the greater the single-factor action, the greater the coupling effect. The contribution of all factors with coupling effect to the pipeline risk index value should be added with the correction index value of the coupling effect in addition to the superposition of single-factor index values.

[0037] That is to say, the pipeline risk defined by the traditional overall risk assessment model is the product of the failure probability and the failure consequence. Therefore, the calculation formula for the pipeline risk value is:

[0038] R = P × C

[0039] In the formula, R is the pipeline risk value; P is the pipeline failure probability value; C is the pipeline failure consequence value.

[0040] If the factors affecting the pipeline risk can be divided into M categories, and the universe of discourse is set as: V = (V1, V2,..., V M ), then the corresponding factor weight and failure probability index for each are sets on V, that is:

[0041] λ = (λ1, λ2,..., λ M ), λ ∈ V

[0042] P = (P1, P2,..., P M ), P ∈ V

[0043] In this application, considering that the contribution of all factors of the coupling effect to the pipeline risk index value, in addition to the superposition of single-factor index values, should also add the correction index value of the coupling effect. Therefore, the calculation formula for the improved pipeline risk value is:

[0044]

[0045]

[0046] In the formula, R is the pipeline risk index score; x is the major category number of the failure probability factor; M is the total number of major factors affecting the pipeline risk; λ x is the index weight of a single major factor; P x is the failure probability index of a single major factor; P' is the correction value of the coupling effect of different types of negative factors on the failure probability; C is the pipeline failure consequence value.

[0047] Therefore, by using the improved index method of this application, first calculate the failure probability index and index weight of a single major factor under the coupling effect, and then add the correction index value of the coupling effect on the failure probability. Through the calculation formula of the improved pipeline risk value, the comprehensive risk of the oil and gas pipeline can be calculated and evaluated.

[0048] Specifically, a method for evaluating the comprehensive risk of an oil and gas pipeline can be realized through the following steps.

[0049] Step S1: For each major factor affecting the pipeline risk, determine the n-level basic indicators respectively to obtain the Kent hazard index set. Among them, n ≥ 2.

[0050] For example, according to the pipeline conditions, M major factors can be selected to evaluate the comprehensive risk of the pipeline. When n = 2, each major factor includes multiple first-level basic indicators, and each first-level basic indicator includes multiple second-level basic indicators.

[0051] Step S2: Determine the score of each basic indicator and the weight value corresponding to each basic indicator.

[0052] Step S3: For a single major factor, determine the scores of negative indicators and positive indicators at each level in ascending order from the lowest level to the highest level.

[0053] Among them, the n-level basic indicator is the lowest level, and the first-level basic indicator is the highest level. The order from the lowest level to the highest level refers to the order from the n-level to the first-level basic indicator.

[0054] Step S4: According to the score P of the first-level negative indicator Ni and the score P of the first-level positive indicator Si of a single major factor, determine the failure probability indicator P x of the single major factor.

[0055] Step S5: Establish a coupling action matrix of failure factors, and determine the correction value P' of the coupling action of different types of negative factors on the failure probability.

[0056] Step S6: Determine the pipeline risk indicator score R according to Equation (1), and Equation (1) is as follows:

[0057]

[0058] In the formula, R is the pipeline risk indicator score; M is the total number of major factors affecting the pipeline risk; x is the serial number of the major factor; λ x is the index weight of a single major factor; P x is the failure probability indicator of a single major factor; P' is the correction value of the coupling action of different types of negative factors on the failure probability; C is the pipeline failure consequence value.

[0059] In this embodiment, Step S3 may specifically include the following sub-steps.

[0060] Sub-step S31: For a single major factor, select at least one n-level negative indicator and at least one n-level positive indicator to conduct a risk analysis of the pipeline situation, and determine the scores of the n-level negative indicator and the n-level positive indicator.

[0061] Sub-step S32: According to the scores of the n-level negative indicator and the n-level positive indicator, determine the scores of the n-1 level negative indicator and the n-1 level positive indicator respectively.

[0062] Sub-step S33: Repeat sub-step S32 until the first-level negative index score P Ni and the first-level positive index score P Si .

[0063] In this embodiment, the n-level negative index score can be calculated based on the sum of the total score of the negative factor index and the weight values corresponding to at least one selected n-level negative index; the n-level positive index score can be calculated based on the sum of the total score of the positive factor index and the weight values corresponding to at least one selected n-level positive index.

[0064] In this embodiment, the (n - 1)-level negative index score can be calculated based on the number of (n - 1)-level negative indexes and the n-level negative index score; the (n - 1)-level positive index score can be calculated based on the number of (n - 1)-level positive indexes and the n-level positive index score.

[0065] In this embodiment, the failure possibility index P of a single major category factor can be determined according to Equation (2) x , and Equation (2) is as follows:

[0066]

[0067] In the formula, P x is the failure possibility index of a single major category factor; P Ni is the first-level negative index score; P Si is the first-level positive index score; D is the total score of the first-level indexes of a single major category factor.

[0068] In this embodiment, D can be 100 - 200.

[0069] In this embodiment, the correction value code with the largest coupling effect in the failure factor coupling effect matrix can be determined as the correction value P' of the coupling effect of different types of negative factors on the failure possibility.

[0070] In this embodiment, the major category factors affecting the pipeline risk may include third-party damage, manufacturing defects (e.g., weld defects, and defects occurring during the manufacturing process), natural disasters, and corrosion.

[0071] In this embodiment, n can be 2 - 5.

[0072] On the other hand, the present invention provides a method for controlling the comprehensive risk of an oil and gas pipeline.

[0073] In another exemplary embodiment of the present invention, the pipeline risk index score is calculated by using the above-mentioned method for evaluating the comprehensive risk of an oil and gas pipeline, and corresponding measures are taken for control according to the pipeline risk index score.

[0074] For example, for third-party damage, control measures can be taken, such as improving pipeline surface facilities like pipeline corridors and markings, strengthening public awareness campaigns, increasing the frequency of pipeline patrols, and enhancing the effectiveness of patrols, to reduce its risk value; for weld defects, control measures can be taken through in-pipeline inspections, weld inspections, and improvement of construction quality, to reduce its risk value; for natural disasters, control measures can be taken through geological disaster warning systems, pre- and post-flood inspections, etc., to reduce its risk value; for corrosion, control measures can be taken by strengthening internal and external pipeline inspections, improving the level of cathodic protection, and reducing the corrosiveness of the medium, to reduce its risk value.

[0075] To better understand the above exemplary embodiments of the present invention, the following further describes them in conjunction with the accompanying drawings and specific examples.

[0076] As Figure 1 shown, a method for evaluating the comprehensive risk of an oil and gas pipeline includes the following steps:

[0077] (1) Determine the Kent hazard index set.

[0078] According to the operating conditions of the pipeline, the factors affecting pipeline risk are divided into 4 categories (i.e., M = 4), and the universe of discourse is set: V = (V1, V2, V3, V4) = (third-party damage, manufacturing defects, natural disasters, corrosion). Then, the corresponding factor weights and failure probability indicators are both sets on V, i.e.: λ = (λ1, λ2, λ3, λ4), λ ∈ V; P = (P1, P2, P3, P4), P ∈ V.

[0079] For each major category of factors, three-level basic indicators can be divided (i.e., n = 3). All the basic indicators included in all major categories of factors together constitute a Kent hazard index set. For example, as Figure 2 shown, for the xth major category of factors, this major category of factors is determined by i first-level basic indicators. For example, the xth major category of factors is determined by the first-level basic indicators U1, U2,... U i collectively; each first-level basic indicator is determined by j second-level basic indicators. For example, the first-level basic indicator U i is determined by the second-level basic indicators U i1 , U i2 ,... U ij collectively; each second-level basic indicator is determined by k third-level basic indicators. For example, the second-level indicator U ij is determined by the third-level basic indicators U ij1 , U ij2 ,... U ijk collectively.

[0080] (2) Calculate the scores of the three-level negative indicators and the three-level positive indicators.

[0081] The basic index score depends on the total score of the basic index (tertiary index) and the weight corresponding to the detailed rules for the pipeline situation.

[0082] For the xth major factor, select at least one negative factor index and at least one positive factor index from the tertiary basic indexes of this major factor to conduct a risk analysis of the pipeline situation, and determine the tertiary negative index score and the tertiary positive index score.

[0083] Based on the sum of the weight values of the selected negative factor indexes and the total score of the negative factor indexes, the tertiary negative index score can be calculated. Based on the sum of the weight values of the selected positive factor indexes and the total score of the positive factor indexes, the tertiary positive index score can be calculated.

[0084] Suppose the discourse universe of the index options for the xth major factor is U = {u1, u2, …, u m}, then the corresponding weight serial number set A of the index options is a set on U, and the corresponding weight set is B, then there is: A = {a1, a2, …, a m}, A ∈ U; B ∈ U. Among them, there are m selectable index options for this factor, i is the serial number of the primary index, j is the serial number of the secondary index included in a certain primary index, k is the serial number of the tertiary index included in a certain secondary index, then i - j - k represents the tertiary index with serial number k included in the secondary index with serial number j in the primary index with serial number i, and a is the serial number of the selected option.

[0085] Let the total score allocated to the tertiary indexes included in a single major factor be S i-j-k , when the selected tertiary negative index and / or tertiary positive index is a single selection, the calculation formulas for the tertiary negative index score and the tertiary positive index score are respectively:

[0086]

[0087]

[0088] When the selected tertiary negative index and / or tertiary positive index is a multiple selection, the factor weight is the sum of the weights corresponding to all options, but it shall not be greater than 1. At this time, the calculation formulas for the tertiary negative index score and the tertiary positive index score are respectively:

[0089]

[0090]

[0091]

[0092] In the formula, is the score of the third-level negative index; is the weight value of the selected third-level negative index; is the score of the third-level positive index; is the weight value of the selected third-level negative index; S i-j-k is the total score of the basic index; S Ni-j-k is the total score of the negative factor index; S Ni-j-k is the total score of the positive factor index.

[0093] (3) Calculation of the second-level negative index score and the second-level positive index score.

[0094] For the xth major factor, based on the third-level negative index score and the number of third-level negative indexes n1, calculate to obtain the second-level negative index score Based on the third-level positive index score and the number of third-level positive indexes n2, calculate to obtain the second-level positive index score

[0095] That is to say, the calculation formulas for the second-level negative index score and the second-level positive index score are respectively:

[0096]

[0097]

[0098] In the formula, is the second-level negative index score; is the third-level negative index score; is the second-level positive index score; is the third-level positive index score; k is the serial number of the third-level index included in the second-level index with the serial number i - j, and n1 and n2 are the numbers of the third-level indexes of the negative factor and the positive factor respectively.

[0099] (4) Calculation of the first-level negative index score and the first-level positive index score.

[0100] For the xth major factor, based on the second-level negative index score and the number of second-level negative indexes L1, calculate to obtain the first-level negative index score Based on the second-level positive index score and the number of second-level positive indexes L2, calculate to obtain the first-level positive index score

[0101] That is to say, the calculation formulas for the first-level negative index score and the first-level positive index score are respectively:

[0102]

[0103]

[0104] In the formula, is the score of the secondary negative index; is the score of the tertiary negative index; is the score of the primary positive index; is the score of the primary positive index; j is the serial number of the secondary index included in the primary index with serial number i, and L1 and L2 are the numbers of secondary indexes of negative factors and positive factors respectively.

[0105] (5) Calculation of the failure possibility index score of the major category factors.

[0106] The index score of the major category factors is related to the primary negative index and positive index.

[0107] Negative factors increase risks, while positive indexes reduce risks. Therefore, the score of the primary index is the score of the negative factor index minus the mitigation score of the positive factor. Since the positive factor acts on the negative factor and reduces the disaster-causing degree of the negative factor, the reduction degree of the negative factor is between (0, 1). Since the score of the primary index of each major category is 100 (i.e., D = 100), the mitigation degree is P Si / 100.

[0108] For the xth major category factor, the failure possibility index score P x of this major category factor is:

[0109]

[0110] In the formula, P x is the failure possibility index of a single major category factor; P Ni is the score of the primary negative index; P Si is the score of the primary positive index; D is the total score of the primary index of a single major category factor, taking 100.

[0111] (6) Correction of the index score due to the coupling effect between failure index factors.

[0112] Here, only the coupling effect between two major category factors is considered. Table 1 is the coupling effect matrix of failure factors.

[0113] Table 1 Code of the correction value of the coupling effect of failure factors on the failure possibility

[0114]

[0115] When there are multiple groups of coupling effects, there is always a group of coupling effects that play a dominant role in an accident. Therefore, when there are multiple groups of couplings, only the effect of the group with the largest coupling is considered. Then:

[0116] P′ = max(P x1-x2 ) (13)

[0117] where P' is the correction value of the coupling effect of different types of negative factors on the failure probability; P x1-x2 is the coupling effect of different types of negative factors on the failure probability.

[0118] (7) Calculation of the pipeline risk index score.

[0119] The calculation formula for the pipeline risk index score is:

[0120]

[0121] In summary, the beneficial effects of the present invention include at least one of the following:

[0122] (1) The evaluation method of the present invention fully considers the mutual relationship between risk influencing factors, can objectively evaluate the comprehensive risk of the pipeline, and reflects the true risk situation of the pipeline;

[0123] (2) The present invention has high calculation efficiency and can greatly improve the scientificity and feasibility of the comprehensive risk assessment of oil and gas pipelines;

[0124] (3) The present invention can point out the direction for risk mitigation decision-making, and accordingly propose targeted risk avoidance measures, which can avoid the occurrence of pipelines or adverse intermediate events and effectively reduce the probability of pipeline accidents.

[0125] Although the present invention has been described above in conjunction with exemplary embodiments and the accompanying drawings, those of ordinary skill in the art should understand that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A method for evaluating the comprehensive risk of an oil and gas pipeline, characterized in that, The evaluation method includes the following steps: S1. For each major factor affecting pipeline risk, determine n-level basic indicators respectively, where n≥2; S2. Determine the score of each basic indicator and the corresponding weight value of each basic indicator; S3. For a single major factor, determine the scores of negative indicators and positive indicators at each level step by step in ascending order from the lower level to the higher level; S4. Determine the failure probability index \(P\) of a single major category factor based on the score \(P\) of the first-level negative index and the score \(P\) of the first-level positive index of the single major category factor Ni and the score \(P\) of the first-level positive index Si , and determine the failure probability index \(P\) of the single major category factor x ; S5. Establish a coupling action matrix of failure factors, and determine the correction value P' of the coupling action of different types of negative factors on the failure possibility; S6. Determine the pipeline risk index score R according to formula (1), and formula (1) is as follows: In formula (1), R is the pipeline risk index score, M is the total number of major factors affecting pipeline risk, x is the serial number of the major factor, and λ x is the index weight of a single major factor, P x is the failure probability index of a single major factor, P' is the correction value of the coupling effect of different types of negative factors on the failure probability, and C is the pipeline failure consequence value; Among them, step S3 specifically includes the following sub-steps: S31. For a single major factor, select at least one n-level negative indicator and at least one n-level positive indicator to conduct a risk analysis on the pipeline situation, and determine the scores of the n-level negative indicator and the n-level positive indicator; S32. According to the scores of the n-level negative indicator and the n-level positive indicator, determine the scores of the n-1-level negative indicator and the n-1-level positive indicator respectively; S33. Repeat step S32 until the first-level negative index score P Ni and the first-level positive index score P Si ; P x Determined according to Equation (2), Equation (2) is shown as follows: In formula (2), D is the total score of the first-level indicators of a single major factor; Determine the code of the correction value with the largest coupling action in the coupling action matrix of failure factors as the correction value P' of the coupling action of different types of negative factors on the failure possibility.

2. The evaluation method for the comprehensive risk of oil and gas pipelines according to claim 1, wherein Calculate the score of the n-level negative indicator based on the sum of the total score of the negative factor indicators and the weight value corresponding to at least one selected n-level negative indicator; calculate the score of the n-level positive indicator based on the sum of the total score of the positive factor indicators and the weight value corresponding to at least one selected n-level positive indicator.

3. The evaluation method for the comprehensive risk of oil and gas pipelines according to claim 2, characterized in that, Calculate the score of the n-1-level negative indicator according to the number of n-1-level negative indicators and the score of the n-level negative indicator; calculate the score of the n-1-level positive indicator according to the number of n-1-level positive indicators and the score of the n-level positive indicator.

4. The evaluation method for the comprehensive risk of oil and gas pipelines according to claim 1, characterized in that, D is 100 to 200.

5. The evaluation method for the comprehensive risk of oil and gas pipelines according to claim 1, characterized in that, The major factors affecting pipeline risk include third-party damage, manufacturing defects, natural disasters, and corrosion.

6. The assessment method for the comprehensive risk of oil and gas pipelines according to claim 1, wherein n is 2 to 5.

7. A control method for comprehensive risks of oil and gas pipelines, characterized in that, Use the evaluation method for the comprehensive risk of oil and gas pipelines described in any one of claims 1 to 6 to calculate the pipeline risk index score, and take corresponding measures for control according to the pipeline risk index score.

Images