Failure assessment method for drilling riser system and related device

Abstract

The invention belongs to the technical field of riser system risk assessment, and discloses a drilling riser system failure assessment method and related device.The drilling riser system failure assessment method comprises the steps that uncertain factor sources of a riser system are obtained; data sampling is carried out on uncertain factor sources of the riser system, and a preset dynamic response index calculation value of the riser system under the storm condition is obtained through analysis; the failure state is judged, and an uncertainty factor source which has the most obvious influence on the vulnerability of the riser system under the extreme storm condition is obtained through analysis; carrying out data sampling on an uncertain factor source which has the most obvious influence on the vulnerability of the marine riser system under the extreme storm condition, and analyzing to obtain a preset dynamic response index calculation value of the marine riser system under the extreme storm condition; the failure state is judged, and uncertain factor indexes which have the most remarkable influence on the vulnerability of the riser system are obtained through analysis; the method breaks through the limitation that a traditional failure assessment method only pays attention to environmental loads, and ensures the accuracy of a failure assessment result.

Description

Technical Field

[0001] The present invention belongs to the technical field of risk assessment of deepwater drilling riser systems, and in particular relates to a failure assessment method and related devices for a drilling riser system. Background Art

[0002] With the continuous growth of global energy demand, the development of oil and gas resources has gradually expanded to deepwater areas. In deepwater drilling operations, the drilling riser system serves as a key channel connecting the seabed wellhead equipment and the offshore drilling platform. It undertakes important functions such as isolating seawater, circulating mud, and supporting auxiliary pipelines. However, affected by the complex marine environment and deepwater operating conditions, the drilling riser system faces a high risk of damage and failure. Once the drilling riser system fails, it is very likely to lead to interruption of drilling operations, leakage of oil and gas resources and pollution of the marine environment, and may also cause serious economic losses and safety accidents.

[0003] In the existing technology, the failure assessment research on drilling riser systems mainly focuses on the changes of the riser system under external environmental loads; however, due to the complex structural characteristics of the riser system itself, its operating status will also be affected by a variety of uncertain factors, resulting in large deviations in the results of existing failure assessment methods. Summary of the Invention

[0004] In response to the technical problems existing in the prior art, the present invention provides a drilling riser system failure assessment method and related devices to solve the technical problem that due to the complex structural characteristics of the riser system itself, its operating status will be affected by multiple uncertain factors, resulting in large deviations in the results of existing failure assessment methods.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: The present invention provides a drilling riser system failure assessment method, comprising: Obtain the sources of uncertainty factors of the riser system; the sources of uncertainty factors of the riser system include the variability of external loads that affect the normal operation of the riser system, the geometric uncertainty factors of the riser system, and the material uncertainty factors of the riser system; Data sampling is performed on sources of uncertainty factors of the riser system to obtain first sample data; based on the first sample data, a finite element simulation analysis is performed on the riser system to obtain a calculated value of a preset dynamic response index of the riser system under storm conditions; Based on the calculated values ​​of the preset dynamic response indicators of the riser system under storm conditions, the failure state of the riser system is determined to obtain the first failure state assessment results. Based on the first failure state assessment results, the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions are analyzed. Data sampling is performed on the sources of uncertainty that most significantly affect the vulnerability of the riser system under extreme storm conditions to obtain second sample data. Based on the second sample data, finite element simulation analysis is performed on the riser system to obtain calculated values ​​of preset dynamic response indicators of the riser system under extreme storm conditions. Based on the calculated values ​​of the preset dynamic response indicators of the riser system under extreme storm conditions, the failure state of the riser system is judged and the second failure state assessment results are obtained. Based on the second failure state assessment results, the uncertainty factor indicators with the most significant impact on the vulnerability of the riser system are analyzed and obtained.

[0006] Furthermore, external load variability factors that affect the normal operation of the riser system include current velocity, wave height and wave period; geometric uncertainty factors of the riser system that affect the normal operation of the riser system include riser outer diameter, riser wall thickness and riser tension ratio; material uncertainty factors of the riser system that affect the normal operation of the riser system include riser Poisson's ratio, riser elastic modulus and riser density.

[0007] Furthermore, the preset dynamic response indicators include the maximum rotation angle of the top flexible joint, the maximum rotation angle of the bottom flexible joint and the maximum equivalent stress.

[0008] Furthermore, based on the calculated values ​​of the preset dynamic response indicators of the riser system under storm conditions, the failure state of the riser system is determined, and a first failure state assessment result is obtained. Based on the first failure state assessment result, the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions are analyzed, including: Based on the thresholds of the riser system's preset dynamic response indicators under different damage states and the calculated values ​​of the riser system's preset dynamic response indicators under storm conditions, and in combination with the limit state equation of the riser system, the failure state of the riser system is judged to obtain a first failure state assessment result; Based on the first failure state assessment result, the failure probability of the riser system is calculated using a logistic regression equation to obtain the first failure probability calculation result; Based on the calculation results of the first failure probability, the vulnerability curve of the riser system is drawn to obtain the first vulnerability curve; Based on the first vulnerability curve, the sources of uncertainty factors of the riser system are analyzed, and the sources of uncertainty factors that have the most significant impact on the vulnerability of the riser system under extreme storm conditions are obtained.

[0009] Furthermore, the calculation process of the first failure probability calculation result is as follows:

[0010] in, is the calculation result of the first failure probability; is the limit state equation; is the resistance variable; is the load variable.

[0011] Furthermore, the logistic regression equation is:

[0012]

[0013] in, For a given feature The probability of a damaging behavior event occurring in the riser system under the following conditions: All are input features; is a logical function; are model coefficients.

[0014] Furthermore, based on the calculated values ​​of the preset dynamic response indicators of the riser system under extreme storm conditions, the failure state of the riser system is determined, and a second failure state assessment result is obtained. Based on the second failure state assessment result, the uncertainty factor indicators with the most significant impact on the vulnerability of the riser system are analyzed and obtained, including: Based on the thresholds of the riser system's preset dynamic response indicators under different damage states and the calculated values ​​of the riser system's preset dynamic response indicators under extreme storm conditions, and in combination with the riser system's limit state equation, the failure state of the riser system is judged to obtain the second failure state assessment result. Based on the second failure state assessment results, the failure probability of the riser system is calculated using a logistic regression equation to obtain the second failure probability calculation result; Based on the calculation results of the second failure probability, the vulnerability curve of the riser system is drawn to obtain the second vulnerability curve; Based on the second vulnerability curve, the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions are analyzed, and the uncertainty factor indicators that most significantly affect the vulnerability of the riser system are obtained.

[0015] The present invention also provides a drilling riser system failure assessment system, comprising: Uncertainty factor source determination module, used to obtain the uncertainty factor sources of the watertight pipe system; The first analysis module is configured to sample data from sources of uncertainty factors of the riser system to obtain first sample data; based on the first sample data, a finite element simulation analysis is performed on the riser system to obtain a calculated value of a preset dynamic response index of the riser system under storm conditions; The first assessment module is configured to determine the failure state of the riser system based on a calculated value of a preset dynamic response index of the riser system under storm conditions, thereby obtaining a first failure state assessment result; and based on the first failure state assessment result, analyze and obtain the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions; The second analysis module is used to sample data from sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions to obtain second sample data; based on the second sample data, a finite element simulation analysis is performed on the riser system to obtain a calculated value of a preset dynamic response index of the riser system under extreme storm conditions; The second evaluation module is used to determine the failure state of the riser system based on the calculated value of the preset dynamic response index of the riser system under extreme storm conditions, and obtain the second failure state evaluation result; based on the second failure state evaluation result, analyze and obtain the uncertainty factor index that has the most significant impact on the vulnerability of the riser system.

[0016] The present invention also provides an electronic device, comprising: a processor suitable for executing a computer program; A computer-readable storage medium having a computer program stored therein, wherein when the computer program is executed by the processor, the drilling riser system failure assessment method is executed.

[0017] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the drilling riser system failure assessment method is implemented.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The failure assessment method for a drilling riser system provided by the present invention integrates the multi-source uncertainty factors of the external load, geometric parameters and material properties of the riser system, and adopts two-stage data sampling and finite element simulation analysis, thereby breaking through the limitation of the traditional failure assessment method that only focuses on the environmental load, ensuring the accuracy of the failure assessment results, and at the same time laying a theoretical foundation for the implementation of an adaptive risk management strategy for deep-water drilling under extreme storm conditions, thereby improving the safety and reliability of operations; specifically, by introducing the external load variability factors that affect the normal function of the riser system, the geometric uncertainty factors of the riser system and the material uncertainty factors of the riser system, the influence of multiple sources of uncertainty factors on the failure of the riser system is comprehensively considered, thereby significantly improving the accuracy of failure assessment; secondly, by sampling the sources of uncertainty factors and performing finite element simulation analysis, the preset dynamic response index calculation values ​​of the riser system under storm conditions that are closer to the actual situation can be obtained, which helps to more accurately Accurately determine the failure state of the riser system and reduce the bias of the assessment results. By analyzing the first failure state assessment results, the sources of uncertainty factors that most significantly affect the riser system's vulnerability under extreme storm conditions can be identified. This helps to gain a deeper understanding of the riser system's failure mechanism under specific conditions and provides direction for subsequent improvement and optimization. After obtaining the sources of uncertainty factors that most significantly affect the riser system's vulnerability under extreme storm conditions, and conducting data sampling and finite element simulation analysis, a more refined failure state assessment structure can be obtained, which helps to more accurately assess the failure risk of the riser system under extreme conditions and provide strong support for the formulation of targeted risk prevention and control measures. By analyzing the second failure state assessment results, the most significant uncertainty factor indicators affecting the riser system's vulnerability are obtained, ensuring the timely identification of potential failure risks of the riser system, allowing effective preventive measures to be taken to avoid serious consequences such as drilling interruptions, oil and gas resource leaks, and marine environmental pollution. This not only reduces economic losses and safety accidents, but also improves the safety and economic benefits of the entire drilling operation.

[0019] The drilling riser system failure assessment system, electronic equipment, computer-readable storage medium and computer program product provided by the present invention have all the advantages of the above-mentioned drilling riser system failure assessment method. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1A flowchart of the drilling riser system failure assessment method provided in Example 1; Figure 2 This is a structural diagram of a drilling riser system; Figure 3 is a schematic diagram of the first vulnerability curve in Example 1; Figure 4 is a schematic diagram of the second vulnerability curve in Example 1; Figure 5 A structural block diagram of a drilling riser system failure assessment system provided in Example 2; Figure 6 This is a structural block diagram of the electronic device provided in Example 3.

[0022] Among them, there are 100 top flexible joints, 200 riser bodies, 300 bottom flexible joints, 400 bottom riser assemblies, 500 blowout preventer components, 600 drilling platforms, and 700 wellhead components. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions, and beneficial effects solved by this application more clearly understood, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application; it is obvious that the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of this application.

[0024] The present invention provides a method for evaluating failure of a drilling riser system, comprising the following steps: Step 100: Obtain sources of uncertainty factors of the watertight pipe system; wherein, sources of uncertainty factors of the watertight pipe system include external load variability factors that affect the normal operation of the watertight pipe system, geometric uncertainty factors of the watertight pipe system, and material uncertainty factors of the watertight pipe system.

[0025] Step 200: Sampling data on sources of uncertainty factors of the watertight riser system to obtain first sample data; based on the first sample data, performing finite element simulation analysis on the watertight riser system to obtain a calculated value of a preset dynamic response index of the watertight riser system under storm conditions.

[0026] Step 300: Based on the calculated value of the preset dynamic response index of the riser system under storm conditions, determine the failure state of the riser system and obtain a first failure state assessment result; based on the first failure state assessment result, analyze and obtain the source of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions.

[0027] Step 400: Sampling data on the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions to obtain second sample data; based on the second sample data, performing finite element simulation analysis on the riser system to obtain a calculated value of a preset dynamic response index of the riser system under extreme storm conditions.

[0028] Step 500: Based on the calculated value of the preset dynamic response index of the watertight riser system under extreme storm conditions, the failure state of the watertight riser system is judged to obtain a second failure state assessment result; based on the second failure state assessment result, the uncertainty factor index that most significantly affects the vulnerability of the watertight riser system is analyzed and obtained.

[0029] The drilling riser system failure assessment method described in the present invention breaks through the limitation of traditional methods that only focus on external loads by introducing external environmental loads, geometric uncertainty factors of the riser system and material uncertainty factors of the riser system, and identifying and analyzing the uncertainty factors of riser system failure in stages; among them, the two-stage dynamic response simulation combining finite element simulation and sensitivity analysis can effectively screen out the key uncertainty indicators that have the most significant impact on system failure, significantly improve the accuracy of the assessment results, and provide more targeted data support for risk warning and structural optimization of riser systems under extreme storm conditions, thereby reducing the risks of operation interruption and environmental pollution caused by assessment deviations.

[0030] The following further explains the drilling riser system failure assessment method provided by the present invention with some specific embodiments: Example 1 As attached Figure 1 As shown, this embodiment 1 provides a drilling riser system failure assessment method, comprising the following steps: Step 1: Obtain the sources of uncertainty factors of the riser system. The sources of uncertainty factors of the riser system include the external load variability factors that affect the normal operation of the riser system, the geometric uncertainty factors of the riser system, and the material uncertainty factors of the riser system. The specific process is as follows: An influencing factor analysis is conducted on the existing riser system operation engineering cases in the case library to obtain the external load variability factors that affect the normal function of the riser, the riser system geometric uncertainty factors and the riser system material uncertainty factors as the sources of uncertainty factors of the riser system.

[0031] Specifically, the external load variability factors that affect the normal operation of the riser system include current velocity, wave height and wave period; the geometric uncertainty factors of the riser system that affect the normal operation of the riser system include the riser outer diameter, riser wall thickness and riser tension ratio; the material uncertainty factors of the riser system that affect the normal operation of the riser system include the riser Poisson's ratio, riser elastic modulus and riser density.

[0032] Step 2: Sample the sources of uncertainty factors of the watertight pipe system to obtain first sample data; based on the first sample data, perform finite element simulation analysis on the watertight pipe system to obtain the calculated value of the preset dynamic response index of the watertight pipe system under storm conditions.

[0033] Specifically, the steps are as follows: Step 21. Use the Latin hypercube sampling method to sample data on the sources of uncertainty factors of the watertight riser system to obtain the first sample data; wherein, based on considering different sources of uncertainty factors of the watertight riser system, data sampling is performed in the following three scenarios; Scenario 1 is to only consider the external load variability factors that affect the normal operation of the watertight riser system, Scenario 2 is to consider the external load variability factors that affect the normal function of the watertight riser and the geometric uncertainty factors of the watertight riser system that affect the normal operation of the watertight riser system; Scenario 3 is to comprehensively consider the external load variability factors that affect the normal function of the watertight riser, the geometric uncertainty factors of the watertight riser system and the material uncertainty factors of the watertight riser system.

[0034] Step 22. Based on the first sample data, use ABAQUS software to perform finite element simulation on the riser system to analyze and calculate the preset dynamic response indicators, and obtain the preset dynamic response indicator calculation value of the riser system under storm conditions; wherein, the preset dynamic response indicators include the maximum rotation angle of the top flexible joint, the maximum rotation angle of the bottom flexible joint and the maximum equivalent stress; that is, the preset dynamic response indicator calculation value of the riser system under storm conditions includes the maximum rotation angle calculation value of the top flexible joint of the riser system under storm conditions, the maximum rotation angle calculation value of the bottom flexible joint of the riser system under storm conditions and the maximum equivalent stress calculation value of the riser system under storm conditions.

[0035] Step 3. Based on the calculated value of the preset dynamic response index of the riser system under storm conditions, determine the failure state of the riser system and obtain the first failure state assessment result; based on the first failure state assessment result, analyze and obtain the source of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions.

[0036] Specifically, the steps are as follows: Step 31: Based on the thresholds of the preset dynamic response indicators of the riser system under different damage states and the calculated values ​​of the preset dynamic response indicators of the riser system under storm conditions, and combined with the limit state equation of the riser system, the failure state of the riser system is judged to obtain the first failure state assessment result.

[0037] It should be noted that the thresholds of the preset dynamic response indicators of the watertight pipe system under different damage states are determined based on the API standard; in the API standard, the damage level of the watertight pipe system is divided into slight damage, moderate damage and complete damage, so as to be applicable to the working conditions during the connection drilling action, and provide a reference for evaluating the performance of the watertight pipe system under different working conditions; among them, the thresholds of the preset dynamic response indicators of the watertight pipe system under different damage states include the thresholds of the maximum rotation angle of the top flexible joint of the watertight pipe system under different damage states, the thresholds of the maximum rotation angle of the bottom flexible joint of the watertight pipe system under different damage states and the thresholds of the maximum equivalent stress of the watertight pipe system under different damage states.

[0038] Specifically, the threshold values ​​of the preset dynamic response index of the riser system under different damage states and the calculated values ​​of the preset dynamic response index of the riser system under storm conditions are substituted into the limit state equation of the riser system to obtain the solution results of the limit state equation of the preset dynamic response index of the riser system under storm conditions; based on the solution results of the limit state equation of the preset dynamic response index of the riser system under storm conditions, the first failure state assessment result is obtained; wherein, the limit state equation of the riser system is as follows:

[0039]

[0040]

[0041] in, is the limit state equation of the maximum equivalent stress of the riser system; is the limit state equation of the rotation angle of the top flexible joint of the riser system; is the limit state equation of the rotation angle of the bottom flexible joint of the riser system; The calculated value of the maximum equivalent stress of the riser system under storm conditions; Calculated value of the maximum rotation angle of the top flexible joint of the riser system under storm conditions; Calculated value of the maximum rotation angle of the bottom flexible joint of the riser system under storm conditions; is the threshold value of the maximum equivalent stress of the riser system under different damage states; is the threshold value of the maximum rotation angle of the top flexible joint of the riser system under different damage states; is the threshold value of the maximum rotation angle of the bottom flexible joint of the riser system under different damage states.

[0042] It is worth noting that when any of the calculated values ​​of the preset dynamic response indicators of the riser system under storm conditions exceeds the threshold value of the preset dynamic response indicators of the riser system under different damage states, it is considered that the corresponding damage behavior event occurs in the riser system; that is, when the solution result of the limit state equation of the preset dynamic response indicator of the riser system is greater than or equal to zero, the riser system is considered to have failed. At this time, the riser system exceeds the safety limit, and the first failure state assessment result is failure, and the output is Y=1; on the contrary, if the solution result of the limit state equation of the preset dynamic response indicator of the riser system is less than zero, the riser system is safe, and the first failure state assessment result is safe, and the output is Y=0.

[0043] Step 32: Based on the first failure state assessment result, the failure probability of the riser system is calculated using the logistic regression equation to obtain the first failure probability calculation result; specifically, based on the first failure state assessment result and combined with the logistic regression equation, the first failure probability calculation result is obtained by calculating the probability of violating the limit state equation of the riser system.

[0044] The calculation process of the first failure probability calculation result is as follows:

[0045] in, is the calculation result of the first failure probability; is the limit state equation; is the resistance variable; is the load variable.

[0046] The expression of the logistic regression equation is as follows:

[0047]

[0048] in, For a given feature The probability of a damaging behavior event occurring in the riser system under the following conditions: All are input features; is a logical function; are model coefficients and are determined by the maximum likelihood method.

[0049] It should be noted that given the feature That is, it includes the factor indicators of the uncertainty factors of the riser system, such as the current velocity; input characteristics This is the result of data sampling on the sources of uncertainty factors in the riser system.

[0050] Step 33: Based on the calculation result of the first failure probability, a vulnerability curve of the riser system is drawn to obtain a first vulnerability curve. Specifically, the input feature The horizontal axis is the calculated result of the first failure probability, and the vertical axis is the curve of the failure probability varying with the load, which is the first vulnerability curve of the watertight pipe system.

[0051] Step 34: Based on the first vulnerability curve, analyze the sources of uncertainty factors of the riser system to obtain the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions.

[0052] The specific process is as follows: By horizontally comparing the curves corresponding to the three scenarios under different damage states in the first vulnerability curve, it is evaluated whether the curve shifts significantly after the introduction of a new source of uncertainty factors; if the first vulnerability curve shifts significantly after the addition of the new source of uncertainty factors, that is, the shift of the first vulnerability curve after the addition of the new source of uncertainty factors exceeds the preset shift threshold, it indicates that the source of uncertainty factors has a significant impact on the vulnerability of the system; if the curve change amplitude is small or basically overlaps, that is, the shift of the first vulnerability curve after the addition of the new source of uncertainty factors is less than the preset shift threshold, it can be determined that its impact on the vulnerability of the system is relatively limited.

[0053] Step 4: Sample data from the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions to obtain second sample data; based on the second sample data, perform finite element simulation analysis on the riser system to obtain the calculated value of the preset dynamic response index of the riser system under extreme storm conditions.

[0054] Specifically, the steps are as follows: Step 41: Based on the control variables and the Latin hypercube sampling method, data sampling is performed on the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions to obtain second sample data.

[0055] Step 42. Based on the second sample data, use ABAQUS software to perform finite element simulation on the riser system to analyze and calculate the preset dynamic response index, and obtain the calculated value of the preset dynamic response index of the riser system under extreme storm conditions; wherein, the calculated value of the preset dynamic response index of the riser system under extreme storm conditions includes the calculated value of the maximum rotation angle of the top flexible joint of the riser system under extreme storm conditions, the calculated value of the maximum rotation angle of the bottom flexible joint of the riser system under extreme storm conditions, and the calculated value of the maximum equivalent stress of the riser system under extreme storm conditions.

[0056] Step 5. Based on the calculated value of the preset dynamic response index of the riser system under extreme storm conditions, determine the failure state of the riser system and obtain the second failure state assessment result; based on the second failure state assessment result, analyze and obtain the uncertainty factor index that has the most significant impact on the vulnerability of the riser system.

[0057] Specifically, the steps are as follows: Step 51: Based on the thresholds of the preset dynamic response indicators of the riser system under different damage states and the calculated values ​​of the preset dynamic response indicators of the riser system under extreme storm conditions, and combined with the limit state equation of the riser system, the failure state of the riser system is judged to obtain the second failure state assessment result.

[0058] Specifically, the threshold values ​​of the preset dynamic response indicators of the riser system under different damage states and the calculated values ​​of the preset dynamic response indicators of the riser system under extreme storm conditions are substituted into the limit state equation of the riser system, and the solution results of the limit state equation of the preset dynamic response indicators of the riser system under extreme storm conditions are calculated; according to the solution results of the limit state equation of the preset dynamic response indicators of the riser system under extreme storm conditions, the second failure state assessment result is obtained.

[0059] It should be noted that the limit state equation of the riser system in step 51 is similar to the limit state equation of the riser system in step 31 above. The difference is that the maximum equivalent stress calculated value of the riser system under storm conditions in step 31 is replaced by Replaced with the calculated maximum equivalent stress value of the riser system under extreme storm conditions , calculate the maximum rotation angle of the top flexible joint of the riser system under storm conditions in step 31 The value is replaced by the calculated maximum rotation angle of the top flexible joint of the riser system under extreme storm conditions And the maximum rotation angle of the bottom flexible joint of the riser system under storm conditions calculated in step 31 Replaced with the calculated maximum rotation angle of the bottom flexible joint of the riser system under extreme storm conditions .

[0060] It should also be noted that when any of the calculated values ​​of the preset dynamic response indicators of the riser system under extreme storm conditions exceeds the threshold values ​​of the preset dynamic response indicators of the riser system under different damage states, it is considered that a corresponding damage behavior event occurs in the riser system under extreme storm conditions; that is, when the solution result of the limit state equation of the preset dynamic response indicators of the riser system under extreme storm conditions is greater than or equal to zero, the riser system is considered to have failed. At this time, the riser system exceeds the safety limit, and the second failure state assessment result is failure, and the output is Y=1; on the contrary, if the solution result of the limit state equation of the preset dynamic response indicators of the riser system under extreme storm conditions is less than zero, the riser system is safe, and the second failure state assessment result is safe, and the output is Y=0.

[0061] Step 52: Based on the second failure state assessment result, the failure probability of the riser system is calculated using the logistic regression equation to obtain the second failure probability calculation result; specifically, based on the second failure state assessment result and combined with the logistic regression equation, the second failure probability calculation result is obtained by calculating the probability of violating the limit state equation of the riser system.

[0062] The calculation process of the second failure probability calculation result is as follows:

[0063] in, is the result of the second failure probability calculation; is the limit state equation; is the resistance variable; is the load variable.

[0064] Step 53: Based on the calculation result of the second failure probability, draw the vulnerability curve of the watertight pipe system to obtain the second vulnerability curve; specifically, with the input feature as the horizontal coordinate and the second failure probability calculation result as the vertical coordinate, draw a curve showing the change of failure probability with load, which is the second vulnerability curve of the watertight pipe system.

[0065] Step 54: Based on the second vulnerability curve, analyze the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions, and obtain the uncertainty factor index that most significantly affects the vulnerability of the riser system.

[0066] The specific process is as follows: By comparing multiple curves under different damage states in the second vulnerability curve horizontally, it is evaluated whether the curve has significantly shifted. If the curve shifts significantly after the addition of the new uncertainty factor indicator, that is, the shift of the curve after the addition of the new uncertainty factor indicator exceeds the preset shift threshold, it means that the uncertainty factor indicator has a significant impact on the system vulnerability. If the curve changes slightly or basically overlaps, that is, the shift of the curve after the addition of the new uncertainty factor indicator is less than the preset shift threshold, it can be determined that its impact on the system vulnerability is relatively limited.

[0067] Example description: A deepwater drilling riser system in a certain sea area is used as an example for research; Figure 2 As shown, the deepwater drilling riser system mainly includes a top flexible joint 100, a riser body 200, a bottom flexible joint 300, a bottom riser assembly 400 and a blowout preventer assembly 500 which are connected in sequence from top to bottom; wherein, the top flexible joint 100 is connected to the drilling platform 600, and the blowout preventer assembly 500 is connected to the wellhead assembly 700.

[0068] In this example, the thresholds of the preset dynamic response indicators of the deepwater drilling riser system under different damage states are shown in Table 1 below; the probability distribution of the basic parameters and sources of uncertainty factors of the deepwater drilling riser system are shown in Tables 2 and 3.

[0069] Table 1 Thresholds of preset dynamic response indicators of deepwater drilling riser system under different damage states

[0070] Table 2 Basic parameters of deepwater drilling riser system

[0071] Table 3 Probability distribution of sources of uncertainty in deepwater drilling riser systems

[0072] In this example, data sampling is first carried out based on the consideration of different sources of uncertainty factors of the riser system, and the following three scenarios are used; Scenario 1 only considers the external load variability factors that affect the normal operation of the riser system, Scenario 2 considers the external load variability factors that affect the normal function of the riser and the riser system geometric uncertainty factors that affect the normal operation of the riser system; Scenario 3 comprehensively considers the external load variability factors that affect the normal function of the riser, the riser system geometric uncertainty factors and the riser system material uncertainty factors.

[0073] Afterwards, the Latin hypercube sampling method was applied for the first time to generate the first sample data, and finite element simulation was performed using ABAQUS software to obtain the calculated values ​​of the preset dynamic response indicators of the riser system under storm conditions; based on the calculated values ​​of the preset dynamic response indicators of the riser system under storm conditions and combined with the limit state equation, the failure state of the deepwater drilling riser system was judged to obtain the first failure state assessment result; based on the first failure state assessment result, the first failure probability calculation result was obtained in combination with the logistic regression equation, and the first vulnerability curve was drawn, and then through comparative analysis, the sources of uncertainty factors that most significantly affected the vulnerability of the riser system under extreme storm conditions were obtained.

[0074] As attached Figure 3 As shown, attached Figure 3 A schematic diagram of the first vulnerability curve is given in the attached Figure 3 It can be seen from the figure that under storm conditions, geometric uncertainty is the most significant source of uncertainty affecting the vulnerability of the riser system, while the impact of material uncertainty is relatively small.

[0075] Next, in order to specifically analyze the significant influence of geometric uncertainty factors, the control variable method is used to sample data in the following four cases; among them, case 1 is that all parameters are not considered, case 2 is that only the outer diameter is considered, case 3 is that the outer diameter and wall thickness are considered, and case 4 is that the outer diameter, wall thickness and tension ratio are considered; specifically, the second sample data is generated by the Latin hypercube sampling method for the above four cases for the second time, and the preset dynamic response index calculation value of the watertight riser system under extreme storm conditions is obtained by simulation using ABAQUS software; according to the preset dynamic response index calculation value of the watertight riser system under extreme storm conditions, combined with the limit state equation, the failure state of the deepwater drilling watertight riser system is judged to obtain the second failure state assessment result; based on the second failure state assessment result, the second failure probability calculation result is obtained in combination with the logistic regression equation, and the second vulnerability curve is drawn, and then through comparative analysis, the uncertainty factor index with the most significant impact on the vulnerability of the watertight riser system is obtained.

[0076] As attached Figure 4 As shown, attached Figure 4 A schematic diagram of the second vulnerability curve is given in Figure 4 It can be seen that under the premise of controlling variables, the fragility curves drawn for Cases 1, 2 and 3 are not significantly different, indicating that the influence of outer diameter and wall thickness on the fragility of the riser is relatively limited. However, in Case 4, after the tension ratio is introduced, the fragility curve shows obvious changes, indicating that the tension ratio is the most significant source of uncertainty for the fragility of the riser.

[0077] The drilling riser system failure assessment method described in Example 1 introduces external environmental loads, geometric uncertainty factors of the riser system, and material uncertainty factors of the riser system, and adopts a two-stage dynamic response simulation combining finite element simulation and sensitivity analysis. It can effectively screen out the key uncertainty indicators that have the most significant impact on system failure, and significantly improve the accuracy of the assessment results.

[0078] Example 2 As attached Figure 5 As shown, this embodiment 2 provides a drilling riser system failure assessment system, including an uncertainty factor source determination module, a first analysis module, a first assessment module, a second analysis module and a second assessment module.

[0079] The uncertainty factor source determination module is used to obtain the uncertainty factor sources of the watertight pipe system.

[0080] The first analysis module is used to sample data from sources of uncertainty factors of the watertight pipe system to obtain first sample data; based on the first sample data, a finite element simulation analysis is performed on the watertight pipe system to obtain a calculated value of a preset dynamic response index of the watertight pipe system under storm conditions.

[0081] The first evaluation module is used to determine the failure state of the riser system based on the calculated value of the preset dynamic response index of the riser system under storm conditions, and obtain the first failure state evaluation result; based on the first failure state evaluation result, analyze and obtain the source of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions.

[0082] The second analysis module is used to sample data from the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions to obtain second sample data; based on the second sample data, finite element simulation analysis is performed on the riser system to obtain the calculated values ​​of preset dynamic response indicators of the riser system under extreme storm conditions.

[0083] The second evaluation module is used to determine the failure state of the riser system based on the calculated value of the preset dynamic response index of the riser system under extreme storm conditions, and obtain the second failure state evaluation result; based on the second failure state evaluation result, analyze and obtain the uncertainty factor index that has the most significant impact on the vulnerability of the riser system.

[0084] Example 3 As attached Figure 6 As shown, this embodiment 3 provides an electronic device, including: a memory for storing a computer program; a processor for implementing the steps of the drilling riser system failure assessment method when executing the computer program; or, the processor implements the functions of each module in the above-mentioned drilling riser system failure assessment system when executing the computer program.

[0085] Exemplarily, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing preset functions, and the instruction segments are used to describe the execution process of the computer program in the electronic device.

[0086] The electronic device may be a computing device such as a desktop computer, laptop, PDA, or cloud server. The electronic device may include, but is not limited to, a processor and memory. Those skilled in the art will appreciate that the above are examples of electronic devices and do not constitute a limitation on electronic devices. The electronic device may include more components than those described above, or a combination of certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0087] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor. The processor is the control center of the electronic device and connects various parts of the entire electronic device using various interfaces and lines.

[0088] The memory may be used to store the computer programs and / or modules, and the processor implements various functions of the electronic device by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory.

[0089] The memory may primarily include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function (such as sound playback or image playback); the data storage area may store data generated based on the use of the mobile phone (such as audio data and a phone book). Furthermore, the memory may include high-speed random access memory (RAM) and non-volatile memory, such as a hard disk, internal memory, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, at least one disk storage device, a flash memory device, or other volatile solid-state storage device.

[0090] Example 4 This embodiment 4 also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the steps of the drilling riser system failure assessment method.

[0091] If the modules / units integrated in the drilling riser system failure assessment system are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.

[0092] Based on this understanding, the present invention can implement all or part of the process of the above-mentioned drilling riser system failure assessment method by using a computer program to instruct related hardware. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of the above-mentioned drilling riser system failure assessment method. The computer program includes computer program code, which can be in source code form, object code form, executable file, or a pre-set intermediate form.

[0093] The computer-readable storage medium may include: any entity or device that can carry the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0094] The above embodiment is only one of the implementation methods that can realize the technical solution of the present invention. The scope of protection claimed by the present invention is not limited only to this embodiment, but also includes changes, replacements and other implementation methods that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention.

Claims

1. A drilling riser system failure assessment method, characterized in that: include: Obtain the sources of uncertainty factors of the riser system; the sources of uncertainty factors of the riser system include the variability of external loads that affect the normal operation of the riser system, the geometric uncertainty factors of the riser system, and the material uncertainty factors of the riser system; Data sampling is performed on sources of uncertainty factors of the riser system to obtain first sample data; based on the first sample data, a finite element simulation analysis is performed on the riser system to obtain a calculated value of a preset dynamic response index of the riser system under storm conditions; Based on the calculated values ​​of the preset dynamic response indicators of the riser system under storm conditions, the failure state of the riser system is determined to obtain the first failure state assessment results. Based on the first failure state assessment results, the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions are analyzed. Data sampling is performed on the sources of uncertainty that most significantly affect the vulnerability of the riser system under extreme storm conditions to obtain second sample data. Based on the second sample data, finite element simulation analysis is performed on the riser system to obtain calculated values ​​of preset dynamic response indicators of the riser system under extreme storm conditions. Based on the calculated values ​​of the preset dynamic response indicators of the riser system under extreme storm conditions, the failure state of the riser system is judged and the second failure state assessment results are obtained. Based on the second failure state assessment results, the uncertainty factor indicators with the most significant impact on the vulnerability of the riser system are analyzed and obtained.

2. A drilling riser system failure assessment method according to claim 1, characterized in that: The external load variability factors that affect the normal operation of the riser system include current velocity, wave height and wave period; the geometric uncertainty factors of the riser system that affect the normal operation of the riser system include the riser outer diameter, riser wall thickness and riser tension ratio; the material uncertainty factors of the riser system that affect the normal operation of the riser system include the riser Poisson's ratio, riser elastic modulus and riser density.

3. The drilling riser system failure assessment method according to claim 1, characterized in that: The preset dynamic response indicators include the maximum rotation angle of the top flexible joint, the maximum rotation angle of the bottom flexible joint and the maximum equivalent stress.

4. The method for failure assessment of a drilling riser system according to claim 1, wherein: Based on the calculated values ​​of the preset dynamic response indicators of the riser system under storm conditions, the failure state of the riser system is determined, and the first failure state assessment results are obtained. Based on the first failure state assessment results, the sources of uncertainty that most significantly affect the vulnerability of the riser system under extreme storm conditions are analyzed, including: Based on the thresholds of the riser system's preset dynamic response indicators under different damage states and the calculated values ​​of the riser system's preset dynamic response indicators under storm conditions, and in combination with the limit state equation of the riser system, the failure state of the riser system is judged to obtain a first failure state assessment result; Based on the first failure state assessment result, the failure probability of the riser system is calculated using a logistic regression equation to obtain the first failure probability calculation result; Based on the calculation results of the first failure probability, the vulnerability curve of the riser system is drawn to obtain the first vulnerability curve; Based on the first vulnerability curve, the sources of uncertainty factors of the riser system are analyzed, and the sources of uncertainty factors that have the most significant impact on the vulnerability of the riser system under extreme storm conditions are obtained.

5. A drilling riser system failure assessment method according to claim 4, characterized in that: The calculation process of the first failure probability calculation result is as follows: in, is the calculation result of the first failure probability; is the limit state equation; is the resistance variable; is the load variable.

6. A drilling riser system failure assessment method according to claim 4, characterized in that: The logistic regression equation is: in, For a given feature The probability of a damaging behavior event occurring in the riser system under the following conditions: All are input features; is a logical function; are model coefficients.

7. The drilling riser system failure assessment method according to claim 1, characterized in that: Based on the calculated values ​​of the preset dynamic response indicators of the riser system under extreme storm conditions, the failure state of the riser system is determined, and the second failure state assessment result is obtained; Based on the results of the second failure state assessment, the uncertainty factors that have the most significant impact on the vulnerability of the riser system are analyzed and obtained, including: Based on the thresholds of the riser system's preset dynamic response indicators under different damage states and the calculated values ​​of the riser system's preset dynamic response indicators under extreme storm conditions, and in combination with the riser system's limit state equation, the failure state of the riser system is judged to obtain the second failure state assessment result. Based on the second failure state assessment results, the failure probability of the riser system is calculated using a logistic regression equation to obtain the second failure probability calculation result; Based on the calculation results of the second failure probability, the vulnerability curve of the riser system is drawn to obtain the second vulnerability curve; Based on the second vulnerability curve, the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions are analyzed, and the uncertainty factor indicators that most significantly affect the vulnerability of the riser system are obtained.

8. A drilling riser system failure assessment system, characterized in that: include: Uncertainty factor source determination module, used to obtain the uncertainty factor source of the watertight pipe system; The first analysis module is configured to sample data from sources of uncertainty factors of the riser system to obtain first sample data; based on the first sample data, a finite element simulation analysis is performed on the riser system to obtain a calculated value of a preset dynamic response index of the riser system under storm conditions; The first assessment module is configured to determine the failure state of the riser system based on a calculated value of a preset dynamic response index of the riser system under storm conditions, thereby obtaining a first failure state assessment result; and based on the first failure state assessment result, analyze and obtain the sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions; The second analysis module is used to sample data from sources of uncertainty factors that most significantly affect the vulnerability of the riser system under extreme storm conditions to obtain second sample data; based on the second sample data, a finite element simulation analysis is performed on the riser system to obtain a calculated value of a preset dynamic response index of the riser system under extreme storm conditions; The second evaluation module is used to determine the failure state of the riser system based on the calculated value of the preset dynamic response index of the riser system under extreme storm conditions, and obtain the second failure state evaluation result; based on the second failure state evaluation result, analyze and obtain the uncertainty factor index that has the most significant impact on the vulnerability of the riser system.

9. An electronic device, characterized in that: include: a processor suitable for executing a computer program; A computer-readable storage medium having a computer program stored therein, wherein the computer program, when executed by the processor, executes the drilling riser system failure assessment method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the drilling riser system failure assessment method according to any one of claims 1 to 7 is implemented.

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