Vortex-induced fatigue analysis method and device for deep-sea steel catenary riser, electronic equipment and storage medium

Abstract

The invention discloses a vortex-induced fatigue analysis method and device for a deep-sea steel catenary riser, electronic equipment and a storage medium, and belongs to the technical field of ocean facilities. The method comprises the following steps: acquiring motion data of an offshore platform; determining an equivalent oscillatory flow of the offshore platform based on the motion data; according to the equivalent oscillatory flow, vortex-induced vibration response of the deep-sea steel catenary riser is determined based on fluid-structure interaction effect analysis; according to the vortex-induced vibration response, the equivalent stress time history of the deep-sea steel catenary riser is obtained through calculation, and therefore a vortex-induced fatigue analysis result is determined. According to the invention, the platform motion can induce the riser to generate vortex-induced vibration, the equivalent mode is established to convert the platform motion into the oscillatory flow, and the fluid-solid coupling effect between the riser and the flow field is considered, so that the calculation is easy to realize and the precision is high; the perfection degree and reliability of the vortex-induced fatigue analysis result of the deep-sea steel catenary riser can be improved, and the fatigue damage degree of the deep-sea steel catenary riser can be accurately mastered.

Description

Technical Field

[0001] This application relates to the field of marine facility technology, and in particular to a method, apparatus, electronic equipment and storage medium for vortex-induced fatigue analysis of deep-sea steel catenary risers. Background Technology

[0002] Currently, offshore oil and gas transportation systems mainly consist of three parts: offshore platforms, offshore risers, and subsea pipelines. Riseres, connecting offshore platforms and subsea oil wells for transporting oil and gas, are key equipment for deep-sea oil and gas extraction. Steel catenary risers, with their advantages of easy installation, low cost, and resistance to high temperatures and pressures, are the preferred riser type for deep-sea oil and gas resource development.

[0003] In related technologies, vortex-induced vibration of steel catenary risers can cause vortex-induced fatigue damage. Therefore, current vortex-induced fatigue analysis of risers focuses on vortex-induced fatigue caused by background ocean currents. However, in practical applications, it has been found that analyzing riser vortex-induced fatigue caused solely by background ocean currents yields results with low accuracy and poor safety.

[0004] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the Invention

[0005] This application provides a method, apparatus, electronic device, and storage medium for vortex-induced fatigue analysis of deep-sea steel catenary risers, which can improve the completeness and reliability of vortex-induced fatigue analysis results of deep-sea steel catenary risers and help to accurately control the degree of fatigue damage of deep-sea steel catenary risers.

[0006] On one hand, this application provides a method for vortex-induced fatigue analysis of deep-sea steel catenary risers, the method comprising the following steps:

[0007] Acquire motion data of an offshore platform; wherein the offshore platform is equipped with and connected to a deep-sea steel catenary riser;

[0008] Based on the motion data of the offshore platform, the equivalent oscillating flow of the offshore platform is determined;

[0009] Based on the equivalent oscillating flow of the offshore platform, and using fluid-structure interaction analysis, the vortex-induced vibration response of the deep-sea steel catenary riser is determined.

[0010] Based on the vortex-induced vibration response of the deep-sea steel catenary riser, the equivalent stress time history of the deep-sea steel catenary riser is calculated, thereby determining the vortex-induced fatigue analysis results of the deep-sea steel catenary riser.

[0011] Optionally, determining the equivalent oscillating flow of the offshore platform based on its motion data includes:

[0012] Based on the obtained motion data of the offshore platform, the heave dynamic response of the offshore platform is constructed;

[0013] Based on the heave dynamic response, the motion process of the offshore platform is equivalent to a cosine oscillating flow.

[0014] Optionally, constructing the heave dynamic response of the offshore platform based on the acquired motion data of the offshore platform includes:

[0015] Based on the obtained motion data of the offshore platform, frequency domain hydrodynamic analysis is performed on the offshore platform to obtain hydrodynamic parameters; the hydrodynamic parameters include the added mass matrix, radiation damping matrix, first-order wave force and motion response amplitude operator;

[0016] Based on the hydrodynamic parameters, a load model is established to obtain the dynamic response analysis of the offshore platform, thereby constructing the heave dynamic response of the offshore platform.

[0017] Optionally, determining the vortex-induced vibration response of the deep-sea steel catenary riser based on the equivalent oscillating flow of the offshore platform and fluid-structure interaction analysis includes:

[0018] Based on the finite element theory, the deep-sea steel catenary riser is discretized to obtain riser units, and the deep-sea steel catenary riser is divided into slices.

[0019] The riser unit is subjected to coordinate transformation, and the riser unit stiffness matrix and unit mass matrix are transformed to the global coordinate system to establish the global stiffness matrix and global mass matrix.

[0020] The flow field for each slice is established, and the equivalent oscillating flow of the offshore platform is taken as the boundary inlet. The computational fluid control equations are solved to calculate the fluid force for each slice.

[0021] The fluid force of each slice is converted into a uniformly distributed load and applied to the riser unit corresponding to each slice;

[0022] Based on fluid-structure interaction analysis, the vortex-induced vibration response of the deep-sea steel catenary riser is solved, and the vortex-induced vibration response of the deep-sea steel catenary riser under the action of equivalent oscillating flow is obtained.

[0023] Optionally, after converting the fluid force of each slice into a uniformly distributed load and applying it to the riser unit corresponding to each slice, the method further includes:

[0024] The displacement, velocity, and acceleration of each riser unit are calculated to update the position of each slice of the deep-sea steel catenary riser.

[0025] Resolve the computational fluid dynamics control equations to calculate the fluid forces for each slice until the calculation results converge.

[0026] Optionally, the step of calculating the equivalent stress time history of the deep-sea steel catenary riser based on its vortex-induced vibration response, thereby determining the vortex-induced fatigue analysis results of the deep-sea steel catenary riser, includes:

[0027] A finite element model of the deep-sea steel catenary riser was established, and the eddy-induced vibration response of the deep-sea steel catenary riser was used as the boundary condition to calculate the equivalent stress time history of the deep-sea steel catenary riser.

[0028] The equivalent stress time history is counted using the rainflow counting method to obtain the equivalent stress amplitude and cycle number;

[0029] Based on the equivalent stress amplitude and cycle number, the fatigue damage value caused by vortex-induced vibration of the deep-sea steel catenary riser is calculated and used as the vortex-induced fatigue analysis result of the deep-sea steel catenary riser.

[0030] Optionally, after counting the equivalent stress time history using the rainflow counting method to obtain the equivalent stress amplitude and cycle number, the method further includes:

[0031] Based on the Goodman model, the equivalent stress amplitude and cycle number are corrected.

[0032] On the other hand, embodiments of this application provide a device for vortex-induced fatigue analysis of deep-sea steel catenary risers, the device comprising:

[0033] The data acquisition module is used to acquire motion data of the offshore platform; wherein the offshore platform is equipped with and connected to the deep-sea steel catenary riser.

[0034] A motion equivalence module is used to determine the equivalent oscillating flow of the offshore platform based on its motion data.

[0035] The response acquisition module is used to determine the vortex-induced vibration response of the deep-sea steel catenary riser based on the equivalent oscillating flow of the offshore platform and fluid-structure interaction effect analysis.

[0036] The analysis and acquisition module is used to calculate the equivalent stress time history of the deep-sea steel catenary riser based on its vortex-induced vibration response, thereby determining the vortex-induced fatigue analysis results of the deep-sea steel catenary riser.

[0037] On the other hand, this application provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-mentioned vortex-induced fatigue analysis method for deep-sea steel catenary risers.

[0038] On the other hand, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned vortex-induced fatigue analysis method for deep-sea steel catenary risers.

[0039] This application embodiment considers that the platform motion can induce vortex-induced vibration in the riser, establishes an equivalent method to convert the platform motion into oscillating flow, and considers the fluid-structure interaction effect between the riser and the flow field. This makes the calculation not only easy to implement but also highly accurate. It can also improve the completeness and reliability of the vortex-induced fatigue analysis results of deep-sea steel catenary risers, and help to accurately control the fatigue damage degree of deep-sea steel catenary risers. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the implementation environment for a vortex-induced fatigue analysis method for a deep-sea steel catenary riser provided in an embodiment of this application;

[0041] Figure 2 This is a flowchart illustrating a method for vortex-induced fatigue analysis of a deep-sea steel catenary riser provided in an embodiment of this application.

[0042] Figure 3 This is a schematic flowchart illustrating the process of determining the vortex-induced vibration response of a deep-sea steel catenary riser, as provided in an embodiment of this application.

[0043] Figure 4 This is a schematic diagram of the structure of a deep-sea steel catenary riser slice provided in an embodiment of this application;

[0044] Figure 5 This is a schematic flowchart of a method for solving the vortex-induced vibration response of a deep-sea steel catenary riser, provided in an embodiment of this application.

[0045] Figure 6 This is a schematic flowchart illustrating the process of determining the vortex-induced fatigue analysis results of a deep-sea steel catenary riser, as provided in an embodiment of this application.

[0046] Figure 7 This is a schematic diagram of the structure of a vortex-induced fatigue analysis device for a deep-sea steel catenary riser provided in an embodiment of this application;

[0047] Figure 8 This is a schematic diagram of the hardware structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0048] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are merely examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0049] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”

[0050] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0052] Currently, offshore oil and gas transportation systems mainly consist of three parts: offshore platforms, offshore risers, and subsea pipelines. Riseres, connecting offshore platforms and subsea oil wells for transporting oil and gas, are key equipment for deep-sea oil and gas extraction. Steel catenary risers, with their advantages of easy installation, low cost, and resistance to high temperatures and pressures, are the preferred riser type for deep-sea oil and gas resource development.

[0053] In related technologies, vortex-induced vibration of steel catenary risers can cause vortex-induced fatigue damage. Therefore, current vortex-induced fatigue analysis of risers focuses on vortex-induced fatigue caused by background ocean currents. However, in practical applications, it has been found that analyzing riser vortex-induced fatigue caused solely by background ocean currents yields results with low accuracy and poor safety.

[0054] In view of this, this application provides a method, apparatus, electronic device, and storage medium for vortex-induced fatigue analysis of deep-sea steel catenary risers. By considering that platform motion can induce vortex-induced vibration in the riser, an equivalent method is established to convert the platform motion into oscillating flow. Furthermore, the fluid-structure interaction effect between the riser and the flow field is considered, making the calculation not only easy to implement but also highly accurate. This also improves the completeness and reliability of the vortex-induced fatigue analysis results for deep-sea steel catenary risers, and helps to accurately control the degree of fatigue damage of deep-sea steel catenary risers.

[0055] It should be noted that in each specific embodiment of the present application, when it comes to the need to perform relevant processing based on data related to the user's identity or characteristics, such as user information, user behavior data, user historical data, and user location information, the user's permission or consent will be obtained first, and the collection, use, and processing of such data will comply with relevant laws, regulations, and standards. In addition, when the embodiment of the present application needs to obtain the user's sensitive personal information, the user's separate permission or consent will be obtained through a pop-up window or by jumping to a confirmation page. After clearly obtaining the user's separate permission or consent, the necessary user-related data for the normal operation of the embodiment of the present application will be obtained.

[0056] The specific implementation methods of the embodiments of this application will be described in detail below with reference to the accompanying drawings. First, a vortex-induced fatigue analysis method for a deep-sea steel catenary riser provided in the embodiments of this application will be described with reference to the accompanying drawings.

[0057] Please refer to Figure 1 , Figure 1 This is a schematic diagram illustrating the implementation environment of a vortex-induced fatigue analysis method for a deep-sea steel catenary riser provided in this application embodiment. In this implementation environment, the main hardware and software components involved include a terminal processor 110 and a server 120.

[0058] Specifically, the terminal processor 110 may contain a control program for a vortex-induced fatigue analysis method for deep-sea steel catenary risers, and the server 120 serves as the backend server for this control program. The terminal processor 110 and the backend server 120 are connected. The vortex-induced fatigue analysis method for deep-sea steel catenary risers provided in this embodiment can be executed on the terminal processor 110 side.

[0059] Server 120 can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms.

[0060] In addition, server 120 can also be a node server in a blockchain network.

[0061] The terminal processor 110 and the server 120 can establish a communication connection via a wireless network. This wireless network uses standard communication technologies and / or protocols. The network can be the Internet or any other network, including but not limited to a Local Area Network (LAN), Metropolitan Area Network (MAN), Wide Area Network (WAN), mobile, or any combination of wireless networks, private networks, or virtual private networks. Furthermore, these hardware and software components can use the same or different communication connection methods; this application does not impose specific limitations in this regard.

[0062] Of course, this is understandable. Figure 1 The implementation environment described in this application is only one of the optional application scenarios for the vortex-induced fatigue analysis method for deep-sea steel catenary risers provided in this embodiment. The actual application is not fixed. Figure 1 The software and hardware environment shown is not specifically limited in this application.

[0063] like Figure 2 As shown, Figure 2 This is a flowchart illustrating a method for vortex-induced fatigue analysis of a deep-sea steel catenary riser provided in an embodiment of this application, specifically including but not limited to steps 100 to 400.

[0064] Step 100: Obtain motion data of the offshore platform; wherein the offshore platform is equipped with and connected to the deep-sea steel catenary riser.

[0065] In the embodiments of this application, deep-sea oil and gas extraction typically employs a semi-submersible platform as the offshore platform, which is paired with a deep-sea steel catenary riser. The deep-sea steel catenary riser is a fluid transport pipeline used for deep-water oil and gas extraction. It can be made of high-strength steel and is arranged in a "catenary" shape underwater. One end is connected to the seabed wellhead, and the other end is connected to the offshore platform, thereby safely and stably transporting oil, gas and other working fluids from the well to the offshore facility.

[0066] Furthermore, offshore platforms have a wide range and large amplitude of motion under the influence of wind, waves and currents. When the platform drags the top of the riser to move horizontally in the water, the riser and the ocean current can form a relative velocity, resulting in a relative oscillating flow field between the riser and the ocean current, which in turn causes cross-flow vortex-induced vibration in a local section of the riser.

[0067] In practical applications, the motion data of an offshore platform can be obtained by acquiring sea state parameters of the sea area where the platform is located. For example, sea state parameters for a certain period can be selected as the data source, such as a sea state that occurs once every ten years, with sea level and seabed current velocities of 1.42 m / s and 0.3 m / s respectively; wave height of 9.6 m and period of 12.8 s; and average wind speed of 42.0 m / s at 10 m above sea level. The motion data of the offshore platform can then be obtained using these sea state parameters.

[0068] Step 200: Based on the motion data of the offshore platform, determine the equivalent oscillating flow of the offshore platform.

[0069] In this embodiment of the application, based on the determined motion data of the offshore platform, the heave motion of the offshore platform can be converted into an equivalent turbulent flow according to the mechanism of riser vortex-induced vibration induced by the heave motion of the platform.

[0070] In practical applications, the heave motion of an offshore platform alters the relative velocity of the flow field, causing periodic velocity component changes on the riser surface, which is equivalent to generating an oscillating flow in front of a stationary riser. Therefore, the dynamic response of an offshore platform can be simulated and analyzed using analysis software such as Ansys AQWA.

[0071] Specifically, as an optional implementation, determining the equivalent oscillating flow of the offshore platform based on its motion data includes:

[0072] Based on the obtained motion data of the offshore platform, the heave dynamic response of the offshore platform is constructed;

[0073] Based on the heave dynamic response, the motion process of the offshore platform is equivalent to a cosine oscillating flow.

[0074] In the embodiments of this application, analysis software such as Ansys AQWA can be used to determine the motion data of the offshore platform based on the frequency domain-time domain coupled analysis method, thereby constructing the heave dynamic response of the offshore platform.

[0075] Furthermore, from the reference frame of the deep-sea steel catenary riser, the platform's motion generates a relative velocity, which is precisely the instantaneous velocity of the offshore platform. Therefore, the platform's motion can be equivalent to a cosine oscillating flow, and its instantaneous velocity V(t) is expressed as shown in the following formula (1):

[0076] V(t)=A·2πfcos(2πft) (1)

[0077] Where V(t) is the instantaneous velocity of the offshore platform; A is the amplitude of the heave motion of the offshore platform; f is the frequency of the heave motion of the offshore platform; and t is time.

[0078] In practical applications, hydrodynamic parameters such as the added mass matrix, radiation damping matrix, first-order wave force, and motion response amplitude operator can be obtained by performing frequency domain hydrodynamic analysis (e.g., using the HydroDyn module).

[0079] Furthermore, by using the time-domain coupling analysis module, the above hydrodynamic parameters are used as boundary conditions. A load model is established considering wind load, current load, and wave load to obtain the dynamic response analysis of the offshore platform. Finally, the heave dynamic response of the offshore platform is obtained.

[0080] Step 300: Based on the equivalent oscillating flow of the offshore platform, and using fluid-structure interaction analysis, determine the vortex-induced vibration response of the deep-sea steel catenary riser.

[0081] In the embodiments of this application, after the motion process of the offshore platform is equivalent to a cosine oscillating flow, the vortex-induced vibration response of the deep-sea steel catenary riser can be analyzed based on the fluid-structure interaction effect.

[0082] In practical applications, the layered method can be used to cut the riser into multiple slices along its longitudinal direction. Each slice can be used to perform local fluid-structure interaction calculations independently. This allows for parallel calculations between different slices while preserving the differences in flow field and structural response at different water depths.

[0083] Specifically, as an optional implementation method, please refer to Figure 3 , Figure 3 This is a schematic flowchart illustrating the process of determining the vortex-induced vibration response of a deep-sea steel catenary riser, provided in an embodiment of this application. The determination of the vortex-induced vibration response of the deep-sea steel catenary riser, based on the equivalent oscillating flow of the offshore platform and fluid-structure interaction analysis, includes:

[0084] Based on the finite element theory, the deep-sea steel catenary riser is discretized to obtain riser units, and the deep-sea steel catenary riser is divided into slices.

[0085] The riser unit is subjected to coordinate transformation, and the riser unit stiffness matrix and unit mass matrix are transformed to the global coordinate system to establish the global stiffness matrix and global mass matrix.

[0086] The flow field for each slice is established, and the equivalent oscillating flow of the offshore platform is taken as the boundary inlet. The computational fluid control equations are solved to calculate the fluid force for each slice.

[0087] The fluid force of each slice is converted into a uniformly distributed load and applied to the riser unit corresponding to each slice;

[0088] Based on fluid-structure interaction analysis, the vortex-induced vibration response of the deep-sea steel catenary riser is solved, and the vortex-induced vibration response of the deep-sea steel catenary riser under the action of equivalent oscillating flow is obtained.

[0089] In this embodiment of the application, when calculating and analyzing the vortex-induced vibration response of a deep-sea steel catenary riser using the layered method, the three-dimensional riser can first be discretized according to the finite element theory to obtain riser units. Each riser unit can be regarded as an Euler-Bernoulli beam. The entire riser is then divided into two-dimensional slices. The riser units in the local coordinate system are then transformed to the global coordinate system to establish the global stiffness matrix and the global mass matrix. Specifically, the angle between the axial direction of the suspended section of the steel catenary riser and the global coordinate axis of the riser can be obtained according to the catenary shape of the riser. The global stiffness matrix and the global mass matrix of the riser are then assembled.

[0090] For example, please refer to Figure 4 and Figure 5 , Figure 4 This is a schematic diagram of the structure of a deep-sea steel catenary riser slice provided in an embodiment of this application. Figure 5 This is a schematic flowchart of a process for solving the vortex-induced vibration response of a deep-sea steel catenary riser, provided in an embodiment of this application. The riser is divided into several slices, and a flow field is established for each slice. The boundary inlet of each two-dimensional flow field slice is the calculated equivalent cosine oscillating flow. The SST k-ω turbulence model can be used, the Reynolds average number method (RANS) can be used to solve the fluid control equations, and the Newmark-β method can be used to solve the riser dynamic equations to calculate the fluid force of each slice.

[0091] Furthermore, the fluid force of each slice is converted into a uniformly distributed load and applied to the riser unit corresponding to each slice. The fluid domain is updated in real time using overlapping grid technology to achieve fluid-structure coupling between the structural field and the fluid domain field. Finally, the riser vortex-induced vibration response under the equivalent oscillating flow is obtained.

[0092] Therefore, by selecting the SST k-ω turbulence model, both turbulence separation and near-wall region prediction can be taken into account. Within the flow domain of each slice, the Reynolds-averaged equation is solved to obtain the instantaneous pressure distribution, and then the transverse eddy current force and the downstream fluid force are calculated and applied to the riser unit of the structural layer. Using the Newmark-β method of time-domain integration, the time histories of transverse displacement, velocity and acceleration are obtained, thereby changing the shape of the fluid-structure boundary. The updated structural boundary is then superimposed into the fluid domain to achieve dynamic adjustment of the mesh for fluid-structure coupling.

[0093] In practical applications, such as Figure 5As shown, after converting the fluid force of each slice into a uniformly distributed load and applying it to the riser unit corresponding to each slice, the method further includes:

[0094] The displacement, velocity, and acceleration of each riser unit are calculated to update the position of each slice of the deep-sea steel catenary riser.

[0095] Resolve the computational fluid dynamics control equations to calculate the fluid forces for each slice until the calculation results converge.

[0096] In this embodiment, the position of each slice of the deep-sea steel catenary riser is updated by calculating the displacement, velocity and acceleration of each riser unit. The updated structural boundary is superimposed into the fluid domain, and the computational fluid control equations are solved again to calculate the fluid force of each slice until the calculation results (such as lateral vortex-induced force and lateral displacement) converge. Finally, the vortex-induced vibration response of the deep-sea steel catenary riser under the action of equivalent oscillating flow is obtained.

[0097] Step 400: Based on the vortex-induced vibration response of the deep-sea steel catenary riser, calculate the equivalent stress time history of the deep-sea steel catenary riser, thereby determining the vortex-induced fatigue analysis results of the deep-sea steel catenary riser.

[0098] In this embodiment of the application, after obtaining the vortex-induced vibration response of the deep-sea steel catenary riser, the vortex-induced vibration response of the deep-sea steel catenary riser can be used as a boundary condition to calculate the equivalent stress time history of the deep-sea steel catenary riser. At the same time, based on the SN curve of the riser material, that is, the cyclic stress amplitude-material failure cycle number curve, the vortex-induced fatigue analysis result of the deep-sea steel catenary riser is determined, thereby analyzing the fatigue damage caused by the vortex-induced vibration of the steel catenary riser due to the movement of the offshore platform.

[0099] Specifically, as an optional implementation method, please refer to Figure 6 , Figure 6 This is a flowchart illustrating the process of determining the vortex-induced fatigue analysis results of a deep-sea steel catenary riser, as provided in an embodiment of this application. The process involves calculating the equivalent stress time history of the deep-sea steel catenary riser based on its vortex-induced vibration response, thereby determining the vortex-induced fatigue analysis results. The steps include:

[0100] A finite element model of the deep-sea steel catenary riser was established, and the eddy-induced vibration response of the deep-sea steel catenary riser was used as the boundary condition to calculate the equivalent stress time history of the deep-sea steel catenary riser.

[0101] The equivalent stress time history is counted using the rainflow counting method to obtain the equivalent stress amplitude and cycle number;

[0102] Based on the equivalent stress amplitude and cycle number, the fatigue damage value caused by vortex-induced vibration of the deep-sea steel catenary riser is calculated and used as the vortex-induced fatigue analysis result of the deep-sea steel catenary riser.

[0103] In this embodiment, a finite element model of a deep-sea steel catenary riser can be established (e.g., using Abaqus finite element software). The vortex-induced vibration response of the riser can be used as a boundary condition to analyze and calculate the equivalent stress time history. Furthermore, the rainflow counting method can be used to count the stress time history, thereby obtaining the equivalent stress amplitude and cycle number experienced by the riser. Ultimately, the fatigue damage value caused by vortex-induced vibration of the riser during a certain time period can be calculated as the vortex-induced fatigue analysis result of the deep-sea steel catenary riser. For example, the fatigue damage value caused by vortex-induced vibration of the riser during a certain time period can be calculated based on Miner's linear damage accumulation theory.

[0104] In practical applications, after counting the equivalent stress time history using the rainflow counting method to obtain the equivalent stress amplitude and cycle number, the equivalent stress amplitude and cycle number can be corrected according to the Goodman model.

[0105] The Goodman model can be expressed as the following formula (2):

[0106]

[0107] Where S is the corrected equivalent stress amplitude; σ a σ is the initial equivalent stress amplitude; m The mean stress is σ. b This refers to the tensile strength of the material.

[0108] Therefore, this application establishes an equivalent method to represent the heave motion of an offshore platform as vortex-induced vibration of the riser caused by oscillating flow. This allows for computational fluid dynamics (CFD) analysis of the riser's vortex-induced vibration response. Furthermore, based on the fluid-structure interaction (FSI) effect between the riser and the flow field, the calculation is not only easy to implement but also highly accurate. In addition, this application calculates the flow field and the dynamic response of the riser. By transferring fluid forces to the riser and analyzing its vortex-induced vibration response, and then updating the flow field mesh based on the riser response to consider the FSI effect between the riser and the flow field, the efficiency of the analysis and computation is improved. This enhances the completeness and reliability of the vortex-induced fatigue analysis results for deep-sea steel catenary risers, helping users accurately grasp the degree of fatigue damage to deep-sea steel catenary risers.

[0109] See also Figure 7 , Figure 7This is a schematic diagram of the structure of a vortex-induced fatigue analysis device for a deep-sea steel catenary riser provided in an embodiment of this application. This application also provides a vortex-induced fatigue analysis device for a deep-sea steel catenary riser, which can implement the above-mentioned vortex-induced fatigue analysis method for deep-sea steel catenary risers. The device includes:

[0110] The data acquisition module 710 is used to acquire motion data of the offshore platform; wherein the offshore platform is equipped with and connected to the deep-sea steel catenary riser.

[0111] The motion equivalent module 720 is used to determine the equivalent oscillating flow of the offshore platform based on the motion data of the offshore platform;

[0112] The response acquisition module 730 is used to determine the vortex-induced vibration response of the deep-sea steel catenary riser based on the equivalent oscillating flow of the offshore platform and fluid-structure interaction effect analysis.

[0113] The analysis and acquisition module 740 is used to calculate the equivalent stress time history of the deep-sea steel catenary riser based on the vortex-induced vibration response of the riser, thereby determining the vortex-induced fatigue analysis results of the riser.

[0114] It is understood that the content of the above method embodiments is applicable to the present device embodiments. The specific functions implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0115] See also Figure 8 , Figure 8 This is a schematic diagram of the hardware structure of an electronic device provided in an embodiment of this application. The electronic device includes:

[0116] The processor 801 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application.

[0117] The memory 802 can be implemented as a read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 802 can store the operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 802 and called by the processor 801 to execute the vortex-induced fatigue analysis method for deep-sea steel catenary risers according to the embodiments of this application.

[0118] The 803 input / output interface is used to implement information input and output.

[0119] The communication interface 804 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0120] Bus 805 transmits information between various components of the device (e.g., processor 801, memory 802, input / output interface 803, and communication interface 804);

[0121] The processor 801, memory 802, input / output interface 803, and communication interface 804 are connected to each other within the device via bus 805.

[0122] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for vortex-induced fatigue analysis of deep-sea steel catenary risers.

[0123] It is understood that the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0124] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0125] This application provides a method, apparatus, electronic device, and storage medium for vortex-induced fatigue analysis of deep-sea steel catenary risers. By considering that platform motion can induce vortex-induced vibration in the riser, an equivalent method is established to convert the platform motion into oscillating flow. Furthermore, the fluid-structure interaction effect between the riser and the flow field is considered, making the calculation not only easy to implement but also highly accurate. This also improves the completeness and reliability of the vortex-induced fatigue analysis results for deep-sea steel catenary risers, helping to accurately control the degree of fatigue damage to deep-sea steel catenary risers.

[0126] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0127] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0128] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0129] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0130] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0131] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0132] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0133] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0134] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0135] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0136] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method for vortex-induced fatigue analysis of deep-sea steel catenary risers, characterized in that, The method includes the following steps: Acquire motion data of an offshore platform; wherein the offshore platform is equipped with and connected to a deep-sea steel catenary riser; Based on the motion data of the offshore platform, the equivalent oscillating flow of the offshore platform is determined; Based on the equivalent oscillating flow of the offshore platform, and using fluid-structure interaction analysis, the vortex-induced vibration response of the deep-sea steel catenary riser is determined. Based on the vortex-induced vibration response of the deep-sea steel catenary riser, the equivalent stress time history of the deep-sea steel catenary riser is calculated, thereby determining the vortex-induced fatigue analysis results of the deep-sea steel catenary riser.

2. The vortex-induced fatigue analysis method for deep-sea steel catenary risers according to claim 1, characterized in that, The determination of the equivalent oscillating flow of the offshore platform based on its motion data includes: Based on the obtained motion data of the offshore platform, the heave dynamic response of the offshore platform is constructed; Based on the heave dynamic response, the motion process of the offshore platform is equivalent to a cosine oscillating flow.

3. The vortex-induced fatigue analysis method for deep-sea steel catenary risers according to claim 2, characterized in that, The step of constructing the heave dynamic response of the offshore platform based on the acquired motion data of the offshore platform includes: Based on the obtained motion data of the offshore platform, frequency domain hydrodynamic analysis is performed on the offshore platform to obtain hydrodynamic parameters; the hydrodynamic parameters include the added mass matrix, radiation damping matrix, first-order wave force and motion response amplitude operator; Based on the hydrodynamic parameters, a load model is established to obtain the dynamic response analysis of the offshore platform, thereby constructing the heave dynamic response of the offshore platform.

4. The vortex-induced fatigue analysis method for deep-sea steel catenary risers according to claim 1, characterized in that, The determination of the vortex-induced vibration response of the deep-sea steel catenary riser based on the equivalent oscillating flow of the offshore platform and fluid-structure interaction effect analysis includes: Based on the finite element theory, the deep-sea steel catenary riser is discretized to obtain riser units, and the deep-sea steel catenary riser is divided into slices. The riser unit is subjected to coordinate transformation, and the riser unit stiffness matrix and unit mass matrix are transformed to the global coordinate system to establish the global stiffness matrix and global mass matrix. The flow field for each slice is established, and the equivalent oscillating flow of the offshore platform is taken as the boundary inlet. The computational fluid control equations are solved to calculate the fluid force for each slice. The fluid force of each slice is converted into a uniformly distributed load and applied to the riser unit corresponding to each slice; Based on fluid-structure interaction analysis, the vortex-induced vibration response of the deep-sea steel catenary riser is solved, and the vortex-induced vibration response of the deep-sea steel catenary riser under the action of equivalent oscillating flow is obtained.

5. The vortex-induced fatigue analysis method for deep-sea steel catenary risers according to claim 4, characterized in that, After converting the fluid force of each slice into a uniformly distributed load and applying it to the riser unit corresponding to each slice, the method further includes: The displacement, velocity, and acceleration of each riser unit are calculated to update the position of each slice of the deep-sea steel catenary riser. Resolve the computational fluid dynamics control equations to calculate the fluid forces for each slice until the calculation results converge.

6. The vortex-induced fatigue analysis method for deep-sea steel catenary risers according to claim 1, characterized in that, The calculation of the equivalent stress time history of the deep-sea steel catenary riser based on its vortex-induced vibration response, thereby determining the vortex-induced fatigue analysis results of the deep-sea steel catenary riser, includes: A finite element model of the deep-sea steel catenary riser was established, and the eddy-induced vibration response of the deep-sea steel catenary riser was used as the boundary condition to calculate the equivalent stress time history of the deep-sea steel catenary riser. The equivalent stress time history is counted using the rainflow counting method to obtain the equivalent stress amplitude and cycle number; Based on the equivalent stress amplitude and cycle number, the fatigue damage value caused by vortex-induced vibration of the deep-sea steel catenary riser is calculated and used as the vortex-induced fatigue analysis result of the deep-sea steel catenary riser.

7. The vortex-induced fatigue analysis method for deep-sea steel catenary risers according to claim 6, characterized in that, After counting the equivalent stress time history using the rainflow counting method to obtain the equivalent stress amplitude and cycle number, the method further includes: Based on the Goodman model, the equivalent stress amplitude and cycle number are corrected.

8. A device for analyzing vortex-induced fatigue of deep-sea steel catenary risers, characterized in that, The device includes: The data acquisition module is used to acquire motion data of the offshore platform; wherein the offshore platform is equipped with and connected to the deep-sea steel catenary riser. A motion equivalence module is used to determine the equivalent oscillating flow of the offshore platform based on its motion data. The response acquisition module is used to determine the vortex-induced vibration response of the deep-sea steel catenary riser based on the equivalent oscillating flow of the offshore platform and fluid-structure interaction effect analysis. The analysis and acquisition module is used to calculate the equivalent stress time history of the deep-sea steel catenary riser based on its vortex-induced vibration response, thereby determining the vortex-induced fatigue analysis results of the deep-sea steel catenary riser.

9. An electronic device, characterized in that, The electronic device includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the vortex-induced fatigue analysis method for deep-sea steel catenary risers as described in 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 the processor, it implements the vortex-induced fatigue analysis method for deep-sea steel catenary risers as described in any one of claims 1 to 7.

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