Method for designing integrity of mechanical system of well control equipment in offshore oil and gas development

Abstract

The present application belongs to the technical field of ocean engineering equipment, and particularly relates to a kind of integrity design method of ocean oil and gas development well control equipment mechanical system. The integrity design method realizes the guarantee of the whole life cycle working reliability of the ocean oil and gas development well control equipment by constructing the integrity index factor of the ocean oil and gas development well control equipment mechanical system integrating multi-source information, and balances the working reliability of each component in the whole life cycle. The integrity design method of the ocean oil and gas development well control equipment mechanical system comprises the following steps: obtaining the performance parameters of the key components of the ocean oil and gas development well control equipment mechanical system; calculating the performance parameters of the overall structure of the ocean oil and gas development well control equipment mechanical system; determining the working condition environmental parameters of the ocean oil and gas development well control equipment; calculating the time-varying reliability of the ocean oil and gas development well control equipment mechanical system; constructing the integrity index factor of the ocean oil and gas development well control equipment mechanical system; and completing the integrity optimization design.

Description

Technical Field

[0001] This invention belongs to the field of marine engineering equipment technology, and in particular relates to a method for designing the integrity of mechanical systems for well control equipment in marine oil and gas development. Background Technology

[0002] Well control equipment, crucial for ensuring the safety of oil and gas well operations and preventing uncontrolled blowouts during offshore oil and gas development, comprises at least two parts: blowout preventer (BOP) assemblies mounted on offshore drilling platforms and subsea BOP assemblies. It is noteworthy that, given the vital role of well control equipment in offshore oil and gas development, its structural design must possess extremely high reliability and be able to effectively cope with various harsh operating conditions. Otherwise, failure of well control equipment could lead to catastrophic consequences and incalculable losses.

[0003] However, further research revealed that the structural design of existing offshore oil and gas development well control equipment still relies on traditional reliability design methods, thus exhibiting the following significant limitations: Firstly, the mechanical systems of offshore oil and gas development well control equipment obtained using existing design methods cannot ensure the continuous and reliable operation of their mechanical structures throughout their entire lifespan; secondly, due to the significant differences in the operating conditions of various components of the well control equipment, it is impossible to effectively coordinate and balance the reliability of different components throughout their entire lifespan. Therefore, it is particularly necessary for those skilled in the art to provide a novel design for the integrity of the mechanical system of offshore oil and gas development well control equipment. Summary of the Invention

[0004] This invention provides a method for designing the mechanical system integrity of marine oil and gas development well control equipment. This method constructs a mechanical system integrity index factor that integrates multi-source information, thereby ensuring the reliability of marine oil and gas development well control equipment throughout its entire life cycle and balancing the reliability of each component throughout its entire life cycle.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] The method for designing the integrity of mechanical systems for well control equipment in offshore oil and gas development includes the following steps:

[0007] Step S1: Obtain the performance parameters of the key components of the mechanical system of the well control equipment for offshore oil and gas development; wherein, the key components of the mechanical system of the well control equipment for offshore oil and gas development include at least the vulnerable components of the mechanical system of the well control equipment for offshore oil and gas development and the drive components of the mechanical system of the well control equipment for offshore oil and gas development.

[0008] Step S2: Calculate the performance parameters of the overall structure of the mechanical system of the well control equipment for offshore oil and gas development;

[0009] Step S3: Determine the operating environment parameters of the well control equipment for offshore oil and gas development; calculate the time-varying reliability of the mechanical system of the well control equipment for offshore oil and gas development.

[0010] Step S4: Construct the integrity index factor for the mechanical system of well control equipment in offshore oil and gas development;

[0011] Step S5: Based on actual engineering needs, set the threshold for the integrity index factor of the mechanical system of the offshore oil and gas development well control equipment. Using the integrity index factor of the mechanical system of the offshore oil and gas development well control equipment as the objective function, the operating environment parameters of the offshore oil and gas development well control equipment as the constraint condition, and the integrity index factor being higher than the threshold as the optimization condition, calculate the optimal combination of performance parameters of key components of the offshore oil and gas development well control equipment mechanical system, thereby completing the integrity optimization design of the offshore oil and gas development well control equipment mechanical system.

[0012] Preferably, the process of calculating the overall structural performance parameters of the mechanical system of the offshore oil and gas development well control equipment in step S2 specifically includes:

[0013] The formula for calculating the sealing performance of the annular blowout preventer core is as follows: ;

[0014] in, For the sealing performance of the ring-shaped blowout preventer core, K represents the pre-compression pressure of the annular blowout preventer core 4, and K is the shape factor of the annular blowout preventer core. The driving pressure for the piston of the annular blowout preventer;

[0015] Annular Blowout Preventer Core Pre-compression Pressure The calculation formula is: ;

[0016] in, The rated pre-compression pressure is given by Cr, where Cr is the compression deformation of the rubber core and d is the aging coefficient of the rubber core. The axial compression ratio of the annular blowout preventer wear pad;

[0017] The formula for calculating the driving performance of the annular blowout preventer's drive piston is as follows: ;

[0018] in, K represents the driving performance of the piston driven by the annular blowout preventer, and K is the shape factor of the annular blowout preventer's rubber core. The rated driving pressure of the driving piston is given by θ, where θ is the inclination angle of the driving piston contact surface. To drive the piston pressure leakage rate;

[0019] The formula for calculating the shearing performance of the blowout preventer blade is as follows: ;

[0020] in, For the shearing performance of the blowout preventer blade, The calibration shearing performance of the blowout preventer blade is determined. The yield strength of the blade. For blade hardness, Poisson's ratio of the blade edge;

[0021] The formula for calculating the driving performance of the shear plate of the gate blowout preventer is: ;

[0022] in, For the driving performance of the shear plate of the gate blowout preventer, To calibrate the drive performance of the shear plate of the gate blowout preventer. The link yield strength, For the stiffness of the connecting rod, The shear plate yield strength, The shear plate hardness;

[0023] The formula for calculating the degradation rate of the sealing performance of the annular blowout preventer core is as follows: ;

[0024] in, The degradation rate of the sealing performance of the annular blowout preventer core. For the initial sealing performance of the annular blowout preventer core, The coefficient of degradation rate of the sealing performance of the annular blowout preventer core is given by t, where t is the degradation time in meters. s The degradation time index represents the sealing performance of the annular blowout preventer core; among which, and m s The sealing performance of the annular blowout preventer core at different times was obtained through fitting calculation.

[0025] The formula for calculating the degradation rate of the driving performance of the annular blowout preventer's drive piston is as follows: ;

[0026] in, The degradation rate of the driving performance of the annular blowout preventer's drive piston. The initial driving performance of the annular blowout preventer drive piston. The coefficient representing the degradation rate of the driving performance of the annular blowout preventer's drive piston is given by t, where t is the degradation time, and m is the time factor. d The degradation time index is the driving performance degradation time index of the annular blowout preventer's drive piston, where, and m d The driving performance of the annular blowout preventer piston at different times was obtained through fitting calculation.

[0027] The formula for calculating the degradation rate of the shearing performance of the blowout preventer blade is as follows: ;

[0028] in, The degradation rate of the shearing performance of the blowout preventer blade. The initial shearing performance of the blowout preventer blade. The degradation rate coefficient of the shear performance of the blowout preventer blade is given by t, where t is the degradation time in meters. sh The degradation time index is the shearing performance of the blowout preventer blade, where... and m sh The results were obtained by fitting and calculating the shear performance of the blowout preventer blade at different times;

[0029] The formula for calculating the degradation rate of the driving performance of the blowout preventer shear plate is as follows: ;

[0030] in, The degradation rate of the driving performance of the shear plate of the gate blowout preventer. The initial driving performance of the shear plate of the gate blowout preventer. The degradation rate coefficient of the driving performance of the shear plate of the gate blowout preventer is given by t, where t is the degradation time in meters. dh The degradation time index is the driving performance of the shear plate of the blowout preventer, where, and m dh The results were obtained by fitting and calculating the driving performance of the blowout preventer shear plate at different times.

[0031] Preferably, the process of determining the operating environment parameters of the offshore oil and gas development well control equipment in step S3 specifically includes:

[0032] The type of installation platform is defined as a deterministic parameter, while the height or water depth of the installation platform, structural weight requirements, structural height requirements, working temperature requirements, and sealing pressure requirements of ocean current velocity are defined as random probabilistic parameters.

[0033] For the random probability parameter, its cumulative distribution function is: ;

[0034] Where pa is an arbitrary random probability parameter. Let be the cumulative distribution function with arbitrary random probability parameters. Let pa be the initial load probability density function with arbitrary random probabilistic parameters. max Let pa be the maximum value of any random probability parameter. min It is the minimum value of any random probability parameter;

[0035] Let any random probability parameter be within the range [pa]min pa max The area is divided into M regions, and random numbers nr are drawn from the uniformly distributed interval [0,1]. In the m-th interval, the sample of any random probability parameter is: ;

[0036] in, Let m be a sample of any random probability parameter in the m-th interval. It is the inverse function of the cumulative distribution function of any random probability parameter.

[0037] Preferably, the process of calculating the time-varying reliability of the mechanical system of the offshore oil and gas development well control equipment in step S3 specifically includes:

[0038] The time-varying reliability calculation method for mechanical systems of well control equipment in offshore oil and gas development is as follows: ;

[0039] Where λ(t) is the time-varying failure rate function, c is the characteristic factor of well control equipment for offshore oil and gas development, representing the annular blowout preventer or the gate blowout preventer; e is the base of the natural logarithm, and t is time;

[0040] ;

[0041] Wherein, β is the shape parameter, η is the scale parameter, and γ is the position parameter. The parameter values ​​are obtained by mathematical estimation of the performance parameters of key components of the mechanical system of well control equipment for offshore oil and gas development and the operating environment parameters of well control equipment for offshore oil and gas development.

[0042] Preferably, the process of constructing the mechanical system integrity index factor for offshore oil and gas development well control equipment in step S4 specifically includes:

[0043] Among them, the integrity index factor of the mechanical system of well control equipment for offshore oil and gas development satisfies: ;

[0044] in, R is the mechanical system integrity index factor for well control equipment in offshore oil and gas development. max R represents the maximum time-varying reliability of the well control equipment's mechanical system. min This represents the minimum time-varying reliability of the well control equipment's mechanical system. This refers to the driving performance of the piston in a ring-shaped blowout preventer or the driving performance of the shear plate in a gate-type blowout preventer.

[0045] For the sealing performance of the rubber core of the annular blowout preventer or the shearing performance of the blade of the gate blowout preventer, a iLet n be the number of key component performance parameters of the mechanical system of well control equipment for any offshore oil and gas development, and a be the number of key component performance parameters of the mechanical system of well control equipment for offshore oil and gas development. i (t) represents the test data of the performance parameters of key components of the mechanical system of any offshore oil and gas development well control equipment at different times; c represents the characteristic factor of the offshore oil and gas development well control equipment, characterizing the annular blowout preventer or the gate blowout preventer; T represents the expected operating temperature of the offshore oil and gas development well control equipment. The average test data of key component performance parameters for mechanical systems of well control equipment in any offshore oil and gas development. Standard deviation of test data for performance parameters of key components of mechanical systems for well control equipment in any offshore oil and gas development.

[0046] This invention provides a method for designing the integrity of a mechanical system for well control equipment in offshore oil and gas development. Specifically, this method includes the following steps: obtaining performance parameters of key components of the mechanical system; calculating the performance parameters of the overall structure of the mechanical system; determining the operating environment parameters of the well control equipment; calculating the time-varying reliability of the mechanical system; constructing an integrity index factor for the mechanical system; and, based on actual engineering needs, setting a threshold for the integrity index factor, using the integrity index factor as the objective function, the operating environment parameters as constraints, and an integrity index factor exceeding the threshold as an optimization condition, calculating the optimal combination of performance parameters for the key components of the mechanical system, thereby completing the integrity optimization design of the mechanical system.

[0047] The method for designing the integrity of mechanical systems for well control equipment in offshore oil and gas development, which features the above-mentioned steps, has at least the following technical advantages compared to existing technologies:

[0048] (1) The integrity design method of the marine oil and gas development well control equipment mechanical system provided by the present invention obtains accurate performance parameters (data) of key components of the marine oil and gas development well control equipment mechanical system through the test platform; and effectively estimates the reliability of the well control equipment throughout its entire life cycle through the time-varying reliability calculation model of the marine oil and gas development well control equipment mechanical system.

[0049] (2) The marine oil and gas development well control equipment mechanical system integrity design method provided by the present invention ensures the working reliability of marine oil and gas development well control equipment throughout its entire life cycle and balances the working reliability of each component throughout its entire life cycle by constructing a marine oil and gas development well control equipment mechanical system integrity index factor that integrates multi-source information. Attached Figure Description

[0050] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the following drawings:

[0051] Figure 1 A flowchart illustrating the method for designing the integrity of the mechanical system of well control equipment for offshore oil and gas development provided by this invention;

[0052] Figure 2 A schematic diagram of the annular blowout preventer structure in well control equipment for offshore oil and gas development.

[0053] Figure 3 A schematic diagram of a gate blowout preventer (BOP) in well control equipment for offshore oil and gas development.

[0054] Figure label:

[0055] 1. Lower housing of annular blowout preventer; 2. Drive piston of annular blowout preventer; 3. Support cylinder of annular blowout preventer; 4. Rubber core of annular blowout preventer; 5. Upper housing of annular blowout preventer; 6. Anti-wear gasket of annular blowout preventer; 7. Bolt; 8. Clamping block; 9. Through screw; 10. Small screw; 11. Gate blowout preventer housing; 12. Gate blowout preventer gland; 13. Cylinder liner of gate blowout preventer; 14. Gate blowout preventer gland; 15. Locking sleeve of gate blowout preventer; 16. Locking rod of gate blowout preventer; 17. Connecting rod of gate blowout preventer; 18. Shearing plate of gate blowout preventer; 19. Blade of gate blowout preventer; 20. Gland blowout preventer gland. Detailed Implementation

[0056] This invention provides a method for designing the mechanical system integrity of marine oil and gas development well control equipment. This method constructs a mechanical system integrity index factor that integrates multi-source information, thereby ensuring the reliability of marine oil and gas development well control equipment throughout its entire life cycle and balancing the reliability of each component throughout its entire life cycle.

[0057] like Figure 1 As shown, the present invention provides a method for designing the integrity of a mechanical system for well control equipment in offshore oil and gas development, which specifically includes the following steps:

[0058] Step S1: Obtain the performance parameters of the key components of the mechanical system for offshore oil and gas development well control equipment. These key components include at least the vulnerable components and the drive components of the mechanical system for offshore oil and gas development well control equipment.

[0059] To facilitate understanding of the present invention by those skilled in the art, the applicant hereby uses a deepwater wellhead subsea blowout preventer (BOP) stack as an example and describes the design process of the mechanical system integrity design method for offshore oil and gas development well control equipment provided by the present invention as follows. Specifically, this deepwater wellhead subsea BOP stack operates in deepwater environments and is used to achieve rapid well sealing, shearing of drill strings, and sealing of the wellhead under extreme conditions such as well blowouts. The deepwater wellhead subsea BOP stack includes an annular BOP structure (see reference...). Figure 2 ) and the structure of the gate blowout preventer (see reference) Figure 3 ).

[0060] It is worth noting that, for reference, Figure 2 ,like Figure 3 As shown, for the subsea blowout preventer assembly with the above-described structure at the deepwater wellhead, its vulnerable components include at least an annular blowout preventer rubber core 4, an annular blowout preventer wear pad 6, and a gate blowout preventer blade 19. Furthermore, the drive assembly includes at least an annular blowout preventer drive piston 2, a gate blowout preventer connecting rod 17, and a gate blowout preventer shear plate 18.

[0061] Further testing was conducted using a testing platform to obtain the performance parameters of the key components of the aforementioned deepwater wellhead subsea blowout preventer assembly in batches, by component, and by time period. Specifically, the performance parameters of the obtained key components are described below:

[0062] Performance parameters of the annular blowout preventer core, including the rubber compression deformation of the core (preferably). ) and the aging coefficient of the rubber core (preferably) ); Performance parameters of the annular blowout preventer wear pad, such as axial compression ratio (preferably ), and core shape factor (preferably) ); Performance parameters of the gate blowout preventer blade, including calibrated shearing performance (preferably ), blade yield strength (preferably) Blade hardness (preferred) ) and the Poisson's ratio of the blade edge (preferably) ), etc.; the performance parameters of the annular blowout preventer drive piston include the rated drive pressure of the drive piston (preferably...). ), drive piston contact surface inclination angle (preferably) ) and drive piston pressure leakage rate (preferably ); Performance parameters of the gate blowout preventer linkage, including calibrated drive performance (preferably ), connecting rod yield strength (preferably) ) and link stiffness (preferably ); Performance parameters of the shear plate of the blowout preventer, such as the shear plate yield strength (preferably) ) and shear plate hardness (preferably) )etc.

[0063] Step S2: Calculate the performance parameters of the overall structure of the mechanical system of the well control equipment for offshore oil and gas development.

[0064] Based on completing step S1, step S2 is further implemented. As a preferred embodiment of the present invention, the following examples are used to illustrate the sealing performance of the annular blowout preventer core, the degradation rate of the sealing performance of the annular blowout preventer core, the driving performance of the annular blowout preventer drive piston, the degradation rate of the driving performance of the annular blowout preventer drive piston, the shearing performance of the gate blowout preventer blade, the degradation rate of the shearing performance of the gate blowout preventer blade, the driving performance of the gate blowout preventer shearing plate, and the degradation rate of the driving performance of the gate blowout preventer shearing plate.

[0065] The formula for calculating the sealing performance of the annular blowout preventer core is as follows: ;

[0066] in, For the sealing performance of the ring-shaped blowout preventer core, K represents the pre-compression pressure of the annular blowout preventer core 4, and K is the shape factor of the annular blowout preventer core. The driving pressure for the piston of the annular blowout preventer.

[0067] Annular Blowout Preventer Core Pre-compression Pressure The calculation formula is: ;

[0068] in, The rated pre-compression pressure is given by Cr, where Cr is the compression deformation of the rubber core and d is the aging coefficient of the rubber core. The axial compression ratio of the annular blowout preventer wear pad.

[0069] By substituting the parameter values ​​from the aforementioned embodiments, the sealing performance of the annular blowout preventer core can be calculated. The pre-compression pressure satisfies the following: . This refers to the actual driving pressure of the piston, which is preferably selected here. .get: .

[0070] The formula for calculating the driving performance of the annular blowout preventer's drive piston is as follows: ;

[0071] in, K represents the driving performance of the piston driven by the annular blowout preventer, and K is the shape factor of the annular blowout preventer's rubber core. The rated driving pressure of the driving piston is given by θ, where θ is the inclination angle of the driving piston contact surface. To drive the piston pressure leakage rate.

[0072] Substituting the parameter values ​​from the aforementioned embodiments, the following calculations are obtained: .

[0073] The formula for calculating the shearing performance of the blowout preventer blade is as follows: ;

[0074] in, For the shearing performance of the blowout preventer blade, The calibration shearing performance of the blowout preventer blade is determined. The yield strength of the blade. For blade hardness, The Poisson's ratio is the blade edge.

[0075] Substituting the parameter values ​​from the aforementioned embodiments, the following calculations are obtained: .

[0076] The formula for calculating the driving performance of the shear plate of the gate blowout preventer is: ;

[0077] in, For the driving performance of the shear plate of the gate blowout preventer, To calibrate the drive performance of the shear plate of the gate blowout preventer. The link yield strength, For the stiffness of the connecting rod, The shear plate yield strength, This refers to the shear plate hardness.

[0078] Substituting the parameter values ​​from the aforementioned embodiments, the following calculations are obtained: .

[0079] In addition, the formula for calculating the degradation rate of the sealing performance of the annular blowout preventer core is as follows: ;

[0080] in, The degradation rate of the sealing performance of the annular blowout preventer core. For the initial sealing performance of the annular blowout preventer core, The coefficient of degradation rate of the sealing performance of the annular blowout preventer core is given by t, where t is the degradation time in meters. s The degradation time index represents the sealing performance of the annular blowout preventer core; among which, and m s The sealing performance of the annular blowout preventer core was calculated by fitting the data at different times.

[0081] The formula for calculating the degradation rate of the driving performance of the annular blowout preventer's drive piston is as follows: ;

[0082] in, The degradation rate of the driving performance of the annular blowout preventer's drive piston. The initial driving performance of the annular blowout preventer drive piston. The coefficient representing the degradation rate of the driving performance of the annular blowout preventer's drive piston is given by t, where t is the degradation time, and m is the time factor. d The degradation time index is the driving performance degradation time index of the annular blowout preventer's drive piston, where, and m d The driving performance of the annular blowout preventer piston at different times was obtained through fitting calculations.

[0083] The formula for calculating the degradation rate of the shearing performance of the blowout preventer blade is as follows: ;

[0084] in, The degradation rate of the shearing performance of the blowout preventer blade. The initial shearing performance of the blowout preventer blade. The degradation rate coefficient of the shear performance of the blowout preventer blade is given by t, where t is the degradation time in meters. sh The degradation time index is the shearing performance of the blowout preventer blade, where... and m sh The results were obtained by fitting and calculating the shear performance of the blowout preventer blade at different times.

[0085] The formula for calculating the degradation rate of the driving performance of the blowout preventer shear plate is as follows: ;

[0086] in, The degradation rate of the driving performance of the shear plate of the gate blowout preventer. The initial driving performance of the shear plate of the gate blowout preventer. The degradation rate coefficient of the driving performance of the shear plate of the gate blowout preventer is given by t, where t is the degradation time in meters. dh The degradation time index is the driving performance of the shear plate of the blowout preventer, where, and m dh The results were obtained by fitting and calculating the driving performance of the blowout preventer shear plate at different times.

[0087] It is worth noting that, taking a 5-year service life as an example, the degradation rate of the above key structural performance is calculated.

[0088] Among them, the degradation rate of the rubber core seal meets the following requirements: ,Pick , , The piston-driven degradation rate satisfies: ,Pick , , The blade shearing degradation rate satisfies: ,Pick , , The shear plate drives the degradation rate, satisfying: ,Pick , , .

[0089] when At that time, we further obtained: , , , .

[0090] Step S3: Determine the operating environment parameters of the well control equipment for offshore oil and gas development; calculate the time-varying reliability of the mechanical system of the well control equipment for offshore oil and gas development.

[0091] Based on completing step S2, step S3 is further implemented. It is worth noting that the specific environmental parameters for the operating conditions of offshore oil and gas development well control equipment include the type of installation platform, the height or water depth of the installation platform, structural weight requirements, structural height requirements, operating temperature requirements, ocean current velocity, and plugging pressure requirements. Specifically, as a preferred embodiment of the present invention, the process of determining the environmental parameters for offshore oil and gas development well control equipment includes:

[0092] The type of installation platform is defined as a deterministic parameter; the height or water depth of the installation platform, structural weight requirements, structural height requirements, operating temperature requirements, and sealing pressure requirements of ocean current velocity are defined as random probabilistic parameters.

[0093] For random probability parameters, the cumulative distribution function is: ;

[0094] Where pa is an arbitrary random probability parameter. Let be the cumulative distribution function with arbitrary random probability parameters. Let pa be the initial load probability density function with arbitrary random probabilistic parameters. max Let pa be the maximum value of any random probability parameter. min It is the minimum value of any random probability parameter;

[0095] Let any random probability parameter be within the range [pa] min pa max The area is divided into M regions, and random numbers nr are drawn from the uniformly distributed interval [0,1]. In the m-th interval, the sample of any random probability parameter is: ;

[0096] in, Let m be a sample of any random probability parameter in the m-th interval. It is the inverse function of the cumulative distribution function of any random probability parameter.

[0097] It should be added that, as an optional implementation of the present invention, the value range of the relevant environmental parameters (all environmental parameters are random probabilistic parameters) can be specifically referred to as follows: Water depth: Operating temperature: (Used for the temperature term in the subsequent integrity index; absolute temperature TK is used in the calculation); Ocean current velocity: Sealing pressure requirements: .

[0098] According to the stratified sampling method described in step S3: the interval is divided into Given a segment with random numbers nr = [0.42, 0.15, 0.77, 0.63, 0.05], the sample of the m-th segment is: .

[0099] Further defining the above environmental parameters as uniformly distributed within an interval, we obtain a set of sample data, namely: water depth sample: ;

[0100] Temperature sample: ;

[0101] Flow rate sample: ;

[0102] Flow rate sample: .

[0103] Furthermore, as a preferred embodiment of the present invention, the process of calculating the time-varying reliability of the mechanical system of the offshore oil and gas development well control equipment in step S3 specifically includes:

[0104] The time-varying reliability calculation method for mechanical systems of well control equipment in offshore oil and gas development is as follows: ;

[0105] Where λ(t) is the time-varying failure rate function, c is the characteristic factor of well control equipment for offshore oil and gas development, representing the annular blowout preventer or the gate blowout preventer; e is the base of the natural logarithm, and t is time;

[0106] ;

[0107] Wherein, β is the shape parameter, η is the scale parameter, and γ is the position parameter. The parameter values ​​are obtained by mathematical estimation of the performance parameters of key components of the mechanical system of well control equipment for offshore oil and gas development and the operating environment parameters of well control equipment for offshore oil and gas development.

[0108] Specifically, by substituting the corresponding parameters, we obtain the time-varying reliability calculation method for the well control equipment mechanical system, which satisfies: , Among them, take , , Year, In the year, then in Year: .

[0109] Step S4: Construct the integrity index factor of the mechanical system of well control equipment for offshore oil and gas development.

[0110] Based on completing step S3, step S4 is further implemented. As a preferred embodiment of the present invention, the process of constructing the integrity index factor of the mechanical system of offshore oil and gas development well control equipment in step S4 specifically includes:

[0111] Among them, the integrity index factor of the mechanical system of well control equipment for offshore oil and gas development satisfies: ;

[0112] in, R is the mechanical system integrity index factor for well control equipment in offshore oil and gas development. max R represents the maximum time-varying reliability of the well control equipment's mechanical system. min This represents the minimum time-varying reliability of the well control equipment's mechanical system. This refers to the driving performance of the piston in a ring-shaped blowout preventer or the driving performance of the shear plate in a gate-type blowout preventer. For the sealing performance of the rubber core of the annular blowout preventer or the shearing performance of the blade of the gate blowout preventer, a i Let n be the number of key component performance parameters of the mechanical system of well control equipment for any offshore oil and gas development, and a be the number of key component performance parameters of the mechanical system of well control equipment for offshore oil and gas development. i (t) represents the test data of the performance parameters of key components of the mechanical system of any offshore oil and gas development well control equipment at different times; c represents the characteristic factor of the offshore oil and gas development well control equipment, characterizing the annular blowout preventer or the gate blowout preventer; T represents the expected operating temperature of the offshore oil and gas development well control equipment. The average test data of key component performance parameters for mechanical systems of well control equipment in any offshore oil and gas development. Standard deviation of test data for performance parameters of key components of mechanical systems for well control equipment in any offshore oil and gas development.

[0113] It should be noted that, for ease of parameter substitution, six key parameters of the annular blowout preventer are selected here and dimensionless:

[0114] For details, please refer to: .

[0115] The mean and standard deviation were calculated from multiple batches of test data:

[0116] ;

[0117] .

[0118] Then take ,but .

[0119] Take the absolute temperature .

[0120] by The year is the evaluation point, taken as... , Then the calculation yields: .

[0121] Will , Perform relativization (normalize to initial value), and in Summing the results at the three time points and substituting them into the integrity factor formula, we finally obtain:

[0122] Annular blowout preventer integrity: .

[0123] Shear gate blowout preventer integrity: .

[0124] Therefore, the integrity index of the blowout preventer mechanical system is taken as: .

[0125] Step S5: Complete the integrity optimization design of the mechanical system of well control equipment for offshore oil and gas development.

[0126] Based on the completion of step S4, further implement step S5. Specifically, the process of completing the integrity optimization design of the mechanical system of offshore oil and gas development well control equipment can be described as follows: According to the actual engineering needs, firstly, set the threshold of the integrity index factor of the mechanical system of offshore oil and gas development well control equipment; then, using the integrity index factor of the mechanical system of offshore oil and gas development well control equipment as the objective function, the operating environment parameters of the offshore oil and gas development well control equipment as the constraint condition, and the integrity index factor being higher than the threshold as the optimization condition, calculate the optimal combination of performance parameters of key components of the mechanical system of offshore oil and gas development well control equipment.

[0127] In a preferred embodiment of the present invention, the integrity index factor of the mechanical system of offshore oil and gas development well control equipment is first designed, and the operating environment parameters of the offshore oil and gas development well control equipment are constrained. Specifically, the variable vector can be designed as follows: The range of values ​​can be referenced as follows: .

[0128] Then, using the system integrity index in The objective is to maximize the value at time t, i.e.: .in, It is worth noting that, due to the aforementioned steps, The current level is already high and is no longer a bottleneck, so optimization should mainly focus on improving... .

[0129] Among them, satisfying the integrity threshold requirement, we get: .

[0130] For ease of calculation, a penalty function can be used: Thus, to actually maximize optimization .

[0131] Finally, the optimal parameters are combined. Specifically, Particle Swarm Optimization (PSO) is used to optimize the above process, with 12 particles, 25 iterations, an inertia weight of 0.7, and a learning factor of 1.5. In each iteration, the particles update their velocity and position based on individual and global optima, and boundary truncation is performed. Fitness evaluation is based on a given performance degradation formula chain. At the target time (5 years), the performance degradation values ​​of the rubber core seal and the drive piston are calculated to obtain the system integrity index, which is used as the optimization objective of PSO for iterative updates until the stopping condition is met. The calculated optimal parameter combination satisfies the following: .

[0132] Substituting further into the existing formula, the key performance characteristics can be obtained, which satisfy: ; and, the pre-compression pressure, satisfying: The sealing performance of the rubber core meets the following requirements: The driving performance of the piston meets the following requirements: .

[0133] The performance after 5 years of degradation is detailed below: ; ; .

[0134] Furthermore, the annular blowout preventer was obtained through the integrity index calculation process. The blowout preventer on the gate remains at its previous value. The final calculation yields, It meets the integrity threshold requirements.

[0135] The optimal combination of key component performance parameters can be obtained by referring to the table below:

[0136] .

[0137] Thus, the integrity design method for the mechanical system of offshore oil and gas development well control equipment provided by this invention completes the integrity optimization design of the mechanical system of offshore oil and gas development well control equipment. The integrity optimization design records the optimal combination of performance parameters for key components of the offshore oil and gas development well control equipment mechanical system.

[0138] This invention provides a method for designing the integrity of a mechanical system for well control equipment in offshore oil and gas development. Specifically, this method includes the following steps: obtaining performance parameters of key components of the mechanical system; calculating the performance parameters of the overall structure of the mechanical system; determining the operating environment parameters of the well control equipment; calculating the time-varying reliability of the mechanical system; constructing an integrity index factor for the mechanical system; and, based on actual engineering needs, setting a threshold for the integrity index factor, using the integrity index factor as the objective function, the operating environment parameters as constraints, and an integrity index factor exceeding the threshold as an optimization condition, calculating the optimal combination of performance parameters for the key components of the mechanical system, thereby completing the integrity optimization design of the mechanical system.

[0139] The method for designing the integrity of mechanical systems for well control equipment in offshore oil and gas development, which features the above-mentioned steps, has at least the following technical advantages compared to existing technologies:

[0140] (1) The integrity design method of the marine oil and gas development well control equipment mechanical system provided by the present invention obtains accurate performance parameters (data) of key components of the marine oil and gas development well control equipment mechanical system through the test platform; and effectively estimates the reliability of the well control equipment throughout its entire life cycle through the time-varying reliability calculation model of the marine oil and gas development well control equipment mechanical system.

[0141] (2) The marine oil and gas development well control equipment mechanical system integrity design method provided by the present invention ensures the working reliability of marine oil and gas development well control equipment throughout its entire life cycle and balances the working reliability of each component throughout its entire life cycle by constructing a marine oil and gas development well control equipment mechanical system integrity index factor that integrates multi-source information.

[0142] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for designing the integrity of mechanical systems for well control equipment in offshore oil and gas development, characterized in that, The steps include the following: Step S1: Obtain the performance parameters of the key components of the mechanical system of the well control equipment for offshore oil and gas development; wherein, the key components of the mechanical system of the well control equipment for offshore oil and gas development include at least the vulnerable components of the mechanical system of the well control equipment for offshore oil and gas development and the drive components of the mechanical system of the well control equipment for offshore oil and gas development. Step S2: Calculate the performance parameters of the overall structure of the mechanical system of the well control equipment for offshore oil and gas development; Step S3: Determine the operating environment parameters of the well control equipment for offshore oil and gas development; calculate the time-varying reliability of the mechanical system of the well control equipment for offshore oil and gas development. Step S4: Construct the integrity index factor for the mechanical system of well control equipment in offshore oil and gas development; Step S5: Based on actual engineering needs, set the threshold for the integrity index factor of the mechanical system of the well control equipment for offshore oil and gas development. Using the integrity index factor of the mechanical system of the well control equipment for offshore oil and gas development as the objective function, the working environment parameters of the well control equipment for offshore oil and gas development as the constraint, and the integrity index factor being higher than the threshold as the optimization condition, calculate the optimal combination of performance parameters of key components of the mechanical system of the well control equipment for offshore oil and gas development, thereby completing the integrity optimization design of the mechanical system of the well control equipment for offshore oil and gas development. The process of calculating the overall structural performance parameters of the mechanical system of the offshore oil and gas development well control equipment in step S2 specifically includes: The formula for calculating the sealing performance of the annular blowout preventer core is as follows: ; in, For the sealing performance of the ring-shaped blowout preventer core, Where is the pre-compression pressure of the annular blowout preventer core, and K is the shape factor of the annular blowout preventer core. The driving pressure for the piston of the annular blowout preventer; Annular Blowout Preventer Core Pre-compression Pressure The calculation formula is: ; in, The rated pre-compression pressure is given by Cr, where Cr is the compression deformation of the rubber core and d is the aging coefficient of the rubber core. The axial compression ratio of the annular blowout preventer wear pad; The formula for calculating the driving performance of the annular blowout preventer's drive piston is as follows: ; in, K represents the driving performance of the piston driven by the annular blowout preventer, and K is the shape factor of the annular blowout preventer's rubber core. The rated driving pressure of the driving piston is given by θ, where θ is the inclination angle of the driving piston contact surface. To drive the piston pressure leakage rate; The formula for calculating the shearing performance of the blowout preventer blade is as follows: ; in, For the shearing performance of the blowout preventer blade, The calibration shearing performance of the blowout preventer blade is determined. The yield strength of the blade. For blade hardness, Poisson's ratio of the blade edge; The formula for calculating the driving performance of the shear plate of the gate blowout preventer is: ; in, For the driving performance of the shear plate of the gate blowout preventer, To calibrate the drive performance of the shear plate of the gate blowout preventer. The link yield strength, For the stiffness of the connecting rod, The shear plate yield strength, The shear plate hardness; The formula for calculating the degradation rate of the sealing performance of the annular blowout preventer core is as follows: ; in, The degradation rate of the sealing performance of the annular blowout preventer core. For the initial sealing performance of the annular blowout preventer core, The coefficient of degradation rate of the sealing performance of the annular blowout preventer core is given by t, where t is the degradation time in meters. s The degradation time index represents the sealing performance of the annular blowout preventer core; among which, and m s The sealing performance of the annular blowout preventer core at different times was obtained through fitting calculation. The formula for calculating the degradation rate of the driving performance of the annular blowout preventer's drive piston is as follows: ; in, The degradation rate of the driving performance of the annular blowout preventer's drive piston. The initial driving performance of the annular blowout preventer drive piston. The coefficient representing the degradation rate of the driving performance of the annular blowout preventer's drive piston is given by t, where t is the degradation time, and m is the time factor. d The degradation time index is the driving performance degradation time index of the annular blowout preventer's drive piston, where, and m d The driving performance of the annular blowout preventer piston at different times was obtained through fitting calculation. The formula for calculating the degradation rate of the shearing performance of the blowout preventer blade is as follows: ; in, The degradation rate of the shearing performance of the blowout preventer blade. The initial shearing performance of the blowout preventer blade. The degradation rate coefficient of the shear performance of the blowout preventer blade is given by t, where t is the degradation time in meters. sh The degradation time index is the shearing performance of the blowout preventer blade, where... and m sh The results were obtained by fitting and calculating the shear performance of the blowout preventer blade at different times; The formula for calculating the degradation rate of the driving performance of the blowout preventer shear plate is as follows: ; in, The degradation rate of the driving performance of the shear plate of the gate blowout preventer. The initial driving performance of the shear plate of the gate blowout preventer. The degradation rate coefficient of the driving performance of the shear plate of the gate blowout preventer is given by t, where t is the degradation time in meters. dh The degradation time index is the driving performance of the shear plate of the blowout preventer, where, and m dh The results were obtained by fitting and calculating the driving performance of the blowout preventer shear plate at different times.

2. The method for designing the integrity of the mechanical system of offshore oil and gas development well control equipment according to claim 1, characterized in that, The process of determining the operating environment parameters of the offshore oil and gas development well control equipment in step S3 specifically includes: The type of installation platform is defined as a deterministic parameter, while the height or water depth of the installation platform, structural weight requirements, structural height requirements, working temperature requirements, and sealing pressure requirements of ocean current velocity are defined as random probabilistic parameters. For the random probability parameter, its cumulative distribution function is: ; Where pa is an arbitrary random probability parameter. Let be the cumulative distribution function with arbitrary random probability parameters. Let pa be the initial load probability density function with arbitrary random probabilistic parameters. max Let pa be the maximum value of any random probability parameter. min It is the minimum value of any random probability parameter; Let any random probability parameter be within the range [pa] min pa max The area is divided into M regions, and random numbers nr are drawn from the uniformly distributed interval [0,1]. In the m-th interval, the sample of any random probability parameter is: ； in, Let m be a sample of any random probability parameter in the m-th interval. It is the inverse function of the cumulative distribution function of any random probability parameter.

3. The method for designing the integrity of the mechanical system of offshore oil and gas development well control equipment according to claim 1, characterized in that, The process of calculating the time-varying reliability of the mechanical system of the well control equipment for offshore oil and gas development in step S3 specifically includes: The time-varying reliability calculation method for mechanical systems of well control equipment in offshore oil and gas development is as follows: ; Where λ(t) is the time-varying failure rate function, c is the characteristic factor of well control equipment for offshore oil and gas development, representing the annular blowout preventer or the gate blowout preventer; e is the base of the natural logarithm, and t is time; ； Wherein, β is the shape parameter, η is the scale parameter, and γ is the position parameter. The parameter values ​​are obtained by mathematical estimation of the performance parameters of key components of the mechanical system of well control equipment for offshore oil and gas development and the operating environment parameters of well control equipment for offshore oil and gas development.

4. The method for designing the integrity of the mechanical system of offshore oil and gas development well control equipment according to claim 1, characterized in that, The process of constructing the integrity index factor of the mechanical system of offshore oil and gas development well control equipment in step S4 specifically includes: Among them, the integrity index factor of the mechanical system of well control equipment for offshore oil and gas development satisfies: ； in, R is the mechanical system integrity index factor for well control equipment in offshore oil and gas development. max R represents the maximum time-varying reliability of the well control equipment's mechanical system. min This represents the minimum time-varying reliability of the well control equipment's mechanical system. This refers to the driving performance of the piston in a ring-shaped blowout preventer or the driving performance of the shear plate in a gate-type blowout preventer. For the sealing performance of the rubber core of the annular blowout preventer or the shearing performance of the blade of the gate blowout preventer, a i Let n be the number of key component performance parameters of the mechanical system of well control equipment for any offshore oil and gas development, and a be the number of key component performance parameters of the mechanical system of well control equipment for offshore oil and gas development. i (t) represents the test data of the performance parameters of key components of the mechanical system of any offshore oil and gas development well control equipment at different times; c represents the characteristic factor of the offshore oil and gas development well control equipment, characterizing the annular blowout preventer or the gate blowout preventer; T represents the expected operating temperature of the offshore oil and gas development well control equipment. The average test data of key component performance parameters for mechanical systems of well control equipment in any offshore oil and gas development. Standard deviation of test data for performance parameters of key components of mechanical systems for well control equipment in any offshore oil and gas development.

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