Vibration reduction tool optimization method and device based on drill string dynamic model

Abstract

The invention relates to the technical field of petroleum and natural gas drilling engineering, in particular to a vibration reduction tool optimization method and device based on a drill string dynamic model, and mainly solves the problems that an existing drill string dynamic model cannot effectively simulate the vibration reduction effect of a vibration damper and cannot determine the arrangement interval of the vibration damper. The method comprises the following steps: establishing a nonlinear vibration model of a drill string system; establishing a damper rigidity replacement mathematical model; s2, solving the nonlinear vibration model in the step S1 by adopting a finite element method to obtain a dynamic response of the drill string system; and changing parameters of the shock absorber, performing drill string vibration simulation based on the nonlinear vibration model, analyzing vibration data of the shock absorber under different parameters, and determining a dessert interval for arrangement of the shock absorber. The device can simulate the longitudinal and transverse torsion damping effect of the damper, so that the arrangement position of the damper is determined, the drilling safety is ensured, the service life of a drill bit is prolonged, the drilling efficiency is improved, and effective reference data is provided for relieving or inhibiting harmful vibration of a drill column.

Description

Technical Field

[0001] This invention relates to the field of oil and gas drilling engineering technology, and in particular to a method and apparatus for optimizing vibration reduction tools based on a drill string dynamics model. Background Technology

[0002] In complex oil and gas well drilling operations, the drill string is subjected to a variety of complex forces, including axial tension and compression, lateral bending, and torsional moments, resulting in nonlinear vibrations. This can lead to accidents such as drill string fatigue fracture, drill bit damage, and wellbore deviation, posing numerous challenges to drilling production. Vibration dampers can effectively reduce drill string vibration. However, current applications of vibration dampers are largely based on field experience, lacking drill string dynamic models that can truly simulate the vibration reduction effect of dampers. Existing drill string dynamic models mostly simulate the response trends of tools that can generate excitation forces, such as hydraulic oscillators, and only analyze single axial vibrations. They cannot effectively simulate the vibration reduction effect of vibration dampers, lack a clear optimization range, and there are no relevant dynamic models to simulate the vibration reduction effect of vibration dampers containing pressure-torsion conversion mechanisms. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention provides a method for optimizing vibration reduction tools based on a drill string dynamics model. This optimization method can simulate the longitudinal and transverse torsional vibration reduction effects of the vibration damper, thereby determining the placement of the vibration damper, ensuring drilling safety, improving drill bit life and drilling efficiency, and providing effective reference data for mitigating or suppressing harmful vibrations of the drill string.

[0004] The technical solution of this invention is: a vibration reduction tool optimization method based on a drill string dynamics model, comprising:

[0005] S1. Establish a nonlinear vibration model of the drill string system, which can characterize the coupling effect of longitudinal, transverse and torsional vibrations of the drill string system;

[0006] S2. Establish a mathematical model for the stiffness replacement of the vibration damper;

[0007] S3. Solve the nonlinear vibration model in step S1 using the finite element method to obtain the dynamic response of the drill string system;

[0008] S4. Change the vibration damper parameters, simulate the drill string vibration based on the nonlinear vibration model, analyze the vibration data of the vibration damper under different parameters, and determine the sweet spot range of the vibration damper arrangement.

[0009] Furthermore, the nonlinear vibration model of the drill string system in step S1 is as follows:

[0010] ,

[0011] ,

[0012]

[0013] In the formula: F u - Lateral external load on the column, N•m;

[0014] F w - The longitudinal external load on the rod, N•m;

[0015] M - Torsional load on the rod, N•m;

[0016] ρ - Density of drill string, kg / m 3 ;

[0017] A - Cross-sectional area of ​​the drill string, in meters 2 ;

[0018] E - Elastic modulus, Pa;

[0019] I - Moment of inertia of the cross section, m 4 ;

[0020] u, v, and w represent the displacements of the rod in the x, y, and z directions, respectively, in meters (m).

[0021] Φ - Torsion angle produced by the oil pipe, in rad;

[0022] ξ - Nonlinear or coupling factor;

[0023] G - Shear modulus, Pa;

[0024] , .

[0025] Furthermore, step S1 includes:

[0026] S11. Establish a three-dimensional coordinate system using the drill string system, and determine the displacement of any point on the cross-section in the three-dimensional coordinate system along the x-axis and y-axis. When the torsional angle Φ generated by the tubing is small, the displacement field function is:

[0027] ,

[0028] Where: Φ - the torsion angle generated by the oil pipe, rad;

[0029] u x - Displacement along the x-axis, in meters;

[0030] U y - Displacement along the y-axis, in meters;

[0031] u z - Displacement along the z-axis, in meters;

[0032] t - time, s;

[0033] u, v, and w represent the displacements of the rod in the x, y, and z directions, respectively, in meters (m).

[0034] S12, The strain in the displacement field of the drill string system is:

[0035] ;

[0036] In the formula: -Strain in the z-axis direction;

[0037] Strain in the -xz direction;

[0038] Strain in the -yz direction;

[0039] ξ - Nonlinear or coupling factor;

[0040] S13, The potential energy of the drill string system is:

[0041] ,

[0042] Where: U - drill string potential energy, J;

[0043] E - Elastic modulus, Pa;

[0044] I - Moment of inertia of the cross section, m 4 ;

[0045] A - Cross-sectional area of ​​the drill string, in meters 2 ;

[0046] G - Shear modulus, Pa;

[0047] γ - Shear strain, dimensionless;

[0048] S14, The kinetic energy of the drill string system is:

[0049] ,

[0050] The non-conservative external force work on the drill string includes three parts: axial force work, lateral force work, and torque work, respectively, with the following expressions:

[0051] ,

[0052] In the formula: W z -Axial force work, J;

[0053] W xy - Lateral force work, J;

[0054] W T - Torque work, J;

[0055] L - Length of the drill string system, in meters;

[0056] F w (z,t) - Longitudinal external load on the drill string, N / m;

[0057] F u (z,t) - The component of the lateral external load on the drill string along the x-axis, N / m;

[0058] F v (z,t) - The component of the lateral external load on the drill string along the y-axis, N / m;

[0059] T(z,t) - Torque on the drill string, N / m;

[0060] S15. According to Hamilton's variational formula, we get:

[0061] ,

[0062] In the formula: δ - variational operator, dimensionless;

[0063] T - Kinetic energy of the drill string, J;

[0064] U - Drill string potential energy, J;

[0065] W - Work done by the drill string, J;

[0066] The nonlinear vibration model of the drill string system was obtained by sorting it out.

[0067] Furthermore, step S11 includes: establishing a three-dimensional coordinate system using the drill string system, wherein the displacement of any point (r, α) on the cross-section in the three-dimensional coordinate system along the x-axis and y-axis directions is:

[0068] ;

[0069] In the formula: α - initial eccentricity angle, rad;

[0070] Φ - Torsion angle produced by the oil pipe, in rad;

[0071] u x - Displacement along the x-axis, in meters;

[0072] u y - Displacement along the y-axis, in meters;

[0073] r - displacement of the center of mass, m;

[0074] u - Displacement of the rod in the x-direction, in meters;

[0075] v - Displacement of the rod in the y direction, in meters;

[0076] When Φ is a small quantity, cosΦ≈1, sinΦ≈1, then:

[0077] ;

[0078] The displacement field function is then:

[0079] ;

[0080] In the formula: u z - Displacement along the z-axis, in meters;

[0081] t - time, s;

[0082] u, v, and w represent the displacements of the rod in the x, y, and z directions, respectively, in meters (m).

[0083] Furthermore, step S12 includes:

[0084] The strain in the displacement field is determined as follows:

[0085] ;

[0086] In the formula: - Dependent variable;

[0087] ξ - Nonlinear or coupling factor;

[0088] For drill string systems, the rod stress is mainly axial stress, then

[0089] ,

[0090] ,

[0091] In the formula: Stress in the -x direction, Pa;

[0092] Stress in the -y direction, Pa;

[0093] - Shear stress in the x and y directions, Pa;

[0094] -Strain in the xy direction;

[0095] -x direction of strain;

[0096] -y direction of strain;

[0097] Strain in the -z direction;

[0098] The strain is obtained by using Einstein's summation law.

[0099] Furthermore, the mathematical model for damper stiffness permutation in step S2 is as follows:

[0100] ,

[0101] Where: K(i,i) - stiffness of the stiffness matrix corresponding to the vibration damper, N / m;

[0102] K z - Stiffness of the vibration damper in the stiffness matrix of the drill string system, N / m.

[0103] Furthermore, the damper parameters in step S4 include: damper placement position, damper preload, and damping stiffness value.

[0104] Furthermore, step S4 includes:

[0105] S41. Based on the nonlinear vibration model of the drill string system, simulate the longitudinal and transverse torsional coupled vibration of the drill string without dampers, and record the vibration data.

[0106] S42. Add vibration dampers to the drill string system, determine a set of vibration damper parameters, perform longitudinal and transverse torsional coupling vibration simulation of the drill string, and record the vibration data.

[0107] S43. Repeat step S42 to simulate the longitudinal and transverse torsional coupling vibration of the drill string, changing the parameters of the vibration damper each time and recording the data respectively.

[0108] S44. Compare the parameters in steps S41 to S43 to obtain the vibration reduction effect of different positions of the vibration damper and determine the sweet spot range of the vibration damper arrangement.

[0109] A vibration reduction tool optimization device based on a drill string dynamics model includes a vibration model establishment module, a vibration damper model establishment module, a calculation module, and a simulation module.

[0110] The vibration model building module is used to build a nonlinear vibration model of the drill string system, which can characterize the coupling effect of longitudinal, transverse and torsional vibrations of the drill string system.

[0111] The vibration damper model building module is used to build a mathematical model of vibration damper stiffness permutation.

[0112] The calculation module is used to solve the nonlinear vibration model to obtain the dynamic response of the drill string system;

[0113] The simulation module is used to simulate drill string vibration, analyze vibration data of the damper under different parameters, and determine the sweet spot range of the damper arrangement.

[0114] A computer-readable storage medium includes a stored computer program, wherein the computer program is executed by an electronic device to perform the method.

[0115] An electronic device includes a processor and a memory, the memory storing at least one computer program, the computer program being loaded and executed by one or more of the processors to enable the computer to implement the vibration damping tool optimization method.

[0116] The present invention has the following beneficial effects: (1) The present invention can accurately replace the stiffness of the damper with the pressure-torsion conversion mechanism into the longitudinal-lateral-torsion coupled finite element model, and realize the numerical prediction of the damping amplitude of the damper.

[0117] (2) The present invention establishes longitudinal-transverse-torsional coupling control equations and dual-coupled Newmark-β solution architecture, achieving the purpose of bidirectional coupling and more closely reflecting the actual vibration situation.

[0118] (3) The model of the present invention is also applicable to the dynamic simulation of other downhole tools such as hydraulic oscillators and screw drills, laying a unified model foundation for subsequent multi-tool collaborative optimization.

[0119] (4) The method of the present invention can clearly define the sweet spot arrangement position of the vibration damper, significantly reduce drill string vibration, reduce wellbore dogleg degree and well deviation fluctuation, improve wellbore quality, and reduce subsequent well workover operations.

[0120] (5) This invention reduces the probability of downhole failures such as drill string breakage and MWD / LWD instrument failure caused by vibration through a digital operation process of “simulation first, then well entry”, and improves the average life of drill bits. Attached Figure Description

[0121] Figure 1 This is a flowchart of the present invention;

[0122] Figure 2 This is a schematic diagram illustrating the solution using a dual-coupled system in this invention;

[0123] Figure 3 This is a schematic diagram of the X-axis amplitude before and after simulating the use of the vibration damper in an embodiment of the present invention;

[0124] Figure 4 This is a schematic diagram simulating the Y-axis amplitude before and after using the vibration damper in an embodiment of the present invention;

[0125] Figure 5 This is a schematic diagram simulating the Z-axis amplitude before and after using the vibration damper in an embodiment of the present invention;

[0126] Figure 6 This is a schematic diagram illustrating the vibration reduction effect of the damper with different damping stiffness under different preload values ​​in an embodiment of the present invention.

[0127] Figure 7 This is a schematic diagram illustrating the vibration reduction effect of simulating vibration dampers arranged at different positions on the drill string in an embodiment of the present invention. Detailed Implementation

[0128] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0129] Depend on Figure 1 As shown, a vibration reduction tool optimization method based on a drill string dynamics model includes:

[0130] S1. Establish a nonlinear longitudinal, transverse and torsional coupled vibration model of the drill string system. For ease of description, it will be referred to as the nonlinear vibration model. The nonlinear vibration model can characterize the coupling effect of longitudinal, transverse and torsional vibrations of the drill string system.

[0131] S2. Establish a mathematical model for the stiffness replacement of the vibration damper;

[0132] S3. Solve the nonlinear vibration model in step S1 using the finite element method to obtain the dynamic response of the drill string system;

[0133] S4. Change the vibration damper parameters, simulate drill string vibration based on the nonlinear vibration model, analyze the vibration data of the vibration damper under different parameters, and determine the sweet spot range for the vibration damper arrangement. The vibration damper parameters include: vibration damper arrangement position, vibration damper preload, and vibration damping stiffness value.

[0134] The steps of this invention will be described in detail below.

[0135] Step S1 includes:

[0136] S11. Using the drill string system, establish a Cartesian three-dimensional coordinate system. The displacement of any point on the cross-section in the three-dimensional coordinate system is equal to the displacement of the centroid o' of the cross-section plus the displacement Φ caused by torsion. Then, the displacement of any point (r, α) on the cross-section along the x-axis and y-axis is:

[0137] (1)

[0138] In the formula: α - initial eccentricity angle, rad;

[0139] Φ - Torsion angle produced by the oil pipe, in rad;

[0140] u x- Displacement along the x-axis, in meters;

[0141] u y - Displacement along the y-axis, in meters;

[0142] r - displacement of the center of mass, m;

[0143] u - Displacement of the rod in the x-direction, in meters;

[0144] v - Displacement of the rod in the y direction, in meters.

[0145] When Φ is a small quantity, cosΦ≈1, sinΦ≈1, substituting into formula (1) and rearranging, we get:

[0146] (2)

[0147] The displacement field function is then:

[0148] (3)

[0149] In the formula: u z - Displacement along the z-axis, in meters;

[0150] t - time, s;

[0151] u, v, and w represent the displacements of the rod in the x, y, and z directions, respectively, in meters.

[0152] S12. According to Green's strain formula, the strain in the displacement field is expressed as:

[0153] (4)

[0154] In the formula: - Dependent variable;

[0155] ξ - Nonlinear or coupling factor;

[0156] When ξ = 1, the actual nonlinear geometric equation of the drill string structure is given. When ξ = 1, equation (4) degenerates into a linear geometric equation. Since the drill string system is a slender rod with a very large length-to-diameter ratio, it can be assumed that the rod stress is mainly axial stress, then:

[0157] ,

[0158] ,

[0159] In the formula: Stress in the -x direction, Pa;

[0160] Stress in the -y direction, Pa;

[0161] - Shear stress in the x and y directions, Pa;

[0162] -Strain in the xy direction;

[0163] -x direction of strain;

[0164] -y direction of strain;

[0165] Strain in the -z direction.

[0166] Using Einstein's summation rule, the strain can be obtained as:

[0167] (5)

[0168] In the formula: , ;

[0169] Strain in the -xz direction;

[0170] The dependent variable in the -yz direction.

[0171] S13, The potential energy of the drill string system is:

[0172] (6)

[0173] In the formula: - Stress, Pa;

[0174] - Dependent variable;

[0175] U - Drill string potential energy, J;

[0176] A - Cross-sectional area of ​​the drill string, in meters 2 ;

[0177] E - Elastic modulus, Pa;

[0178] G - Shear modulus, Pa;

[0179] γ - Shear strain, dimensionless.

[0180] in:

[0181] ;

[0182] Substituting equation (5) into equation (6), and rearranging, we obtain the potential energy U of the drill string system as:

[0183] (7)

[0184] Where: I - moment of inertia of the cross section, m 4 .

[0185] S14. Obtain the velocity in each direction by taking the partial derivative of the displacement with respect to time t:

[0186]

[0187] Therefore, the kinetic energy of the drill string system is:

[0188] (8)

[0189] In the formula: -Drill string density, kg / m 3 .

[0190] The non-conservative external force work on the drill string includes three parts: axial force work, lateral force work, and torque work, respectively, with the following expressions:

[0191] (9)

[0192] In the formula: W z -Axial force work, J;

[0193] W xy - Lateral force work, J;

[0194] W T - Torque work, J;

[0195] L - Length of the drill string system, in meters;

[0196] F w (z,t) - Longitudinal external load on the drill string, N / m;

[0197] F u (z,t) - The component of the lateral external load on the drill string along the x-axis, N / m;

[0198] F v (z,t) - The component of the lateral external load on the drill string along the y-axis, N / m;

[0199] T(z,t) - Torque on the drill string, N / m.

[0200] S15. Substituting equations (7)-(9) into Hamilton's variational formula, we get:

[0201] (10)

[0202] In the formula: δ - variational operator, dimensionless;

[0203] T - Kinetic energy of the drill string, J;

[0204] U - Drill string potential energy, J;

[0205] W - Work done by the drill string, J.

[0206] After processing, the longitudinal-transverse-torsional coupled nonlinear vibration control equations of the drill string system are obtained:

[0207] (11a)

[0208] (11b)

[0209] (11c)

[0210] In the formula: F u - Lateral external load on the column, N•m;

[0211] F w - The longitudinal external load on the rod, N•m;

[0212] M - Torsional load on the rod, N•m;

[0213] ρ - Density of drill string, kg / m 3 ;

[0214] A - Cross-sectional area of ​​the drill string, in meters 2 ;

[0215] E - Elastic modulus, Pa;

[0216] I - Moment of inertia of the cross section, m 4 ;

[0217] u, v, and w represent the displacements of the rod in the x, y, and z directions, respectively, in meters (m).

[0218] Φ - Torsion angle produced by the oil pipe, in rad;

[0219] ξ - Nonlinear or coupling factor;

[0220] G - Shear modulus, Pa;

[0221] , .

[0222] Equation (11a) is the control equation for the transverse vibration u of the rod. Interchanging u and v yields the control equation for the transverse vibration v. Equations (11b) and (11c) are the control equations for the longitudinal and torsional directions of the rod, respectively. From the control equations, the following preliminary conclusions can be drawn:

[0223] If nonlinear longitudinal and transverse torsional coupling is considered, the vibration frequency in each direction includes not only the natural frequency and excitation frequency in that direction, but also various combinations and harmonics of the vibration frequency and excitation frequency in the other three directions.

[0224] If there is no excitation or initial disturbance in the lateral and torsional directions, longitudinal vibration cannot induce lateral and torsional vibration.

[0225] If there is no initial longitudinal condition of zero and no external excitation, transverse and torsional vibrations can induce longitudinal vibrations.

[0226] If one of the transverse initial conditions is zero and there is no external excitation, and there is no torsional vibration, transverse vibration in the other direction cannot cause that transverse vibration;

[0227] If the initial torsional condition is zero and there is no external excitation, a lateral vibration alone will not cause a torsional vibration.

[0228] In this invention, the purpose of step S2 is to establish a mathematical model for the stiffness replacement of the vibration damper. Typically, the drill string system includes a pressure-torque conversion mechanism and a disc spring mechanism. The pressure-torque conversion mechanism is a multi-threaded combination structure that can realize the mutual conversion of axial force and torsional force. When the vibration damper is subjected to axial force and torsional force applied by the drill bit and drill string pressure, a longitudinal and transverse torsional coupling effect is generated on the drill string. The pressure-torque conversion mechanism can apply excessive axial force to the disc spring mechanism. The disc spring mechanism is set with a preload torque starting amount to achieve different stiffness adjustments. The formula for the mutual conversion of axial force and torsional force is:

[0229] (12)

[0230] In the formula: -Conversion torque, N / m;

[0231] - Initial axial force during drilling, N;

[0232] - Helix angle of multi-start thread, °;

[0233] - Multi-start thread helical self-locking angle, °;

[0234] -Mole diameter of multi-start thread, in meters;

[0235] - Initial drill bit torque, N / m.

[0236] When the torque borne by the vibration damper reaches the starting torque, the stiffness of the drill string system is replaced; when it exceeds the limit torque, the stiffness is restored to the original system stiffness value.

[0237] (13)

[0238] In the formula: - Stiffness value of the vibration damper in the stiffness matrix of the drill string system, N / m;

[0239] - Original stiffness value of the drill string system, N / m;

[0240] - Stiffness value of the damper disc spring damping mechanism, N / m;

[0241] -Preset starting torque value for the shock absorber, N / m;

[0242] - Shock absorber limit torque value, N / m.

[0243] (14)

[0244] In the formula: , where represents the stiffness value of the stiffness matrix corresponding to the vibration damper, in N / m.

[0245] Step S3 includes the following steps:

[0246] S31. Express the longitudinal displacement w and torsional displacement of the rod using Lagrange interpolation functions. Represent the lateral displacements u and v in the x and y directions of the rod using cubic Hermitian interpolation functions:

[0247] (15)

[0248]

[0249] In the formula: The unit length is denoted as .

[0250] S32. Substituting the displacement function into the energy functional yields the standard forms of the strain energy function U and the kinetic energy function T, expressed in terms of nodal displacement vectors:

[0251] (16)

[0252] The element matrix in the formula is:

[0253]

[0254] in:

[0255]

[0256] In the formula: m1 and m2 are the transverse mass matrix; m3 is the longitudinal mass matrix; m4 is the torsional mass matrix; the unit mass matrix is ​​the same as the unit mass matrix in the uncoupled case, referring to formula (8) because the coupling term is not considered in the kinetic energy function.

[0257] k1 is the transverse linear stiffness matrix of the rod, k2 is the longitudinal linear stiffness matrix, k3 is the torsional linear stiffness matrix, and the rest are longitudinal-transverse-torsional coupled stiffness matrices. Note that k4 to k... 23 The element stiffness matrix is ​​time-varying, as it is related to the nodal displacement *d* of the elements at each moment. After assembling the structural elements, the discrete-form dynamic equations of the system are obtained:

[0258] (17)

[0259] In the formula, M represents the overall mass matrix of the drill string system;

[0260] Damping of the K-drill string system;

[0261] C-Stiffness of the drill string system;

[0262] The array and load column vectors of the F-drill string system.

[0263] S33. The Newmark-β method is used to solve the discrete equations. Because the discrete equations are a system of second-order ordinary differential equations, for the drill string system, the influence of longitudinal tension on lateral and torsional stiffness must be considered. However, the longitudinal coupling vibration caused by the lateral displacement cannot be ignored. However, regardless of the choice... still These methods can only satisfy unidirectional coupling. To achieve bidirectional coupling (longitudinal-transverse-torsional), if both methods are used simultaneously... and The element stiffness matrix is ​​not fixed, and the potential energy of the system is not conserved, leading to divergent calculation results. Therefore, this invention employs a dual-coupled system solution, where two unidirectionally coupled systems are solved independently and alternately to achieve bidirectional coupling. The solution steps are as follows: Figure 2 .

[0264] Step S4 includes:

[0265] S41. Based on the nonlinear vibration model of the drill string system, simulate the longitudinal and transverse torsional coupling vibration of the drill string without dampers, and record the vibration data.

[0266] S42. Add vibration dampers to the drill string system. After determining a set of vibration damper parameters, perform longitudinal and transverse torsional coupling vibration simulation of the drill string and record the vibration data.

[0267] S43. Repeat step S42 to simulate longitudinal and transverse torsional coupling vibration of the drill string, changing the parameters of the vibration damper each time and recording the data.

[0268] S44. Compare the parameters in steps S41 to S43 to obtain the vibration reduction effect of different positions of the vibration damper and determine the sweet spot range of the vibration damper arrangement.

[0269] This invention also provides a vibration reduction tool optimization device based on a drill string dynamics model, including a vibration model establishment module, a vibration damper model establishment module, a calculation module, and a simulation module.

[0270] The vibration model building module is used to build a nonlinear vibration model of the drill string system, which can characterize the coupling effect of longitudinal, transverse and torsional vibrations of the drill string system.

[0271] The vibration damper model building module is used to build a mathematical model of vibration damper stiffness permutation.

[0272] The calculation module is used to solve the nonlinear vibration model to obtain the dynamic response of the drill string system;

[0273] The simulation module is used to simulate drill string vibration, analyze vibration data of the damper under different parameters, and determine the sweet spot range of the damper arrangement.

[0274] The present invention also provides a computer-readable storage medium including a stored computer program, wherein the computer program is executed by an electronic device to perform the method.

[0275] The present invention also provides an electronic device, including a processor and a memory, wherein the memory stores at least one computer program, the computer program being loaded and executed by one or more of the processors to enable the computer to implement the vibration reduction tool optimization method described above.

[0276] Example:

[0277] (1) Using the nonlinear vibration model of the drill string system of the present invention, longitudinal and transverse torsional coupling vibration simulation of the drill string with and without vibration dampers is carried out. By analyzing the vibration data, the vibration reduction effect of the vibration damper is clarified.

[0278] Among them, such as Figure 3 , Figure 4 , Figure 5 The figures show the drill string vibration caps in the X, Y, and Z axes before and after using the vibration damper. As can be seen from the figures, using the vibration damper can effectively reduce drill string vibration. In the X and Y axes, the vibration reduction efficiency can reach about 20%, and in the Z axis, the vibration reduction effect can reach about 25%. The use of the vibration damper can effectively reduce drill string vibration and protect the safety of the drill bit.

[0279] (2) Determine the location of the vibration damper, change the vibration damping stiffness value of the vibration damper by adjusting the preload of the vibration damper, replace the relevant parameters of the stiffness matrix, analyze the simulation data, and clarify the influence of stiffness on the vibration damping effect.

[0280] In this embodiment, the disc spring's elastic modulus is 210 GPa, which translates to a basic impact stiffness of 1.26 GPa. By adjusting the preload, the damping stiffness of the damper is changed. Figure 6 To determine the Z-axis amplitude using vibration dampers of different stiffness, such as Figure 6 As shown, changing the preload of the vibration damper can effectively enhance its vibration damping effect.

[0281] (3) Change the distance between the damper and the drill bit to obtain the damping effect of the damper at different positions and obtain the sweet spot range of the damper arrangement.

[0282] Figure 7 The Z-axis amplitude of the vibration damper at different distances from the drill bit is determined by... Figure 7 It can be seen that the farther the vibration damper is from the drill bit, the more effective its vibration damping is. Therefore, when arranging vibration dampers, they should be placed as close to the drill bit as possible.

[0283] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A vibration reduction tool optimization method based on a drill string dynamics model, characterized in that... include: S1. Establish a nonlinear vibration model of the drill string system, which can characterize the coupling effect of longitudinal, transverse and torsional vibrations of the drill string system; S2. Establish a mathematical model for the stiffness replacement of the vibration damper; S3. Solve the nonlinear vibration model in step S1 using the finite element method to obtain the dynamic response of the drill string system; S4. Change the vibration damper parameters, simulate the drill string vibration based on the nonlinear vibration model, analyze the vibration data of the vibration damper under different parameters, and determine the sweet spot range of the vibration damper arrangement.

2. The vibration reduction tool optimization method based on drill string dynamics model according to claim 1, characterized in that: The nonlinear vibration model of the drill string system in step S1 is as follows: ， ， ， In the formula: F u - Lateral external load on the column, N•m; F w - The longitudinal external load on the rod, N•m; M - Torsional load on the rod, N•m; ρ - Density of drill string, kg / m 3 ; A - Cross-sectional area of ​​the drill string, in meters 2 ; E - Elastic modulus, Pa; I - Moment of inertia of the cross section, m 4 ; u, v, and w represent the displacements of the rod in the x, y, and z directions, respectively, in meters (m). Φ - Torsion angle produced by the oil pipe, in rad; ξ - Nonlinear or coupling factor; G - Shear modulus, Pa; ， 。 3. The vibration reduction tool optimization method based on drill string dynamics model according to claim 2, characterized in that: Step S1 includes: S11. Establish a three-dimensional coordinate system using the drill string system, and determine the displacement of any point on the cross-section in the three-dimensional coordinate system along the x-axis and y-axis. When the torsional angle Φ generated by the tubing is small, the displacement field function is: ， Where: Φ - the torsion angle generated by the oil pipe, rad; u x - Displacement along the x-axis, in meters; U y - Displacement in the y-axis direction, in meters; u z - Displacement along the z-axis, in meters; t - time, s; u, v, and w represent the displacements of the rod in the x, y, and z directions, respectively, in meters (m). S12, The strain in the displacement field of the drill string system is: ， In the formula: -Strain in the z-axis direction; Strain in the -xz direction; Strain in the -yz direction; ξ - Nonlinear or coupling factor; S13, The potential energy of the drill string system is: ， Where: U - drill string potential energy, J; E - Elastic modulus, Pa; I - Moment of inertia of the cross section, m 4 ; A - Cross-sectional area of ​​the drill string, in meters 2 ; G - Shear modulus, Pa; γ - Shear strain, dimensionless; S14, The kinetic energy of the drill string system is: ， The non-conservative external force work on the drill string includes three parts: axial force work, lateral force work, and torque work, respectively, with the following expressions: ， In the formula: W z -Axial force work, J; W xy - Lateral force work, J; W T - Torque work, J; L - Length of the drill string system, in meters; F w (z,t) - Longitudinal external load on the drill string, N / m; F u (z,t) - The component of the lateral external load on the drill string along the x-axis, N / m; F v (z,t) - The component of the lateral external load on the drill string along the y-axis, N / m; T(z,t) - Torque on the drill string, N / m; S15. According to Hamilton's variational formula, we get: ， In the formula: δ - variational operator, dimensionless; T - Kinetic energy of the drill string, J; U - Drill string potential energy, J; W - Work done by the drill string, J; The nonlinear vibration model of the drill string system was obtained by sorting it out.

4. The vibration reduction tool optimization method based on drill string dynamics model according to claim 3, characterized in that: Step S11 includes: establishing a three-dimensional coordinate system using the drill string system, wherein the displacement of any point (r, α) on the cross-section of the three-dimensional coordinate system along the x-axis and y-axis directions is: ， In the formula: α - initial eccentricity angle, rad; Φ - Torsion angle produced by the oil pipe, in rad; u x - Displacement along the x-axis, in meters; u y - Displacement in the y-axis direction, in meters; r - displacement of the center of mass, m; u - Displacement of the rod in the x-direction, in meters; v - Displacement of the rod in the y direction, in meters; When Φ is a small quantity, cosΦ≈1, sinΦ≈1, then: ； The displacement field function is then: ； In the formula: u z - Displacement along the z-axis, in meters; t - time, s; u, v, and w represent the displacements of the rod in the x, y, and z directions, respectively, in meters (m).

5. The vibration reduction tool optimization method based on drill string dynamics model according to claim 3, characterized in that: Step S12 includes: The strain in the displacement field is determined as follows: ； In the formula: - Dependent variable; ξ - Nonlinear or coupling factor; For drill string systems, the rod stress is mainly axial stress, then ， ， In the formula: Stress in the -x direction, Pa; Stress in the -y direction, Pa; - Shear stress in the x and y directions, Pa; -Strain in the xy direction; -x direction of strain; -y direction of strain; Strain in the -z direction; The strain is obtained by using Einstein's summation law.

6. The vibration reduction tool optimization method based on drill string dynamics model according to claim 1, characterized in that: The mathematical model for damper stiffness permutation in step S2 is as follows: ， Where: K(i,i) - stiffness of the stiffness matrix corresponding to the vibration damper, N / m; K z - Stiffness of the vibration damper in the stiffness matrix of the drill string system, N / m.

7. The vibration reduction tool optimization method based on drill string dynamics model according to claim 1, characterized in that: The damper parameters in step S4 include: damper placement, damper preload, and damping stiffness.

8. The vibration reduction tool optimization method based on drill string dynamics model according to claim 7, characterized in that: Step S4 includes: S41. Based on the nonlinear vibration model of the drill string system, simulate the longitudinal and transverse torsional coupled vibration of the drill string without dampers, and record the vibration data. S42. Add vibration dampers to the drill string system, determine a set of vibration damper parameters, perform longitudinal and transverse torsional coupling vibration simulation of the drill string, and record the vibration data. S43. Repeat step S42 to simulate the longitudinal and transverse torsional coupling vibration of the drill string, changing the parameters of the vibration damper each time and recording the data respectively. S44. Compare the parameters in steps S41 to S43 to obtain the vibration reduction effect of different positions of the vibration damper and determine the sweet spot range of the vibration damper arrangement.

9. A vibration reduction tool optimization device based on a drill string dynamics model, characterized in that: It includes a vibration model building module, a vibration damper model building module, a calculation module, and a simulation module. The vibration model building module is used to build a nonlinear vibration model of the drill string system, which can characterize the coupling effect of longitudinal, transverse and torsional vibrations of the drill string system. The vibration damper model building module is used to build a mathematical model of vibration damper stiffness permutation. The calculation module is used to solve the nonlinear vibration model to obtain the dynamic response of the drill string system; The simulation module is used to simulate drill string vibration, analyze vibration data of the damper under different parameters, and determine the sweet spot range of the damper arrangement.

10. A computer-readable storage medium, characterized in that: It includes a stored computer program, wherein the computer program is executed by an electronic device to perform the method of any one of claims 1 to 8.

11. An electronic device, characterized in that: The system includes a processor and a memory, wherein the memory stores at least one computer program, which is loaded and executed by one or more of the processors to enable the computer to implement the vibration damping tool optimization method according to any one of claims 1-8.

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