Multi-gas commingling pilot production string collision mechanical analysis method and device

Abstract

The invention relates to a multi-gas commingling pilot production tubular column collision mechanical analysis method and device, and the method comprises the steps: taking an ocean current direction as an X direction and a direction vertical to a seabed as a Z direction, and building a Cartesian coordinate system; on the basis of a Cartesian coordinate system, based on an elastic-plastic mechanics theory, considering the influence of internal fluid, establishing a multi-gas commingling pilot production string and marine riser collision mechanical analysis model, analyzing and calculating the model, and outputting contact collision mechanical characteristics; target well engineering parameters are collected, through a Hermite interpolation method, the collision mechanical analysis model is discretized, time steps and space steps of calculation are divided, the model is iteratively solved through generalized pairs, and the collision mechanical distribution characteristics of the multi-gas commingling pilot production tubular column are obtained; and further analyzing a collision mechanical distribution rule, and assembling a collision suppression short section at a multi-gas commingling pilot production pipe column part with large collision force distribution.

Description

Technical Field

[0001] This invention relates to the field of marine oil and gas development technology, specifically to a method and apparatus for collision mechanics analysis of multi-gas co-production test tubing. Background Technology

[0002] As offshore oil and gas development gradually shifts from shallow to deep waters, in order to improve economic efficiency and resource utilization and reduce development costs, combined extraction of shallow gas, deep gas, and natural gas hydrates is being carried out (hereinafter referred to as "multi-gas combined extraction"). During the trial production of multi-gas combined extraction, the riser may deform under the influence of marine environmental loads, causing contact and collision with the internal test production string. This results in complex coupled vibration and deformation of the riser and test production string, leading to wear and reduced strength of the riser's inner wall, which may ultimately cause string failure and induce safety accidents.

[0003] Current research on the impact of contact collisions on the mechanical properties of the riser mainly utilizes finite element software such as ANSYS and ABAQUS for simulation. However, research on the dynamic characteristics analysis of the coupled system of the riser and test production tubing under dynamic contact collisions is still limited. The contact collision laws between the test production tubing and the riser, and their impact mechanism on the mechanical properties of the riser, are not yet fully understood. Furthermore, in the process of multi-gas co-production, in addition to external marine loads, there is also the issue of hydrate phase transformation within the test production tubing. The gas-liquid-solid interface in the multiphase flow system of natural gas hydrate wellbores is complex and variable in morphology. Under the action of internal and external loads, the contact collision between the test production tubing and the riser will be exacerbated.

[0004] Therefore, it is urgent to grasp the collision mechanism between the riser and the test production string and propose collision suppression methods based on a close combination of external marine environmental loads and internal fluid effects. Summary of the Invention

[0005] To address the aforementioned problems, the purpose of this invention is to provide a method and apparatus for collision mechanics analysis of multi-gas combined production test tubing. This method can calculate the collision force distribution characteristics of the test tubing, and then use the apparatus to suppress areas of severe collision, thereby extending the service life of the multi-gas combined production test tubing.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The collision mechanics analysis method for multi-gas combined production test tubing described in this invention includes the following steps: Establish a Cartesian coordinate system with the direction of ocean current as the X direction and the direction perpendicular to the seabed as the Z direction. Based on the Cartesian coordinate system and the theory of elastoplastic mechanics, and considering the influence of internal fluids, a collision mechanical analysis model of the multi-gas combined production test string and the riser is established. The model is then analyzed and calculated to output the contact collision mechanical characteristics. Target well engineering parameters were collected, and the collision mechanics analysis model was discretized using the Hermite interpolation method, dividing the computation into time and space steps. Furthermore, a generalized... The collision mechanics distribution characteristics of the multi-gas combined production test string were obtained by iteratively solving the model. Further analysis of the collision mechanics distribution characteristics led to the installation of collision suppression short sections in the multi-gas combined production test string sections where the collision force distribution was large.

[0007] The collision mechanics analysis method for multi-gas combined production test tubing, preferably, involves establishing a collision mechanics analysis model between the internal production tubing and the riser based on elastoplastic mechanics theory and considering the influence of internal fluids, and then analyzing and calculating the model to output the contact collision mechanics characteristics. Specifically, this includes the following steps: Based on the actual site conditions, the multi-gas combined production test string was reasonably simplified; Based on the Euler-Bernoulli beam theory, a simplified mechanical equilibrium equation for the multi-gas combined production test string and riser is established, and the relationship between the collision force and deformation of the riser and the multi-gas combined production test string is established based on the elastoplastic mechanics theory. Based on the relationship between the collision force and deformation of the riser and the multi-gas combined production test string, the improved Morrison equation considering the combined effects of waves and ocean currents is used to describe the external marine environmental load.

[0008] The collision mechanics analysis method for the multi-gas combined mining test string is preferably described in that the multi-gas combined mining test string is reasonably simplified according to the actual field conditions. Specifically, the cross section of the multi-gas combined mining test string is considered to be a uniform circular ring, shear deformation is not considered, and the riser and the multi-gas combined mining test string are regarded as Euler-Bernoulli beams.

[0009] The aforementioned method for analyzing the collision mechanics of multi-gas combined production test tubing, preferably, involves establishing simplified mechanical equilibrium equations for the multi-gas combined production test tubing and riser based on Euler-Bernoulli beam theory, specifically as follows: The mechanical equation of the riser in the X direction is:

[0010] The mechanical equation of the multi-gas combined production test string in the X direction is:

[0011] The mechanical equations of the fluid element in the X direction are:

[0012] According to the theory of mechanics of materials, the expressions for bending moment and shear force are:

[0013]

[0014] Furthermore, the axial tension of the multi-gas combined production test string is:

[0015] Solving the above equations simultaneously, we obtain the mechanical equilibrium equations for the riser:

[0016] Similarly, the mechanical equilibrium equation for the multi-gas combined production test string is:

[0017] in, Damping for the riser structure; The radial velocity of the riser pipe in the direction of flow; and These are the mass per unit length of the riser pipe and the mass of the internal tubing column, respectively. It is the radial acceleration in the downstream direction; For concentrated loads; The load distributed per unit length of the riser pipe; The water-jacking pipe turns in the direction of the flow. This represents the rate of change of shear force across the riser section. Axial tension in the tubular section; and These are the cross-sectional areas of the riser and the test production tubing, respectively. and These are the pressures of the riser and the test production tubing, respectively. For downstream marine environmental loads; The force of impact; The damping coefficient of the test production tubing structure; The mass of fluid per unit length of the riser pipe; The fluid flow velocity; The curvature of the riser pipe; The cross-sectional area of ​​the fluid unit; For fluid unit pressure; and These are the bending stiffnesses of the riser and the multi-gas combined production test string, respectively. The angle of the cross section; The bending moment of the column section; Shear force at the section of the tubular column; This represents the lateral displacement of the tubular column; The axial rate of change of the rotation angle; For curvature; is the axial rate of change of curvature; for Axial tension at the point; Tension at the top of the tubular column; The axial load per unit length; Axial velocity of the riser pipe; for Cross-sectional tension; Displacement is in the downstream direction; This refers to the axial position of the tubing string; For downstream marine environmental loads; and The velocity of liquid and gas in the internal tubular column; Mass of fluid per unit length of riser pipe; and These represent the masses of the liquid and gas in the internal tubular column, respectively. The force of impact; This represents the rate of change of the slope of the downstream displacement over time. This refers to the inherent ability of the tubular column to resist bending deformation.

[0018] The aforementioned method for analyzing the collision mechanics of multi-gas combined production test tubing, preferably, involves establishing the relationship between the collision force and deformation of the riser and the multi-gas combined production test tubing based on elastoplastic mechanics theory, specifically as follows: Relationship between collision force and deformation between riser and multi-gas combined production test string:

[0019]

[0020] Further simplification yields the formula for calculating the collision force:

[0021]

[0022] The contact and collision problem between the riser and the multi-gas combined production test string can be simplified into a contact and collision problem occurring at multiple nodes, which can be further transformed into:

[0023]

[0024]

[0025] Furthermore, the boundary conditions include upper constraints and lower constraints. The lower constraints are as follows:

[0026] The upper constraint is:

[0027] in, and The Poisson's ratios of the materials for the riser and the test production tubing, respectively; The elastic modulus of the riser material; This is the contact half length; Load is distributed over the contact area; Radial coordinates; This represents the displacement along the flow direction (i.e., the axial coordinate of the contact area). The outer radius of the test production tubing; Contact pressure; The Poisson's ratio of the test tube material; The elastic modulus of the test tube material; The outer radius of the riser column; This refers to the relative deformation between the tubular sections; For the axial load of the tubular column; It is the equivalent elastic modulus; This refers to the real-time radial displacement of the test production tubing. This is the initial radial clearance; It is a viscous damping force; It is the viscous damping coefficient; The radial velocity of the test production tubing; The total collision force; The resultant force of contact pressure; The time derivative of the lateral displacement of the test production tubing; This refers to the lateral displacement of the lower end of the tubular column; This is the lateral offset at the bottom of the platform; The curvature of the lower end of the tubular column; This refers to the lower corner of the tubing. The torsion angle at the lower end of the tubing; This refers to the stiffness of the upper flexible joint. This refers to the stiffness of the flexible joint at the lower end. This refers to the lateral displacement of the upper end of the tubular column; This represents the total length of the tubing. This refers to the shear force at the upper end.

[0028] The aforementioned multi-gas combined production test string collision mechanics analysis method preferably employs an improved Morrison equation considering the combined effects of waves and ocean currents to describe the external marine environmental load, specifically: The formula for calculating marine load is:

[0029] in: For marine environmental loads; This is the drag coefficient; The density of seawater; The outer diameter of the tubular column; The lateral velocity of the water flow; This refers to the lateral displacement of the tubular column; The inertia coefficient; The cross-sectional area of ​​the tubular column; This represents the lateral acceleration of the water flow.

[0030] The aforementioned multi-gas combined production test string collision mechanics analysis method, preferably, involves discretizing the collision mechanics analysis model using the Hermite interpolation method, dividing the calculation into time steps and spatial steps, and utilizing generalized... The model was iteratively solved to obtain the collision mechanics distribution characteristics of the multi-gas combined production test string, specifically: Based on the Euler-Bernoulli beam theory, the element displacement field is obtained through Hermite interpolation, and the mechanical equations of the above-mentioned riser and multi-gas combined production test string are discretized to obtain:

[0031] in, and These are the overall mass matrices of the riser and the test production tubing, respectively. and These are the overall damping matrices for the riser and the test production tubing, respectively. and These are the overall stiffness matrices of the riser and the test production tubing, respectively. and These are the displacements of the riser and the test production tubing, respectively. and These are the acceleration vectors of the riser and the test production string, respectively. The marine load vector for the riser; This is the collision force vector; In this case, the multi-gas combined production test string is in a state of collision with the riser for a long time, and will face high-frequency collision effects. Therefore, the generalized α method is used for iterative solution, including: Forming the stiffness matrix quality matrix and damping matrix ; Set initial values d 0、 v 0、 a 0; Furthermore, initial value d 0、 v 0、 a The calculation method for 0 is as follows:

[0032] in: The acceleration vector at the moment of implicit time integration initiation; The velocity vector at the moment of implicit time integration initiation; The displacement vector at the start of the implicit time integration; This represents the nodal external load vector at startup. for The nodal displacement vector at time t; This represents the initial offset during tubular installation. for The nodal velocity vector at time t; The initial velocity caused by the platform shaking; for The nodal acceleration vector at time t; The inverse of the mass matrix; for The nodal external load vector at time t; Select time step and The integral constant is calculated as follows: , , , , , ,

[0033] in: These are the damping control parameters for the mass matrix; For the time interpolation parameters of the load; The time interpolation parameter for the displacement; For the time interpolation parameter of velocity; These are the weighting coefficients of the stiffness matrix in the effective stiffness matrix; This is the time scaling factor for the mass matrix in the effective stiffness matrix; This is the time scaling factor for the damping matrix in the effective stiffness matrix; The weighting coefficients for the velocity term in the payload vector; These are the weighting coefficients for the acceleration term in the payload vector; These are supplementary coefficients for the velocity term in the payload vector; These are the weighting coefficients for the displacement terms in the effective load vector; For time step; Further, calculate the effective stiffness matrix:

[0034] further, The effective load vector satisfies:

[0035] The displacement is:

[0036] The acceleration and velocity are:

[0037]

[0038] in: In a broad sense The core of the method is the linearization matrix; The contribution of the mass matrix to the effective stiffness matrix; This represents the contribution of the damping matrix to the effective stiffness matrix. The contribution of the stiffness matrix to the effective stiffness matrix; for The equivalent external load vector at time t; for Weighting ratio of time-bound load; for The nodal external load vector at time t; for Weighting ratio of time-bound load; for The nodal external load vector at time t; for The nodal acceleration vector at time t; for The nodal velocity vector at time t; for The nodal displacement vector at time t; It is the inverse of the effective stiffness matrix; for arrive The change in displacement at any given moment; Contribution to the acceleration of the past; Contribution to the current acceleration.

[0039] The collision mechanics analysis method for the multi-gas combined production test tubing, preferably, includes a collision suppression section comprising: a section body, a spring plate, a first connecting lug, a second connecting lug, and a connecting bolt; The short section body has a ring structure and is used to be sleeved on the outside of the multi-gas combined production test string; The upper part of the short section body is provided with a plurality of first connecting ears, and the first connecting ears are provided with unloading holes. A set of connecting bolts passes through the corresponding unloading holes and the first end of the spring sheet, so that the first end of the spring sheet is connected to the first connecting ear. The length of the unloading hole is greater than the outer diameter of the connecting bolt, so that when the spring sheet is deformed by force, the force is unloaded through the unloading hole. The lower part of the short section body is provided with a plurality of second connecting ears, and the second connecting ears are provided with connecting holes. The diameter of the connecting holes is adapted to the diameter of the connecting bolts. Another set of the connecting bolts passes through the corresponding connecting holes and the second end of the spring sheet, so that the second end of the spring sheet is fixedly connected to the second connecting ears.

[0040] The collision mechanics analysis method for the multi-gas co-production test string is preferably used in which the engineering parameters of the target well collected include: wellbore trajectory, well structure, marine environmental load, and basic parameters of the riser and the multi-gas co-production test string.

[0041] The present invention also provides a collision mechanics analysis device for multi-gas combined production test tubing, comprising: The first processing unit is used to establish a Cartesian coordinate system with the direction of ocean current as the X direction and the direction perpendicular to the seabed as the Z direction. The second processing unit is used to establish a collision mechanical analysis model between the multi-gas combined production test string and the riser based on the Cartesian coordinate system, the theory of elastoplastic mechanics, and the influence of internal fluids, and to analyze and calculate the model and output the contact collision mechanical characteristics. The third processing unit collects the target well's engineering parameters, discretizes the collision mechanics analysis model using the Hermite interpolation method, divides the calculation into time and space steps, and utilizes generalized... The collision mechanics distribution characteristics of the multi-gas combined production test string were obtained by iteratively solving the model. The fourth processing unit is used to further analyze the distribution law of collision mechanics and to assemble collision suppression short sections in the multi-gas combined production test string where the collision force distribution is large.

[0042] The present invention has the following advantages due to the adoption of the above technical solutions: This invention, based on elastoplastic mechanics theory, considers the influence of hydrate phase transformation during multi-gas combined production and establishes a collision mechanics model of the coupling effect between the riser and the test production string. This model is solved using the finite element method combined with the generalized α method to calculate the dynamic parameters of the test production string, understand the contact and collision law between the test production string and the riser, and further utilize a device to suppress areas of severe collision, thereby extending the service life of the multi-gas combined production test production string. This has significant engineering implications for ensuring the safe development of marine natural gas hydrates. Attached Figure Description

[0043] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings: Figure 1This is a schematic diagram of the collision suppression section in this invention; Figure 2 This is a schematic diagram illustrating the application scenario of the multi-gas combined production test string in this invention; Figure 3 This is a schematic diagram of the mechanical analysis of the collision between the multi-gas combined production test string and the riser in this invention. Figure 4 This is a schematic diagram of the contact and collision mechanical characteristics of the multi-gas combined production test string and the riser in this invention. Figure 5 This is a statistical diagram of the collision force between the multi-gas combined production test string and the riser in this invention; Figure 6 This is a diagram showing the mechanical characteristics of the collision force between the multi-gas combined production test string and the riser in this invention. Detailed Implementation

[0044] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0045] This invention provides a collision mechanics analysis method for multi-gas combined mining test tubing. Based on elastoplastic mechanics theory, it considers the influence of hydrate phase transformation during multi-gas combined mining and establishes a collision mechanics model of the coupling effect between the riser and the test tubing. This model is solved using the finite element method combined with the generalized α method to calculate the dynamic parameters of the test tubing, understand the contact and collision law between the test tubing and the riser, and further utilize a device to suppress areas of severe collision, thereby extending the service life of the multi-gas combined mining test tubing.

[0046] The collision mechanics analysis method for multi-gas combined production test tubing provided by this invention includes the following steps: S1. Establish a Cartesian coordinate system with the direction of ocean current as the X direction and the direction perpendicular to the seabed as the Z direction. S2. Based on the Cartesian coordinate system and the theory of elastoplastic mechanics, and considering the influence of internal fluids, a collision mechanical analysis model of the multi-gas combined production test string and the riser is established. The model is then analyzed and calculated to output the contact collision mechanical characteristics. S3. Collect target well engineering parameters, discretize the collision mechanics analysis model using the Hermite interpolation method, divide the calculation into time and space steps, and utilize generalized... The collision mechanics distribution characteristics of the multi-gas combined production test string were obtained by iteratively solving the model. S4. Further analyze the characteristics of the collision mechanics distribution pattern, and assemble collision suppression short sections in the multi-gas combined production test string section where the collision force distribution is large.

[0047] In the above embodiments, preferably, the step of establishing a collision mechanics analysis model between the internal mining string and the riser of a multi-gas combined mining test string based on elastoplastic mechanics theory and considering the influence of internal fluids, and analyzing and calculating the model to output the contact collision mechanics characteristics, specifically includes the following steps: Based on the actual site conditions, the multi-gas combined production test string was reasonably simplified; Based on the Euler-Bernoulli beam theory, a simplified mechanical equilibrium equation for the multi-gas combined production test string and riser is established, and the relationship between the collision force and deformation of the riser and the multi-gas combined production test string is established based on the elastoplastic mechanics theory. Based on the relationship between the collision force and deformation of the riser and the multi-gas combined production test string, the improved Morrison equation considering the combined effects of waves and ocean currents is used to describe the external marine environmental load.

[0048] In the above embodiments, preferably, as follows: Figure 2 As shown, based on the actual site conditions, the multi-gas combined production test string is reasonably simplified. Specifically, the cross-section of the multi-gas combined production test string is considered to be a uniform circular ring, and shear deformation is not considered. The riser and the multi-gas combined production test string are regarded as Euler-Bernoulli beams.

[0049] In the above embodiments, preferably, the simplified mechanical equilibrium equations for the multi-gas combined production test string and riser based on the Euler-Bernoulli beam theory are as follows: The mechanical equation of the riser in the X direction is:

[0050] The mechanical equation of the multi-gas combined production test string in the X direction is:

[0051] The mechanical equations of the fluid element in the X direction are:

[0052] According to the theory of mechanics of materials, the expressions for bending moment and shear force are:

[0053]

[0054] Furthermore, the axial tension of the multi-gas combined production test string is:

[0055] Solving the above equations simultaneously, we obtain the mechanical equilibrium equations for the riser:

[0056] Similarly, the mechanical equilibrium equation for the multi-gas combined production test string is:

[0057] in, Damping for the riser structure; The radial velocity of the riser pipe in the direction of flow; and These are the mass per unit length of the riser pipe and the mass of the internal tubing column, respectively. It is the radial acceleration in the downstream direction; For concentrated loads; The load distributed per unit length of the riser pipe; The water-jacking pipe turns in the direction of the flow. This represents the rate of change of shear force across the riser section. Axial tension in the tubular section; and These are the cross-sectional areas of the riser and the test production tubing, respectively. and These are the pressures of the riser and the test production tubing, respectively. For downstream marine environmental loads; The force of impact; The damping coefficient of the test production tubing structure; The mass of fluid per unit length of the riser pipe; The fluid flow velocity; The curvature of the riser pipe; The cross-sectional area of ​​the fluid unit; For fluid unit pressure; and These are the bending stiffnesses of the riser and the multi-gas combined production test string, respectively. The angle of the cross section; The bending moment of the column section; Shear force at the section of the tubular column; This represents the lateral displacement of the tubular column; The axial rate of change of the rotation angle; For curvature; is the axial rate of change of curvature; for Axial tension at the point; Tension at the top of the tubular column; The axial load per unit length; Axial velocity of the riser pipe; for Cross-sectional tension; Displacement is in the downstream direction; This refers to the axial position of the tubing string; For downstream marine environmental loads; and The velocity of liquid and gas in the internal tubular column; Mass of fluid per unit length of riser pipe; and These represent the masses of the liquid and gas in the internal tubular column, respectively. The force of impact; This represents the rate of change of the slope of the downstream displacement over time. This refers to the inherent ability of the tubular column to resist bending deformation.

[0058] In the above embodiments, preferably, as follows: Figure 3 As shown, the relationship between the collision force and deformation of the riser and the multi-gas combined production test string, established based on the theory of elastoplastic mechanics, is as follows: Relationship between collision force and deformation between riser and multi-gas combined production test string:

[0059]

[0060] Further simplification yields the formula for calculating the collision force:

[0061]

[0062] The contact and collision problem between the riser and the multi-gas combined production test string can be simplified into a contact and collision problem occurring at multiple nodes, which can be further transformed into:

[0063]

[0064]

[0065] Furthermore, the boundary conditions include upper constraints and lower constraints. The lower constraints are as follows:

[0066] The upper constraint is:

[0067] in, and The Poisson's ratios of the materials for the riser and the test production tubing, respectively; The elastic modulus of the riser material; This is the contact half length; Load is distributed over the contact area; Radial coordinates; This represents the displacement along the flow direction (i.e., the axial coordinate of the contact area). The outer radius of the test production tubing; Contact pressure; The Poisson's ratio of the test tube material; The elastic modulus of the test tube material; The outer radius of the riser column; This refers to the relative deformation between the tubular sections; For the axial load of the tubular column; It is the equivalent elastic modulus; This refers to the real-time radial displacement of the test production tubing. This is the initial radial clearance; It is a viscous damping force; It is the viscous damping coefficient; The radial velocity of the test production tubing; The total collision force; The resultant force of contact pressure; The time derivative of the lateral displacement of the test production tubing; This refers to the lateral displacement of the lower end of the tubular column; This is the lateral offset at the bottom of the platform; The curvature of the lower end of the tubular column; This refers to the lower corner of the tubing. The torsion angle at the lower end of the tubing; This refers to the stiffness of the upper flexible joint. This refers to the stiffness of the flexible joint at the lower end. This refers to the lateral displacement of the upper end of the tubular column; This represents the total length of the tubing. This refers to the shear force at the upper end.

[0068] In the above embodiments, preferably, the use of the improved Morrison equation considering the combined effects of waves and ocean currents to describe the external marine environmental load specifically includes: The formula for calculating marine load is:

[0069] in: For marine environmental loads; This is the drag coefficient; The density of seawater; The outer diameter of the tubular column; The lateral velocity of the water flow; This refers to the lateral displacement of the tubular column; The inertia coefficient; The cross-sectional area of ​​the tubular column; This represents the lateral acceleration of the water flow.

[0070] In the above embodiments, preferably, the collision mechanics analysis model is discretized using the Hermite interpolation method, dividing the computation into time steps and spatial steps, and utilizing generalized... The model was iteratively solved to obtain the collision mechanics distribution characteristics of the multi-gas combined production test string, specifically: Based on the Euler-Bernoulli beam theory, the element displacement field is obtained through Hermite interpolation, and the mechanical equations of the above-mentioned riser and multi-gas combined production test string are discretized to obtain:

[0071] in, and These are the overall mass matrices of the riser and the test production tubing, respectively. and These are the overall damping matrices for the riser and the test production tubing, respectively. and These are the overall stiffness matrices of the riser and the test production tubing, respectively. and These are the displacements of the riser and the test production tubing, respectively. and These are the acceleration vectors of the riser and the test production string, respectively. The marine load vector for the riser; Collision force vector; In this case, the multi-gas combined production test string is in a state of collision with the riser for a long time, and will face high-frequency collision effects. Therefore, the generalized α method is used for iterative solution, including: Forming the stiffness matrix quality matrix and damping matrix ; Set initial values d 0、 v 0、 a 0; Furthermore, initial value d 0、 v 0、 a The calculation method for 0 is as follows:

[0072] in: The acceleration vector at the moment of implicit time integration initiation; The velocity vector at the moment of implicit time integration initiation; The displacement vector at the start of the implicit time integration; This represents the nodal external load vector at startup. for The nodal displacement vector at time t; This represents the initial offset during tubular installation. for The nodal velocity vector at time t; The initial velocity caused by the platform shaking; for The nodal acceleration vector at time t; It is the inverse of the mass matrix; for The nodal external load vector at time t; Select time step and The integral constant is calculated as follows: , , , , , ,

[0073] in: These are the damping control parameters for the mass matrix; For the time interpolation parameters of the load; The time interpolation parameter for the displacement; For the time interpolation parameter of velocity; These are the weighting coefficients of the stiffness matrix in the effective stiffness matrix; This is the time scaling factor for the mass matrix in the effective stiffness matrix; This is the time scaling factor for the damping matrix in the effective stiffness matrix; The weighting coefficients for the velocity term in the payload vector; These are the weighting coefficients for the acceleration term in the payload vector; These are supplementary coefficients for the velocity term in the payload vector; These are the weighting coefficients for the displacement terms in the effective load vector; For time step; Further, calculate the effective stiffness matrix:

[0074] further, The effective load vector satisfies:

[0075] The displacement is:

[0076] The acceleration and velocity are:

[0077]

[0078] in: In a broad sense The core of the method is the linearization matrix; The contribution of the mass matrix to the effective stiffness matrix; This represents the contribution of the damping matrix to the effective stiffness matrix. The contribution of the stiffness matrix to the effective stiffness matrix; for The equivalent external load vector at time t; for Weighting ratio of time-bound load; for The nodal external load vector at time t; for Weighting ratio of time-bound load; for The nodal external load vector at time t; for The nodal acceleration vector at time t; for The nodal velocity vector at time t; for The nodal displacement vector at time t; It is the inverse of the effective stiffness matrix; for arrive The change in displacement at any given moment; Contribution to the acceleration of the past; Contribution to the current acceleration.

[0079] In the above embodiments, preferably, as follows: Figure 1 As shown, the collision suppression section includes: section body 1, spring plate 2, first connecting lug 3, second connecting lug 4, and connecting bolt 5; The short section body 1 has a ring-shaped structure and is used to be sleeved on the outside of the multi-gas combined production test string. The upper part of the short section body 1 is provided with several first connecting ears 3. The first connecting ears 3 are provided with unloading holes. A set of connecting bolts 5 pass through the corresponding unloading holes and the first end of the spring plate 2 so that the first end of the spring plate 2 is connected to the first connecting ears 3. The length of the unloading hole is greater than the outer diameter of the connecting bolt so that the spring plate can unload the force through the unloading hole when it is deformed by force. The lower part of the short section body 1 is provided with a plurality of second connecting ears 4. The second connecting ears 4 are provided with connecting holes. The diameter of the connecting holes is adapted to the diameter of the connecting bolts. Another set of connecting bolts 5 passes through the corresponding connecting holes and the second end of the spring plate 2 so that the second end of the spring plate 2 is fixedly connected to the second connecting ears 4.

[0080] In the above embodiments, preferably, the collected target well engineering parameters include: wellbore trajectory, well structure, marine environmental load, and basic parameters of riser and multi-gas co-production test production string.

[0081] The present invention also provides a collision mechanics analysis device for multi-gas combined production test tubing, comprising: The first processing unit is used to establish a Cartesian coordinate system with the direction of ocean current as the X direction and the direction perpendicular to the seabed as the Z direction. The second processing unit is used to establish a collision mechanical analysis model between the multi-gas combined production test string and the riser based on the Cartesian coordinate system, the theory of elastoplastic mechanics, and the influence of internal fluids, and to analyze and calculate the model and output the contact collision mechanical characteristics. The third processing unit collects the target well's engineering parameters, discretizes the collision mechanics analysis model using the Hermite interpolation method, divides the calculation into time and space steps, and utilizes generalized... The collision mechanics distribution characteristics of the multi-gas combined production test string were obtained by iteratively solving the model. The fourth processing unit is used to further analyze the distribution law of collision mechanics and to assemble collision suppression short sections in the multi-gas combined production test string where the collision force distribution is large.

[0082] Example 1: In the first embodiment, the present invention takes a deep-water area in the South China Sea as an example to study the dynamic characteristics of the deep-water riser-test production string coupling system and analyzes the collision mechanical distribution law of the test production string.

[0083] Taking a deep-water well in the South China Sea as an example, the specific parameters of the multi-gas combined production test string are shown in the table below:

[0084] The mechanical properties of the riser and the internal multi-gas combined production test string during the deformation process of the riser-test production string coupling system are as follows: Figure 4 As shown, the displacement difference between the riser and the test production tubing is almost a stable positive value above 800m, and is close to the gap value between them. This indicates that in this area, the test production tubing and the deformed sidewall of the riser are almost always in close contact. However, the displacement difference gradually decreases to a negative value in the lower region, indicating that the test production tubing in the lower region gradually comes into contact with the pre-deformation sidewall of the riser. Figure 5 As shown in the collision force statistics chart, the average collision force between the test production tubing and the riser reaches its maximum value of 2100N at the bottom. The collision force also reaches its maximum value 200-300m below the water surface. Therefore, the collision between the drill pipe and the riser is most severe at the bottom wellhead position.

[0085] Example 2: In the second embodiment, the collision mechanics analysis model of the multi-gas combined production test string proposed in this invention is used to analyze the collision mechanics characteristics of the test string under different ocean current velocities. For example... Figure 6 As shown in the figure, the average collision force between the test tubing and the riser increases significantly with the increase of ocean current velocity. When the ocean current velocity is 1.21 m / s, the maximum collision force at the bottom increases to 3520 N, and the collision becomes more intense, especially increasing the collision force with the bottom of the riser and at a position about 250 m below the water surface.

[0086] Based on the collision characteristics calculated using the collision mechanics analysis model of the multi-gas combined production test string, reasonable anti-collision short section units are selected for the multi-gas combined production test string. The specific configuration is shown in the table below:

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for collision mechanics analysis of multi-gas combined production test tubing, characterized in that, Includes the following steps: Establish a Cartesian coordinate system with the direction of ocean current as the X direction and the direction perpendicular to the seabed as the Z direction. Based on the Cartesian coordinate system and the theory of elastoplastic mechanics, and considering the influence of internal fluids, a collision mechanical analysis model of the multi-gas combined production test string and the riser is established. The model is then analyzed and calculated to output the contact collision mechanical characteristics. Target well engineering parameters were collected, and the collision mechanics analysis model was discretized using the Hermite interpolation method, dividing the computation into time and space steps. Furthermore, a generalized... The collision mechanics distribution characteristics of the multi-gas combined production test string were obtained by iteratively solving the model. Analyze the characteristics of collision mechanics distribution and assemble collision suppression short sections in the multi-gas combined production test string where the collision force distribution is large.

2. The collision mechanics analysis method for multi-gas combined production test tubing according to claim 1, characterized in that, Based on the theory of elastoplastic mechanics and considering the influence of internal fluids, a collision mechanics analysis model of the internal production string and the riser in multi-gas combined production test string is established. This model is then analyzed and calculated to output the contact collision mechanics characteristics. The specific steps include: Based on the actual site conditions, the multi-gas combined production test string was reasonably simplified; Based on the Euler-Bernoulli beam theory, a simplified mechanical equilibrium equation for the multi-gas combined production test string and riser is established, and the relationship between the collision force and deformation of the riser and the multi-gas combined production test string is established based on the elastoplastic mechanics theory. Based on the relationship between the collision force and deformation of the riser and the multi-gas combined production test string, the improved Morrison equation considering the combined effects of waves and ocean currents is used to describe the external marine environmental load.

3. The collision mechanics analysis method for multi-gas combined production test tubing according to claim 2, characterized in that, Based on the actual site conditions, the multi-gas combined production test string is reasonably simplified. Specifically, the cross-section of the multi-gas combined production test string is considered to be a uniform circular ring, and shear deformation is not considered. The riser and the multi-gas combined production test string are regarded as Euler-Bernoulli beams.

4. The collision mechanics analysis method for multi-gas combined production test tubing according to claim 2, characterized in that, Based on the Euler-Bernoulli beam theory, a simplified mechanical equilibrium equation for the multi-gas combined production test string and riser is established, specifically as follows: The mechanical equation of the riser in the X direction is: The mechanical equation of the multi-gas combined production test string in the X direction is: The mechanical equations of the fluid element in the X direction are: According to the theory of mechanics of materials, the expressions for bending moment and shear force are: Furthermore, the axial tension of the multi-gas combined production test string is: Solving the above equations simultaneously, we obtain the mechanical equilibrium equations for the riser: Similarly, the mechanical equilibrium equation for the multi-gas combined production test string is: in, Damping for the riser structure; The radial velocity of the riser pipe in the direction of flow; and These are the mass per unit length of the riser pipe and the mass of the internal tubing column, respectively. It is the radial acceleration in the downstream direction; For concentrated loads; The load distributed per unit length of the riser pipe; The water-jacking pipe turns in the direction of the flow. This represents the rate of change of shear force across the riser section. Axial tension in the tubular section; and These are the cross-sectional areas of the riser and the test production tubing, respectively. and These are the pressures of the riser and the test production tubing, respectively. For downstream marine environmental loads; The force of impact; The damping coefficient of the test production tubing structure; The mass of fluid per unit length of the riser pipe; The fluid flow velocity; The curvature of the riser pipe; The cross-sectional area of ​​the fluid unit; For fluid unit pressure; and These are the bending stiffnesses of the riser and the multi-gas combined production test string, respectively. The angle of the cross section; The bending moment of the column section; Shear force at the section of the tubular column; This represents the lateral displacement of the tubular column; The axial rate of change of the rotation angle; For curvature; is the axial rate of change of curvature; for Axial tension at the point; Tension at the top of the tubular column; The axial load per unit length; Axial velocity of the riser pipe; for Cross-sectional tension; Displacement is in the downstream direction; This refers to the axial position of the tubing string; For downstream marine environmental loads; and The velocity of liquid and gas in the internal tubular column; Mass of fluid per unit length of riser pipe; and These represent the masses of the liquid and gas in the internal tubular column, respectively. The force of impact; This represents the rate of change of the slope of the downstream displacement over time. This refers to the inherent ability of the tubular column to resist bending deformation.

5. The collision mechanics analysis method for multi-gas combined production test tubing according to claim 2, characterized in that, The relationship between the collision force and deformation of the riser and the multi-gas combined production test string, established based on the theory of elasto-plastic mechanics, is as follows: Relationship between collision force and deformation between riser and multi-gas combined production test string: Further simplification yields the formula for calculating the collision force: The contact and collision problem between the riser and the multi-gas combined production test string can be simplified into a contact and collision problem occurring at multiple nodes, which can be further transformed into: Boundary conditions include upper constraints and lower constraints. The lower constraints are as follows: The upper constraint is: in, and The Poisson's ratios of the materials for the riser and the test production tubing, respectively; The elastic modulus of the riser material; This is the contact half length; Load is distributed over the contact area; Radial coordinates; This represents the displacement along the flow direction (i.e., the axial coordinate of the contact area). The outer radius of the test production tubing; Contact pressure; The Poisson's ratio of the test tube material; The elastic modulus of the test tube material; The outer radius of the riser column; This refers to the relative deformation between the tubular sections; For the axial load of the tubular column; It is the equivalent elastic modulus; This refers to the real-time radial displacement of the test production tubing. This is the initial radial clearance; It is a viscous damping force; It is the viscous damping coefficient; The radial velocity of the test production tubing; The total collision force; The resultant force of contact pressure; The time derivative of the lateral displacement of the test production tubing; This refers to the lateral displacement of the lower end of the tubular column; This is the lateral offset at the bottom of the platform; The curvature of the lower end of the tubular column; This refers to the lower corner of the tubing. The torsion angle at the lower end of the tubing; This refers to the stiffness of the upper flexible joint. This refers to the stiffness of the flexible joint at the lower end; This refers to the lateral displacement of the upper end of the tubular column; This represents the total length of the tubing. This refers to the shear force at the upper end.

6. The collision mechanics analysis method for multi-gas combined production test tubing according to claim 2, characterized in that, The improved Morrison equation, which considers the combined effects of waves and ocean currents, is used to describe the external marine environmental loads. Specifically: The formula for calculating marine load is: in: For marine environmental loads; This is the drag coefficient; The density of seawater; The outer diameter of the tubular column; The lateral velocity of the water flow; This refers to the lateral displacement of the tubular column; The inertia coefficient; The cross-sectional area of ​​the tubular column; This represents the lateral acceleration of the water flow.

7. The collision mechanics analysis method for multi-gas combined production test tubing according to claim 4, characterized in that, The collision mechanics analysis model is discretized using the Hermite interpolation method, dividing the computation into time and space steps, and then utilizing generalized... The model was iteratively solved to obtain the collision mechanics distribution characteristics of the multi-gas combined production test string, specifically: Based on the Euler-Bernoulli beam theory, the element displacement field is obtained through Hermite interpolation, and the mechanical equations of the above-mentioned riser and multi-gas combined production test string are discretized to obtain: in, and These are the overall mass matrices of the riser and the test production tubing, respectively. and These are the overall damping matrices for the riser and the test production tubing, respectively. and These are the overall stiffness matrices of the riser and the test production tubing, respectively. and These are the displacements of the riser and the test production tubing, respectively. and These are the acceleration vectors of the riser and the test production string, respectively. The marine load vector for the riser; This is the collision force vector; In this case, the multi-gas combined production test string is in a state of collision with the riser for a long time, and will face high-frequency collision effects. Therefore, the generalized α method is used for iterative solution, including: Forming the stiffness matrix quality matrix and damping matrix ; Set initial values d 0、 v 0、 a 0; Furthermore, initial value d 0、 v 0、 a The calculation method for 0 is as follows: in: The acceleration vector at the moment of implicit time integration initiation; The velocity vector at the moment of implicit time integration initiation; The displacement vector at the start of the implicit time integration; This represents the nodal external load vector at startup. for The nodal displacement vector at time t; This represents the initial offset during tubular installation. for The nodal velocity vector at time t; The initial velocity caused by the platform shaking; for The nodal acceleration vector at time t; The inverse of the mass matrix; for The nodal external load vector at time t; Select time step and The integral constant is calculated as follows: ， ， ， ， ， ， in: These are the damping control parameters for the mass matrix; For the time interpolation parameters of the load; The time interpolation parameter for the displacement; For the time interpolation parameter of velocity; These are the weighting coefficients of the stiffness matrix in the effective stiffness matrix; This is the time scaling factor for the mass matrix in the effective stiffness matrix; This is the time scaling factor for the damping matrix in the effective stiffness matrix; The weighting coefficients for the velocity term in the payload vector; These are the weighting coefficients for the acceleration term in the payload vector; These are supplementary coefficients for the velocity term in the payload vector; These are the weighting coefficients for the displacement terms in the effective load vector; For time step; Further, calculate the effective stiffness matrix: further, The effective load vector satisfies: The displacement is: The acceleration and velocity are: in: In a broad sense The core of the method is the linearization matrix; The contribution of the mass matrix to the effective stiffness matrix; This represents the contribution of the damping matrix to the effective stiffness matrix. The contribution of the stiffness matrix to the effective stiffness matrix; for The equivalent external load vector at time t; for Weighting ratio of time-bound load; for The nodal external load vector at time t; for Weighting ratio of time-bound load; for The nodal external load vector at time t; for The nodal acceleration vector at time t; for The nodal velocity vector at time t; for The nodal displacement vector at time t; It is the inverse of the effective stiffness matrix; for arrive The change in displacement at any given moment; Contribution to the acceleration of the past; Contribution to the current acceleration.

8. The collision mechanics analysis method for multi-gas combined production test tubing according to claim 1, characterized in that, The collision suppression section includes: a section body, a spring plate, a first connecting lug, a second connecting lug, and a connecting bolt; The short section body has a ring structure and is used to be sleeved on the outside of the multi-gas combined production test string; The upper part of the short section body is provided with a plurality of first connecting ears, and the first connecting ears are provided with unloading holes. A set of connecting bolts passes through the corresponding unloading holes and the first end of the spring sheet, so that the first end of the spring sheet is connected to the first connecting ear. The length of the unloading hole is greater than the outer diameter of the connecting bolt, so that when the spring sheet is deformed by force, the force is unloaded through the unloading hole. The lower part of the short section body is provided with a plurality of second connecting ears, and the second connecting ears are provided with connecting holes. The diameter of the connecting holes is adapted to the diameter of the connecting bolts. Another set of the connecting bolts passes through the corresponding connecting holes and the second end of the spring sheet, so that the second end of the spring sheet is fixedly connected to the second connecting ears.

9. The collision mechanics analysis method for multi-gas combined production test tubing according to claim 1, characterized in that, The collected target well engineering parameters include: wellbore trajectory, well structure, marine environmental load, and basic parameters of the riser and multi-gas co-production test string.

10. A collision mechanics analysis device for multi-gas combined production test tubing, characterized in that, include: The first processing unit is used to establish a Cartesian coordinate system with the direction of ocean current as the X direction and the direction perpendicular to the seabed as the Z direction. The second processing unit is used to establish a collision mechanical analysis model between the multi-gas combined production test string and the riser based on the Cartesian coordinate system, the theory of elastoplastic mechanics, and the influence of internal fluids, and to analyze and calculate the model and output the contact collision mechanical characteristics. The third processing unit collects the target well's engineering parameters, discretizes the collision mechanics analysis model using the Hermite interpolation method, divides the calculation into time and space steps, and utilizes generalized... The collision mechanics distribution characteristics of the multi-gas combined production test string were obtained by iteratively solving the model. The fourth processing unit is used to further analyze the distribution law of collision mechanics and to assemble collision suppression short sections in the multi-gas combined production test string where the collision force distribution is large.

Images