Downhole mechanical specific energy prediction method and device based on multi-body dynamics, medium and equipment

Abstract

This invention discloses a method, device, medium, and equipment for predicting downhole mechanical specific energy based on multibody dynamics calculation. The method includes the following steps: based on the multibody dynamics model of the drilling system, and adjusted according to actual engineering conditions, a multibody dynamics model of the drilling system under the drilling bit rock-breaking condition is obtained; the parameters of the drilling bit rock-breaking condition in the actual engineering are used as input parameters and substituted into the multibody dynamics model of the drilling system under the drilling bit rock-breaking condition for simulation calculation to obtain the simulation output parameters under the drilling bit rock-breaking condition; based on the simulation output parameters under the drilling bit rock-breaking condition, the downhole mechanical specific energy based on multibody dynamics calculation is obtained.

Description

Technical Field

[0001] This invention relates to the field of petroleum engineering technology, specifically to a method, device, medium, and equipment for predicting downhole mechanical specific energy based on multibody dynamics. Background Technology

[0002] In deep geological exploration fields such as oil drilling, drilling efficiency and cost control are key factors determining the quality of operations. Rock fracturing is the core physical behavior of the drilling process, and its efficiency directly affects the drilling rate and drill string life.

[0003] Currently, it is not possible to predict downhole mechanical specific energy based on multibody dynamics. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a method for predicting downhole mechanical specific energy based on multibody dynamics, thereby solving the current problem that downhole mechanical specific energy cannot be predicted based on multibody dynamics.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, this invention discloses a method for predicting downhole mechanical specific energy based on multibody dynamics calculations, including... Step A: Based on the multibody dynamics model of the drilling system, adjust according to the actual engineering to obtain the multibody dynamics model of the drilling system under the rock breaking condition of the drill bit; Step B: Take the actual drill bit rock breaking condition parameters as input parameters, substitute them into the drilling system multibody dynamics model under the drill bit rock breaking condition for simulation calculation, and obtain the simulation output parameters under the drill bit rock breaking condition. Step C: Based on the simulation output parameters of the drill bit rock breaking condition, obtain the downhole mechanical specific energy based on multibody dynamics calculation.

[0006] Step A includes the following steps: Step A1: Obtain the drill bit cutting coefficient, critical drilling pressure, friction coefficient between the drill bit and the rock, friction coefficient between the drill pipe and the well wall, as well as the drilling fluid density and viscosity in actual engineering. Step A2: Based on the drill bit cutting coefficient and critical drilling pressure in the actual engineering, update the drill bit cutting coefficient and critical drilling pressure in the existing drilling system multibody dynamics model. Based on the friction coefficient between the drill bit and the rock and the friction coefficient between the drill pipe and the well wall in the actual engineering, update the friction coefficient between the rock and the well wall in the existing drilling system multibody dynamics model. Based on the drilling fluid density and viscosity in the actual engineering, update the drilling fluid density and viscosity in the existing drilling system multibody dynamics model to obtain the drilling system multibody dynamics model under the drill bit rock breaking condition.

[0007] Step B includes the following steps: Step B1: Obtain the wellbore trajectory curve, well structure type and drill string combination form, as well as the mechanical feed rate and top drive speed in the actual project, wherein the mechanical feed rate and the top drive speed are well surface control parameters; Step B2: The wellbore trajectory curve, well structure type, and drill string assembly form in the actual project are used as the parameters of the drill bit rock breaking condition in the actual project. The mechanical feed rate and top drive speed in the actual project are used as boundary conditions. These parameters are substituted into the multibody dynamics model of the drilling system under the drill bit rock breaking condition for simulation calculation to obtain the simulation output parameters under the drill bit rock breaking condition. The simulation output parameters under the drill bit rock breaking condition are the drill bit pressure, drill bit torque, drill bit speed, and drill bit speed calculated by the simulation model.

[0008] In step C, the calculation expression for the downhole mechanical specific energy based on multibody dynamics is obtained as follows:

[0009] In the formula, The specific energy of downhole machinery is calculated based on multibody dynamics. The drill bit pressure calculated from the simulation model; The drill bit torque calculated from the simulation model; The drill bit rotation speed calculated from the simulation model; ROP The drill bit speed calculated from the simulation model; D This is the drill bit diameter.

[0010] Secondly, the present invention also discloses a downhole mechanical specific energy prediction device based on multibody dynamics calculation, comprising: The first processing unit is used to obtain the drilling system multibody dynamics model under the drilling bit rock breaking condition based on the drilling system multibody dynamics model and adjusted according to the actual engineering. The second processing unit is used to take the drill bit rock breaking condition parameters in the actual engineering as input parameters, substitute them into the drilling system multibody dynamics model under the drill bit rock breaking condition for simulation calculation, and obtain the simulation output parameters under the drill bit rock breaking condition. The third processing unit is used to obtain the downhole mechanical specific energy based on multibody dynamics calculations according to the simulation output parameters of the drill bit rock breaking condition.

[0011] Thirdly, the present invention also discloses a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the above-described method.

[0012] Fourthly, the present invention also discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method described above.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention discloses a method for predicting downhole mechanical specific energy based on multibody dynamics calculations, comprising the following steps: Based on a multibody dynamics model of the drilling system, and adjusted according to actual engineering conditions, a multibody dynamics model of the drilling system under the drilling bit rock-breaking condition is obtained; the parameters of the drilling bit rock-breaking condition in the actual engineering are used as input parameters and substituted into the multibody dynamics model of the drilling system under the drilling bit rock-breaking condition for simulation calculation, obtaining the simulation output parameters under the drilling bit rock-breaking condition; based on the simulation output parameters under the drilling bit rock-breaking condition, the downhole mechanical specific energy calculated based on multibody dynamics is obtained. This invention discloses a method for predicting downhole mechanical specific energy based on multibody dynamics calculations, which can obtain downhole mechanical specific energy calculated based on multibody dynamics, solving the current problem of not being able to predict downhole mechanical specific energy based on multibody dynamics. Attached Figure Description

[0014] Figure 1 This is a flowchart of the downhole mechanical specific energy prediction method based on multibody dynamics calculation provided in Embodiment 1 of the present invention. Detailed Implementation

[0015] 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.

[0016] Example 1: A method for predicting downhole mechanical specific energy based on multibody dynamics calculation Embodiment 1 of this invention provides a method for predicting downhole mechanical specific energy based on multibody dynamics calculations, referring to... Figure 1 This includes the following steps: Step A: Based on the multibody dynamics model of the drilling system, and adjusted according to the actual engineering conditions, obtain the multibody dynamics model of the drilling system under the rock-breaking condition of the drill bit, including the following steps: Step A1: Obtain the drill bit cutting coefficient, critical drilling pressure, friction coefficient between the drill bit and the rock, friction coefficient between the drill pipe and the well wall, as well as the drilling fluid density and viscosity in actual engineering. Step A2: Based on the drill bit cutting coefficient and critical drilling pressure in the actual engineering, update the drill bit cutting coefficient and critical drilling pressure in the existing drilling system multibody dynamics model. Based on the friction coefficient between the drill bit and the rock and the friction coefficient between the drill pipe and the well wall in the actual engineering, update the friction coefficient between the rock and the well wall in the existing drilling system multibody dynamics model. Based on the drilling fluid density and viscosity in the actual engineering, update the drilling fluid density and viscosity in the existing drilling system multibody dynamics model to obtain the drilling system multibody dynamics model under the drill bit rock breaking condition.

[0017] The drilling system multibody dynamics model is a mathematical and physical model used to describe the dynamic behavior of the drilling system from the surface equipment to the drill bit at the bottom of the well. It is a high-fidelity forward model of drilling system dynamics. Based on the theory of distributed parametric systems, the model comprehensively considers the random contact between the drill string and the wellbore, and couples the interaction model between the drill bit and the rock, the influence of drilling fluid and drill string, and the influence of wellbore trajectory on drill string morphology.

[0018] It is worth mentioning that the multibody dynamics model of the drilling system is existing technology, as detailed in the journal article (Steeringability rapid evaluation of the slide drilling system based on multi-bodydynamics model). Geoenergy Science and Engineering (Jiaqi Chen, Kejie Wang, Xinyu Tang, and Gexue Ren. 237:212813, 2024), which will not be elaborated further.

[0019] Step B: Using the actual drill bit rock-breaking conditions parameters from the engineering project as input parameters, substitute them into the multibody dynamics model of the drilling system under the drill bit rock-breaking conditions for simulation calculation, and obtain the simulation output parameters under the drill bit rock-breaking conditions, including the following steps: Step B1: Obtain the wellbore trajectory curve, well structure type and drill string combination form, as well as the mechanical feed rate and top drive speed in the actual project, wherein the mechanical feed rate and the top drive speed are well surface control parameters; Step B2: The wellbore trajectory curve, well structure type, and drill string assembly form in the actual project are used as the parameters of the drill bit rock breaking condition in the actual project. The mechanical feed rate and top drive speed in the actual project are used as boundary conditions. These parameters are substituted into the multibody dynamics model of the drilling system under the drill bit rock breaking condition for simulation calculation to obtain the simulation output parameters under the drill bit rock breaking condition. The simulation output parameters under the drill bit rock breaking condition are the drill bit pressure, drill bit torque, drill bit speed, and drill bit speed calculated by the simulation model.

[0020] The input parameters of the multibody dynamics model of the drilling system under the rock-breaking condition are the wellbore trajectory curve, wellbore structure type and drill string combination form, and the output parameters are the drill bit pressure on bit (WOB), drill bit torque (TQ), drill bit rotation speed (RPM), and drill bit speed on bit (ROP) calculated by the simulation model.

[0021] Specifically, the mechanical feed rate is the speed at which the traveling carriage is lowered, and the top drive speed is the speed at which the top drive rotates.

[0022] The input file is simulated using a multibody dynamics solver for drilling systems. The process mainly includes: selecting an appropriate step size and integration order; incorporating all complete and non-complete constraints into the overall dynamic equations composed of rigid and flexible elements; and solving using the Newton-Raphson iterative method. If both the iteration accuracy and integration accuracy meet the requirements, the solution is applied to the next time step.

[0023] Step C: Based on the simulation output parameters of the drill bit rock breaking condition, obtain the downhole mechanical specific energy based on multibody dynamics calculation.

[0024] The calculation expression for the downhole mechanical specific energy based on multibody dynamics is as follows:

[0025] In the formula, The specific energy of downhole machinery is calculated based on multibody dynamics. The drill bit pressure calculated from the simulation model; The drill bit torque calculated from the simulation model; The drill bit rotation speed calculated from the simulation model; ROP The drill bit speed calculated from the simulation model; D This is the drill bit diameter.

[0026] Extract the drill bit pressure, torque, rotational speed, and drill bit feed rate from the final calculated results and substitute them into the input. The downhole mechanical specific energy can be calculated from the formula. Thus, downhole mechanical specific energy prediction based on multibody dynamics calculations can be achieved.

[0027] In order to quantitatively evaluate and optimize the rock crushing process, the industry has introduced mechanical energy specificity (MSE) as a key performance evaluation indicator.

[0028] MSE (Mechanical Energy Segregation) is defined as the mechanical energy consumed in breaking a unit volume of rock. Its theoretical basis stems from the law of conservation of energy, aiming to establish a relationship between the energy input during drilling and the work output during rock breaking. Ideally, when all the energy used for rock is effectively used for its volumetric breaking, the MSE value should approach the rock's intrinsic specific energy. Therefore, MSE is considered an idealized benchmark for measuring the energy utilization efficiency of a drilling system.

[0029] Example 2: A downhole mechanical specific energy prediction device based on multibody dynamics calculation Embodiment 2 of the present invention provides a downhole mechanical specific energy prediction device based on multibody dynamics calculation, comprising: The first processing unit is used to obtain the drilling system multibody dynamics model under the drilling bit rock breaking condition based on the drilling system multibody dynamics model and adjusted according to the actual engineering. The second processing unit is used to take the drill bit rock breaking condition parameters in the actual engineering as input parameters, substitute them into the drilling system multibody dynamics model under the drill bit rock breaking condition for simulation calculation, and obtain the simulation output parameters under the drill bit rock breaking condition. The third processing unit is used to obtain the downhole mechanical specific energy based on multibody dynamics calculations according to the simulation output parameters of the drill bit rock breaking condition.

[0030] Example 3: A computer-readable storage medium Embodiment 3 of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method of Embodiment 1.

[0031] Example 4: A computer device Embodiment 4 of the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the method of Embodiment 1.

[0032] 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 predicting downhole mechanical specific energy based on multibody dynamics calculation, characterized in that, include Step A: Based on the multibody dynamics model of the drilling system, adjust according to the actual engineering to obtain the multibody dynamics model of the drilling system under the rock breaking condition of the drill bit; Step B: Take the actual drill bit rock breaking condition parameters as input parameters, substitute them into the drilling system multibody dynamics model under the drill bit rock breaking condition for simulation calculation, and obtain the simulation output parameters under the drill bit rock breaking condition. Step C: Based on the simulation output parameters of the drill bit rock breaking condition, obtain the downhole mechanical specific energy based on multibody dynamics calculation.

2. The method for predicting downhole mechanical specific energy based on multibody dynamics calculation according to claim 1, characterized in that, Step A includes the following steps: Step A1: Obtain the drill bit cutting coefficient, critical drilling pressure, friction coefficient between the drill bit and the rock, friction coefficient between the drill pipe and the well wall, as well as the drilling fluid density and viscosity in actual engineering. Step A2: Based on the drill bit cutting coefficient and critical drilling pressure in the actual engineering, update the drill bit cutting coefficient and critical drilling pressure in the existing drilling system multibody dynamics model. Based on the friction coefficient between the drill bit and the rock and the friction coefficient between the drill pipe and the well wall in the actual engineering, update the friction coefficient between the rock and the well wall in the existing drilling system multibody dynamics model. Based on the drilling fluid density and viscosity in the actual engineering, update the drilling fluid density and viscosity in the existing drilling system multibody dynamics model to obtain the drilling system multibody dynamics model under the drill bit rock breaking condition.

3. The method for predicting downhole mechanical specific energy based on multibody dynamics calculation according to claim 1, characterized in that, Step B includes the following steps: Step B1: Obtain the wellbore trajectory curve, well structure type and drill string combination form, as well as the mechanical feed rate and top drive speed in the actual project, wherein the mechanical feed rate and the top drive speed are well surface control parameters; Step B2: The wellbore trajectory curve, well structure type, and drill string assembly form in the actual project are used as the parameters of the drill bit rock breaking condition in the actual project. The mechanical feed rate and top drive speed in the actual project are used as boundary conditions. These parameters are substituted into the multibody dynamics model of the drilling system under the drill bit rock breaking condition for simulation calculation to obtain the simulation output parameters under the drill bit rock breaking condition. The simulation output parameters under the drill bit rock breaking condition are the drill bit pressure, drill bit torque, drill bit speed, and drill bit speed calculated by the simulation model.

4. The method for predicting downhole mechanical specific energy based on multibody dynamics calculation according to claim 1, characterized in that, In step C, the calculation expression for the downhole mechanical specific energy based on multibody dynamics is obtained as follows: In the formula, The specific energy of downhole machinery is calculated based on multibody dynamics. The drill bit pressure calculated from the simulation model; The drill bit torque calculated from the simulation model; The drill bit rotation speed calculated from the simulation model; ROP The drill bit speed calculated from the simulation model; D This is the drill bit diameter.

5. A downhole mechanical specific energy prediction device based on multibody dynamics calculation, characterized in that, include The first processing unit is used to obtain the drilling system multibody dynamics model under the drilling bit rock breaking condition based on the drilling system multibody dynamics model and adjusted according to the actual engineering. The second processing unit is used to take the drill bit rock breaking condition parameters in the actual engineering as input parameters, substitute them into the drilling system multibody dynamics model under the drill bit rock breaking condition for simulation calculation, and obtain the simulation output parameters under the drill bit rock breaking condition. The third processing unit is used to obtain the downhole mechanical specific energy based on multibody dynamics calculations according to the simulation output parameters of the drill bit rock breaking condition.

6. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the steps of the method described in any one of claims 1 to 4.

7. A computer device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the steps of the method according to any one of claims 1 to 4.

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