Method for optimizing screw motor stator and rotor linear for directional drilling

Abstract

The application discloses a screw motor stator-rotor linear optimization method for directional drilling, relates to the technical field of directional drilling of oil and natural gas, and comprises the following steps: according to the design requirements of a screw motor for directional drilling, design parameters of an eccentricity, a rotor head number, a stator head number, a base circle diameter and a theoretical equidistance radius are determined, and an initial linear data set containing discrete data points is generated based on an internal or external cycloid equation; a non-uniform rational B-spline method is used to perform curve reconstruction on the initial linear data set, local fairing treatment is performed on regions with curvature mutations by adjusting control point weight factors and node vectors of the non-uniform rational B-spline curve, and a smooth linear parameter model is generated; and based on the smooth linear parameter model, a thermodynamic coupling simulation model based on a rubber viscoelastic constitutive relation is established to simulate periodic plunger movement of the screw motor under a rated working condition.

Description

Technical Field

[0001] This invention relates to the field of directional drilling technology for oil and gas, and in particular to a method for optimizing the stator and rotor profiles of screw motors used in directional drilling. Background Technology

[0002] In the field of directional drilling technology for oil and gas, the screw motor (also known as the mud motor) is a core downhole power tool, and its performance directly affects drilling efficiency, trajectory control accuracy, and operating costs. The core working principle of the screw motor relies on a conjugate pair consisting of a stator rubber bushing and a metal rotor. The end face profile (i.e., the cross-sectional contour curve) of this pair determines the formation of the sealing cavity, the volume change law, and the power transmission characteristics. Traditional profile design theory is mainly based on the classical mathematical equations of the epicycloid, epicycloid, and their equidistant lines. It balances macroscopic performance indicators such as flow area, contact stress, and volumetric efficiency by optimizing key geometric parameters (such as eccentricity, number of heads, and equidistant radius). With the development of computational fluid dynamics and finite element analysis technology, existing technical solutions, based on parametric modeling, can now perform single-field or multi-field coupled simulations of steady-state mechanical performance, leakage, and flow field distribution for specific profiles to evaluate and select superior profile solutions. For example, by establishing a finite element model of the stator-rotor contact, the stress distribution under specific speeds and pressure differences can be analyzed, thereby optimizing the linear profile to reduce peak contact stress and extend the service life of the stator rubber. These methods constitute the mainstream technical path for the current design and optimization of screw motor linear profiles, significantly improving the initial design performance of the motor.

[0003] Existing optimization methods based on geometric parameter optimization and static performance simulation face a profound physical challenge when addressing the increasing demands of high-speed, high-load conditions in modern directional drilling: As a viscoelastic material, the stator rubber, under high-frequency alternating contact stress, experiences internal heat accumulation due to hysteresis, a key factor leading to material performance degradation, accelerated thermal aging, and ultimately, early failure. Current simulation optimizations typically treat material physical properties (such as elastic modulus and Poisson's ratio) as constants or simplify thermal effects to boundary heat flow based on a constant friction coefficient. They fail to accurately characterize the endogenous heating mechanism of rubber under periodic large deformation due to strain energy loss and its dynamic impact on temperature from the thermo-mechanical coupling level of the material constitutive relationship. Therefore, while the optimized linear shape using traditional methods may theoretically achieve local optima in contact stress or volumetric efficiency, in actual high-speed operation, the failure to effectively control internal hysteresis heat generation in the rubber may lead to local stator temperature rise exceeding the material's tolerance limit, thus shortening the effective service life of the motor under harsh conditions. This limits the potential for performance improvements in screw motors in pursuit of higher mechanical drilling speeds and longer lifespans. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, this invention provides a method for optimizing the stator and rotor profiles of screw motors used in directional drilling to solve the problems of uncontrolled temperature rise and accelerated thermal aging caused by the viscoelastic hysteresis of the stator rubber under high-speed operating conditions.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a method for optimizing the stator and rotor profile of a screw motor for directional drilling, which includes determining the design parameters of eccentricity, number of rotor heads, number of stator heads, base circle diameter and theoretical equidistant radius according to the design requirements of the screw motor for directional drilling, and generating an initial profile dataset containing discrete data points based on the epicycloid or epicycloid equation. The initial linear dataset is reconstructed using the non-uniform rational B-spline method. By adjusting the control point weight factors and node vectors of the non-uniform rational B-spline curves, local smoothing is performed on regions with abrupt curvature changes to generate a smooth linear parameter model. Based on the smooth linear parameter model, a thermodynamic coupling simulation model based on the rubber viscoelastic constitutive relation is established to simulate the periodic piston movement of the screw motor under rated operating conditions. The internal heat generation rate and temperature field distribution of the stator rubber bushing under alternating contact stress due to the hysteresis effect are calculated, and the thermodynamic coupling analysis results including the maximum temperature rise value and heat generation power are obtained. With the maximum temperature value in the thermo-coupling analysis results not exceeding the rubber thermal aging failure threshold as a constraint, the control point parameters of the non-uniform rational B-spline curve in the smooth linear parameter model are iteratively corrected based on the back propagation algorithm until the temperature constraint condition is met, and qualified linear data are output. Based on the qualified linear profile data, the performance indicators of flow area, volumetric efficiency, and contact line length are calculated, generating the final stator and rotor profile curve equations and cross-sectional drawings for CNC machining or 3D printing. As a preferred embodiment of the stator and rotor profile optimization method for directional drilling screw motors described in this invention, the generation of the initial profile dataset further includes correcting the intracycloid or extracycloid equation based on the drilling fluid solid particle content, wherein a solid particle correction factor is introduced. Dynamically adjust the equidistant radius; The correction factor The calculation formula is: ; in, As a correction factor, This represents the actual volume concentration of the drilling fluid solid phase. To preset the reference concentration, This is a correction factor.

[0007] As a preferred embodiment of the directional drilling screw motor stator and rotor alignment optimization method of the present invention, wherein: the adjustment basis of the control point weight factor is: to assign greater weight values ​​to discrete points in the curvature abrupt change region in the initial alignment data; The formula for calculating the weight value is: ; in, For the first Curvature at discrete points The average curvature of all discrete points, This is the weighting adjustment coefficient.

[0008] As a preferred embodiment of the stator and rotor profile optimization method for directional drilling screw motors described in this invention, the thermodynamic coupling simulation model also considers the influence of solid particles on rubber wear, and adjusts the solid particle concentration... Correlate the results of the thermo-coupling analysis to the maximum temperature rise value, and correct the value using a wear correction factor μ. The formula for calculating the wear correction factor is: ; in, This is the wear correction factor. The drilling fluid flow rate, For reference flow rate, This represents the wear and tear effect coefficient.

[0009] As a preferred embodiment of the stator and rotor profile optimization method for directional drilling screw motors described in this invention, the backpropagation algorithm adjusts the control point parameters of the non-uniform rational B-spline curve based on the temperature sensitivity matrix T. The formula for calculating the temperature sensitivity matrix is: ; in, This is the temperature sensitivity matrix. This represents the change in the maximum temperature rise. For the first The adjustment amount of each control point parameter. This is a reference temperature change.

[0010] As a preferred embodiment of the stator and rotor profile optimization method for directional drilling screw motors described in this invention, the evaluation of the qualified profile data further includes evaluation based on vibration suppression indices. ; The formula for calculating the vibration suppression index is as follows: ; in, As a vibration suppression index, This represents the total number of discrete points.

[0011] As a preferred embodiment of the stator and rotor profile optimization method for directional drilling screw motors described in this invention, the calculation of the performance indicators further includes the volumetric efficiency variation coefficient. Calculation; The volumetric efficiency variation coefficient The calculation formula is: ; in, The coefficient of variation for volumetric efficiency. The standard deviation of volumetric efficiency. This represents the average volumetric efficiency. When the volumetric efficiency variation coefficient If the value is below 0.05, the qualified line type data is determined to meet the stability requirements.

[0012] As a preferred embodiment of the stator and rotor profile optimization method for directional drilling screw motors described in this invention, the following steps are performed: before outputting the final profile curve equations of the stator and rotor, the curvature continuity of the qualified profile data is verified. The verification is performed when the maximum absolute value of the rate of change of the profile curvature is less than a preset threshold ε, and the value of ε ranges from 0.001 to 0.01 mm. -1 At that time, it is confirmed that the qualified line type data meets the high-order continuity requirements.

[0013] In a second aspect, the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, wherein when the computer program is executed by the processor, it implements any step of the method for optimizing the stator and rotor profile of a screw motor for directional drilling as described in the first aspect of the present invention.

[0014] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, it implements any step of the method for optimizing the stator and rotor profile of a screw motor for directional drilling as described in the first aspect of the present invention.

[0015] The beneficial effects of this invention are as follows: The initial cycloidal profile is reconstructed using a non-uniform rational B-spline method. By locally adjusting the control point weight factors and node vectors, smoothing of curvature abrupt change regions is achieved, eliminating the inherent local stress concentration of traditional profiles at the geometric level. This provides a structural basis for suppressing instantaneous temperature rise in the contact area. A thermodynamic coupling simulation model based on the viscoelastic constitutive relationship of rubber is established. Combined with a solid particle wear correction coefficient, the hysteretic heat generation process of stator rubber under periodic contact stress is accurately simulated. This reveals the intrinsic heat generation mechanism of rubber from a material constitutive perspective, extending the evaluation from static mechanical evaluation to dynamic thermodynamic performance evaluation. With the maximum temperature not exceeding the rubber thermal aging failure threshold as a constraint, the NURBS control points are iteratively corrected using a backpropagation algorithm, achieving a leap from thermal failure analysis to active thermal management design. Finally, a comprehensive evaluation is conducted by combining vibration suppression indices and volumetric efficiency variation coefficients to generate processing drawings that meet high-order continuity requirements. This enables the optimized profile to possess better thermal stability and service life under high-speed, high-solids-content conditions. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A flowchart illustrating the method for optimizing the stator and rotor profiles of screw motors used in directional drilling. Detailed Implementation

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0019] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0020] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0021] Reference Figure 1As one embodiment of the present invention, this embodiment provides a method for optimizing the stator and rotor profiles of a screw motor for directional drilling, comprising the following steps: S1. The generation of the initial linear dataset also includes correcting the intracycloid or epicycloid equation based on the drilling fluid solid particle content, wherein a solid particle correction factor is introduced. Dynamically adjust the equidistant radius; The correction factor The calculation formula is: ; in, As a correction factor, This represents the actual volume concentration of the drilling fluid solid phase. To preset the reference concentration, This is a correction factor.

[0022] Furthermore, in the generation of the initial linear dataset, the method of correcting the traditional cycloidal equation based on the drilling fluid solid particle content is improved by introducing a solid particle correction factor. The theoretical equidistant radius is dynamically adjusted. This method establishes a quantitative relationship between drilling fluid solids concentration and linear parameters, where the correction factor... Using formula Calculation, where To monitor the actual volume concentration of the drilling fluid solid phase in real time. The reference concentration is preset according to the drilling conditions. The material correction factor, which reflects the effect of particle erosion, typically ranges from 0.01 to 0.05. This step directly incorporates the field drilling fluid operating parameters into the initial stage of the profile design. This ensures that the generated initial profile, while meeting basic geometric sealing requirements, pre-considers the actual erosion effect of solid particles on the stator rubber, providing a geometric basis closer to actual operating conditions for subsequent optimization.

[0023] S2. The adjustment basis for the control point weight factor is: to assign a larger weight value to the discrete points in the curvature change region in the initial linear dataset; The formula for calculating the weight value is: ; in, For the first Curvature at discrete points The average curvature of all discrete points, This is the weighting adjustment coefficient.

[0024] Furthermore, during the linear curve reconstruction process, the adjustment criteria for the weighting factors of the control points of the non-uniform rational B-spline were quantitatively designed. This adjustment method, based on the discrete point curvature distribution characteristics of the initial linear dataset, assigns greater weight values ​​to discrete points in curvature abrupt change regions. Specifically, the weight values... Through formula The calculation determines that, among which For the first Curvature values ​​at discrete points The average curvature of all discrete points, The weighting adjustment coefficient is set according to the material properties, with a value range of 0.5-2.0. This step establishes a quantitative relationship between curvature distribution and weight allocation, which can automatically identify and prioritize high curvature regions, making the curve reconstruction process more effective in eliminating curvature abrupt changes at connection points of traditional cycloids, and providing a calculation basis for generating smoother line shapes with better geometric continuity.

[0025] The thermodynamic coupling simulation model described in S3 also considers the influence of solid particles on rubber wear, adjusting the concentration of solid particles... Correlate the results of the thermo-coupling analysis to the maximum temperature rise value, and correct the value using a wear correction factor μ. The formula for calculating the wear correction factor is: ; in, This is the wear correction factor. The drilling fluid flow rate, For reference flow rate, This represents the wear and tear effect coefficient.

[0026] Furthermore, the combined effect of solid particles on rubber wear was further considered in the thermodynamic coupling simulation model. This method correlates the drilling fluid solid particle concentration C with the thermodynamic coupling analysis results, and dynamically corrects the calculated maximum temperature rise value using a wear correction coefficient μ. The formula for calculating the wear correction coefficient μ is as follows: This step incorporates the quantitative relationship between the concentration and flow rate of solid particles and wear heat generation into the thermodynamic analysis, enabling the model to more accurately predict the actual temperature rise of the stator rubber under solid-liquid two-phase flow conditions, and providing a more realistic operating load input for subsequent line shape optimization.

[0027] S4. The backpropagation algorithm adjusts the control point parameters of the non-uniform rational B-spline curve based on the temperature sensitivity matrix T. The formula for calculating the temperature sensitivity matrix is: ; in, This is the temperature sensitivity matrix. This represents the change in the maximum temperature rise. For the first The adjustment amount of each control point parameter. This is a reference temperature change.

[0028] Furthermore, in the backpropagation algorithm, the control point parameters of the non-uniform rational B-spline curve are optimized and adjusted based on the temperature sensitivity matrix T. This calculation establishes the gradient relationship between the linear geometry parameters and the thermodynamic response, enabling the optimization algorithm to analyze the sensitivity of each control point to the temperature rise of the rubber and to selectively adjust the geometric parameters that have the greatest impact on temperature, thereby improving the efficiency and accuracy of linear optimization aimed at thermal stability.

[0029] S5. The evaluation of the qualified linearity data also includes evaluation based on vibration suppression index. ; The formula for calculating the vibration suppression index is as follows: ; in, As a vibration suppression index, This represents the total number of discrete points.

[0030] Furthermore, the evaluation of qualified alignment data includes a quantitative assessment based on the vibration suppression index V. This index quantifies the uniformity of the curvature distribution of the optimized alignment, effectively reflecting the dynamic impact level generated during operation. A more uniform curvature distribution and a smaller vibration suppression index V value indicate better dynamic stability of the alignment at high speeds, which is beneficial for reducing vibration noise and extending the service life of components.

[0031] S5. The calculation of the performance indicators also includes the volumetric efficiency variation coefficient. Calculation; The volumetric efficiency variation coefficient The calculation formula is: ; in, The coefficient of variation for volumetric efficiency. The standard deviation of volumetric efficiency. This represents the average volumetric efficiency. When the volumetric efficiency variation coefficient If the value is below 0.05, the qualified line type data is determined to meet the stability requirements.

[0032] Furthermore, a new volumetric efficiency variation coefficient has been added to the performance index calculation. Evaluation dimensions. Volumetric efficiency coefficient of variation. Through formula Calculation, where This represents the standard deviation of the volumetric efficiency of each chamber in a screw motor over one complete motion cycle. This represents the average internal efficiency for the corresponding period. When When the value is below 0.05, the linear profile can be considered to meet the stability requirements. This indicator quantifies the fluctuation of volumetric efficiency and reflects the flow stability and torque output smoothness of the optimized linear profile during operation, ensuring that the screw motor has stable power output characteristics during operation.

[0033] S6. Before outputting the final profile curve equations of the stator and rotor, the curvature continuity of the qualified line shape data is verified. The line shape curvature change rate is verified when the maximum absolute value is less than a preset threshold ε, and the value of ε is in the range of 0.001-0.01 mm. -1 At that time, it is confirmed that the qualified line type data meets the high-order continuity requirements.

[0034] Furthermore, before outputting the final contour curve, the curvature continuity of the qualified line type data is verified. This verification is performed by calculating the maximum absolute value of the rate of change of the line type curvature. If it is less than a preset threshold ε (ranging from 0.001 to 0.01 mm), then... -1 During this process, it is confirmed that the line shape meets the high-order continuity requirements. This step uses mathematical methods to quantitatively verify the high-order geometric continuity of the optimized line shape, ensuring that the line shape not only meets the requirements of thermal stability and smooth motion, but also has excellent smoothness characteristics, providing geometric quality assurance for subsequent precision machining and long-term reliable operation.

[0035] This embodiment also provides a computer device applicable to the method for optimizing the stator and rotor profiles of a screw motor for directional drilling, comprising: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the method for optimizing the stator and rotor profiles of a screw motor for directional drilling as proposed in the above embodiment.

[0036] The computer device can be a terminal, comprising a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0037] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the method for optimizing the stator and rotor profiles of a screw motor for directional drilling as proposed in the above embodiments. The storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0038] In summary, this invention reconstructs the initial cycloidal profile using a non-uniform rational B-spline method. By locally adjusting the control point weighting factors and node vectors, it smooths the curvature abrupt change region, eliminating the inherent local stress concentration of traditional profiles at the geometric level. This provides a structural basis for suppressing instantaneous temperature rise in the contact area. A thermodynamic coupling simulation model based on the viscoelastic constitutive relation of rubber is established. Combined with a solid particle wear correction coefficient, it accurately simulates the hysteretic heat generation process of stator rubber under periodic contact stress, revealing the intrinsic heat generation mechanism of rubber from a material constitutive perspective. This extends the evaluation from static mechanical evaluation to dynamic thermodynamic performance evaluation. With the maximum temperature not exceeding the rubber thermal aging failure threshold as a constraint, the backpropagation algorithm iteratively corrects the NURBS control points, achieving a leap from thermal failure analysis to active thermal management design. Finally, a comprehensive evaluation is performed using vibration suppression indices and volumetric efficiency variation coefficients to generate processing drawings that meet high-order continuity requirements. This enables the optimized profile to have better thermal stability and service life under high-speed, high-solids-content conditions.

[0039] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for optimizing the stator and rotor profiles of a screw motor used in directional drilling, characterized in that: include, Based on the design requirements of screw motors for directional drilling, the design parameters of eccentricity, number of rotor heads, number of stator heads, base circle diameter and theoretical equidistant radius are determined, and an initial linear dataset containing discrete data points is generated based on the epicycloid or epicycloid equation. The initial linear dataset is reconstructed using the non-uniform rational B-spline method. By adjusting the control point weight factors and node vectors of the non-uniform rational B-spline curves, local smoothing is performed on regions with abrupt curvature changes to generate a smooth linear parameter model. Based on the smooth linear parameter model, a thermodynamic coupling simulation model based on the rubber viscoelastic constitutive relation is established to simulate the periodic piston movement of the screw motor under rated operating conditions. The internal heat generation rate and temperature field distribution of the stator rubber bushing under alternating contact stress due to the hysteresis effect are calculated, and the thermodynamic coupling analysis results including the maximum temperature rise value and heat generation power are obtained. With the maximum temperature value in the thermo-coupling analysis results not exceeding the rubber thermal aging failure threshold as a constraint, the control point parameters of the non-uniform rational B-spline curve in the smooth linear parameter model are iteratively corrected based on the back propagation algorithm until the temperature constraint condition is met, and qualified linear data are output. Based on the qualified line shape data, the performance indicators of flow area, volumetric efficiency and contact line length are calculated, and the final contour curve equations and cross-sectional drawings of the stator and rotor for CNC machining or 3D printing are generated.

2. The method for optimizing the stator and rotor profiles of a screw motor for directional drilling as described in claim 1, characterized in that: The generation of the initial linear dataset also includes correcting the intracycloid or epicycloid equation based on the drilling fluid solid particle content, wherein a solid particle correction factor is introduced. Dynamically adjust the equidistant radius; The correction factor The calculation formula is: ； in, As a correction factor, This represents the actual volume concentration of the drilling fluid solid phase. To preset the reference concentration, This is a correction factor.

3. The method for optimizing the stator and rotor profiles of a screw motor for directional drilling as described in claim 2, characterized in that: The adjustment of the control point weight factor is based on assigning greater weight values ​​to discrete points in the curvature abrupt change region of the initial linear dataset. The formula for calculating the weight value is: ； in, For the first Curvature at discrete points The average curvature of all discrete points, This is the weighting adjustment coefficient.

4. The method for optimizing the stator and rotor profiles of a screw motor for directional drilling as described in claim 3, characterized in that: The thermodynamic coupling simulation model also considers the influence of solid particles on rubber wear, adjusting the concentration of solid particles... Correlate the results of the thermo-coupling analysis to the maximum temperature rise value, and correct the value using a wear correction factor μ. The formula for calculating the wear correction factor is: ； in, This is the wear correction factor. The drilling fluid flow rate, For reference flow rate, This represents the wear and tear effect coefficient.

5. The method for optimizing the stator and rotor profiles of a screw motor for directional drilling as described in claim 4, characterized in that: The backpropagation algorithm adjusts the control point parameters of the non-uniform rational B-spline curve based on the temperature sensitivity matrix T. The formula for calculating the temperature sensitivity matrix is: ； in, This is the temperature sensitivity matrix. This represents the change in the maximum temperature rise. For the first The adjustment amount of each control point parameter. This is a reference temperature change.

6. The method for optimizing the stator and rotor profiles of a screw motor for directional drilling as described in claim 5, characterized in that: The evaluation of the qualified linearity data also includes based on vibration suppression indicators. ; The formula for calculating the vibration suppression index is as follows: ； in, As a vibration suppression index, This represents the total number of discrete points.

7. The method for optimizing the stator and rotor profiles of a screw motor for directional drilling as described in claim 6, characterized in that: The calculation of the performance indicators also includes the volumetric efficiency variation coefficient. Calculation; The volumetric efficiency variation coefficient The calculation formula is: ； in, The coefficient of variation for volumetric efficiency. The standard deviation of volumetric efficiency. This represents the average volumetric efficiency. When the volumetric efficiency variation coefficient If the value is below 0.05, the qualified line type data is determined to meet the stability requirements.

8. The method for optimizing the stator and rotor profiles of a screw motor for directional drilling as described in claim 7, characterized in that, Before outputting the final profile curve equations of the stator and rotor, the curvature continuity of the qualified line shape data is verified. The verification is performed when the maximum absolute value of the rate of change of the line shape curvature is less than a preset threshold ε, and the value of ε ranges from 0.001 to 0.01 mm. -1 At that time, it is confirmed that the qualified line type data meets the high-order continuity requirements.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the method for optimizing the stator and rotor profiles of a screw motor for directional drilling as described in any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the method for optimizing the stator and rotor profiles of a screw motor for directional drilling as described in any one of claims 1 to 8.

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