Method and device for judging length of non-magnetic drill collar of drilling tool and storage medium

Abstract

This invention discloses a method, device, and storage medium for determining the length of non-magnetic drill collars. The method involves obtaining the pole strength coefficients of each section of the ferromagnetic drill string during the non-drilling process; obtaining the pole strength of each section of the ferromagnetic drill string during the drilling process; estimating the axial magnetic interference intensity of each section of the ferromagnetic drill string on wireless logging-while-drilling (LMD) points during drilling based on the pole strength coefficients of each section of the ferromagnetic drill string during the non-drilling process and the pole strength of each section of the ferromagnetic drill string during drilling; and obtaining the final magnetic interference intensity based on the final magnetic interference intensity. The method then determines whether the length of the non-magnetic drill collar is appropriate based on the final magnetic interference intensity. This invention allows for accurate understanding of the magnetic interference distribution in the downhole drilling tool assembly, thereby determining the appropriateness of the non-magnetic drill collar length.

Description

Technical Field

[0001] This invention relates to the field of oil and gas drilling equipment technology, and in particular to a method, equipment and storage medium for determining the length of a non-magnetic drill collar. Background Technology

[0002] With the development of reservoir development needs and integrated drilling technologies, extended reach wells and horizontal wells have become widespread. These technologies can significantly improve and increase the productivity of a block, but they also place higher demands on the accuracy of wellbore description. The selection of the length of the non-magnetic drill collar directly affects the measurement accuracy of the wellbore trajectory. During drilling, the measurement of the MWD azimuth angle of directional wells is mainly affected by axial magnetic interference from the drill string. Currently, the calculation of axial magnetic interference from the drill string is still based on "experience" and guesswork, and there is no complete and systematic method for calculating the axial magnetic interference of iron drill strings.

[0003] Therefore, existing technologies still need improvement. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a method, device, and storage medium for determining the length of a non-magnetic drill collar, thereby resolving the technical issues existing in the calculation of axial drilling magnetic interference in the prior art.

[0005] To address the aforementioned technical problems, some embodiments of the present invention disclose a method for determining the length of a non-magnetic drill collar, comprising: Obtain the extreme strength coefficients of each section of the ferromagnetic drill bit during the non-drilling process; To obtain the extreme strength of each section of the ferromagnetic drill bit during the drilling process; Based on the pole strength coefficients of each section of the ferromagnetic drill bit during the non-drilling process and the pole strength of each section of the ferromagnetic drill bit during the drilling process, the axial magnetic interference intensity of each section of the ferromagnetic drill bit to the wireless drilling measurement point during the drilling process is estimated, and the final magnetic interference intensity is obtained based on the axial magnetic interference intensity of each section of the ferromagnetic drill bit to the wireless drilling measurement point during the drilling process. The appropriateness of the length of the non-magnetic drill collar is determined based on the final magnetic interference intensity.

[0006] In some embodiments, obtaining the pole strength coefficient of each section of the ferromagnetic drill bit during the drilling process includes obtaining the demagnetization coefficient of each section of the ferromagnetic drill bit.

[0007] In some embodiments, obtaining the pole strength coefficients of each section of the ferromagnetic drill bit during the drilling process further includes: performing magnetic field modeling on each section of the ferromagnetic drill bit.

[0008] In some embodiments, the pole strength coefficients of each ferromagnetic drill bit are obtained based on the magnetization modeling and observation data of each ferromagnetic drill bit segment.

[0009] In some embodiments, determining whether the length of the non-magnetic drill collar is appropriate based on the final magnetic interference intensity includes: The azimuth deviation is determined based on the final magnetic interference intensity, and the appropriateness of the non-magnetic drill collar length is determined based on whether the azimuth deviation and the final magnetic interference intensity are within a predetermined range.

[0010] In some embodiments, a magnetic field model is performed on each section of the ferromagnetic drill bit, and the pole strength coefficient of each section of the ferromagnetic drill bit is obtained based on the magnetic field model and observation data.

[0011] In some embodiments, the magnetic field modeling of each section of the ferromagnetic drill bit includes: modeling each section of the ferromagnetic drill bit as an elongated ellipsoid and calculating the demagnetization coefficient.

[0012] In some embodiments, the calculation of the demagnetization coefficient includes:

[0013] Where N is the demagnetization coefficient; m is the aspect ratio of the elongated ellipsoid.

[0014] In some embodiments, the major axis radius of the planar model of the elongated ellipsoid of any segment of the ferromagnetic drill bit is equal to half the length of that segment of the ferromagnetic drill bit; The minor axis radius of the plane model of the elongated ellipsoid of any segment of the ferromagnetic drill bit is:

[0015] Where b is the minor axis radius of the plane modeling of the elongated ellipsoid of the ferromagnetic drill bit segment, V is the volume of each ferromagnetic drill bit segment, and a is the major axis radius of the plane modeling of the elongated ellipsoid of the ferromagnetic drill bit segment.

[0016] In some embodiments, obtaining the extreme strength coefficients of each section of the ferromagnetic drill string during the drilling process includes: The maximum pole strength of each section of the ferromagnetic drill bit was calculated based on the demagnetization coefficient obtained from the magnetic field modeling and the observation data. The pole strength coefficient of each section of the ferromagnetic drill bit is obtained based on the calculated maximum pole strength of each section.

[0017] In some embodiments, the calculated maximum pole strength values ​​of each section of the ferromagnetic drill bit are obtained based on the demagnetization coefficient obtained from magnetic field modeling and observation data, including:

[0018] in, The calculated maximum extreme strength values ​​for each section of the ferromagnetic drill bit. Let A be the geomagnetic field strength, and A be the cross-sectional area of ​​the minor radius of the elongated ellipsoid. ρ is the vacuum permeability, and N is the demagnetization coefficient.

[0019] In some embodiments, the pole strength coefficient of each ferromagnetic drill bit is obtained by performing linear regression on the maximum pole strength calculation values ​​of all ferromagnetic drill bits, based on the calculated maximum pole strength values ​​of each ferromagnetic drill bit segment.

[0020] In some embodiments, obtaining the pole strength of each section of the ferromagnetic drill bit during drilling includes: calculating the pole strength of each section of the ferromagnetic drill bit during drilling based on the demagnetization coefficient obtained from magnetic field modeling, the maximum permeability and minimum permeability of the ferromagnetic drill bit during drilling.

[0021] In some embodiments, obtaining the extreme strength of each section of the ferromagnetic drill bit during drilling includes:

[0022]

[0023] in, The extreme strength of each section of the ferromagnetic drill bit. The intensity of the Earth's magnetic field during drilling. The magnetic field strength during drilling. The short-radius cross-sectional area is used to model the elongated ellipsoid of each section of the ferromagnetic drill bit. This represents the maximum magnetic permeability of the ferromagnetic drill bit during the drilling process. This represents the minimum magnetic permeability of ferromagnetic drill bits during the drilling process. The demagnetizing coefficient is... is the vacuum permeability.

[0024] In some embodiments, the maximum magnetic permeability of the ferromagnetic drill bit during drilling is...

[0025] in, The maximum local magnetic field strength, expressed in nT. is the relative permeability.

[0026] In some embodiments, the minimum magnetic permeability of the ferromagnetic drill bit during drilling is...

[0027] in, The maximum local magnetic field strength, expressed in nT. is the relative permeability.

[0028] In some embodiments, estimating the axial magnetic interference intensity of each section of the ferromagnetic drill string to the wireless logging-while-drilling (LWD) point during drilling includes: During drilling, the magnetic interference intensity at a point L away from the wireless drilling measurement point

[0029] in, denoted as , where is the magnetic interference intensity at a point L away from the wireless drilling measurement point; Q is the magnetic field intensity at a point L away from the wireless drilling measurement point during the drilling process.

[0030] In some embodiments, the final magnetic interference intensity is derived based on the axial magnetic interference intensity of each section of the ferromagnetic drill string to the wireless drilling measurement points during drilling, including: The final magnetic interference intensity is calculated by using the pole strength coefficients of each section of the ferromagnetic drill bit during the non-drilling process as the pole strength coefficients of each section of the ferromagnetic drill bit during the drilling process.

[0031] In some embodiments, deriving the azimuth deviation based on the final magnetic interference intensity includes:

[0032] Where Inc is the design well inclination angle, Azi is the design azimuth angle, Dip is the local magnetic inclination angle, and Bt is the local magnetic field strength. The final magnetic interference intensity, This refers to the azimuth deviation.

[0033] In some embodiments, determining whether the length of the non-magnetic drill collar is appropriate based on whether the azimuth deviation is within a predetermined range includes: the azimuth deviation is not greater than 0.6°, and the final magnetic interference intensity is not greater than 600.

[0034] In some embodiments, the ferromagnetic drilling segments include a weighted drill pipe, a drill bit, and a stabilizer.

[0035] On the other hand, embodiments of the present invention also disclose a computer device, which includes a processor, an input device, an output device, and a memory. The processor, input device, output device, and memory are interconnected. The memory is used to store a computer program, which includes program instructions. The processor is configured to call the program instructions to execute the aforementioned method for determining the length of a non-magnetic drill collar.

[0036] Thirdly, embodiments of the present invention also disclose a computer-readable storage medium storing a computer program, the computer program including program instructions, which, when executed by a processor, cause the processor to execute the aforementioned method for determining the length of a non-magnetic drill collar.

[0037] By adopting the above technical solution, the present invention has at least the following beneficial effects: This invention provides a method, device, and storage medium for determining the length of non-magnetic drill collars. It accurately assesses the magnetic interference distribution in downhole BHAs (bottom hole assembly), thereby determining the suitability of the non-magnetic drill collar length. Based on a flat, elongated elliptical model, a magnetization magnetic field model is created for the ferromagnetic drill string. The residual magnetic field strength and induced magnetic field strength at the drill string's poles after magnetization are calculated. The relative permeability of the ferromagnetic drill string during drilling is calculated based on the maximum and minimum values ​​of the local magnetic field strength. Ground observation data is used to correct the theoretical calculations with coefficients, ultimately determining the magnitude of the interfering magnetic field and the azimuth deviation caused by the interfering magnetic field during drilling. This information is then used to determine the suitability of the non-magnetic drill collar length. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. 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.

[0039] Figure 1 This is a distance diagram from the pole of each section of the ferromagnetic drill bit to the wireless drilling measurement point, as disclosed in some embodiments of the present invention for a method for determining the length of a non-magnetic drill collar. Figure 2 A schematic diagram of a flat, elongated ellipse model of a ferromagnetic drilling tool, which is provided by the present invention for a method of determining the length of a non-magnetic drill collar; Figure 3 The flowchart of the algorithm for determining the length of a non-magnetic drill collar provided by the present invention; Figure 4 A schematic diagram of ground observation values ​​for a method of determining the length of a non-magnetic drill collar provided by the present invention; Figure 5 This is a schematic diagram illustrating the calculation of relative permeability for a method of determining the length of a non-magnetic drill collar provided by the present invention. Detailed Implementation

[0040] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure. This disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0041] These embodiments are provided to make the disclosure thorough and complete, and to fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0042] Furthermore, the terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Terms such as "including" or "contains" mean that the element preceding the word covers the element listed after the word, and do not exclude the possibility of covering other elements as well.

[0043] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the specific meaning of each term in this disclosure can be understood by those skilled in the art as appropriate. All terms used in this disclosure have the same meaning as understood by those skilled in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted with an idealized or highly formalized meaning, unless expressly defined herein.

[0044] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0045] To accurately determine the distribution of magnetic interference in downhole borehole borehole harmonic interference (BHA) and assess the suitability of the non-magnetic drill collar length, some embodiments of this invention disclose a method for determining the suitability of the non-magnetic drill collar length, which includes a novel method for calculating drill string magnetic interference. This method uses a flattened elliptical model to model the magnetizing magnetic field of the ferromagnetic drill string, calculating the residual magnetic field strength and induced magnetic field strength at the drill string's poles after magnetization. Based on the maximum and minimum values ​​of the local magnetic field strength, the relative permeability of the ferromagnetic drill string during drilling is calculated. Ground-based grindrod observation data is used to correct the theoretical calculations with coefficients, ultimately yielding the magnitude of the interfering magnetic field and the azimuth deviation caused by the interfering magnetic field during drilling. The method includes: obtaining the pole strength coefficients of each section of the ferromagnetic drill bit during the non-drilling process; during drilling, since the length of the BHA is much smaller than the overall drill bit length, the proportion of the pole strength coefficients of each section of the ferromagnetic drill bit in the BHA can be considered to remain unchanged, so this invention applies the coefficients to calculate the pole strength of each section of the ferromagnetic drill bit during the drilling process; obtaining the pole strength of each section of the ferromagnetic drill bit during the drilling process; estimating the axial magnetic interference intensity of each section of the ferromagnetic drill bit to the wireless drilling measurement point during the drilling process based on the pole strength coefficients of each section of the ferromagnetic drill bit during the non-drilling process and the pole strength of each section of the ferromagnetic drill bit during the drilling process, and obtaining the final magnetic interference intensity based on the axial magnetic interference intensity of each section of the ferromagnetic drill bit to the wireless drilling measurement point during the drilling process; and determining whether the length of the non-magnetic drill collar is appropriate based on the final magnetic interference intensity. This embodiment eliminates the use of empirical and estimated values ​​of the magnetic pole strength of the ferromagnetic drill bit during the drilling process; it can calculate the magnetic field strength of the ferromagnetic drill bit based on the flat elongated ellipse model and the local magnetic field strength, and can adapt to the magnetic field calculation of various types and sizes of drill bit combinations.

[0046] like Figures 1 to 5 As shown, some embodiments of the present invention disclose a method for determining the length of a non-magnetic drill collar, comprising the following steps: Step S1: Based on the BHA (Bottomhole Attachment), calculate the distance from the pole of each ferromagnetic drill string section to the wireless logging point, such as... Figure 1 As shown, D1 is the distance from the lowest point of the non-magnetic drill collar to the drill bit, D2 is the distance from the measuring point of the wireless drilling instrument to the drill bit, D3 is the distance from the lower end of the weighted drill rod to the drill bit, and D4 is the length of the weighted drill rod. Step S2: Calculate the pole strength of each section of the ferromagnetic drill bit; For each section of the ferromagnetic drill bit, a flattened ellipsoid model is constructed, and its demagnetization coefficient N is calculated. The model is as follows: Figure 2 As shown; based on the model of this elongated ellipsoid, the demagnetization coefficient can be calculated using the following formula:

[0047] Where m is the aspect ratio of the elongated ellipsoid.

[0048]

[0049] Where a and b are the major and minor axes radii of the planar elongated ellipsoid.

[0050]

[0051] The length of each section of the ferromagnetic drill bit is .

[0052]

[0053] Where V is the volume of each section of the ferromagnetic drill bit.

[0054]

[0055] in, Let m be the linear density of each section of the ferromagnetic drill bit, and m be the mass of each section of the ferromagnetic drill bit.

[0056] The area A of the minor radius section of the elongated ellipsoid is: .

[0057] The magnetic pole strength of each section of the ferromagnetic drill bit is Q, with units of Wb, and is given by the following formula:

[0058] in, With a vacuum permeability of 4 wb m / A, The relative permeability, Earth's magnetic field strength ; Specifically, step S2 may include steps S21 and S22, where S21 is the calculation of the pole strength coefficient: Linear regression was performed on the pole strength of all ferromagnetic drill bits to obtain the pole strength coefficient; According to wellhead observation data from Grindrod, the maximum magnetic pole strength of the drill collar is 950. wb, the maximum magnetic pole strength of the centralizer is 380 wb, the maximum magnetic pole strength of the motor and drill bit is 450. wb, according to the expression in Q, because Much greater than 1, the maximum extreme strength of each section of the ferromagnetic drill bit is: .

[0059] The linear combination of all maximum pole intensities is The pole intensity coefficients are obtained by performing least squares linear regression on the three parameters k1, k2, and k3. , , Its loss function is E1:

[0060]

[0061] in, This represents the maximum value of the extreme strength at the drill bit. This represents the maximum value of the extreme strength of the drill collar (weighted drill pipe). The maximum value of the extreme strength of the centralizer drill bit. This is the penalty coefficient.

[0062] During drilling, since the length of the BHA is much smaller than the overall drill string length, the ratio of the strength coefficients of each pole of the BHA ferromagnetic drill string can be considered to remain constant. Therefore, this coefficient is also applicable to the calculation of the pole strength of each section of the ferromagnetic drill string during drilling. The specific steps are as follows: S22 is to calculate the extreme strength of each ferromagnetic drill bit during the drilling process; During drilling, the relative magnetic permeability is affected by various factors. Magnetic induction intensity during drilling The changes occur, and the extreme strengths of each section of the ferromagnetic drill bit are:

[0063]

[0064] in, The intensity of the geomagnetic field during drilling. The magnetic field strength during drilling;

[0065] in, This represents the maximum magnetic permeability of the ferromagnetic drill bit during the drilling process. The maximum local magnetic field strength, expressed in nT;

[0066] in, Minimum intensity of the geomagnetic field This represents the minimum magnetic permeability of ferromagnetic drill bits during the drilling process. In step S22, according to Figure 5 The relative permeability can be obtained, where e is the axial magnetic disturbance. Given the local magnetic field strength, calculate the magnetic interference along the z-axis at any two measuring points. The slope of this straight line represents the induced magnetization magnetic field. Then, based on the induced magnetic field and the distribution of poles in each section of the iron drill bit, the relative permeability is calculated. ;

[0067] Where n is the number of poles in each section of the iron drill bit. The distance from the pole of each section of the iron drill string to the wireless logging point. This refers to the cross-sectional length of each section of the iron drill bit.

[0068] Step S3: Calculate the magnetic interference intensity of each section of the ferromagnetic drill bit pole to the wireless drilling measurement point under drilling conditions; Based on the magnetic field distribution law of the elongated ellipsoid, the magnetic poles are distributed at both ends of the major semi-axis of the ellipsoid and have opposite polarities. The direction pointing towards the drill bit is selected as the positive direction of the magnetic field strength. The magnetic pole strength distribution of the ferromagnetic drill bit is that the magnetic field strength is positive near the non-magnetic pole and negative far from the non-magnetic pole. During drilling, the magnetic field strength at a point L away from the ferromagnetic drill bit is given by the following value in tons (T):

[0069] The magnetic interference intensity of the upper pole of the weighted drill pipe to the wireless drilling measurement point is:

[0070] in, To increase the magnetic pole strength at the drill pipe poles; The magnetic interference intensity of the lower pole of the weighted drill pipe to the wireless drilling measurement point is:

[0071] The magnetic interference intensity of the drill bit pole to the wireless drilling measurement point is:

[0072] in, The magnetic pole strength at the drill bit's pole; The magnetic pole strength at the pole of the stabilizer; The magnetic interference intensity of the centralizer pole to the wireless drilling measurement point is:

[0073] Then the final magnetic interference intensity is calculated as follows:

[0074] Step S4: Calculate the azimuth deviation under this magnetic interference intensity.

[0075] in, The design inclination angle is given by Azi, the design azimuth angle value, Dip, the local magnetic inclination angle, and Bt, the local magnetic field strength. Step S5: Determine , Whether to allow further expansion within the outer perimeter depends on determining whether the non-magnetic length is appropriate; generally, the maximum value is taken. 0.6°, maximum It is 600.

[0076] This invention also discloses a computer device, which includes a processor, an input device, an output device, and a memory. The processor, input device, output device, and memory are interconnected. The memory is used to store a computer program, which includes program instructions. The processor is configured to call the program instructions to execute the aforementioned method for determining the length of a non-magnetic drill collar.

[0077] Some embodiments of the present invention also disclose a computer-readable storage medium storing a computer program, the computer program including program instructions, which, when executed by a processor, cause the processor to perform the aforementioned method for determining the length of a non-magnetic drill collar.

[0078] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0079] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner.

Claims

1. A method for determining the length of a non-magnetic drill collar, characterized in that, include: Obtain the extreme strength coefficients of each section of the ferromagnetic drill bit during the non-drilling process; To obtain the extreme strength of each section of the ferromagnetic drill bit during the drilling process; Based on the pole strength coefficients of each section of the ferromagnetic drill bit during the non-drilling process and the pole strength of each section of the ferromagnetic drill bit during the drilling process, the axial magnetic interference intensity of each section of the ferromagnetic drill bit to the wireless drilling measurement point during the drilling process is estimated, and the final magnetic interference intensity is obtained based on the axial magnetic interference intensity of each section of the ferromagnetic drill bit to the wireless drilling measurement point during the drilling process. The appropriateness of the length of the non-magnetic drill collar is determined based on the final magnetic interference intensity.

2. The method for determining the length of a non-magnetic drill collar according to claim 1, characterized in that, Obtaining the extreme strength coefficients of each section of the ferromagnetic drill bit during the drilling process includes obtaining the demagnetization coefficients of each section of the ferromagnetic drill bit.

3. The method for determining the length of a non-magnetic drill collar according to claim 2, characterized in that, Obtaining the pole strength coefficients of each section of the ferromagnetic drill bit during the drilling process also includes: performing magnetic field modeling on each section of the ferromagnetic drill bit.

4. The method for determining the length of a non-magnetic drill collar according to claim 1, characterized in that, The pole strength coefficients of each ferromagnetic drill bit were obtained based on the magnetic field modeling and observation data of each ferromagnetic drill bit segment.

5. The method for determining the length of a non-magnetic drill collar according to claim 1, characterized in that, Judging whether the length of the non-magnetic drill collar is appropriate based on the final magnetic interference intensity includes: The azimuth deviation is determined based on the final magnetic interference intensity, and the appropriateness of the non-magnetic drill collar length is determined based on whether the azimuth deviation and the final magnetic interference intensity are within a predetermined range.

6. The method for determining the length of a non-magnetic drill collar according to claim 5, characterized in that, Magnetic field modeling was performed on each section of the ferromagnetic drill bit, and the pole strength coefficient of each section of the ferromagnetic drill bit was obtained based on the magnetic field modeling and observation data.

7. The method for determining the length of a non-magnetic drill collar according to claim 6, characterized in that, The magnetic field modeling of each section of the ferromagnetic drill bit includes: modeling each section of the ferromagnetic drill bit as an elongated ellipsoid and calculating the demagnetization coefficient.

8. The method for determining the length of a non-magnetic drill collar according to claim 7, characterized in that, The calculation of the demagnetization coefficient includes: Where N is the demagnetization coefficient; m is the aspect ratio of the elongated ellipsoid.

9. The method for determining the length of a non-magnetic drill collar according to claim 8, characterized in that, The major axis radius of the plane modeled by the elongated ellipsoid of any segment of the ferromagnetic drill bit is equal to half the length of that segment of the ferromagnetic drill bit; The minor axis radius of the plane model of the elongated ellipsoid of any segment of the ferromagnetic drill bit is: Where b is the minor axis radius of the plane modeling of the elongated ellipsoid of the ferromagnetic drill bit segment, V is the volume of each ferromagnetic drill bit segment, and a is the major axis radius of the plane modeling of the elongated ellipsoid of the ferromagnetic drill bit segment.

10. The method for determining the length of a non-magnetic drill collar according to claim 1, characterized in that, The extreme strength coefficients of each section of the ferromagnetic drill string during the drilling process include: The maximum pole strength of each section of the ferromagnetic drill bit was calculated based on the demagnetization coefficient obtained from the magnetic field modeling and the observation data. The pole strength coefficient of each section of the ferromagnetic drill bit is obtained based on the calculated maximum pole strength of each section.

11. The method for determining the length of a non-magnetic drill collar according to claim 10, characterized in that, Based on the demagnetization coefficient obtained from magnetic field modeling and the observation data, the calculated maximum pole strength values ​​of each section of the ferromagnetic drill bit include: in, The calculated maximum extreme strength values ​​for each section of the ferromagnetic drill bit. Let A be the geomagnetic field strength, and A be the cross-sectional area of ​​the minor radius of the elongated ellipsoid. ρ is the vacuum permeability, and N is the demagnetization coefficient.

12. The method for determining the length of a non-magnetic drill collar according to claim 10, characterized in that, The pole strength coefficient of each ferromagnetic drill bit is obtained by performing linear regression on the calculated maximum pole strength values ​​of all ferromagnetic drill bits.

13. The method for determining the length of a non-magnetic drill collar according to claim 1, characterized in that, The extreme strength of each section of the ferromagnetic drill bit during drilling is obtained by: calculating the demagnetization coefficient based on the magnetic field modeling, and the extreme strength of each section of the ferromagnetic drill bit during drilling based on the maximum and minimum magnetic permeability of the ferromagnetic drill bit.

14. The method for determining the length of a non-magnetic drill collar according to claim 1, characterized in that, The extreme strength of each section of the ferromagnetic drill bit during drilling includes: in, The extreme strength of each section of the ferromagnetic drill bit. The intensity of the Earth's magnetic field during drilling. The magnetic field strength during drilling. The short-radius cross-sectional area is used to model the elongated ellipsoid of each section of the ferromagnetic drill bit. This represents the maximum magnetic permeability of the ferromagnetic drill bit during the drilling process. This represents the minimum magnetic permeability of ferromagnetic drill bits during the drilling process. The demagnetizing coefficient is... is the vacuum permeability.

15. The method for determining the length of a non-magnetic drill collar according to claim 14, characterized in that, Maximum magnetic permeability of ferromagnetic drill bits during drilling in, The maximum local magnetic field strength, expressed in nT. is the relative permeability.

16. The method for determining the length of a non-magnetic drill collar according to claim 14, characterized in that, Minimum magnetic permeability of ferromagnetic drill bits during drilling in, The maximum local magnetic field strength, expressed in nT. is the relative permeability.

17. The method for determining the length of a non-magnetic drill collar according to claim 1, characterized in that, The estimation of the axial magnetic interference intensity of each section of the ferromagnetic drill string to the wireless logging-while-drilling points during drilling includes: During drilling, the magnetic interference intensity at a point L away from the wireless drilling measurement point in, denoted as , where is the magnetic interference intensity at a point L away from the wireless drilling measurement point; Q is the magnetic field intensity at a point L away from the wireless drilling measurement point during the drilling process.

18. The method for determining the length of a non-magnetic drill collar according to claim 1, characterized in that, The final magnetic interference intensity is derived from the axial magnetic interference intensity of each section of the ferromagnetic drill bit to the wireless drilling monitoring points during the drilling process, including: The final magnetic interference intensity is calculated by using the pole strength coefficients of each section of the ferromagnetic drill bit during the non-drilling process as the pole strength coefficients of each section of the ferromagnetic drill bit during the drilling process.

19. The method for determining the length of a non-magnetic drill collar according to claim 5, characterized in that, The azimuth deviation, derived from the final magnetic interference intensity, includes: Where Inc is the design well inclination angle, Azi is the design azimuth angle, Dip is the local magnetic inclination angle, and Bt is the local magnetic field strength. The final magnetic interference intensity, This refers to the azimuth deviation.

20. The method for determining the length of a non-magnetic drill collar according to claim 5, characterized in that, Whether the length of the non-magnetic drill collar is appropriate based on whether the azimuth deviation is within a predetermined range includes: the azimuth deviation is not greater than 0.6°, and the final magnetic interference intensity is not greater than 600.

21. The method for determining the length of a non-magnetic drill collar according to claim 1, characterized in that, Each section of the ferromagnetic drilling process includes a weighted drill pipe, a drill bit, and a centralizer.

22. A computer device, characterized in that, The device includes a processor, an input device, an output device, and a memory, which are interconnected. The memory stores a computer program, which includes program instructions. The processor is configured to call the program instructions to execute the non-magnetic drill collar length determination method as described in any one of claims 1-21.

23. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, the computer program including program instructions, which, when executed by a processor, cause the processor to perform the method for determining the length of a non-magnetic drill collar as described in any one of claims 1-21.

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