A method, device, equipment and medium for calculating casing outer diameter and wall thickness

Abstract

The application discloses a casing outer diameter and wall thickness calculation method, device, equipment and medium, including the following steps: obtaining a plurality of well inner radii and casing average wall thickness; selecting four well inner radii perpendicular to each other from the plurality of well inner radii; calculating ideal ellipse parameters from the four well inner radii; calculating corrosion depth at each orientation from the well inner radii corresponding to a plurality of azimuth angles and the ideal ellipse parameters; calculating average wall thickness before casing corrosion from the casing average wall thickness and the corrosion depth at each orientation; calculating casing outer radius at each orientation on the casing circumference from the average wall thickness before casing corrosion and ideal ellipse radius at each orientation; and calculating casing wall thickness at each orientation on the casing circumference from the casing outer radius at each orientation on the casing circumference and the well inner radius corresponding to the plurality of azimuth angles. The application calculates the casing outer diameter and wall thickness by establishing an ideal ellipse and combining the actual corrosion condition, thereby improving the accuracy and reliability of casing strength calculation and safety check.

Description

Technical Field

[0001] This invention belongs to the field of oil well pipe technology, and specifically relates to a method, device, equipment and medium for calculating the outer diameter and wall thickness of casing. Background Technology

[0002] With increasing well depth and the application of shale gas horizontal wells and large-scale fracturing technology, the service environment of casing is becoming increasingly harsh, leading to greater risks of casing deformation and corrosion. To ensure the safe operation of casing, strength calculations and safety checks are essential. Casing strength calculations require two crucial dimensional parameters: outer diameter and wall thickness. Currently, the outer radius of the casing is primarily obtained by adding the inner radius measured by a multi-arm caliper to the average wall thickness obtained from electromagnetic flaw detection logging. However, the casing wall thickness obtained from electromagnetic flaw detection logging is the average wall thickness along the circumference, which cannot specifically reflect the variation in casing wall thickness at different circumferential locations. For locations where corrosion pits cause thinning of the casing wall, the calculated wall thickness still uses the measured average wall thickness value, resulting in strength calculation results greater than the actual value. Furthermore, the calculated outer radius for different circumferential locations is uniformly calculated using the sum of the measured maximum inner radius and the average wall thickness, which does not match reality. This is especially true for cases with corrosion pits or deformation, where the calculated outer diameter deviates significantly from reality, leading to substantial discrepancies between the calculated and actual strength results. Therefore, the traditional methods for determining the outer diameter and wall thickness of the casing cannot accurately reflect the geometry of the casing, resulting in a large deviation between the calculated casing strength and the actual value. This leads to insufficient accuracy in casing strength calculation and safety verification, resulting in potential safety hazards in the casing. Summary of the Invention

[0003] The purpose of this invention is to provide a method, apparatus, equipment, and medium for calculating the outer diameter and wall thickness of a casing, so as to solve the technical problem of insufficient accuracy in the existing methods for calculating the outer diameter and wall thickness of casings.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] In a first aspect, a method for calculating the outer diameter and wall thickness of a casing includes the following steps:

[0006] Obtain the logging inner radius and average casing wall thickness corresponding to several azimuth angles;

[0007] Select four logging inner radii that are perpendicular to each other from a number of logging inner radii corresponding to several azimuth angles;

[0008] The parameters of the ideal ellipse are calculated based on the inner radii of four logging points that are perpendicular to each other in azimuth.

[0009] The corrosion depth at each position on the casing circumference is calculated based on the logging inner radius corresponding to several azimuth angles and the ideal ellipse parameters.

[0010] The average wall thickness of the casing before corrosion is calculated based on the average wall thickness of the casing and the corrosion depth at each position around the circumference of the casing.

[0011] Calculate the outer radius of the casing at each position on the circumference of the casing based on the average wall thickness of the casing before corrosion and the radius of the ellipse at each position.

[0012] The casing wall thickness at each location on the casing circumference is calculated based on the outer radius of the casing at each location and the logging inner radius corresponding to several azimuth angles.

[0013] A further improvement of the present invention is that the logging inner radius corresponding to the plurality of azimuth angles is measured using a multi-arm caliper.

[0014] A further improvement of the present invention is that the average wall thickness of the casing is obtained by electromagnetic flaw detection.

[0015] A further improvement of the present invention is that: among the four logging inner radii that are perpendicular to each other, there are L1, L11, L21 and L31, L1≈L21≈Lmax, L11≈L31≈Lmin, and L11 and L31 are on the same straight line, and L21 and L1 are on the same straight line.

[0016] A further improvement of the present invention is that the ideal ellipse parameters include the length of the major semi-axis of the ideal ellipse, the length of the minor semi-axis of the ideal ellipse, and the radius of the ideal ellipse.

[0017] A further improvement of the present invention is that: the lengths of the major and minor axes of the ideal ellipse are calculated based on the inner radii of four well logging points with mutually perpendicular azimuth angles, and the radius of the ideal ellipse is calculated based on the lengths of the major and minor axes of the ideal ellipse.

[0018] A further improvement of the present invention is that the multi-arm caliper is a 40-arm caliper.

[0019] In a second aspect, a device for calculating the outer diameter and wall thickness of a casing includes:

[0020] Data acquisition module: used to acquire the logging inner radius and average casing wall thickness corresponding to several azimuth angles;

[0021] Data filtering module: used to select four logging inner radii with mutually perpendicular azimuths from a number of logging inner radii corresponding to several azimuth angles;

[0022] Ideal Ellipse Parameter Calculation Module: Used to calculate the parameters of an ideal ellipse based on the inner radii of four logging points that are perpendicular to each other in azimuth.

[0023] Corrosion Depth Calculation Module: Used to calculate the corrosion depth at each position on the casing circumference based on the logging inner radius corresponding to several azimuth angles and the ideal ellipse parameters;

[0024] The module for calculating the average wall thickness of the casing before corrosion is used to calculate the average wall thickness of the casing before corrosion based on the average wall thickness of the casing and the corrosion depth at each position around the casing circumference.

[0025] The casing outer radius calculation module is used to calculate the outer radius of the casing at various points on the circumference of the casing based on the average wall thickness of the casing before corrosion and the radius of the ellipse in each direction.

[0026] Casing wall thickness calculation module: Used to calculate the casing wall thickness at various locations around the casing circumference based on the outer radius of the casing at each location and the logging inner radius corresponding to several azimuth angles.

[0027] Thirdly, a computer device 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 aforementioned method for calculating the outer diameter and wall thickness of a sleeve.

[0028] Fourthly, a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned method for calculating the outer diameter and wall thickness of a sleeve.

[0029] Compared with the prior art, the present invention has at least the following beneficial effects:

[0030] 1. This invention establishes an ideal ellipse by measuring the inner radius of the well and the average wall thickness of the casing, and calculates the outer diameter and wall thickness of the casing based on the parameters of the ideal ellipse and the actual corrosion situation. This makes the calculated values ​​of the outer diameter and wall thickness at different locations closer to the true values, thereby improving the accuracy and reliability of casing strength calculation and safety verification.

[0031] 2. This invention calculates the radius of an ideal ellipse by calculating its major and minor semi-axis. The calculation structure is accurate and the calculation steps are simple.

[0032] 3. This invention uses a 40-arm caliper to ensure sufficient parameters without causing an excessive number of parameters. Attached Figure Description

[0033] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0034] In the attached diagram:

[0035] Figure 1 This is a schematic diagram of the cross-section of the casing in the method for calculating the outer diameter and wall thickness of the casing according to the present invention;

[0036] Figure 2 This is a schematic diagram showing the dimensions of the corrosion pit inside the casing in the casing calculation method for casing outer diameter and wall thickness according to the present invention;

[0037] Figure 3 This is a flowchart of a method for calculating the outer diameter and wall thickness of a casing according to the present invention;

[0038] Figure 4 This is a structural block diagram of a casing outer diameter and wall thickness calculation device according to the present invention.

[0039] Wherein: 1-inner surface of the casing; 2-outer surface of the casing; 3-cross section of the casing; 4-corrosion pit inside the casing; 5-ideal ellipse. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0041] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this invention is for describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0042] Example 1

[0043] A method for calculating the outer diameter and wall thickness of a casing, such as Figure 1-3 As shown, it includes the following steps:

[0044] S1. Obtain the logging inner radius and average casing wall thickness corresponding to several azimuth angles;

[0045] When obtaining the logging inner radius corresponding to several azimuth angles, a multi-arm caliper is used for measurement, and electromagnetic flaw detection is used to obtain the average casing wall thickness.

[0046] In S1, the logging inner radii corresponding to several azimuth angles are L1, L2, ..., Lx.

[0047] S2. Select four logging inner radii that are perpendicular to each other from the logging inner radii corresponding to several azimuth angles;

[0048] In S2, among the four logging inner radii selected, the two longer logging inner radii are equal to or close to the maximum logging inner radius, and the two smaller logging inner radii are equal to or close to the minimum logging radius. Furthermore, the two longer logging inner radii are on the same straight line, and the two shorter logging inner radii are on the same straight line.

[0049] Let L1 and L21 be the two larger logging inner radii, and L11 and L31 be the two smaller logging inner radii.

[0050] S3. Calculate the lengths of the major and minor axes of the ideal ellipse based on the four mutually perpendicular inner radii of the logging azimuth angles.

[0051]

[0052]

[0053] S4. Calculate the azimuth angle (θ) at each position on the circumference of the sleeve based on the lengths of the major and minor axes of the ideal ellipse. i Ideal ellipse radius;

[0054]

[0055] In the formula, k i The direction angle is θ i The radius of the ellipse is determined, where i = 1, 2, ..., x.

[0056] S5. Calculate the corrosion depth at each position of the casing circumference based on the logging inner radius corresponding to several azimuth angles and the radius of the ellipse processed at each position of the casing circumference.

[0057] e i =L i -k i ;

[0058] In the formula, θ represents the direction angle. i The corrosion depth is given by i = 1, 2, ..., x.

[0059] S6. Calculate the average wall thickness of the casing before corrosion based on the average wall thickness of the casing and the corrosion depth at each position around the circumference of the casing.

[0060]

[0061] In the formula, n is the average wall thickness of the casing before corrosion.

[0062] S7. Calculate the outer radius of the casing at each position on the circumference of the casing based on the average wall thickness of the casing before corrosion and the radius of the ellipse at each position.

[0063] D i =n+k i ;

[0064] In the formula, D i Let i represent the outer radius of the casing at each position on the circumference of the casing, where i = 1, 2, ..., x.

[0065] S8. Calculate the casing wall thickness at each position on the casing circumference based on the outer radius of the casing at each position on the casing circumference and the logging inner radius corresponding to several azimuth angles.

[0066] t i =D i-L i .

[0067] In the formula, t i This represents the wall thickness of the casing at various points around its circumference, where i = 1, 2, ..., x.

[0068] Example 2

[0069] Example 1 illustrates a method for calculating the outer diameter and wall thickness of a casing, using data from a specific cross-section of the casing obtained by a 40-arm caliper and electromagnetic flaw detection.

[0070] ① Obtain measurement data

[0071] The 40-arm caliper is a contact-type detection device. Each arm end contacts the inner surface of the casing. During the axial movement of the 40-arm caliper inside the casing, 40 inner radius values ​​can be measured for each cross section of the casing. The results are shown in Table 1.

[0072] The electromagnetic flaw detector uses the principle of electromagnetic induction to measure the wall thickness of the casing. It is a non-contact device. The wall thickness measured by the electromagnetic flaw detector is the average wall thickness of the casing, which cannot specifically reflect the wall thickness of the casing in various directions. The measured result is m = 7.61 mm.

[0073] Table 1. Logging data (mm) from a 40mm boom caliper.

[0074]

[0075]

[0076] ② Determine the parameters of the ideal ellipse for the deformable sleeve.

[0077] Four logging inner radii, L1, L11, L21, and L31, were determined. Their orientations are mutually perpendicular, and L1 and L21 are equal to or close to the maximum logging inner radius, and L11 and L31 are equal to or close to the minimum logging inner radius. From the data in Table 1, L1 = L21 = 63.35 mm, and L11 = L31 = 61.07 mm.

[0078] Calculate the lengths of the major and minor semi-axis of the ideal ellipse as follows:

[0079]

[0080] ③ Calculate the corrosion depth on the inner surface of the casing.

[0081] First, calculate the azimuth angle at each position around the circumference of the sleeve (θ). i The radius of the ideal ellipse is:

[0082] Where i = 1, 2, ..., 39, 40,

[0083] Then, the difference between the 40-arm logging radius and the ideal ellipse radius at each position around the casing circumference is calculated to obtain the casing corrosion depth, as shown in Table 2.

[0084] Table 2. Casing Corrosion Depth (mm)

[0085]

[0086] ④ Calculate the average wall thickness of the casing before corrosion.

[0087] Since the original casing wall thickness is relatively uniform, assuming that the wall thickness values ​​in all directions are the same before the casing is corroded, the average wall thickness n before the casing is corroded is calculated using the following formula: n = 7.751 mm.

[0088]

[0089] ⑤ Calculate the outer radius and wall thickness of the casing.

[0090] The sum of the radius of the ellipse at each position of the casing circumference and the average wall thickness of the casing before corrosion is the outer radius of the casing. The difference between the outer radius at each position of the casing circumference and the 40-arm logging radius is the casing wall thickness. The outer radius and wall thickness of the casing are shown in Table 3 and Table 4, respectively.

[0091] Table 3 Outer radius of the casing (mm)

[0092]

[0093] Table 4. Casing wall thickness (mm)

[0094]

[0095]

[0096] Example 3

[0097] like Figure 3 As shown, a device for calculating the outer diameter and wall thickness of a casing includes:

[0098] Data acquisition module: used to acquire the logging inner radius and average casing wall thickness corresponding to several azimuth angles;

[0099] Data filtering module: used to select four logging inner radii with mutually perpendicular azimuths from a number of logging inner radii corresponding to several azimuth angles;

[0100] Ideal Ellipse Semi-Axis Length Calculation Module: Used to calculate the lengths of the major and minor semi-axis of an ideal ellipse based on the inner radii of four well logging points that are perpendicular to each other in azimuth.

[0101] Ideal Ellipse Radius Calculation Module: Used to calculate the radius of the ideal ellipse in each direction of the casing circumference based on the lengths of the major and minor axes of the ideal ellipse;

[0102] Corrosion Depth Calculation Module: Used to calculate the corrosion depth at each position on the casing circumference based on the logging inner radius corresponding to several azimuth angles and the radius of the ellipse processed at each position on the casing circumference.

[0103] The module for calculating the average wall thickness of the casing before corrosion is used to calculate the average wall thickness of the casing before corrosion based on the average wall thickness of the casing and the corrosion depth at each position around the casing circumference.

[0104] The casing outer radius calculation module is used to calculate the outer radius of the casing at various points on the circumference of the casing based on the average wall thickness of the casing before corrosion and the radius of the ellipse in each direction.

[0105] Casing wall thickness calculation module: Used to calculate the casing wall thickness at various locations around the casing circumference based on the outer radius of the casing at each location and the logging inner radius corresponding to several azimuth angles.

[0106] Example 4

[0107] The present invention also provides 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 a method for calculating the outer diameter and wall thickness of a sleeve as described in Embodiment 1.

[0108] Example 5

[0109] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a method for calculating the outer diameter and wall thickness of a sleeve as described in Embodiment 1.

[0110] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

[0111] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0112] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0113] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0114] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0115] 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 it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for calculating the outer diameter and wall thickness of a casing, characterized in that, Includes the following steps: Obtain the logging inner radius and average casing wall thickness corresponding to several azimuth angles; Select four logging inner radii that are perpendicular to each other from a number of azimuth inner radii; wherein, the four logging inner radii include two longer logging inner radii located on one straight line and two shorter logging inner radii located on another straight line, the two longer logging inner radii being equal to or close to the maximum logging inner radius, and the two shorter logging inner radii being equal to or close to the minimum logging inner radius. The parameters of the ideal ellipse are calculated based on the inner radii of four logging points that are perpendicular to each other in azimuth. The corrosion depth at each position on the casing circumference is calculated based on the logging inner radius corresponding to several azimuth angles and the ideal ellipse parameters. The average wall thickness of the casing before corrosion is calculated based on the average wall thickness of the casing and the corrosion depth at each position around the circumference of the casing. Calculate the outer radius of the casing at each position on the circumference of the casing based on the average wall thickness of the casing before corrosion and the radius of the ellipse at each position. The casing wall thickness at each location on the casing circumference is calculated based on the outer radius of the casing at each location and the logging inner radius corresponding to several azimuth angles.

2. The method for calculating the outer diameter and wall thickness of a casing according to claim 1, characterized in that, The logging inner radius corresponding to the aforementioned azimuth angles is measured using a multi-arm caliper.

3. The method for calculating the outer diameter and wall thickness of a casing according to claim 1, characterized in that, The average wall thickness of the casing was obtained using electromagnetic flaw detection.

4. The method for calculating the outer diameter and wall thickness of a casing according to claim 1, characterized in that, The parameters of the ideal ellipse include the length of the major semi-axis, the length of the minor semi-axis, and the radius.

5. The method for calculating the outer diameter and wall thickness of a casing according to claim 4, characterized in that, The lengths of the major and minor axes of the ideal ellipse are calculated based on the inner radii of four wells with mutually perpendicular azimuth angles, and the radius of the ideal ellipse is calculated based on the lengths of the major and minor axes of the ideal ellipse.

6. The method for calculating the outer diameter and wall thickness of a casing according to claim 2, characterized in that, The multi-arm caliper is a 40-arm caliper.

7. A device for calculating the outer diameter and wall thickness of a casing, characterized in that, include: Data acquisition module: used to acquire the logging inner radius and average casing wall thickness corresponding to several azimuth angles; Data filtering module: used to select four logging inner radii that are perpendicular to each other from several logging inner radii corresponding to several azimuth angles; wherein, the four logging inner radii include two longer logging inner radii located on one straight line and two shorter logging inner radii located on another straight line, the two longer logging inner radii are equal to or close to the maximum logging inner radius, and the two shorter logging inner radii are equal to or close to the minimum logging inner radius; Ideal Ellipse Parameter Calculation Module: Used to calculate the parameters of an ideal ellipse based on the inner radii of four logging points that are perpendicular to each other in azimuth. Corrosion Depth Calculation Module: Used to calculate the corrosion depth at each position on the casing circumference based on the logging inner radius corresponding to several azimuth angles and the ideal ellipse parameters; The module for calculating the average wall thickness of the casing before corrosion is used to calculate the average wall thickness of the casing before corrosion based on the average wall thickness of the casing and the corrosion depth at each position around the casing circumference. The casing outer radius calculation module is used to calculate the outer radius of the casing at various points on the circumference of the casing based on the average wall thickness of the casing before corrosion and the radius of the ellipse in each direction. Casing wall thickness calculation module: Used to calculate the casing wall thickness at various locations around the casing circumference based on the outer radius of the casing at each location and the logging inner radius corresponding to several azimuth angles.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method for calculating the outer diameter and wall thickness of a casing as described in any one of claims 1-6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the method for calculating the outer diameter and wall thickness of a sleeve as described in any one of claims 1-6.

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