Method and device for calculating wellbore ellipticity, computing equipment and storage medium

Abstract

The application discloses a borehole ellipticity calculation method and device, a calculation device and a storage medium. The method comprises the following steps: acquiring reflection echo logging data of each azimuth at each depth point in a depth interval; calculating the distance between the logging instrument center and the well wall at each azimuth at each depth point according to the reflection echo logging data of each azimuth at each depth point; performing elliptical fitting processing according to the distance between the logging instrument center and the well wall at each azimuth at the to-be-processed depth point and the adjacent multiple depth points and the angle of each azimuth; and determining the borehole ellipticity of the to-be-processed depth point according to the fitting result. In the foregoing manner, the data of the adjacent multiple depth points are used for elliptical fitting, the borehole ellipticity can be acquired only by using the while-drilling ultrasonic caliper logging instrument, and the fitting accuracy of the borehole ellipticity can be improved.

Description

Technical Field

[0001] This invention relates to the field of well logging technology, specifically to a method, apparatus, computing device, and storage medium for calculating wellbore ellipticity. Background Technology

[0002] Ultrasonic logging while drilling utilizes the ultrasonic reflection method to obtain the wellbore diameter in real time. During drilling, this technology can monitor the wellbore condition in real time, providing early warnings of wellbore erosion and stability, thus providing necessary logging parameters for drilling safety. In addition, accurate wellbore results support the correction of neutron porosity while drilling, which is of great significance for accurate formation evaluation while drilling.

[0003] Currently, ultrasonic logging-while-drilling (AWD) rigs are equipped with three transducers arranged in a specific pattern. During measurement, all three transducers emit ultrasonic waves simultaneously, and the borehole diameter, center, and other relevant parameters can be determined using geometric calculations. However, actual wellbores may not be circular, especially under the influence of geostress; many wellbores are elliptical, and existing WAD instruments cannot obtain the ellipticity of the wellbore. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide a method, apparatus, computing device and storage medium for calculating wellbore ellipticity that overcomes or at least partially solves the above problems.

[0005] According to one aspect of the present invention, a method for calculating wellbore ellipticity is provided, the method comprising:

[0006] Acquire reflected echo logging data at various depth points and in various orientations within the depth range;

[0007] Based on the reflected echo logging data at each depth point and each azimuth, calculate the distance between the center of the logging instrument and the well wall at each depth point and each azimuth.

[0008] Based on the distance between the logging instrument center and the well wall at each depth point and its adjacent depth points, as well as the angles at each azimuth, ellipse fitting is performed.

[0009] The wellbore ellipticity at the depth point to be processed is determined based on the fitting results.

[0010] In one alternative approach, calculating the distance between the logging instrument center and the wellbore at each depth point and each azimuth, based on the reflected echo logging data at each depth point and each azimuth, further includes:

[0011] For any depth point, peak detection is performed on the reflected echo logging data at each direction at that depth point to obtain the time information of each waveform peak.

[0012] Based on the time information of each waveform peak, the mud sound velocity, and the radius of the logging instrument, the distance between the center of the logging instrument and the well wall in each azimuth is calculated.

[0013] In one alternative approach, the method further includes:

[0014] The standard casing is measured using logging instruments to obtain reflected echo logging data of the standard casing; the system time error is determined based on the reflected echo logging data and inner diameter of the standard casing.

[0015] Based on the time information of each waveform peak, mud velocity, and the radius of the logging instrument, the distance between the center of the logging instrument and the wellbore wall at each azimuth is calculated, further including:

[0016] Based on the system time error, the time information of each waveform peak, the mud sound velocity, and the radius of the logging instrument, the distance between the center of the logging instrument and the well wall at each azimuth is calculated.

[0017] In one alternative approach, ellipse fitting is performed based on the distances between the logging instrument center and the wellbore wall at each azimuth of the depth point to be processed and multiple adjacent depth points, as well as the angles at each azimuth. This further includes:

[0018] For any depth point among the depth points to be processed and multiple adjacent depth points, calculate the corresponding coordinate value in the preset coordinate system based on the distance between the center of the logging instrument and the well wall at any position of that depth point and the angle of that position.

[0019] Ellipse fitting is performed based on each coordinate value.

[0020] In one alternative approach, after acquiring the reflected echo logging data at each depth point and azimuth within the depth range, the method further includes:

[0021] Median filtering was applied to the reflected echo logging data at various depths and in various orientations.

[0022] Based on the reflected echo logging data at various depth points and in various azimuths, the distance between the logging instrument center and the wellbore at each depth point and in each azimuth is calculated, further including:

[0023] Based on the filtered reflected echo logging data at each depth point and in each azimuth, the distance between the logging instrument center and the well wall at each depth point and in each azimuth is calculated.

[0024] In one alternative approach, median filtering of the reflected echo logging data at each depth point and each azimuth further includes:

[0025] For any depth point, based on the reflected echo logging data of any azimuth at that depth point and multiple adjacent depth points, the reflected echo logging data of that azimuth at that depth point are subjected to median filtering.

[0026] In one alternative approach, median filtering of the reflected echo logging data at each depth point and each azimuth further includes:

[0027] For any depth point, obtain the median waveform amplitude of each waveform amplitude at any time in each direction; subtract the median waveform amplitude at that time from each waveform amplitude at that time in each direction.

[0028] According to another aspect of the present invention, a device for calculating wellbore ellipticity is provided, the device comprising:

[0029] The acquisition module is suitable for acquiring reflected echo logging data at various depth points and directions within a depth range.

[0030] The analysis module is suitable for calculating the distance between the center of the logging instrument and the well wall at each depth point and each azimuth based on the reflected echo logging data at each depth point and each azimuth.

[0031] The fitting module is suitable for performing ellipse fitting based on the distance between the center of the logging instrument and the well wall at each azimuth and the angle at each azimuth of the depth point to be processed and multiple adjacent depth points at each depth point.

[0032] The processing module is suitable for determining the wellbore ellipticity at the depth point to be processed based on the fitting results.

[0033] In one alternative approach, the analysis module is further adapted to:

[0034] For any depth point, peak values ​​are detected in the reflected echo logging data at each azimuth of that depth point to obtain the time information of each waveform peak. Based on the time information of each waveform peak, the mud velocity, and the radius of the logging instrument, the distance between the center of the logging instrument and the well wall at each azimuth is calculated.

[0035] In one alternative approach, the analysis module is further adapted to:

[0036] Acquire reflected echo logging data of standard casing; wherein, the reflected echo logging data of standard casing is obtained by measuring the standard casing using logging instruments; based on the reflected echo logging data and inner diameter of standard casing, determine the system time error;

[0037] Based on the system time error, the time information of each waveform peak, the mud sound velocity, and the radius of the logging instrument, the distance between the center of the logging instrument and the well wall at each azimuth is calculated.

[0038] In one alternative approach, the fitting module is further adapted to:

[0039] For any depth point among the depth points to be processed and multiple adjacent depth points, the coordinate value in the preset coordinate system is calculated based on the distance between the logging instrument and the well wall at any azimuth of the depth point and the angle of that azimuth; ellipse fitting is then performed based on each coordinate value.

[0040] In one alternative embodiment, the apparatus further includes a filtering module adapted to perform median filtering on reflected echo logging data at various depth points and in various orientations.

[0041] The analysis module is further adapted to: calculate the distance between the center of the logging instrument and the well wall at each depth point and each azimuth based on the filtered reflected echo logging data at each depth point and each azimuth.

[0042] In an alternative embodiment, the filtering module is further adapted to: for any depth point, perform median filtering on the reflected echo logging data at any azimuth of the depth point and a plurality of adjacent depth points.

[0043] In an alternative approach, the filtering module is further adapted to: for any depth point, obtain the median waveform amplitude of each waveform amplitude at any time in each orientation; and subtract the median waveform amplitude at that time from each waveform amplitude at that time in each orientation.

[0044] According to another aspect of the present invention, a computing device is provided, comprising: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus;

[0045] The memory is used to store at least one executable instruction, which causes the processor to perform the operation corresponding to the above-described method for calculating the wellbore ellipticity.

[0046] According to another aspect of the present invention, a computer storage medium is provided, the storage medium storing at least one executable instruction that causes a processor to perform an operation corresponding to the above-described method for calculating wellbore ellipticity.

[0047] According to the present invention, a method, apparatus, computing device, and storage medium for calculating wellbore ellipticity include: acquiring reflected echo logging data at various azimuths at various depth points within a depth range; calculating the distance between the logging instrument center and the wellbore at each depth point and azimuth based on the reflected echo logging data at each depth point and azimuth; performing ellipse fitting processing based on the distance between the logging instrument center and the wellbore at each azimuth and the angles at each azimuth of the depth point to be processed and its multiple adjacent depth points; and determining the wellbore ellipticity of the depth point to be processed based on the fitting result. By using data from multiple adjacent depth points for ellipse fitting, the wellbore ellipticity can be obtained using only a drilling ultrasonic logging instrument, and the accuracy of the fitted wellbore ellipticity can be improved.

[0048] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0049] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0050] Figure 1 A flowchart illustrating the method for calculating wellbore ellipticity provided in an embodiment of the present invention is shown;

[0051] Figure 2 A schematic diagram showing the waveform analysis results of multiple depth points in an embodiment of the present invention is provided.

[0052] Figure 3 A schematic diagram of the waveforms before and after deep median filtering is shown in another embodiment of the present invention;

[0053] Figure 4 A schematic diagram of the waveforms before and after azimuth median filtering is shown in another embodiment of the present invention;

[0054] Figure 5 A schematic diagram of the cross-section of a standard casing and logging instrument is shown in another embodiment of this application;

[0055] Figure 6 A schematic diagram showing the wellbore ellipticity calculation results in another embodiment of the present invention is shown;

[0056] Figure 7A schematic diagram of the structure of the wellbore ellipticity calculation device provided in an embodiment of the present invention is shown;

[0057] Figure 8 A schematic diagram of the structure of a computing device provided in an embodiment of the present invention is shown. Detailed Implementation

[0058] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0059] Figure 1 A flowchart illustrating the method for calculating wellbore ellipticity provided in an embodiment of the present invention is shown, as follows: Figure 1 As shown, the method includes the following steps:

[0060] Step S110: Obtain reflected echo logging data at each depth point and each orientation within the depth range.

[0061] Well logging is performed within a depth range using a logging instrument (ultrasonic logging while drilling). The number of waveform channels acquired at each depth point within this range is N, representing N reflected echo logging data from different azimuths. The number of waveform channels depends on the specific ultrasonic logging instrument used. Each azimuth corresponds one-to-one with an ultrasonic transducer. A reflected echo logging data point for one azimuth is the reflected echo logging data acquired by emitting ultrasonic waves through the corresponding ultrasonic transducer. Ultrasonic logging while drilling instruments typically contain 3 or 4 ultrasonic transducers, enabling the acquisition of 3 or 4 reflected echo logging data points from different azimuths.

[0062] Step S120: Based on the reflected echo logging data at each depth point and each azimuth, calculate the distance between the center of the logging instrument and the well wall at each depth point and each azimuth.

[0063] For each depth point, based on the reflected echo logging data collected at that depth point in various directions, the distance between the center of the logging instrument and the well wall at each direction at that depth point is calculated.

[0064] Step S130: Based on the distance between the center of the logging instrument and the well wall at each azimuth of the depth point to be processed and its multiple adjacent depth points, as well as the angle at each azimuth, ellipse fitting is performed.

[0065] When it is necessary to calculate the ellipticity of the depth point to be processed, ellipse fitting is performed based on the data of the depth point to be processed, the K adjacent depth points above the depth point to be processed, and the K adjacent depth points below the depth point to be processed (i.e., a total of 2k+1 depth points). The data of each depth point includes the distance between the center of the logging instrument and the well wall in each azimuth and the angle in each azimuth.

[0066] The azimuth angle is determined based on the rotation angle of the logging instrument itself and the angle at which the ultrasonic transducers are distributed on the logging instrument.

[0067] Figure 2 This diagram illustrates the waveform analysis results of multiple depth points in an embodiment of the present invention. In this diagram, depth point nDep-1 represents the first depth point above the depth point nDep to be processed, depth point nDep-2 represents the second depth point above the depth point nDep to be processed, depth point nDep+1 represents the first depth point below the depth point nDep to be processed, and depth point nDep+2 represents the second depth point below the depth point nDep to be processed. Figure 2 The diagram shows the different positions of the drill collar within the wellbore. The outermost square represents the formation, the middle ellipse represents the wellbore, and the innermost circle is a schematic diagram of the drill collar. Three ultrasonic transducers are installed on the drill collar; T1, T2, and T3 represent the azimuths of the three transducers, as shown in the figure. At different depth points, the instruments are distributed at different azimuth angles. Ellipse fitting is performed based on the distances between the centers of the three logging instruments and the wellbore wall calculated at these five depth points, as well as the azimuth angles of the three ultrasonic transducers.

[0068] Step S140: Determine the wellbore ellipticity at the depth point to be processed based on the fitting results.

[0069] The definition of wellbore ellipticity is: (maximum diameter - minimum diameter) / standard wellbore diameter. The elliptic information of the depth point to be processed is obtained by fitting through the above steps, and the wellbore ellipticity of the depth point to be processed is further calculated.

[0070] According to the wellbore ellipticity calculation method of this application, reflected echo logging data at each depth point and in each azimuth within a depth range are obtained; based on the reflected echo logging data at each depth point and in each azimuth, the distance between the logging instrument center and the wellbore at each depth point and in each azimuth is calculated; based on the distance between the logging instrument center and the wellbore at each azimuth and the angle at each azimuth of the depth point to be processed and its multiple adjacent depth points, ellipse fitting is performed; and the wellbore ellipticity of the depth point to be processed is determined based on the fitting result. Through the above method, ellipse fitting is performed using data from multiple adjacent depth points, and the wellbore ellipticity can be obtained using only a drilling ultrasonic logging instrument, thus improving the accuracy of the fitted wellbore ellipticity.

[0071] Existing ultrasonic logging-while-drilling instruments often contain residual signals from the transmitted pulse in the ultrasonic reflected echo signals. These signals interfere with the extraction of the reflected echo signals from the wellbore, leading to errors in wellbore calculation. Specifically, the ultrasonic transducer oscillates during excitation, resulting in residual signals in the ultrasonic signal. If the residual signal lasts for a long time, or if the ultrasonic transducer is very close to the wellbore, or if the ultrasonic reflected echo signal is severely attenuated in a heavy mud environment (in which case the transducer residual signal is easily detected), it will lead to errors in the peak value detection of the reflected echo, thus making it impossible to obtain true wellbore information.

[0072] Therefore, in one optional implementation, after obtaining the reflected echo logging data at each depth point and each azimuth, median filtering is performed on the reflected echo logging data at each depth point and each azimuth. In subsequent processes, the filtered reflected echo logging data is used to calculate the relevant parameters for fitting the ellipse. Median filtering is a nonlinear digital filter technique often used to remove noise from images or other signals. By performing median filtering on the reflected echo signal, the influence of ultrasonic transducer residual vibration can be eliminated.

[0073] In one optional implementation, depth median filtering is used. Specifically, for any depth point, median filtering is performed on the reflected echo logging data of any azimuth at that depth point and a plurality of adjacent depth points.

[0074] Based on the reflected echo logging data from any azimuth at the depth point and several adjacent depth points, the waveform amplitudes at any time within that azimuth at the depth point and several adjacent depth points are obtained, and the median waveform amplitude is determined. Then, the median waveform amplitude is subtracted from the waveform amplitude at that azimuth and time at the depth point to obtain the filtered reflected echo logging data for that azimuth at the depth point. The same method is used to process the reflected echo logging data for each azimuth to obtain the filtered reflected echo logging data for that depth point.

[0075] For example, to perform median filtering on the reflected echo logging data at the T1 azimuth of the depth point nDep to be processed, the waveform amplitudes at the T1 azimuth and S1 time of depth points nDep-1, nDep-2, nDep to be processed, nDep+1, and nDep+2 are obtained respectively, and the median waveform amplitude is determined. The median waveform amplitude is then subtracted from the waveform amplitude at the S1 time of the T1 azimuth of the depth point nDep to be processed. For each time point, the same method is used to process the data, thereby obtaining the filtered reflected echo logging data at the T1 azimuth of the depth point nDep to be processed.

[0076] In another optional implementation, the azimuth median is used for filtering. Specifically, for any depth point, the median waveform amplitude of each waveform amplitude at any time in each azimuth is obtained; the median waveform amplitude at that time is subtracted from each waveform amplitude at that time in each azimuth.

[0077] For example, to perform median filtering on the reflected echo logging data of the three azimuths of the depth point nDep to be processed, the waveform amplitudes of the three azimuths at time S1 are obtained based on the reflected echo logging data of the three azimuths, and the median waveform amplitude of the three waveform amplitudes is determined. Then, the median waveform amplitude at time S1 is subtracted from the waveform amplitude of the three azimuths at time S1. The same processing is performed for each time point to obtain the filtered reflected echo logging data of the three azimuths of the depth point nDep to be processed.

[0078] Figure 3 The diagram illustrates waveforms before and after deep median filtering according to another embodiment of the present invention. The diagram shows the original reflected echo waveforms at azimuth 1, azimuth 2, and azimuth 3, as well as the waveforms after median filtering at each azimuth. Figure 3 Taking the waveform within the dashed box as an example, the original waveform in azimuth 3 contains residual vibration signal waveforms for a period of time starting from the initial time. However, after deep median filtering, the waveform curve for the corresponding period becomes a straight line, indicating that the residual vibration signal of the ultrasonic transducer has been greatly eliminated.

[0079] Figure 4 This diagram illustrates waveforms before and after azimuth median filtering according to another embodiment of the present invention. The diagram shows the original reflected echo waveforms for azimuth 1, azimuth 2, and azimuth 3, as well as the waveforms after azimuth median filtering for each azimuth. Figure 4 It is evident that the residual vibration signal of the ultrasonic transducer at some depth points has been weakened, but the effect is only average at other depth points. The main reason is that the receiving sensitivity of the ultrasonic transducer is inconsistent, and the phase of the residual vibration cannot be completely consistent.

[0080] In an optional implementation, calculating the distance between the logging instrument center and the wellbore at each depth point and each azimuth, based on the reflected echo logging data at each depth point and each azimuth, further includes:

[0081] For any given depth point, peak detection is performed on the reflected echo logging data at each azimuth of that depth point to obtain the time information of each waveform peak. Based on the time information of each waveform peak, the mud velocity, and the radius of the logging instrument, the distance between the center of the logging instrument and the wellbore at each azimuth is calculated. The peak detection result can be obtained by taking the signal envelope or directly taking the peak value of the signal amplitude.

[0082] For any given depth point, based on the reflected echo logging data from N azimuth directions, obtain the time positions where the amplitude of the reflected echo waveform is maximum in each of the N azimuth directions: TR i =max(Z), i = 1, 2...N, Z represents the waveform amplitude; then, determine the distance between the center of the logging instrument and the well wall at N azimuth positions (using D). i (This is represented by the formula below.)

[0083]

[0084] Where V represents the sound velocity of mud, which can be measured using a mud velocity meter. R represents the distance between the ultrasonic transducer and the wellbore at azimuth i, and R represents the radius of the logging instrument.

[0085] In another optional implementation, the method further includes: measuring a standard casing using a logging instrument to obtain reflected echo logging data of the standard casing; determining the system time error based on the reflected echo logging data and inner diameter of the standard casing. The step of calculating the distance between the logging instrument center and the wellbore at each azimuth further includes: calculating the distance between the logging instrument center and the wellbore at each azimuth based on the system time error, the time information of each waveform peak value, the mud velocity, and the radius of the logging instrument.

[0086] The time corresponding to the maximum amplitude of the signal or the time corresponding to the envelope signal is not the starting point of the signal. The waveform amplitude at the starting point of the signal is small and difficult to measure. Therefore, if the distance between the logging instrument center and the wellbore is calculated based on the time corresponding to the maximum amplitude of the waveform or the time corresponding to the envelope signal, a certain error (system time error) will be introduced. Based on this, in order to eliminate the system time error, measurements are taken in a standard casing, and the system time error is calculated from the measured data.

[0087] Figure 5A schematic diagram of the cross-section of a standard casing and a logging instrument is shown in another embodiment of this application. The large circle represents the cross-section of the standard casing, and the small circle represents the cross-section of the logging instrument. The standard casing is a standard cylinder with a known inner diameter. A rectangular coordinate system is established with the center of the logging instrument as the origin. The logging instrument shown in the figure has three ultrasonic transducers. The angle between the ultrasonic transducer 3 and the positive x-axis is 30 degrees.

[0088] Considering system time error, the distance d between the center of the logging instrument and the wall of the standard casing in azimuth i is... i The specific calculation formula is as follows:

[0089]

[0090] Where V represents the sound velocity of mud, t i δ represents the time of the waveform peak determined by analyzing the reflected echo logging data from the i-azimuth of a standard casing. t The system time error is represented by R, the inner diameter of the logging instrument is represented by R, and the first item on the right is the distance between the ultrasonic transducer and the pipe wall.

[0091] Based on the distances from the three locations and the angles of those three locations in the coordinate system, the coordinates of the three points on the circle can be calculated as follows:

[0092]

[0093] Substituting the three coordinate points above into the equation for solving the circle, we can obtain the center and radius of the circle. The specific calculation formula is as follows:

[0094]

[0095]

[0096] Among them, (x 01 y 01 Let ) represent the center of the circle, and r represent the inner diameter of the standard casing. Since the mud velocity, the peak waveform times at various azimuths of the standard casing, the inner diameter of the logging instrument, and the inner diameter of the standard casing are all known, the unknown system time error can be calculated based on the above equation.

[0097] In this method, the specific formula for calculating the distance between the center of the logging instrument and the wellbore at any depth point in the i-azimuth direction is as follows:

[0098]

[0099] Among them, D i ′ represents the distance between the center of the logging instrument and the wellbore wall at azimuth i, R iThe time of the waveform peak value is represented by R, the radius of the logging instrument is represented by V, and the mud velocity is represented by δ. t This indicates the system time error. By taking system time error into account, this method can improve the accuracy of the calculated distance between the logging instrument center and the wellbore.

[0100] In one optional implementation, the ellipse fitting process, based on the distance between the logging instrument center and the wellbore wall at each azimuth of the depth point to be processed and the angles at each azimuth, further includes: for any depth point among the depth points to be processed and the multiple adjacent depth points, calculating the corresponding coordinate values ​​in a preset coordinate system based on the distance between the logging instrument and the wellbore wall at any azimuth of that depth point and the angle at that azimuth; and performing ellipse fitting based on each coordinate value. Since the rotation angle of the logging instrument is inconsistent at different depth points, it is necessary to convert the distance between the logging instrument center and the wellbore wall at each azimuth and the angles at each azimuth into coordinate values ​​in the same coordinate system, thereby obtaining multiple points on the same ellipse.

[0101] It should be noted that the product of the number of depth points to be processed and their multiple adjacent depth points and the number of ultrasonic transducers should not be less than 5. In practice, the number of multiple depth points can be set to a higher value to improve the accuracy of the fitted wellbore ellipse.

[0102] In one optional implementation, the least squares method is used for ellipse fitting, and the specific fitting method is as follows:

[0103] Assume the equation of the ellipse is: Ax 2 +Bxy+Cy 2 +Dx+Ey+1=0

[0104] Let P j (x j ,y j (j=1,2,……m) are measurement points on the elliptical contour, m≥5. Based on the least squares principle, the objective function for fitting is:

[0105]

[0106] To minimize F, the following condition must be met:

[0107]

[0108] Based on this, the following equation can be constructed:

[0109]

[0110] By solving the equations, the values ​​of A, B, C, D, and E can be obtained. Furthermore, the five parameters of the ellipse can be calculated: the position parameter (θ, x0, y0) and the shape parameter (a, b), where (x0, y0) represents the center of the ellipse, θ represents the eccentricity angle, a represents the major axis, and b represents the minor axis. The specific calculation formulas are as follows:

[0111]

[0112]

[0113]

[0114]

[0115]

[0116] Figure 6 A schematic diagram of the wellbore ellipticity calculation results according to another embodiment of the present invention is shown. In the figure, the first line 61 is the major axis curve of the ellipse, which is drawn according to the length of the major axis of the ellipse fitted at each depth point. The second line 62 is the minor axis curve of the ellipse, which is drawn according to the length of the minor axis of the ellipse fitted at each depth point. The third line 63 is the ellipticity curve, which is drawn according to the ellipticity at each depth point. The fourth line 64 is a two-dimensional cross-sectional view of the wellbore at multiple depth points. Using the method of this application, the ellipticity information of the wellbore can be obtained using limited data.

[0117] Figure 7 A schematic diagram of the wellbore ellipticity calculation device provided in an embodiment of the present invention is shown, as follows: Figure 7 As shown, the device includes:

[0118] The acquisition module 71 is suitable for acquiring reflected echo logging data at various depth points and directions within the depth range.

[0119] Analysis module 72 is suitable for calculating the distance between the center of the logging instrument and the well wall at each depth point and each azimuth based on the reflected echo logging data at each depth point and each azimuth.

[0120] The fitting module 73 is adapted to perform ellipse fitting based on the distance between the center of the logging instrument and the well wall at each azimuth of the depth point to be processed and its multiple adjacent depth points, as well as the angle at each azimuth.

[0121] Processing module 74 is adapted to determine the wellbore ellipticity of the depth point to be processed based on the fitting results.

[0122] In an alternative embodiment, the analysis module 72 is further adapted to:

[0123] For any depth point, peak values ​​are detected in the reflected echo logging data at each azimuth of that depth point to obtain the time information of each waveform peak. Based on the time information of each waveform peak, the mud velocity, and the radius of the logging instrument, the distance between the center of the logging instrument and the well wall at each azimuth is calculated.

[0124] In an alternative embodiment, the analysis module 72 is further adapted to:

[0125] Acquire reflected echo logging data of standard casing; wherein, the reflected echo logging data of standard casing is obtained by measuring the standard casing using logging instruments; based on the reflected echo logging data and inner diameter of standard casing, determine the system time error;

[0126] Based on the system time error, the time information of each waveform peak, the mud sound velocity, and the radius of the logging instrument, the distance between the center of the logging instrument and the well wall at each azimuth is calculated.

[0127] In an alternative embodiment, the fitting module 73 is further adapted to:

[0128] For any depth point among the depth points to be processed and multiple adjacent depth points, the coordinate value in the preset coordinate system is calculated based on the distance between the center of the logging instrument and the well wall at any azimuth of the depth point and the angle of that azimuth; ellipse fitting is then performed based on each coordinate value.

[0129] In one alternative embodiment, the apparatus further includes a filtering module adapted to perform median filtering on reflected echo logging data at various depth points and in various orientations.

[0130] The analysis module 72 is further adapted to: calculate the distance between the center of the logging instrument and the well wall at each azimuth based on the filtered reflected echo logging data at each depth point and each azimuth.

[0131] In an alternative embodiment, the filtering module is further adapted to: for any depth point, perform median filtering on the reflected echo logging data at any azimuth of the depth point and a plurality of adjacent depth points.

[0132] In an alternative approach, the filtering module is further adapted to: for any depth point, obtain the median waveform amplitude of each waveform amplitude at any time in each orientation; and subtract the median waveform amplitude at that time from each waveform amplitude at that time in each orientation.

[0133] According to the wellbore ellipticity calculation device of this application embodiment, reflected echo logging data at each depth point and in each azimuth within a depth range are acquired; based on the reflected echo logging data at each depth point and in each azimuth, the distance between the logging instrument center and the wellbore at each depth point and in each azimuth is calculated; based on the distance between the logging instrument center and the wellbore at each azimuth and the angle at each azimuth of the depth point to be processed and its multiple adjacent depth points, elliptic fitting processing is performed; and the wellbore ellipticity of the depth point to be processed is determined based on the fitting result. Through the above method, elliptic fitting is performed using data from multiple adjacent depth points, and the wellbore ellipticity can be obtained using only a drilling ultrasonic logging instrument, thereby improving the accuracy of the fitted wellbore ellipticity.

[0134] This invention provides a non-volatile computer storage medium storing at least one executable instruction that can execute the wellbore ellipticity calculation method in any of the above method embodiments.

[0135] Figure 8 The diagram shows a structural schematic of a computing device provided in an embodiment of the present invention. The specific embodiments of the present invention do not limit the specific implementation of the computing device.

[0136] like Figure 8 As shown, the computing device may include: a processor 802, a communications interface 804, a memory 806, and a communications bus 808.

[0137] The processor 802, communication interface 804, and memory 806 communicate with each other via communication bus 808. Communication interface 804 is used to communicate with other network elements such as clients or other servers. Processor 802 executes program 810, specifically performing the relevant steps in the above-described embodiment of the method for calculating the wellbore ellipticity of the calculation device.

[0138] Specifically, program 810 may include program code that includes computer operation instructions.

[0139] Processor 802 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The computing device includes one or more processors, which may be processors of the same type, such as one or more CPUs; or processors of different types, such as one or more CPUs and one or more ASICs.

[0140] Memory 806 is used to store program 810. Memory 806 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0141] The algorithms or displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general-purpose systems can also be used in conjunction with the teachings herein. The required structure for constructing such systems is apparent from the above description. Furthermore, the embodiments of the present invention are not directed to any particular programming language. It should be understood that the content of the invention described herein can be implemented using various programming languages, and the above description of specific languages ​​is for the purpose of disclosing the best mode of implementation of the invention.

[0142] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0143] Similarly, it should be understood that, in order to streamline the invention and aid in understanding one or more of the various inventive aspects, features of the embodiments of the invention are sometimes grouped together in a single embodiment, figure, or description thereof in the above description of exemplary embodiments of the invention. However, this disclosure should not be construed as reflecting an intention that the claimed invention requires more features than expressly recited in each claim. Rather, as reflected in the claims, inventive aspects lie in fewer than all features of the single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.

[0144] Those skilled in the art will understand that modules in the device of the embodiments can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiments can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components. Except where at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or device so disclosed. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0145] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0146] The various component embodiments of the present invention can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some or all of the components according to the embodiments of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such programs implementing the present invention can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0147] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be construed as limiting the order of execution.

Claims

1. A method for calculating wellbore ellipticity, characterized in that, The method includes: Acquire reflected echo logging data at various depth points and in various orientations within the depth range; Based on the reflected echo logging data at various depth points and azimuth positions, the distance between the logging instrument center and the wellbore at each depth point and azimuth position is calculated. Specifically, for any depth point, peak detection is performed on the reflected echo logging data at each azimuth position to obtain the time information of each waveform peak. The logging instrument is used to measure a standard casing to obtain the reflected echo logging data of the standard casing. Based on the reflected echo logging data and inner diameter of the standard casing, the system time error is determined. Based on the system time error, the time information of each waveform peak, and the mud sound... Based on the velocity and radius of the logging instrument, the distance between the center of the logging instrument and the well wall at each azimuth is calculated. Ellipse fitting is then performed on the depth point to be processed and its adjacent depth points, considering the distance between the center of the logging instrument and the well wall at each azimuth and the angle of each azimuth. Specifically, for any depth point among the depth points to be processed and its adjacent depth points, the coordinates in a preset coordinate system are calculated based on the distance between the center of the logging instrument and the well wall at any azimuth and the angle of that azimuth. Ellipse fitting is then performed based on these coordinates. The wellbore ellipticity at the depth point to be processed is determined based on the fitting results.

2. The method according to claim 1, characterized in that, After acquiring the reflected echo logging data at each depth point and azimuth within the depth range, the method further includes: Median filtering was applied to the reflected echo logging data at various depths and in various orientations. The step of calculating the distance between the center of the logging instrument and the wellbore at each depth point and each azimuth based on the reflected echo logging data at each depth point and each azimuth further includes: Based on the filtered reflected echo logging data at each depth point and in each azimuth, the distance between the logging instrument center and the well wall at each depth point and in each azimuth is calculated.

3. The method according to claim 2, characterized in that, The median filtering processing of the reflected echo logging data at each depth point and each azimuth further includes: For any depth point, based on the reflected echo logging data of any azimuth at that depth point and multiple adjacent depth points, the reflected echo logging data of that azimuth at that depth point are subjected to median filtering.

4. The method according to claim 2, characterized in that, The median filtering processing of the reflected echo logging data at each depth point and each azimuth further includes: For any depth point, obtain the median waveform amplitude of each waveform amplitude at any time in each direction; subtract the median waveform amplitude at that time from each waveform amplitude at that time in each direction.

5. A device for calculating the ellipticity of a wellbore, characterized in that, The device includes: The acquisition module is suitable for acquiring reflected echo logging data at various depth points and directions within a depth range. The analysis module is adapted to calculate the distance between the center of the logging instrument and the wellbore at each depth point and each azimuth based on the reflected echo logging data at each depth point and each azimuth. Specifically, for any depth point, peak detection is performed on the reflected echo logging data at each depth point and each azimuth to obtain the time information of each waveform peak value. The logging instrument is used to measure a standard casing to obtain the reflected echo logging data of the standard casing. Based on the reflected echo logging data and inner diameter of the standard casing, the system time error is determined. Based on the system time error, the time information of each waveform peak value, the mud velocity, and the radius of the logging instrument, the distance between the center of the logging instrument and the wellbore at each azimuth is calculated. The fitting module is adapted to perform ellipse fitting based on the distance between the logging instrument center and the well wall at each azimuth of the depth point to be processed and its multiple adjacent depth points, as well as the angle of each azimuth; wherein, for any depth point among the depth points to be processed and its multiple adjacent depth points, the coordinate value corresponding to the depth point is calculated in a preset coordinate system based on the distance between the logging instrument center and the well wall at any azimuth of that depth point and the angle of that azimuth; and ellipse fitting is performed based on each coordinate value. The processing module is adapted to determine the wellbore ellipticity of the depth point to be processed based on the fitting results.

6. A computing device, comprising: The processor, memory, communication interface, and communication bus are provided, wherein the processor, memory, and communication interface communicate with each other via the communication bus. The memory is used to store at least one executable instruction that causes the processor to perform the operation corresponding to the wellbore ellipticity calculation method as described in any one of claims 1-4.

7. A computer storage medium storing at least one executable instruction that causes a processor to perform an operation corresponding to the method for calculating wellbore ellipticity as described in any one of claims 1-4.

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