Cement sheath thickness measurement method and apparatus, device, and storage medium

Abstract

Disclosed are a cement sheath thickness measurement method and apparatus, a device, and a storage medium. The cement sheath thickness measurement method comprises: acquiring Lamb wave full-waveform data received at different azimuths at a certain depth point of a target depth interval; performing waveform processing on the Lamb wave full-waveform data received at the different azimuths at the depth point, and determining a group delay corresponding to the depth point at the different azimuths; on the basis of the group delay corresponding to the depth point at the different azimuths, determining corresponding circumferential cement sheath thicknesses at the different azimuths of the depth point; and repeating the described steps until the corresponding circumferential cement sheath thicknesses at each depth point of the target depth interval at the different azimuths are acquired. By means of the measurement method, accurate calculation of the cement sheath thicknesses between a casing and a formation can be simply and quickly realized, thereby enabling an accurate evaluation of the cementing quality.

Description

Cement sheath thickness measurement method, device, equipment and storage medium

[0001] Cross-reference to Related Applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411077806.0, filed August 7, 2024, the contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of applied geophysics and oil and gas exploration, and in particular, to a cement sheath thickness measurement method, a cement sheath thickness measurement device, an electronic device, and a computer-readable storage medium. BACKGROUND

[0004] With the gradual development of oil and gas exploration and development in China towards ultra-deep layers, factors such as wellbore collapse and casing misalignment can easily cause cement sheath defects during cementing, thereby affecting fluid layer isolation and safe production of oil and gas wells, and thus there is a need for cementing quality evaluation methods to check whether cement sheath defects exist.

[0005] In the prior art, conventional cementing quality evaluation methods such as CBL (acoustic amplitude logging), VDL (acoustic variable density logging), etc. are difficult to accurately evaluate the quality of cementing and cement sheath defects. SUMMARY

[0006] The purpose of the embodiments of the present application is to provide a cement sheath thickness measurement method, at least to solve the technical problem that conventional cementing quality evaluation methods in the prior art are difficult to accurately evaluate the quality of cementing.

[0007] To achieve the above-mentioned purpose, in a first aspect, a cement sheath thickness measurement method is provided, which comprises the following steps: acquiring Lamb wave full-wave waveform data received at different azimuths of a certain depth point in a target depth interval; performing waveform processing on the Lamb wave full-wave waveform data received at different azimuths of the depth point to determine the group delay corresponding to the depth point at different azimuths; based on the group delay corresponding to the depth point at different azimuths, determining the annular cement sheath thickness corresponding to the depth point at different azimuths; repeating the above steps until the annular cement sheath thickness corresponding to each depth point at different azimuths in the target depth interval is obtained.

[0008] In a second aspect, a cement sheath thickness measurement device is provided, and the cement sheath measurement device comprises: an acquisition module configured to acquire Lamb wave full wave waveform data received at different azimuths of a certain depth point in a target depth interval; a first determination module configured to perform waveform processing on the Lamb wave full wave waveform data received at different azimuths of the depth point, and determine group delay corresponding to the depth point at different azimuths; a second determination module configured to determine a ring-direction cement sheath thickness corresponding to the depth point at different azimuths based on the group delay corresponding to the depth point at different azimuths; and a loop module configured to repeatedly perform the above steps until ring-direction cement sheath thicknesses corresponding to each depth point at different azimuths in the target depth interval are obtained.

[0009] In a third aspect, an electronic device is provided, and the electronic device comprises a processor and a memory, and the memory stores at least one computer program, and the at least one computer program is loaded and executed by one or more processors to enable the processor to perform the cement sheath thickness measurement method.

[0010] In a fourth aspect, a computer readable storage medium is provided, and the computer readable storage medium stores at least one program code, and the program code is loaded and executed by a processor to enable the computer to perform the cement sheath thickness measurement method.

[0011] One of the above technical solutions has the following beneficial effects:

[0012] (1) The cement sheath thickness measurement method provided by the above technical solution first uses the group delay dip of the curved Lamb wave to calculate the cement sheath thickness between the casing and the formation, and the method can simply and quickly calculate the cement sheath thickness, and the calculation result is relatively accurate.

[0013] (2) The cement sheath thickness measurement result obtained by the above technical solution can not only be used to accurately evaluate the quality of cementing, but also provides a possibility for field application of cement displacement efficiency and other engineering applications.

[0014] Other features and advantages of the embodiments of the present application will be described in detail in the following specific implementation part. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific implementation to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0016] FIG. 1 is a flow diagram of a cement sheath thickness measurement method provided by an embodiment of the present application;

[0017] FIG. 2A is a schematic diagram of a cross section of a casing well model provided by an embodiment of the present application;

[0018] Fig. 2B is a schematic diagram of a propagation trajectory according to an embodiment of the present application;

[0019] Fig. 3A is a schematic diagram of a full wave waveform of a Lamb wave received by a near receiver according to an embodiment of the present application;

[0020] Fig. 3B is a schematic diagram of a waveform spectrum obtained by performing Fourier transform on the full wave waveform of the Lamb wave according to an embodiment of the present application;

[0021] Fig. 4A is a schematic diagram of a waveform group delay spectrum of a fast cement after casing according to different thicknesses according to an embodiment of the present application;

[0022] Fig. 4B is a schematic diagram of a waveform group delay spectrum of a slow cement after casing according to different thicknesses according to an embodiment of the present application;

[0023] Fig. 5 is a schematic diagram of imaging of a cement ring thickness between a casing and a formation according to an embodiment of the present application;

[0024] Fig. 6 is a schematic diagram of a flow of another cement ring thickness measurement method according to an embodiment of the present application;

[0025] Fig. 7 is a schematic diagram of a structure of a cement ring thickness measurement device according to an embodiment of the present application;

[0026] Fig. 8 is a schematic diagram of a structure of an electronic device according to an embodiment of the present application.

[0027] Legend of reference numerals 101 - acquisition module, 102 - first determination module, 103 - second determination module, 104 - loop module, 201 - processor, 202 - memory. DETAILED DESCRIPTION

[0028] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0029] In the present application, the orientation words such as "upper", "lower", "top", "bottom" are generally used for the directions shown in the drawings or the mutual positional relationship of the components in the vertical, perpendicular or gravity direction, unless otherwise specified. "First", "second" and the like are merely used for convenient description and distinction, and cannot be understood as indicating or implying relative importance.

[0030] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection" and the like should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or indirect connection; it can be wired connection, or wireless connection. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0031] In the prior art, the cement sheath thickness measurement method is generally used to detect whether the cement sheath has defects, but the cement sheath thickness measurement result obtained by this method is not very accurate. Considering the technical problem that the conventional cementing quality evaluation method in the prior art is difficult to accurately evaluate the quality of cementing, the present application provides a cement sheath thickness measurement method, which measures the full wave waveform of different directions in the well by rotating the after-casing imaging logging instrument, and then performs a series of waveform processing on the full wave waveform to obtain the group delay of the curved Lamb wave, and calculates the annular thickness of the cement sheath between the casing and the formation by using the group delay of the curved Lamb wave. Compared with the cement sheath thickness measurement method in the prior art, the present application can accurately calculate the annular thickness of the cement sheath, which is of great significance to the evaluation of cementing quality. In specific implementation, the above method can be executed by an electronic device, which can be a server, a terminal or other device with processing function.

[0032] The technical solutions of the present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described in detail in some embodiments.

[0033] As shown in FIG. 1, the present application provides a cement sheath thickness measurement method, which comprises the following steps:

[0034] Step S101, acquiring the Lamb wave full wave waveform data received at different directions of a depth point in a target depth interval.

[0035] Specifically, it is assumed that the target depth interval is provided with n depth points in total, i represents the i-th depth point of the target depth interval, and 1≤i≤n. When i=1, it indicates that the ultrasonic Lamb wave logging instrument is located at the first depth point of the target depth interval, at this time, the ultrasonic Lamb wave logging instrument is rotated one round in the well according to the preset number of rotations, and the Lamb wave full wave waveform data received at different positions of the first depth point of the target depth interval can be obtained; similarly, when i=2, the ultrasonic Lamb wave logging instrument is rotated one round at the second depth point according to the preset number of rotations, and the Lamb wave full wave waveform data received at different positions of the second depth point of the target depth interval can be obtained; and so on, when i=n, the ultrasonic Lamb wave logging instrument is rotated one round at the n-th depth point according to the preset number of rotations, and the Lamb wave full wave waveform data received at different positions of the n-th depth point of the target depth interval can be obtained.

[0036] It should be noted that in the field of oil and gas exploration and development, the ultrasonic Lamb wave logging instrument is widely used in oilfield casing corrosion and cementing quality evaluation. The ultrasonic Lamb wave logging instrument uses the direct ultrasonic Lamb wave signal measured by the oblique incidence probe and the cement acoustic impedance information measured by the vertical probe to jointly invert the gas-liquid-solid properties of the medium outside the casing. This measurement method is not affected by the cement density and can evaluate the cementing quality of low-density cement. During the propagation of the ultrasonic Lamb wave signal along the casing, energy is also leaked to the cement ring, and then reflected when encountering the formation interface. These reflected signals are also accepted by the sensor. Therefore, the direct signal and reflected signal of the Lamb wave can be used to calculate the thickness of the cement ring, and further evaluate the eccentric position of the casing in the wellbore.

[0037] FIG. 2A shows a casing well two-dimensional model, which can be seen that the casing well two-dimensional model is instrument, wellbore mud, casing, and cement ring in turn from inside to outside, wherein the radius (distance to the well axis) of the wellbore mud is r1, the radius (distance to the well axis) of the casing is r2, and the radius (distance to the well axis) of the cement ring is r3. FIG. 2B shows the sound wave propagation path in the casing well model, which can be seen that the probe emits a sound source at an angle of θ, and the receiver receives the curved Lamb wave leaked in the casing at the same angle; the source distance close to the receiver is y, and the distance between the near and far receivers is d. The curved Lamb wave logging adopts oblique incidence transmission excitation and oblique incidence receiving mode, the receiving source can be between 30cm and 40cm, the full wave waveform at different positions is measured by rotating the casing imaging logging instrument in the well, and the preset number of transmissions is repeated for one round of rotation, for example, the number of repeated transmissions for one round of rotation can be 36 times.

[0038] In step S102, the Lamb wave full wave waveform data received at different positions of the depth point is processed to determine the group delay corresponding to the depth point at different positions.

[0039] Specifically, the process of determining the group delay corresponding to the depth point at different azimuths by waveform processing the Lamb wave full wave waveform data received at the depth point at different azimuths can include but is not limited to the following sub-step S1021~sub-step S1022.

[0040] In the sub-step S1021, the Lamb wave full wave waveform data received at the i th depth point at different azimuths is respectively subjected to two-dimensional discrete Fourier transform to obtain the amplitude spectrum and the phase spectrum corresponding to the i th depth point at different azimuths.

[0041] For example, the Lamb wave full wave waveform data received at any azimuth of the i th depth point can be subjected to two-dimensional discrete Fourier transform according to formula (1).

[0042] In the formula, F(u, v) is the two-dimensional discrete Fourier transform value corresponding to the i th depth point at any azimuth; f wave (x, y) is the Lamb wave full wave waveform data received at any azimuth of the i th depth point; x and y are spatial domain coordinates, and the value ranges are respectively 0≤x

[0043] FIG. 3A shows the Lamb wave full wave waveform received by the near-far receiver arranged at a certain depth point in the target depth interval, and FIG. 3B shows the amplitude spectrum of the full wave waveform obtained by subjecting the Lamb wave full wave waveform to two-dimensional discrete Fourier transform.

[0044] In the sub-step S1022, the phase spectrum corresponding to the i th depth point at different azimuths is respectively subjected to derivation to obtain the group delay corresponding to the i th depth point at different azimuths.

[0045] For example, the group delay corresponding to the i th depth point at a certain azimuth can be obtained according to formula (2).

[0046] In the formula, δgroupdelay(ω) is the group delay function value corresponding to the i th depth point at a certain azimuth; φ(ω) is the phase spectrum function corresponding to the i th depth point at a certain azimuth.

[0047] Of course, the present application is not limited thereto, and other ways such as wavelet transform can also be selected to perform waveform processing on the Lamb wave full wave waveform data to obtain the amplitude spectrum and the phase spectrum of the full wave waveform.

[0048] In step S103, the hoop cement sheath thickness corresponding to the depth point at different azimuths is determined based on the group delay corresponding to the depth point at different azimuths.

[0049] Specifically, the process of determining the annular cement sheath thickness corresponding to the depth point at different azimuths based on the group delay corresponding to the depth point at different azimuths can include but is not limited to the following sub-steps S1031-S1032.

[0050] In sub-step S1031, waveform analysis is performed on the group delay corresponding to the i th depth point at different azimuths to determine the group delay recess interval corresponding to the i th depth point at different azimuths.

[0051] In sub-step S1032, the annular cement sheath thickness corresponding to the i th depth point at different azimuths is determined based on the group delay recess interval corresponding to the i th depth point at different azimuths.

[0052] For example, the annular cement sheath thickness corresponding to the i th depth point at a certain azimuth can be determined according to formula (3).

[0053] In the formula, T (depth,azimuth) is the annular cement sheath thickness corresponding to the i th depth point at a certain azimuth; V s is the velocity of the annulus medium; and Δf is the group delay recess interval corresponding to the i th depth point at a certain azimuth.

[0054] In step S104, the above steps S101-S103 are repeatedly executed until the annular cement sheath thickness corresponding to each depth point at different azimuths in the target depth interval is obtained.

[0055] Specifically, after obtaining the measurement result of the annular cement sheath thickness corresponding to the i th depth point at different azimuths, it is determined whether 1≤i

[0056] Further, in a possible implementation, in sub-step S1031, the process of performing waveform analysis on the group delay corresponding to the i th depth point at different azimuths to determine the group delay recess interval corresponding to the i th depth point at different azimuths can include but is not limited to the following sub-steps S10311-S10315.

[0057] In sub-step S10311, based on the group delay function corresponding to the i th depth point at the k th azimuth, a waveform group delay spectrum corresponding to the i th depth point at the k th azimuth is obtained.

[0058] Specifically, it is assumed that the preset number of times is m, that is, the ultrasonic Lamb wave logging instrument needs to rotate m times at each depth point in the target depth interval, k represents the position of any depth point in the target depth interval in the ring direction, and 1≤k≤m. In the case where the ultrasonic Lamb wave logging instrument is located at the i th depth point in the target depth interval, when k=1, it means that the ultrasonic Lamb wave logging instrument is at the first position of the i th depth point; when k=2, it means that the ultrasonic Lamb wave logging instrument is at the second position of the i th depth point; and so on, when k=m, it means that the ultrasonic Lamb wave logging instrument is at the m th position of the i th depth point.

[0059] By performing data processing on the group delay function corresponding to the i th depth point at the k th position, the waveform group delay spectrum corresponding to the i th depth point at the k th position can be obtained.

[0060] In substep S10312, waveform analysis is performed on the waveform group delay spectrum corresponding to the i th depth point at the k th position, and the maximum peak in the waveform group delay spectrum is identified.

[0061] For example, the maximum peak can be identified by finding the highest peak value in the waveform group delay spectrum, and the frequency position of the maximum peak can be located by the abscissa of the waveform group delay spectrum.

[0062] In substep S10313, based on the frequency position of the maximum peak, the first valley adjacent to the maximum peak on the left side of the maximum peak is determined, and the second valley adjacent to the maximum peak on the right side of the maximum peak is determined.

[0063] In substep S10314, the frequency position of the second valley is subtracted from the frequency position of the first valley to obtain the group delay recess interval corresponding to the i th depth point at the k th position.

[0064] In substep S10315, the above substeps S10311 to S10314 are repeatedly executed until the group delay recess intervals corresponding to the i th depth point at different positions are obtained.

[0065] Specifically, after obtaining the group delay recess interval corresponding to the i th depth point at the k th position, it is determined whether 1≤k

[0066] Fig. 4A shows the wave group delay spectrum of the cemented fast cement behind casing at different thicknesses, and Fig. 4B shows the wave group delay spectrum of the cemented slow cement behind casing at different thicknesses. As can be seen from the analysis of Fig. 4A and Fig. 4B, as the thickness of the cement sheath increases, the interval between the group delay dips gradually decreases. When the fast cement is cemented between the casing and the formation, only the leaked shear wave is in the cement, and only the reflected shear wave is at the cement-formation interface, and the amplitude spectrum has good periodicity, so the thickness of the cement sheath can be directly estimated by the interval between the frequency dips. When the slow cement is cemented between the casing and the formation, the longitudinal wave and the shear wave leak into the cement sheath, and when the two waves reach the cement-formation interface, mode conversion occurs, and the types of reflected waves include longitudinal wave-longitudinal wave, longitudinal wave-shear wave, shear wave-longitudinal wave, and shear wave-shear wave, etc. At this time, by comparing the amplitude spectrum of the full wave of the slow cement with the amplitude spectrum of the full wave of the fast cement, it can be found that the number of group delay dips in the amplitude spectrum of the full wave of the slow cement increases, but the interval between the group delay dips still decreases as the thickness of the cement sheath increases. In addition, by comparing the peak frequency of the amplitude spectrum at different thicknesses, it can also be found that the peak frequency gradually decreases as the thickness of the cement sheath decreases.

[0067] Further, in a possible implementation, in the step S1032, if the annulus medium is mud, the longitudinal wave velocity of the mud can be determined as the velocity V f of the annulus medium. f

[0068] Further, in a possible implementation, the cement sheath thickness measurement method further includes a step S105 of azimuthally imaging the circumferential cement sheath thickness corresponding to each depth point in the target depth interval at different azimuths.

[0069] For example, Fig. 5 shows a cement sheath thickness imaging schematic diagram between the casing and the formation, and it can be seen that the cement sheath thickness measurement method provided by the embodiments of the present application makes it possible for the field application of cement displacement efficiency and other engineering applications.

[0070] As shown in Fig. 6, the embodiments of the present application further provide another cement sheath thickness measurement method, which includes the following steps:

[0071] In step S201, Lamb wave full wave waveform data received at different azimuths of a depth point in a target depth interval is obtained.

[0072] Specifically, the Lamb wave full wave waveform data received at different azimuths of the i th depth point can be obtained by referring to the step S101 in the above embodiments, which will not be described here.

[0073] ​Step S202, waveform processing is performed on the Lamb wave full wave waveform data received at different azimuths of the depth point to determine the group delay corresponding to the depth point at different azimuths.

[0074] Specifically, the group delay corresponding to the i-th depth point at different azimuths can be determined by referring to step S102 in the above embodiment, which will not be repeated here.

[0075] Step S203, based on the group delay corresponding to the depth point at different azimuths, the annular cement sheath thickness corresponding to the depth point at different azimuths is determined.

[0076] Specifically, the annular cement sheath thickness corresponding to the i-th depth point at different azimuths can be determined by referring to step S103 in the above embodiment, which will not be repeated here.

[0077] Step S204, comparing the inversion caliper value with the caliper logging value to verify whether the measurement result of the annular cement sheath thickness corresponding to the depth point at different azimuths is reasonable.

[0078] Specifically, first, the inversion caliper value C can be obtained according to the annular cement sheath thickness corresponding to the i-th depth point at different azimuths and the outer diameter of the casing. Then, the inversion caliper value C is compared with the caliper logging value C0. If the inversion caliper value C is less than the caliper logging value C0, it indicates that the measurement result of the annular cement sheath thickness corresponding to the i-th depth point at different azimuths is reasonable, and the annular cement sheath thickness corresponding to the i-th depth point at different azimuths can be output. If the inversion caliper value C is greater than the caliper logging value C0, it indicates that the measurement result of the annular cement sheath thickness corresponding to the i-th depth point at different azimuths is unreasonable, and the velocity V f of the annulus medium should be adjusted, and the step S203 is returned to, in which the annular cement sheath thickness corresponding to the i-th depth point at different azimuths is recalculated by using the adjusted velocity V f of the annulus medium.

[0079] Step S205, the above steps S201 to S204 are repeatedly executed until the annular cement sheath thickness corresponding to each depth point at different azimuths in the target depth interval is obtained.

[0080] Specifically, after obtaining the measurement result of the annular cement sheath thickness corresponding to the i-th depth point at different azimuths, it is judged whether 1≤i

[0081] Further, in a possible implementation, in step S204, the process of obtaining the inverted caliper value according to the annular cement sheath thickness and the casing outer diameter corresponding to the i th depth point at different orientations can be refined as the following flow:

[0082] (1) comparing the annular cement sheath thicknesses corresponding to the i th depth point at different orientations, determining a minimum annular cement sheath thickness value T1;

[0083] (2) determining a second orientation opposite to the first orientation in the cement sheath based on the first orientation corresponding to the minimum annular cement sheath thickness value T1;

[0084] (3) adding the minimum annular cement sheath thickness value T1, the annular cement sheath thickness value T2 corresponding to the second orientation, and the casing outer diameter to obtain the inverted caliper value C.

[0085] Further, in a possible implementation, the cement sheath thickness measurement method further includes step S206: azimuthally imaging the annular cement sheath thicknesses corresponding to each depth point at different orientations in the target depth interval.

[0086] In addition, the implementation environment of the embodiment includes at least one terminal and a server, and the method is executed on the terminal or the server respectively. The terminal and the server can be in communication connection to realize interactive transmission of information.

[0087] The terminal can be any electronic product that can interact with the user through one or more ways such as keyboard, touchpad, touch screen, voice interaction, etc., such as PC (Personal Computer), PPC (Pocket Personal Computer), tablet computer, etc.

[0088] The server can be a server, a server cluster composed of multiple servers, a cloud server providing cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN (Content Delivery Network), and basic cloud computing services such as big data and artificial intelligence platforms.

[0089] As shown in FIG. 7, the embodiment of the present application further provides a cement sheath thickness measurement device, which comprises an acquisition module 101, a first determination module 102, a second determination module 103, and a loop module 104.

[0090] The acquisition module 101 is configured to acquire Lamb wave full-wave waveform data received at different orientations by a certain depth point in a target depth interval.

[0091] The first determining module 102 is configured to perform waveform processing on the Lamb wave full-wave waveform data received at different azimuths of the depth point to determine group delays corresponding to the depth point at different azimuths.

[0092] The second determining module 103 is configured to determine annular cement sheath thicknesses corresponding to the depth point at different azimuths based on the group delays corresponding to the depth point at different azimuths.

[0093] The circulating module 104 is configured to repeatedly perform the process of obtaining the Lamb wave full-wave waveform data received at different azimuths of a certain depth point to determining annular cement sheath thicknesses corresponding to the depth point at different azimuths until annular cement sheath thicknesses corresponding to each depth point at different azimuths in a target depth range are obtained.

[0094] It should be noted that the above-provided apparatus is only taken as an example for dividing the above-described function modules, and in actual application, the above-described functions can be completed by different function modules according to needs, that is, the internal structure of the apparatus is divided into different function modules to complete all or part of the above-described functions. In addition, the apparatus provided in the above embodiments and the method provided in the above embodiments belong to the same concept, and the specific implementation process is shown in the method embodiments, which will not be described here.

[0095] As shown in FIG. 8, the embodiment of the present application further provides an electronic device, which includes a processor 201 and a memory 202, and the memory stores at least one computer program, the at least one computer program is loaded and executed by one or more processors described above, so that the processor implements the cement sheath thickness measurement method in the above embodiments.

[0096] Of course, the electronic device can also have a wired or wireless network interface, a keyboard, an input and output interface and other components for realizing the functions of the device, so as to perform input and output, and the electronic device can also include other components for realizing the functions of the device, which will not be described here.

[0097] The embodiment of the present application further provides a computer readable storage medium, the computer readable storage medium stores at least one program code, the program code is loaded and executed by the processor, so that the computer implements the cement sheath thickness measurement method in the above embodiments.

[0098] Optionally, the computer readable storage medium can be a Read-Only Memory (ROM), a Random Access Memory (RAM), a Compact Disc Read-Only Memory (CD-ROM), a magnetic tape, a floppy disk and an optical disc data storage device, etc. Those skilled in the art can understand that all or part of the steps of the above-mentioned embodiment methods can be completed by a program instructing related hardware, the program is stored in a storage medium, and the storage medium includes a plurality of instructions for enabling a single-chip microcomputer, a chip or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The foregoing storage medium includes a U disk, a mobile hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disc or an optical disc, and various media capable of storing program codes.

[0099] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the specific details in the above-described embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0100] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

Claims

1. A method for measuring the thickness of a cement ring, characterized in that, The method for measuring the thickness of the cement ring includes: Acquire Lamb wave full-wave waveform data received at different azimuths at a certain depth point within the target depth range; Waveform processing is performed on the Lamb wave full-wave waveform data received at different azimuths of the depth point to determine the group delay corresponding to the depth point at different azimuths. Based on the group delay corresponding to the depth point at different orientations, the circumferential cement ring thickness corresponding to the depth point at different orientations is determined. Repeat the above steps until the thickness of the circumferential cement ring at different orientations for each depth point in the target depth range is obtained.

2. The method for measuring the thickness of a cement ring according to claim 1, characterized in that, The step of performing waveform processing on the Lamb wave full-wave waveform data received at different azimuths of the depth point to determine the group delay corresponding to the depth point at different azimuths includes: Two-dimensional discrete Fourier transforms were performed on the Lamb wave full-wave waveform data received at different azimuths of the depth point to obtain the amplitude spectrum and phase spectrum corresponding to the depth point at different azimuths. Differentiate the phase spectrum at different orientations of the depth point to obtain the group delay at different orientations of the depth point.

3. The method for measuring the thickness of a cement ring according to claim 2, characterized in that, Perform a two-dimensional discrete Fourier transform on the Lamb wave full-wave waveform data received at a certain depth point and a certain orientation using the following formula: where \(F(u, v)\) is the two-dimensional discrete Fourier transform value corresponding to a certain depth point at a certain azimuth; \(f\) wave (x, y) is the Lamb wave full-wave waveform data received at a certain depth point at a certain azimuth; \(x\) and \(y\) are spatial domain coordinates, and the value ranges are \(0\leq x < M\) and \(0\leq y < N\) respectively; \(u\) and \(v\) are frequency domain coordinates, and the value ranges are \(0\leq u < M\) and \(0\leq v < N\) respectively; \(M\) is the summation sequence; \(N\) is the sequence number of the waveform data; \(j\) is a complex number.

4. The method for measuring the thickness of a cement ring according to claim 2, characterized in that, The group delay at a given depth point in a given orientation can be obtained using the following formula: Where δgroupdelay(ω) is the group delay function value corresponding to a certain depth point at a certain orientation; φ(ω) is the phase spectrum function corresponding to a certain depth point at a certain orientation.

5. The method for measuring the thickness of a cement ring according to claim 1, characterized in that, The determination of the circumferential cement ring thickness at different orientations based on the group delay at the depth point includes: Waveform analysis was performed on the group delay at different azimuths of the depth point to determine the group delay dip interval at different azimuths. Based on the group delay depression intervals corresponding to the depth point at different orientations, the circumferential cement ring thickness corresponding to the depth point at different orientations is determined.

6. The method for measuring the thickness of a cement ring according to claim 5, characterized in that, The step of performing waveform analysis on the group delay corresponding to the depth point at different azimuths to determine the group delay dip interval corresponding to the depth point at different azimuths includes: Based on the group delay function corresponding to the depth point at a certain orientation, the waveform group delay spectrum corresponding to the depth point at that orientation is obtained. Based on the waveform group delay spectrum corresponding to the depth point at this location, waveform analysis is performed to identify the maximum peak in the waveform group delay spectrum. Based on the frequency position of the maximum peak, the first trough closest to the maximum peak is determined to the left of the maximum peak, and the second trough closest to the maximum peak is determined to the right of the maximum peak. The difference between the frequency position of the second trough and the frequency position of the first trough is used to obtain the group delay depression interval corresponding to the depth point at that orientation. Repeat the above steps until the group delay depression intervals corresponding to the depth point in different orientations are obtained.

7. The method for measuring the thickness of a cement ring according to claim 5, characterized in that, The thickness of the circumferential cement sheath at a given depth point and location can be determined using the following formula: Among them, T (depth,azimuth) V represents the thickness of the circumferential cement ring at a given depth and orientation. s Δf represents the velocity of the annular medium; Δf represents the group delay depression interval corresponding to a certain depth point at a certain orientation.

8. The method for measuring the thickness of a cement ring according to claim 7, characterized in that, If the annular medium is mud, the longitudinal wave velocity of the mud is determined as the velocity of the annular medium.

9. The method for measuring the thickness of a cement ring according to claim 7, characterized in that, If the annular medium is solid cement, the transverse wave velocity of the solid cement is determined as the velocity of the annular medium.

10. The method for measuring the thickness of a cement ring according to claim 1, characterized in that, The method for measuring the thickness of the cement ring also includes: Based on the circumferential cement sheath thickness and casing outer diameter at different azimuths of a certain depth point, the inverted well diameter value is obtained. By comparing the inverted wellbore value with the wellbore logging value, it can be determined whether the measurement results of the circumferential cement sheath thickness at different azimuths of this depth point are reasonable. If the inverted wellbore value is less than the wellbore logging value, then the measurement results of the circumferential cement sheath thickness at different azimuths of the depth point are deemed reasonable, and the circumferential cement sheath thickness at different azimuths of the depth point is output. If the inverted wellbore diameter value is greater than the wellbore diameter logging value, it is determined that the measurement results of the circumferential cement sheath thickness at different azimuths of the depth point are unreasonable, and the circumferential cement sheath thickness at different azimuths of the depth point is determined again.

11. The method for measuring the thickness of a cement ring according to claim 10, characterized in that, The method of obtaining the inverted wellbore diameter value based on the circumferential cement sheath thickness and casing outer diameter at different azimuths of a certain depth point includes: By comparing the circumferential cement ring thickness at different orientations of a certain depth point, the minimum circumferential cement ring thickness value is determined. Based on the first orientation corresponding to the minimum circumferential cement ring thickness value, determine the second orientation in the cement ring that is opposite to the first orientation; The minimum circumferential cement sheath thickness value, the circumferential cement sheath thickness value corresponding to the second orientation, and the casing outer diameter are added to obtain the inverted well diameter value.

12. The method for measuring the thickness of a cement ring according to claim 1, characterized in that, The method for measuring the thickness of the cement ring also includes: Azimuth imaging is performed on the thickness of the circumferential cement ring at different azimuths for each depth point within the target depth range.

13. A cement ring thickness measuring device, characterized in that, The cement ring measuring device includes: The acquisition module is used to acquire Lamb wave full-wave waveform data received at different azimuths from a certain depth point within the target depth range. The first determining module is used to perform waveform processing on the Lamb wave full-wave waveform data received at different azimuths of the depth point, and to determine the group delay corresponding to the depth point at different azimuths. The second determining module is used to determine the circumferential cement ring thickness corresponding to the depth point in different orientations based on the group delay corresponding to the depth point in different orientations. The loop module is used to repeatedly execute the above steps until the circumferential cement ring thickness corresponding to each depth point in the target depth range at different orientations is obtained.

14. An electronic device, characterized in that, The electronic device includes a processor and a memory, the memory storing at least one computer program, which is loaded and executed by one or more of the processors to cause the processors to perform the cement ring thickness measurement method according to any one of claims 1 to 12.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one piece of program code, which is loaded and executed by a processor to cause the computer to perform the cement ring thickness measurement method according to any one of claims 1 to 12.

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