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

Abstract

The invention provides a cement sheath thickness measurement method, device and equipment and a storage medium, and belongs to the field of applied geophysics and oil-gas exploration, and the measurement method comprises the steps: obtaining full-wave waveform data of a Lamb wave received at different orientations at a certain depth point in a target depth interval; performing waveform processing on the full-wave waveform data of the Lamb wave received at different orientations of the depth point, and determining corresponding group delays of the depth point at different orientations; based on the group delays corresponding to the depth point in different orientations, circumferential cement sheath thicknesses corresponding to the depth point in different orientations are determined; and repeatedly executing the steps until the circumferential cement sheath thickness corresponding to each depth point of the target depth interval in different directions is obtained. Through the method provided by the invention, accurate calculation of the thickness of the cement sheath between the casing and the stratum can be simply and quickly realized, and the well cementation quality can be accurately evaluated.

Description

TECHNICAL FIELD

[0001] 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

[0002] With the gradual development of oil and gas exploration and development in China towards ultra-deep strata, the high temperature and high pressure environment of high pressure permeable layers can affect the cement setting process, thereby causing cement sheath defects in the cementing process, and thus affecting the strength and safety of the casing, so it is necessary to use a cementing quality evaluation method to check whether the cement sheath has defects.

[0003] In the prior art, conventional cementing quality evaluation methods such as CBL (acoustic amplitude logging), VDL (acoustic variable density logging) and the like cannot accurately evaluate the quality of cementing. SUMMARY

[0004] In view of the technical problem in the prior art that conventional cementing quality evaluation methods cannot accurately evaluate the quality of cementing, the present application provides a cement sheath thickness measurement method, which can simply and quickly achieve accurate calculation of the cement sheath thickness between the casing and the formation, and thus accurately evaluate the quality of cementing.

[0005] To achieve the above-mentioned purpose, the present application provides a cement sheath thickness measurement method, 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; 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; and 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.

[0006] In an exemplary embodiment of the present application, the 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 can comprise: performing two-dimensional discrete Fourier transform on the Lamb wave full wave waveform data received at different azimuths of the depth point respectively to obtain the amplitude spectrum and the phase spectrum corresponding to the depth point at different azimuths; and performing derivation on the phase spectrum corresponding to the depth point at different azimuths respectively to obtain the group delay corresponding to the depth point at different azimuths.

[0007] In an exemplary embodiment of the present application, the two-dimensional discrete Fourier transform on the Lamb wave full wave waveform data received at a certain azimuth of a certain depth point can be performed according to the following formula:

[0008]

[0009] wherein F(u, v) is a two-dimensional discrete Fourier transform value corresponding to a certain depth point at a certain orientation; f wave (x, y) is a Lamb wave full wave waveform data received by a certain depth point at a certain orientation; M is a summation sequence; N is a serial number of the waveform data; j is a complex number.

[0010] In an exemplary embodiment of the present application, a group delay corresponding to a certain depth point at a certain orientation can be obtained according to the following formula:

[0011]

[0012] wherein δ groupdelay (ω) is a group delay function value corresponding to a certain depth point at a certain orientation; φ(ω) is a phase spectrum function corresponding to a certain depth point at a certain orientation.

[0013] In an exemplary embodiment of the present application, the determination of the annular cement sheath thickness corresponding to the depth point at different orientations based on the group delay corresponding to the depth point at different orientations can include: performing waveform analysis on the group delay corresponding to the depth point at different orientations respectively to determine the frequency notch interval corresponding to the depth point at different orientations; determining the annular cement sheath thickness corresponding to the depth point at different orientations based on the frequency notch interval corresponding to the depth point at different orientations.

[0014] In an exemplary embodiment of the present application, the waveform analysis on the group delay corresponding to the depth point at different orientations respectively to determine the frequency notch interval corresponding to the depth point at different orientations can include: obtaining a waveform spectrum diagram corresponding to the depth point at a certain orientation based on a group delay function corresponding to the depth point at the orientation; performing waveform analysis on the waveform spectrum diagram corresponding to the depth point at the orientation to identify a maximum wave crest in the waveform spectrum diagram; determining a first wave trough adjacent to the maximum wave crest on the left side of the maximum wave crest and a second wave trough adjacent to the maximum wave crest on the right side of the maximum wave crest based on a frequency position of the maximum wave crest; obtaining the frequency notch interval corresponding to the depth point at the orientation by subtracting the frequency position of the first wave trough from the frequency position of the second wave trough; and repeating the above steps until the frequency notch interval corresponding to the depth point at different orientations is obtained.

[0015] In an exemplary embodiment of the present application, the annular cement sheath thickness corresponding to a certain depth point at a certain orientation can be determined according to the following formula:

[0016]

[0017] wherein, T (depth,azimuth) is the annular cement thickness corresponding to a certain depth point at a certain azimuth; V s is the velocity of the annulus medium; and Δf is the frequency depression interval corresponding to a certain depth point at a certain azimuth.

[0018] In an exemplary embodiment of the present application, if the annulus medium is mud, the longitudinal wave velocity of the mud can be determined as the velocity of the annulus medium.

[0019] In an exemplary embodiment of the present application, if the annulus medium is solid cement, the transverse wave velocity of the solid cement can be determined as the velocity of the annulus medium.

[0020] In an exemplary embodiment of the present application, the cement thickness measurement method can further comprise: obtaining an inverted caliper value based on the annular cement thicknesses corresponding to a certain depth point at different azimuths and the outer diameter of the casing; comparing the inverted caliper value with a caliper logging value to determine whether the annular cement thicknesses corresponding to the certain depth point at different azimuths are calculated reasonably; if the inverted caliper value is less than the caliper logging value, it is determined that the annular cement thicknesses corresponding to the certain depth point at different azimuths are calculated reasonably, and the annular cement thicknesses corresponding to the certain depth point at different azimuths are output; and if the inverted caliper value is greater than the caliper logging value, it is determined that the annular cement thicknesses corresponding to the certain depth point at different azimuths are calculated unreasonably, and the annular cement thicknesses corresponding to the certain depth point at different azimuths are determined again.

[0021] In an exemplary embodiment of the present application, the obtaining of the inverted caliper value based on the annular cement thicknesses corresponding to a certain depth point at different azimuths and the outer diameter of the casing can comprise: comparing the annular cement thicknesses corresponding to the certain depth point at different azimuths to determine a minimum annular cement thickness value; determining a second azimuth opposite to a first azimuth corresponding to the minimum annular cement thickness value; and adding the minimum annular cement thickness value, the annular cement thickness value corresponding to the second azimuth, and the outer diameter of the casing to obtain the inverted caliper value.

[0022] In an exemplary embodiment of the present application, the cement thickness measurement method can further comprise: azimuthally imaging the annular cement thicknesses corresponding to each depth point at different azimuths in a target depth interval.

[0023] A second aspect of the present invention provides a cement ring thickness measuring device, the cement ring measuring device comprising: an acquisition module for acquiring Lamb wave full-wave waveform data received at different azimuths of a depth point within a target depth range; a first determination module for 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; a second determination module for determining the circumferential cement ring thickness corresponding to the depth point at different azimuths based on the group delay corresponding to the depth point at different azimuths; and a looping module for repeatedly executing the above steps until the circumferential cement ring thickness corresponding to each depth point within the target depth range at different azimuths is obtained.

[0024] A third aspect of the present invention provides an electronic device comprising a processor and a memory, the memory storing at least one computer program, the at least one computer program being loaded and executed by one or more of the processors to cause the processors to perform the cement ring thickness measurement method as described above.

[0025] A fourth aspect of the present invention provides a computer-readable storage medium storing at least one piece of program code, which is loaded and executed by a processor to cause a computer to perform the cement ring thickness measurement method as described above.

[0026] The present invention has at least the following technical effects through the technical solution provided by the present invention:

[0027] (1) The cement sheath thickness measurement method of the present invention uses the group delay depression of the curved Lamb wave to calculate the cement sheath thickness between the casing and the formation for the first time. This method can calculate the cement sheath thickness simply and quickly, and the calculation result is relatively accurate.

[0028] (2) The cement sheath thickness measurement results obtained by the present invention can not only be used to accurately evaluate the quality of cementing, but also provide the possibility for engineering applications such as cement displacement efficiency in the field.

[0029] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0030] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0031] Figure 1 A schematic flowchart of a cement ring thickness measurement method provided in an embodiment of the present invention;

[0032] Figure 2AA schematic diagram of a cross-section of a casing well model provided in an embodiment of the present invention;

[0033] Figure 2B A schematic diagram of the propagation trajectory provided in an embodiment of the present invention;

[0034] Figure 3A This is a schematic diagram of the full-wave Lamb wave received by a near-far receiver according to an embodiment of the present invention;

[0035] Figure 3B This is a schematic diagram of the waveform spectrum obtained after performing a Fourier transform on the full-wave Lamb wave, as provided in an embodiment of the present invention.

[0036] Figure 4A A schematic diagram of the waveform spectrum of post-bonded rapid cement at different thicknesses provided in an embodiment of the present invention;

[0037] Figure 4B A schematic diagram of the waveform spectrum of post-bonded slow cement at different thicknesses provided in an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of the cement sheath thickness imaging between the casing and the formation provided in an embodiment of the present invention;

[0039] Figure 6 A schematic flowchart of another cement ring thickness measurement method provided in an embodiment of the present invention;

[0040] Figure 7 This is a schematic diagram of the structure of the cement ring thickness measuring device provided in an embodiment of the present invention;

[0041] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0042] Explanation of reference numerals in the attached figures

[0043] 101-Acquisition module, 102-First determination module, 103-Second determination module, 104-Loop module, 201-Processor, 202-Memory. Detailed Implementation

[0044] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0046] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used to describe the relative positional relationships of components in relation to the directions shown in the accompanying drawings or in relation to vertical, perpendicular, or gravitational directions. Terms such as "first" and "second" are used merely for ease of description and distinction and should not be construed as indicating or implying relative importance.

[0047] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integrated connection; they can refer to a direct connection or an indirect connection; they can refer to a wired connection or a wireless connection. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0048] In existing technologies, techniques such as acoustic amplitude logging and acoustic variable density logging are generally used to inspect for defects in the cement sheath. However, these methods do not provide accurate cement sheath thickness measurements. Considering the difficulty of accurately evaluating cementing quality using conventional methods, this invention provides a cement sheath thickness measurement method. This method involves rotating a back-casing imaging logging tool in the well to measure full-wavelength waveforms at different azimuths. The full-wavelength waveforms are then processed to obtain the group delay of a curved Lamb wave. The group delay depression of the curved Lamb wave is then used to calculate the circumferential thickness of the cement sheath between the casing and the formation. Compared to existing cement sheath thickness measurement methods, this invention can accurately calculate the circumferential thickness of the cement sheath, which is of great significance for cementing quality evaluation. In practical implementation, the above method can be executed by electronic equipment, such as servers or terminals with processing capabilities.

[0049] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings and embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0050] like Figure 1 As shown, this embodiment of the invention provides a method for measuring the thickness of a cement ring, which includes the following steps:

[0051] Step S101: Obtain Lamb wave full-wave waveform data received at different orientations from a certain depth point within the target depth range.

[0052] Specifically, assuming there are n depth points in the target depth range, where i represents the nth depth point in the target depth range, and 1 ≤ i ≤ n. When i = 1, it indicates that the ultrasonic Lamb wave logging tool is located at the first depth point in the target depth range. At this time, by rotating the ultrasonic Lamb wave logging tool once in the well according to the preset number of rotations, the full wave waveform data of the Lamb wave received at different azimuths of the first depth point in the target depth range can be obtained. Similarly, when i = 2, by rotating the ultrasonic Lamb wave logging tool once at the second depth point according to the preset number of rotations, the full wave waveform data of the Lamb wave received at different azimuths of the second depth point in the target depth range can be obtained. And so on, when i = n, by rotating the ultrasonic Lamb wave logging tool once at the nth depth point according to the preset number of rotations, the full wave waveform data of the Lamb wave received at different azimuths of the nth depth point in the target depth range can be obtained.

[0053] It should be noted that in the field of oil and gas exploration and development, ultrasonic Lamb wave logging tools are widely used for evaluating casing corrosion and cementing quality in oilfields. Ultrasonic Lamb wave logging tools utilize the attenuation of 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 unaffected by 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 into the cement sheath, and then reflected at the formation interface. These reflected signals are also received by the sensor. Therefore, the thickness of the cement sheath can be calculated using the direct and reflected Lamb wave signals, thereby evaluating the eccentricity of the casing in the wellbore.

[0054] Figure 2A A two-dimensional model of a casing well is shown. It can be seen that, from the inside out, the two-dimensional model of the casing well consists of instruments, well mud, casing, and cement sheath. The radius of the well mud (distance from the well axis) is r1, the radius of the casing (distance from the well axis) is r2, and the radius of the cement sheath (distance from the well axis) is r3. Figure 2B The acoustic wave propagation path in the casing well model is shown. It can be seen that the incident angle of the sound source emitted by the probe is θ, and the receiver receives the tortuous Lamb wave leaking from the casing at the same angle. The source distance near the receiver is y, and the distance between the near and far receivers is d. The tortuous Lamb wave logging uses an oblique incidence emission excitation and oblique incidence reception mode. The receiving source can be between 30cm and 40cm. The full-wave waveform at different azimuths is measured by rotating the logging tool behind the casing in the well. The transmission is repeated a preset number of times per rotation; for example, it can be repeated 36 times per rotation.

[0055] Step S102: Perform 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.

[0056] Specifically, the process 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 may include, but is not limited to, the following sub-steps S1021 to S1022.

[0057] In step S1021, two-dimensional discrete Fourier transform is performed on the Lamb wave full-wave waveform data received at different orientations at the i-th depth point to obtain the amplitude spectrum and phase spectrum corresponding to the i-th depth point at different orientations.

[0058] For example, a two-dimensional discrete Fourier transform can be performed on the Lamb wave full-wave waveform data received at any orientation of the i-th depth point according to formula (1).

[0059]

[0060] In the formula, F(u,v) is the two-dimensional discrete Fourier transform value of the i-th depth point at any orientation; f wave (x,y) represents the Lamb wave full-wave waveform data received at any orientation of the i-th depth point; M is the summation sequence; N is the sequence number of the waveform data; j is a complex number.

[0061] Figure 3A The diagram shows the full Lamb wave waveform received by near and far receivers positioned at a specific depth point within the target depth range. Figure 3B The amplitude spectrum of the Lamb wave full-wave waveform is shown by performing a two-dimensional discrete Fourier transform on the full-wave waveform.

[0062] In step S1022, the phase spectrum of the i-th depth point at different orientations is differentiated to obtain the group delay of the i-th depth point at different orientations.

[0063] For example, the group delay corresponding to the i-th depth point at a certain orientation can be obtained according to formula (2).

[0064]

[0065] In the formula, δ groupdelay φ(ω) is the group delay function value corresponding to the i-th depth point at a certain orientation; φ(ω) is the phase spectrum function corresponding to the i-th depth point at a certain orientation.

[0066] Of course, the present invention is not limited to this. Other methods, such as wavelet transform, can also be used to process the Lamb wave full-wave waveform data to obtain the amplitude spectrum and phase spectrum of the full-wave waveform.

[0067] Step S103: Based on the group delay corresponding to the depth point at different orientations, determine the circumferential cement ring thickness corresponding to the depth point at different orientations.

[0068] Specifically, the process of determining the circumferential cement sheath thickness corresponding to the depth point at different azimuths based on the group delay corresponding to the depth point at different azimuths may include but is not limited to the following sub-steps S1031 to sub-step S1032.

[0069] In sub-step S1031, perform waveform analysis on the group delays corresponding to the i-th depth point at different azimuths respectively, and determine the frequency depression intervals corresponding to the i-th depth point at different azimuths.

[0070] In sub-step S1032, based on the frequency depression intervals corresponding to the i-th depth point at different azimuths, determine the circumferential cement sheath thickness corresponding to the i-th depth point at different azimuths.

[0071] For example, the circumferential cement sheath thickness corresponding to the i-th depth point at a certain azimuth can be determined according to formula (3).

[0072]

[0073] In the formula, T (depth,azimuth) is the circumferential cement sheath thickness corresponding to the i-th depth point at a certain azimuth; V s is the velocity of the annulus medium; Δf is the frequency depression interval corresponding to the i-th depth point at a certain azimuth.

[0074] Step S104, repeatedly execute the above steps S101 to step S103 until the circumferential cement sheath thicknesses corresponding to each depth point in the target depth interval at different azimuths are obtained.

[0075] Specifically, after obtaining the measurement results of the circumferential cement sheath thickness corresponding to the i-th depth point at different azimuths, judge whether 1 ≤ i < n is satisfied. If it is satisfied, jump to step S101 and continue to calculate the circumferential cement sheath thickness corresponding to the (i + 1)-th depth point at different azimuths. If it is not satisfied, the calculation ends and the measurement results of the circumferential cement sheath thicknesses corresponding to each depth point in the target depth interval at different azimuths are output.

[0076] Furthermore, in a possible implementation manner, in sub-step S1031, the process of performing waveform analysis on the group delays corresponding to the i-th depth point at different azimuths respectively and determining the frequency depression intervals corresponding to the i-th depth point at different azimuths may include but is not limited to the following sub-steps S10311 to sub-step S10315.

[0077] In sub-step S10311, based on the group delay function corresponding to the i-th depth point at the k-th azimuth, obtain the waveform frequency spectrum diagram corresponding to the i-th depth point at the k-th azimuth.

[0078] Specifically, assume that the preset number of times is m, that is, the ultrasonic Lamb wave logging tool 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 at the k-th azimuth in the circumferential direction, and 1 ≤ k ≤ m. When the ultrasonic Lamb wave logging tool is at the i-th depth point in the target depth interval, when k = 1, it means that the ultrasonic Lamb wave logging tool is at the first azimuth of the i-th depth point; when k = 2, it means that the ultrasonic Lamb wave logging tool is at the second azimuth of the i-th depth point; and so on. When k = m, it means that the ultrasonic Lamb wave logging tool is at the m-th azimuth of the i-th depth point.

[0079] By processing the group delay function corresponding to the i-th depth point at the k-th azimuth, the waveform spectrum diagram corresponding to the i-th depth point at the k-th azimuth can be obtained.

[0080] Sub-step S10312: Perform waveform analysis based on the waveform spectrum diagram corresponding to the i-th depth point at the k-th azimuth, and identify the maximum wave peak in this waveform spectrum diagram.

[0081] For example, the maximum wave peak can be identified by finding the highest peak in the waveform spectrum diagram, and the frequency position of the maximum wave peak can be located through the abscissa of the waveform spectrum diagram.

[0082] Sub-step S10313: Based on the frequency position of the maximum wave peak, determine the first wave valley closest to the maximum wave peak on the left side of the maximum wave peak, and determine the second wave valley closest to the maximum wave peak on the right side of the maximum wave peak.

[0083] Sub-step S10314: Subtract the frequency position of the second wave valley from the frequency position of the first wave valley to obtain the frequency depression interval corresponding to the i-th depth point at the k-th azimuth.

[0084] Sub-step S10315: Repeat the above sub-steps S10311 to S10314 until the frequency depression intervals corresponding to the i-th depth point at different azimuths are obtained.

[0085] Specifically, after obtaining the frequency depression interval corresponding to the i-th depth point at the k-th azimuth, it is judged whether 1 ≤ k < m is satisfied. If it is satisfied, jump to sub-step S10311 to continue calculating the frequency depression interval corresponding to the i-th depth point at the (k + 1)-th azimuth. If it is not satisfied, the calculation is terminated, and the frequency depression intervals corresponding to the i-th depth point at different azimuths are output.

[0086] Figure 4A The waveform spectrum diagrams of the post-casing cementing fast cement under different thicknesses are shown. Figure 4B The waveform spectrum diagrams of the post-casing cementing slow cement under different thicknesses are shown. By analyzing Figure 4A andFigure 4B It can be seen that as the thickness of the cement sheath increases, the interval between frequency depressions (i.e., the frequency depression interval) gradually decreases. When fast cement is bonded between the casing and the formation, only leaked shear waves are present in the cement, and only reflected shear waves are present at the cement-formation interface. The amplitude spectrum exhibits good periodicity. Therefore, the thickness of the cement sheath can be directly estimated using the size of the interval between frequency depressions. When slow cement is bonded between the casing and the formation, both P-waves and S-waves leak into the cement sheath. Both types of waves undergo mode conversion when they reach the cement-formation interface. The types of reflected waves include P-wave-P-wave, P-wave-S-wave, S-wave-P-wave, and S-wave-S-wave. Comparing the amplitude spectrum of the full wave of the slow cement with that of the fast cement reveals that the number of frequency depression positions in the amplitude spectrum of the slow cement increases, but it is still evident that the interval between frequency depressions decreases significantly with increasing cement sheath thickness. Furthermore, by comparing the peak frequencies of the amplitude spectra at different thicknesses, it can be found that the peak frequencies gradually decrease with decreasing cement sheath thickness.

[0087] Furthermore, in one possible implementation, in step S1032, if the annular medium is mud, the longitudinal wave velocity of the mud can be determined as the velocity V of the annular medium. f If the annular medium is solid cement, the transverse wave velocity of the solid cement can be determined as the velocity V of the annular medium. f .

[0088] Furthermore, in one possible implementation, the cement ring thickness measurement method further includes step S105, which involves performing azimuth imaging on the circumferential cement ring thickness corresponding to each depth point in the target depth range at different azimuth positions.

[0089] For example, Figure 5 A schematic diagram of the cement sheath thickness imaging between the casing and the formation is shown. It can be seen that the cement sheath thickness measurement method provided by the embodiments of the present invention provides the possibility for engineering applications such as cement replacement efficiency in the field.

[0090] like Figure 6 As shown in the figure, this embodiment of the invention also provides another method for measuring the thickness of a cement ring, which includes the following steps:

[0091] Step S201: Obtain Lamb wave full-wave waveform data received at different orientations from a certain depth point within the target depth range.

[0092] Specifically, step S101 in the above embodiment can be used to obtain the Lamb wave full-wave waveform data received at different orientations at the i-th depth point, which will not be elaborated here.

[0093] Step S202: Perform waveform processing on the Lamb wave full-wave waveform data received at different azimuths of this depth point, and determine the group delay corresponding to this depth point at different azimuths.

[0094] Specifically, refer to step S102 in the above embodiment to determine the group delay corresponding to the i-th depth point at different azimuths, which will not be elaborated here.

[0095] Step S203: Based on the group delay corresponding to this depth point at different azimuths, determine the circumferential cement sheath thickness corresponding to this depth point at different azimuths.

[0096] Specifically, refer to step S103 in the above embodiment to determine the circumferential cement sheath thickness corresponding to the i-th depth point at different azimuths, which will not be elaborated here.

[0097] Step S204: Compare the inverted wellbore diameter value with the wellbore diameter logging value to verify whether the measurement results of the circumferential cement sheath thickness corresponding to this depth point at different azimuths are reasonable.

[0098] Specifically, first obtain the inverted wellbore diameter value C according to the circumferential cement sheath thickness and the casing outer diameter corresponding to the i-th depth point at different azimuths. Then compare the inverted wellbore diameter value C with the wellbore diameter logging value C0. If the inverted wellbore diameter value C is less than the wellbore diameter logging value C0, it means that the measurement results of the circumferential cement sheath thickness corresponding to the i-th depth point at different azimuths are reasonable, and at this time, output the circumferential cement sheath thickness corresponding to the i-th depth point at different azimuths; if the inverted wellbore diameter value C is greater than the wellbore diameter logging value C0, it means that the measurement results of the circumferential cement sheath thickness corresponding to the i-th depth point at different azimuths are unreasonable, and at this time, the velocity V of the annulus medium should be adjusted f , and return to step S203, and recalculate the circumferential cement sheath thickness corresponding to the i-th depth point at different azimuths by using the adjusted velocity V of the annulus medium f recalculate the circumferential cement sheath thickness corresponding to the i-th depth point at different azimuths.

[0099] Step S205: Repeat the above steps S201 to S204 until the circumferential cement sheath thicknesses corresponding to each depth point in the target depth interval at different azimuths are obtained.

[0100] Specifically, after obtaining the measurement results of the circumferential cement sheath thickness corresponding to the i-th depth point at different azimuths, determine whether 1 ≤ i < n is satisfied. If it is satisfied, jump to step S201 to continue calculating the circumferential cement sheath thickness corresponding to the i + 1-th depth point at different azimuths. If it is not satisfied, the calculation terminates, and output the measurement results of the circumferential cement sheath thicknesses corresponding to each depth point in the target depth interval at different azimuths. In this way, by using the wellbore diameter logging value C0 to verify the measurement results of the circumferential cement sheath thickness, the measurement accuracy of the circumferential cement sheath thickness can be further ensured.

[0101] Furthermore, in one possible implementation, step S204, the process of obtaining the inverted well diameter value based on the circumferential cement sheath thickness and casing outer diameter corresponding to the i-th depth point at different orientations, can be refined into the following process:

[0102] (1) Compare the thickness of the circumferential cement ring at different orientations of the i-th depth point to determine the minimum circumferential cement ring thickness value T1;

[0103] (2) Based on the first orientation corresponding to the minimum circumferential cement ring thickness value T1, determine the second orientation in the cement ring that is opposite to the first orientation;

[0104] (3) Add the minimum circumferential cement sheath thickness value T1 and the circumferential cement sheath thickness value T2 corresponding to the second orientation to the outer diameter of the casing to obtain the inverted well diameter value C.

[0105] Furthermore, in one possible implementation, the cement ring thickness measurement method further includes step S206, which involves performing azimuth imaging on the circumferential cement ring thickness corresponding to each depth point in the target depth range at different azimuth positions.

[0106] Furthermore, the implementation environment of this embodiment includes at least one terminal and one server, and the method is executed on the terminal or the server respectively. The terminal and the server can establish a communication connection to achieve interactive information transmission.

[0107] The terminal can be any electronic product that can interact with the user through one or more methods such as keyboard, touchpad, touch screen, voice interaction, etc., such as PC (Personal Computer), PPC (Pocket Personal Computer), tablet computer, etc.

[0108] A server can be a single server, a server cluster consisting of multiple servers, or a cloud server that provides basic cloud computing services such as 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 big data and artificial intelligence platforms.

[0109] like Figure 7 As shown, this embodiment of the invention also provides a cement ring thickness measuring device, which includes an acquisition module 101, a first determination module 102, a second determination module 103, and a circulation module 104.

[0110] The acquisition module 101 is used to acquire Lamb wave full-wave waveform data received at different orientations at a certain depth point in the target depth range.

[0111] The first determining module 102 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.

[0112] The second determining module 103 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.

[0113] The loop module 104 is used to repeatedly execute the process of acquiring Lamb wave full-wave waveform data received at different orientations at a certain depth point until the thickness of the circumferential cement ring corresponding to the depth point at different orientations is determined, until the thickness of the circumferential cement ring corresponding to each depth point in the target depth range at different orientations is obtained.

[0114] It should be noted that the above-described device is only illustrated by the division of the functional modules described above. In practical applications, the functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. Furthermore, the device and method provided in the above embodiments belong to the same concept, and their specific implementation process can be found in the method embodiments, which will not be repeated here.

[0115] like Figure 8 As shown, this embodiment of the invention also provides an electronic device, which includes a processor 201 and a memory 202. The memory stores at least one computer program, which is loaded and executed by one or more of the processors to enable the processors to implement the cement ring thickness measurement method in the above embodiments.

[0116] Of course, the electronic device may also have wired or wireless network interfaces, keyboards, and input / output interfaces for input and output. The electronic device may also include other components for implementing the various functions of the device, which will not be elaborated here.

[0117] This invention also provides a computer-readable storage medium storing at least one piece of program code, which is loaded and executed by a processor to enable a computer to implement the cement ring thickness measurement method described in the above embodiments.

[0118] Optionally, the computer-readable storage medium may 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, or an optical disc data storage device, etc. Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in each embodiment of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc.

[0119] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0120] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0121] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

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 of a point at a certain depth at a certain orientation; f wave (x,y) represents the Lamb wave full-wave waveform data received at a certain depth point in a certain orientation; 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, δ groupdelay φ(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 frequency dip interval at different azimuths of the depth point. Based on the frequency recess intervals corresponding to the depth point at different orientations, the thickness of the circumferential cement ring 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 frequency 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 spectrum corresponding to the depth point at that orientation is obtained. Based on the waveform spectrum diagram corresponding to the depth point at this location, waveform analysis is performed to identify the maximum peak in the waveform spectrum diagram. 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 frequency position of the second trough is subtracted from the frequency position of the first trough to obtain the frequency dip interval corresponding to the depth point in that orientation. Repeat the above steps until the frequency dip 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 frequency dip 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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