Method and system for evaluating cementation quality of second interface of cement sheath

Abstract

The invention provides a cement sheath second interface cementation quality evaluation method and system, and relates to the field of well cementation, and the control method comprises the steps: determining an evaluation reference value of a reference depth point of a cement sheath based on post-casing imaging logging data of the cement sheath; then determining an evaluation depth section of the cement sheath, and performing cementation evaluation on each evaluation direction of each evaluation depth point of the evaluation depth section in the circumferential direction of the cement sheath by using the evaluation reference value and post-casing imaging logging data to obtain a direction evaluation result; and obtaining a cement sheath second interface orientation cementation imaging graph based on all orientation evaluation results, and evaluating the cement sheath second interface cementation quality by using the cement sheath second interface orientation cementation imaging graph. According to the cement sheath second interface cementation quality evaluation method provided by the invention, cementation quality evaluation can be carried out on the cement sheath second interface at different depths and different directions, and cementation imaging of the second interface is realized.

Description

Technical Field

[0001] The present invention relates to the field of cementing technology, and in particular to a method for evaluating the second interface bonding quality of a cement sheath, a device for evaluating the second interface bonding quality of a cement sheath, a computer device, a computer-readable storage medium, and a computer program product. Background Art

[0002] Cementing is a critical step in oil and gas well drilling and completion operations. After drilling is complete, pre-prepared casing is lowered into the well and cement slurry is injected to fill the gap between the casing and the wellbore. This secures the casing and prevents it from shifting or collapsing due to formation pressure or wellbore fluid pressure, ensuring the stability and safety of the well. Furthermore, cement slurry injection isolates different formations below the well, such as oil, gas, and water, preventing them from interfering with each other, ensuring that oil and gas can flow smoothly through the casing or that water can be injected into the designated formation. The quality of cementing is crucial to the lifespan of the oil and gas well, safe production, and overall profitability.

[0003] To accurately evaluate cementing quality, conventional acoustic logging is often used. This method uses the amplitude or attenuation of acoustic waves propagating along the casing to assess the bond strength between the casing and cement (the primary interface) and between the cement and the formation (the secondary interface). However, conventional acoustic variable density logging lacks the ability to identify sectors when evaluating the cement sheath secondary interface bond strength. It can only provide a qualitative assessment of the bond strength and is unable to identify channeling at the cement sheath secondary interface in the wellbore. Summary of the Invention

[0004] In response to the technical problem that the existing technology cannot evaluate the bonding quality of the second interface of the cement sheath, the present invention provides a method for evaluating the bonding quality of the second interface of the cement sheath, a device for evaluating the bonding quality of the second interface of the cement sheath, a computer device, a computer-readable storage medium and a computer program product. Using the method for evaluating the bonding quality of the second interface of the cement sheath, the bonding quality of the second interface of the cement sheath can be evaluated at different depths and different orientations, thereby realizing bonding imaging of the second interface.

[0005] To achieve the above-mentioned objectives, the first aspect of the present invention provides a method for evaluating the bonding quality of the second interface of a cement sheath, the method comprising: determining an evaluation reference value of a reference depth point of the cement sheath based on post-casing imaging logging data of the cement sheath; determining an evaluation depth segment of the cement sheath, and using the evaluation reference value and the post-casing imaging logging data to perform bonding evaluation on each evaluation depth point of the evaluation depth segment in each evaluation orientation in the circumferential direction of the cement sheath to obtain an azimuth evaluation result; wherein the evaluation depth segment includes multiple evaluation depth points, and each evaluation depth point includes multiple evaluation orientations in the circumferential direction of the cement sheath; determining an azimuth evaluation result of the evaluation orientation based on the comparison result; obtaining an azimuth bonding imaging map of the second interface of the cement sheath based on the azimuth evaluation results of all evaluation depth points in all evaluation orientations in the circumferential direction of the cement sheath, and using the azimuth bonding imaging map of the second interface of the cement sheath to evaluate the bonding quality of the second interface of the cement sheath.

[0006] Furthermore, the following steps are adopted to perform bonding evaluation on a certain evaluation depth point in a certain evaluation orientation in the circumferential direction of the cement sheath using the evaluation reference value and the post-casing imaging logging data: extracting the full-wave waveform of the evaluation orientation from the post-casing imaging logging data; performing spectral analysis on the full-wave waveform of the evaluation orientation to obtain an evaluation orientation amplitude spectrum; obtaining an azimuth evaluation value based on the evaluation azimuth amplitude spectrum; comparing the azimuth evaluation value and the evaluation reference value to obtain a comparison result; and determining the azimuth evaluation result of the evaluation orientation based on the comparison result.

[0007] Furthermore, the method also includes: obtaining acoustic variable density logging data of the cement sheath; determining the logging data with the weakest casing wave and the strongest formation wave from the acoustic variable density logging data, and using the depth point corresponding to the logging data as the reference depth point.

[0008] Furthermore, the evaluation reference value is used to characterize the bonding quality of the reference depth point; the evaluation reference value of the reference depth point of the cement sheath is determined based on the post-casing imaging logging data of the cement sheath, including: extracting the multi-azimuth full-wave waveform of the reference depth point from the post-casing imaging logging data; and determining the evaluation reference value based on the multi-azimuth full-wave waveform of the reference depth point.

[0009] Furthermore, the determining of the evaluation reference value based on the multi-azimuth full-wave waveform of the reference depth point includes: performing spectral analysis on the multi-azimuth full-wave waveform of the reference depth point to obtain reference amplitude spectra in multiple directions; determining an amplitude minimum spectrum from the reference amplitude spectra in multiple directions; and determining the evaluation reference value based on the amplitude minimum spectrum.

[0010] Furthermore, the determining of the evaluation reference value based on the amplitude minimum amplitude spectrum includes: determining two minimum frequencies adjacent to a first center frequency; wherein the first center frequency is the center frequency of the amplitude minimum amplitude spectrum; respectively determining minimum amplitude values ​​corresponding to the two minimum frequencies; obtaining an initial evaluation reference value based on the sum of the minimum amplitude values ​​corresponding to the two minimum frequencies; obtaining the evaluation reference value based on the initial evaluation reference value: Sum ref =k Sum0; where Sum ref is the evaluation reference value, Sum0 is the initial evaluation reference value, and k is a constant.

[0011] Furthermore, the azimuth evaluation value is obtained based on the evaluation azimuth amplitude spectrum, including: flipping the evaluation azimuth amplitude spectrum to obtain a flipped evaluation azimuth amplitude spectrum; determining a plurality of flipped maxima and a plurality of frequency points corresponding to the flipped maxima from the flipped evaluation azimuth amplitude spectrum; screening out two extreme frequency points adjacent to the second center frequency from the plurality of frequency points corresponding to the flipped maxima; wherein the second center frequency is the center frequency of the flipped evaluation azimuth amplitude spectrum; determining extreme amplitude values ​​corresponding to the two extreme frequency points in the evaluation azimuth amplitude spectrum; and obtaining the azimuth evaluation value based on the sum of the extreme amplitude values ​​corresponding to the two extreme frequency points.

[0012] Furthermore, the orientation evaluation result of the evaluation orientation is determined based on the comparison result, including: if the orientation evaluation value is greater than the evaluation reference value, determining that the evaluation orientation has poor bonding; if the orientation evaluation value is less than or equal to the evaluation reference value, determining that the evaluation orientation has good bonding.

[0013] According to a second aspect of the present invention, there is provided a cement sheath second interface bonding quality evaluation device, the cement sheath second interface bonding quality evaluation device comprising: an evaluation reference value determination module for determining an evaluation reference value of a reference depth point of the cement sheath based on post-casing imaging logging data of the cement sheath; an azimuth evaluation result determination module for determining an evaluation depth segment of the cement sheath, and performing bonding evaluation on each evaluation depth point of the evaluation depth segment in each evaluation azimuth in the circumferential direction of the cement sheath using the evaluation reference value and the post-casing imaging logging data to obtain an azimuth evaluation result; wherein the evaluation depth segment includes multiple evaluation depth points, and each evaluation depth point includes multiple evaluation azimuths in the circumferential direction of the cement sheath; a bonding quality evaluation result determination module for obtaining an azimuth bonding imaging map of the cement sheath second interface based on the azimuth evaluation results of all evaluation depth points in all evaluation azimuths in the circumferential direction of the cement sheath, and evaluating the bonding quality of the cement sheath second interface using the azimuth bonding imaging map of the cement sheath second interface.

[0014] A third aspect of the present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the cement sheath second interface bonding quality evaluation method described above.

[0015] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for evaluating the second interface bonding quality of the cement sheath as described above.

[0016] A fifth aspect of the present invention provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of the method for evaluating the bonding quality of the second interface of the cement sheath as described above.

[0017] The technical solution provided by the present invention has at least the following technical effects:

[0018] The method for evaluating the bonding quality of the cement sheath second interface of the present invention first determines the evaluation reference value of the reference depth point of the cement sheath based on the post-casing imaging logging data of the cement sheath. Then, the evaluation depth section of the cement sheath is determined, and the evaluation reference value and the post-casing imaging logging data are used to perform a bonding evaluation on each evaluation depth point of the evaluation depth section in each evaluation orientation in the circumferential direction of the cement sheath to obtain an azimuth evaluation result. Based on the azimuth evaluation results of all evaluation depth points in all evaluation orientations in the circumferential direction of the cement sheath, an azimuth bonding imaging map of the cement sheath second interface is obtained, and the azimuth bonding imaging map of the cement sheath second interface is used to evaluate the bonding quality of the cement sheath second interface. Through the method for evaluating the bonding quality of the cement sheath second interface provided by the present invention, it is possible to evaluate the bonding quality of the cement sheath second interface at different depths and different orientations, and realize bonding imaging of the second interface.

[0019] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0021] Figure 1 A flowchart of a method for evaluating the bonding quality of the second interface of a cement sheath provided in an embodiment of the present invention;

[0022] Figure 2 The full-wave waveform amplitude spectrum of the rapid cement after casing bonding in a cement sheath second interface bonding quality evaluation method provided by an embodiment of the present invention;

[0023] Figure 3The full-wave waveform amplitude spectrum of the slow cement after casing bonding in a cement sheath second interface bonding quality evaluation method provided by an embodiment of the present invention;

[0024] Figure 4 An azimuth bonding imaging diagram of the second interface of the cement sheath in a method for evaluating the bonding quality of the second interface of the cement sheath provided in an embodiment of the present invention;

[0025] Figure 5 A schematic diagram of a cement sheath second interface bonding quality evaluation device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The following describes the specific implementation of the embodiment of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiment of the present invention and is not used to limit the embodiment of the present invention.

[0027] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0028] In the present invention, unless otherwise specified, directional words such as "up, down, top, bottom" are usually used to describe the relative positions of components in the directions shown in the drawings or in the vertical, perpendicular or gravity directions.

[0029] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0030] Please refer to Figure 1-Figure 4 An embodiment of the present invention provides a method for evaluating the bonding quality of a cement sheath second interface. The method comprises: step S101: determining an evaluation reference value of a reference depth point of the cement sheath based on post-casing imaging logging data of the cement sheath; step S102: determining an evaluation depth segment of the cement sheath, and using the evaluation reference value and the post-casing imaging logging data to perform bonding evaluation on each evaluation depth point of the evaluation depth segment in each evaluation azimuth in the circumferential direction of the cement sheath to obtain an azimuth evaluation result; wherein the evaluation depth segment includes multiple evaluation depth points, and each evaluation depth point includes multiple evaluation azimuths in the circumferential direction of the cement sheath; step S103: obtaining an azimuth bonding imaging map of the cement sheath second interface based on the azimuth evaluation results of all evaluation depth points in all evaluation azimuths in the circumferential direction of the cement sheath, and evaluating the bonding quality of the cement sheath second interface using the azimuth bonding imaging map of the cement sheath second interface.

[0031] First, step S101 is performed: determining an evaluation reference value of a reference depth point of the cement sheath based on the post-casing imaging logging data of the cement sheath.

[0032] Furthermore, the method also includes: obtaining acoustic variable density logging data of the cement sheath; determining the logging data with the weakest casing wave and the strongest formation wave from the acoustic variable density logging data, and using the depth point corresponding to the logging data as the reference depth point.

[0033] Specifically, in this embodiment of the present invention, acoustic variable density logging data of the cement sheath is first acquired. The logging data where the casing wave is weakest and the formation wave is strongest is determined from the acoustic variable density logging data, and the depth of this logging data is used as the reference depth. The cement sheath exhibits good bonding at the depth where the casing wave is weakest and the formation wave is strongest. Therefore, this depth is used as the reference depth. Subsequently, azimuth evaluation values ​​at other locations are compared with the evaluation reference value at this reference depth to determine whether the cement sheath is bonded well at that location.

[0034] Furthermore, the evaluation reference value is used to characterize the bonding quality of the reference depth point; the evaluation reference value of the reference depth point of the cement sheath is determined based on the post-casing imaging logging data of the cement sheath, including: extracting the multi-azimuth full-wave waveform of the reference depth point from the post-casing imaging logging data; and determining the evaluation reference value based on the multi-azimuth full-wave waveform of the reference depth point.

[0035] Furthermore, the determining of the evaluation reference value based on the multi-azimuth full-wave waveform of the reference depth point includes: performing spectral analysis on the multi-azimuth full-wave waveform of the reference depth point to obtain reference amplitude spectra in multiple directions; determining an amplitude minimum spectrum from the reference amplitude spectra in multiple directions; and determining the evaluation reference value based on the amplitude minimum spectrum.

[0036] Furthermore, the determining of the evaluation reference value based on the amplitude minimum amplitude spectrum includes: determining two minimum frequencies adjacent to a first center frequency; wherein the first center frequency is the center frequency of the amplitude minimum amplitude spectrum; respectively determining minimum amplitude values ​​corresponding to the two minimum frequencies; obtaining an initial evaluation reference value based on the sum of the minimum amplitude values ​​corresponding to the two minimum frequencies; obtaining the evaluation reference value based on the initial evaluation reference value: Sum ref =k Sum0; where Sum ref is the evaluation reference value, Sum0 is the initial evaluation reference value, and k is a constant.

[0037] Specifically, in an embodiment of the present invention, after-casing imaging logging data for a cement pipe is acquired. This data includes Ultrasonic Lamb Wave Imaging Logs (UCCS) and Schlumberger Ultrasonic After-Casing Logs (IBC). Multi-azimuth full-wave waveforms are extracted from the after-casing imaging logging data at a reference depth point. In this embodiment, the reference depth points include 36 azimuths in the circumferential direction. Spectral analysis is performed on the multi-azimuth full-wave waveforms to obtain reference amplitude spectra for multiple azimuths. The maximum amplitude of the reference amplitude spectrum for each azimuth is determined, the minimum of the multiple maximum amplitudes is selected, and the minimum amplitude spectrum corresponding to the maximum amplitude is selected. Based on the minimum amplitude spectrum, an evaluation reference value is determined. The evaluation reference value is used to characterize the cementation quality at the reference depth point. At the same depth point, the cement sheath bond quality varies for different azimuths. Therefore, after determining the reference depth point, the azimuth with the best bond quality at that depth point is selected. The azimuth evaluation values ​​of other azimuths are compared with the evaluation reference value for that azimuth to determine whether the cement sheath bond quality at other azimuths is good.

[0038] After determining the minimum amplitude spectrum, determine the center frequency (first center frequency) of the minimum amplitude spectrum, select adjacent minimum points (minimum frequencies) on the left and right sides of the first center frequency, determine the minimum amplitude value corresponding to the minimum frequency, and then add the two minimum amplitude values ​​to obtain the initial evaluation reference value Sum0. Determine the evaluation reference value Sum ref :Sum ref =k Sum0, k is a constant, and in this embodiment, k=1.2.

[0039] Then, step S102 is executed: determining the evaluation depth section of the cement sheath, and using the evaluation reference value and the post-casing imaging logging data to perform a bonding evaluation on each evaluation depth point of the evaluation depth section in each evaluation orientation in the circumferential direction of the cement sheath to obtain an orientation evaluation result; wherein, the evaluation depth section includes multiple evaluation depth points, and each evaluation depth point includes multiple evaluation orientations in the circumferential direction of the cement sheath.

[0040] Furthermore, the following steps are adopted to perform bonding evaluation on a certain evaluation depth point in a certain evaluation orientation in the circumferential direction of the cement sheath using the evaluation reference value and the post-casing imaging logging data: extracting the full-wave waveform of the evaluation orientation from the post-casing imaging logging data; performing spectral analysis on the full-wave waveform of the evaluation orientation to obtain an evaluation orientation amplitude spectrum; obtaining an azimuth evaluation value based on the evaluation azimuth amplitude spectrum; comparing the azimuth evaluation value and the evaluation reference value to obtain a comparison result; and determining the azimuth evaluation result of the evaluation orientation based on the comparison result.

[0041] Furthermore, the azimuth evaluation value is obtained based on the evaluation azimuth amplitude spectrum, including: flipping the evaluation azimuth amplitude spectrum to obtain a flipped evaluation azimuth amplitude spectrum; determining a plurality of flipped maxima and a plurality of frequency points corresponding to the flipped maxima from the flipped evaluation azimuth amplitude spectrum; screening out two extreme frequency points adjacent to the second center frequency from the plurality of frequency points corresponding to the flipped maxima; wherein the second center frequency is the center frequency of the flipped evaluation azimuth amplitude spectrum; determining extreme amplitude values ​​corresponding to the two extreme frequency points in the evaluation azimuth amplitude spectrum; and obtaining the azimuth evaluation value based on the sum of the extreme amplitude values ​​corresponding to the two extreme frequency points.

[0042] Specifically, in an embodiment of the present invention, an evaluation depth section for the cement sheath requiring bonding quality evaluation is selected based on actual needs. This evaluation depth section includes multiple continuous evaluation depth points, each of which includes multiple evaluation orientations of the cement sheath in the circumferential direction. In this embodiment, the same depth point includes 36 orientations in the circumferential direction. When evaluating the bonding quality in the evaluation depth section, it is necessary to use the evaluation reference value and post-casing imaging logging data to perform a bonding quality evaluation on each evaluation orientation at each evaluation depth point to obtain an azimuth evaluation result. The azimuth evaluation results of all evaluation orientations at all evaluation depth points are then integrated to obtain the evaluation results of the evaluation depth section, forming an azimuth bonding imaging map of the second interface of the cement sheath.

[0043] The specific steps for performing a bonding evaluation on a certain evaluation depth point in the evaluation depth section at a certain evaluation orientation in the circumferential direction of the cement sheath are as follows: extracting the full-wave waveform of the evaluation orientation from the post-casing imaging logging data, performing spectrum analysis on the full-wave waveform of the evaluation orientation, and obtaining an evaluation orientation amplitude spectrum. The evaluation orientation amplitude spectrum is flipped to obtain a flipped evaluation orientation amplitude spectrum, and multiple flipped maxima and multiple frequency points corresponding to the flipped maxima are determined from the flipped evaluation orientation amplitude spectrum. The center frequency of the flipped evaluation orientation amplitude spectrum (i.e., the evaluation orientation amplitude spectrum) is determined, and the frequency points on the left and right sides of the center frequency, i.e., the extreme frequency points, are selected from the multiple frequency points. The extreme amplitude values ​​corresponding to the two extreme frequency points are determined in the evaluation orientation amplitude spectrum, and then the two extreme amplitude values ​​are added to obtain the azimuth evaluation value of the evaluation orientation. In this embodiment, the azimuth evaluation value can be calculated using MATLAB technology.

[0044] After determining the azimuth evaluation value of the evaluation position, the azimuth evaluation value of the next evaluation position at the same depth is calculated according to the above method until the azimuth evaluation values ​​of all evaluation positions at the same depth are calculated. Then, the azimuth evaluation values ​​of all evaluation positions at the next depth are calculated until the azimuth evaluation values ​​of all evaluation positions at all depths in the evaluation depth segment are calculated.

[0045] In one possible implementation, 420-460 m is selected as the evaluation depth range to be evaluated. A random depth point, such as 425 m, is selected within the evaluation depth range. The azimuth evaluation value of the first evaluation position at 425 m is calculated according to the above method. The azimuth evaluation value of the second evaluation position is then calculated, and this process continues until the azimuth evaluation values ​​for all 36 evaluation positions are calculated. The azimuth evaluation values ​​for the 36 positions at 426 m are then calculated, and so on, until the azimuth evaluation values ​​for all positions at all depths between 420 and 460 m are calculated.

[0046] According to the cement sheath second interface bonding quality evaluation method provided by the embodiment of the invention, the azimuth evaluation value can be determined by flipping processing, thereby avoiding the error caused by curve fluctuation in the process of directly calculating the minimum value in the evaluation azimuth amplitude spectrum, and improving the calculation accuracy of the azimuth evaluation value.

[0047] Furthermore, the orientation evaluation result of the evaluation orientation is determined based on the comparison result, including: if the orientation evaluation value is greater than the evaluation reference value, determining that the evaluation orientation has poor bonding; if the orientation evaluation value is less than or equal to the evaluation reference value, determining that the evaluation orientation has good bonding.

[0048] Specifically, in an embodiment of the present invention, after calculating the evaluation reference value of the evaluation orientation, the evaluation reference value is compared with the evaluation reference value. If the orientation evaluation value is greater than the evaluation reference value, it indicates that the evaluation orientation is poorly bonded, and the evaluation orientation is marked as 1 in the cement sheath second interface orientation bonding imaging map; if the orientation evaluation value is less than or equal to the evaluation reference value, it indicates that the evaluation orientation is well bonded, and the evaluation orientation is marked as 0 in the cement sheath second interface orientation bonding imaging map.

[0049] Finally, step S103 is executed: based on the azimuth evaluation results of all evaluation orientations of all evaluation depth points in the circumferential direction of the cement sheath, an azimuth bonding imaging diagram of the second interface of the cement sheath is obtained, and the azimuth bonding imaging diagram of the second interface of the cement sheath is used to evaluate the bonding quality of the second interface of the cement sheath.

[0050] Specifically, in this embodiment of the present invention, the azimuth evaluation results for all evaluation depths at all evaluation orientations along the circumferential direction of the cement sheath are plotted on a graph to produce an azimuth bond image of the cement sheath's second interface. This azimuth bond image provides an intuitive understanding of the cement sheath's bond quality at each evaluation depth.

[0051] Please refer to Figure 2-4 In one possible implementation, the above method is used to evaluate the bonding quality of the cement sheath at a depth of 400-460 m. Figure 4This is an azimuthal bonding imaging diagram of the second interface of the cement sheath of fast cement. In ultrasonic Lamb wave logging, its oblique incidence working mode can excite bending ultrasonic Lamb waves in the casing. The bending ultrasonic Lamb waves will leak energy into the cement sheath when propagating along the casing. When fast cement is bonded between the casing and the formation, only shear waves are leaked, and the reflected waves at the interface between the cement and the formation are also only shear waves. Spectral dips will appear in the amplitude spectrum with good periodicity. The interval size of the dip frequency can be used to directly estimate the cement thickness. The amplitude value at the dip is sensitive to the bonding condition, such as Figure 1 As shown in the figure. When slow cement is bonded between the casing and the formation, longitudinal and shear waves leak into the cement sheath. When the two waves reach the interface between the cement and the formation, mode conversion occurs. The types of reflected waves include longitudinal wave-long wave, longitudinal wave-short wave / short wave-long wave, and shear wave-short wave. At this time, the amplitude spectrum of the full wave recorded has more notch positions than that of fast cement. However, it can still be clearly observed that as the bonding of the second interface of the cement sheath deteriorates, the amplitude value of the depression increases significantly, as shown in the figure. Figure 2 shown.

[0052] When the bonding of the second interface of the cement sheath is poor, the amplitude characteristic of the reflected wave recorded in the full wave does not change significantly, especially when the thickness of the cement sheath is relatively thin. There is overlap between different component waves in the time domain, and it is difficult to intuitively judge the bonding quality of the second interface of the cement sheath. However, when the bonding of the second interface is good or poor, the sign of the reflection coefficient outside the cement sheath is opposite. If the bonding of the second interface of the cement sheath is good, the wave impedance of the general formation is higher than that of the cement sheath, and the phase of the reflected wave is consistent with that of the direct wave. When the bonding of the second interface is poor, the outside of the cement sheath is fluid, and its wave impedance is lower than that of the cement sheath. The phase of the reflected wave is opposite to that of the direct wave. The change in the phase of the reflected wave makes the positions of the peak and valley in the amplitude spectrum exactly opposite, such as Figure 1 The vertical line in the figure indicates the position where, for slow cement, the spectrum becomes more complex due to the diverse types of reflected waves. In the actual calculation model, when the cement sheath second interface is poorly bonded, a fluid layer is added between the cement sheath and the formation, which is equivalent to an increase in the number of model layers compared to when the cement sheath is well bonded. However, the amplitude spectra of both fast and slow cement are significantly shifted upward when the cement sheath second interface is poorly bonded, and the vibration energy at the notch position is significantly enhanced. This intuitive comparison feature can effectively determine the bonding condition of the cement sheath second interface.

[0053] Please refer to Figure 5According to a second aspect of the present invention, there is provided a cement sheath second interface bonding quality evaluation device, the cement sheath second interface bonding quality evaluation device comprising: an evaluation reference value determination module for determining an evaluation reference value of a reference depth point of the cement sheath based on the post-casing imaging logging data of the cement sheath; an azimuth evaluation result determination module for determining an evaluation depth segment of the cement sheath, and performing bonding evaluation on each evaluation depth point of the evaluation depth segment in each evaluation azimuth in the circumferential direction of the cement sheath using the evaluation reference value and the post-casing imaging logging data to obtain an azimuth evaluation result; wherein the evaluation depth segment includes a plurality of evaluation depth points, and each evaluation depth point includes a plurality of evaluation azimuths in the circumferential direction of the cement sheath; the bonding quality evaluation result determination module for obtaining an azimuth bonding imaging map of the cement sheath second interface based on the azimuth evaluation results of all evaluation depth points in all evaluation azimuths in the circumferential direction of the cement sheath.

[0054] A third aspect of the present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the cement sheath second interface bonding quality evaluation method described above.

[0055] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for evaluating the second interface bonding quality of the cement sheath as described above.

[0056] A fifth aspect of the present invention provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of the method for evaluating the bonding quality of the second interface of the cement sheath as described above.

[0057] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within 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 scope of protection of the present invention.

[0058] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0059] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for evaluating the bonding quality of the second interface of cement sheath, characterized in that: The cement sheath second interface bonding quality evaluation method includes: Determine the evaluation reference value of the reference depth point of the cement sheath based on the post-casing imaging logging data of the cement sheath; Determine an evaluation depth section of the cement sheath, and perform a cementation evaluation on each evaluation depth point in the evaluation depth section at each evaluation azimuth in the circumferential direction of the cement sheath using the evaluation reference value and the post-casing imaging logging data to obtain an azimuth evaluation result; wherein the evaluation depth section includes a plurality of evaluation depth points, and each evaluation depth point includes a plurality of evaluation azimuths in the circumferential direction of the cement sheath; Based on the azimuth evaluation results of all evaluation depth points in all evaluation orientations in the circumferential direction of the cement sheath, the azimuth bonding imaging map of the second interface of the cement sheath is obtained, and the azimuth bonding imaging map of the second interface of the cement sheath is used to evaluate the bonding quality of the second interface of the cement sheath.

2. The method for evaluating the bonding quality of the second interface of cement sheath according to claim 1, characterized in that: The following steps are used to perform cementation evaluation on a certain evaluation depth point at a certain evaluation direction in the circumferential direction of the cement sheath using the evaluation reference value and the post-casing imaging logging data: Extracting the full-wave waveform of the evaluation azimuth from the post-casing imaging logging data; Performing spectrum analysis on the full-wave waveform of the evaluation direction to obtain the evaluation direction amplitude spectrum; Obtaining an azimuth evaluation value based on the evaluation azimuth amplitude spectrum; Comparing the orientation evaluation value with the evaluation reference value to obtain a comparison result; An orientation evaluation result of the evaluation orientation is determined based on the comparison result.

3. The method for evaluating the bonding quality of the cement sheath second interface according to claim 1, characterized in that: The method further comprises: Obtain acoustic variable density logging data of cement sheath; The logging data with the weakest casing wave and the strongest formation wave is determined from the acoustic variable density logging data, and the depth point corresponding to the logging data is used as the reference depth point.

4. The method for evaluating the bonding quality of the cement sheath second interface according to claim 1, characterized in that: The evaluation reference value is used to characterize the cementing quality at the reference depth point; the evaluation reference value of the reference depth point of the cement sheath is determined based on the post-casing imaging logging data of the cement sheath, including: extracting the multi-azimuth full-wave waveform of the reference depth point from the post-casing imaging logging data; An evaluation reference value is determined based on the multi-azimuth full-wave waveform of the reference depth point.

5. The method for evaluating the bonding quality of the cement sheath second interface according to claim 4, characterized in that: The determining of the evaluation reference value based on the multi-azimuth full-wave waveform of the reference depth point includes: Performing spectrum analysis on the multi-azimuth full-wave waveforms of the reference depth points to obtain reference amplitude spectra in multiple azimuths; determining a minimum amplitude spectrum from reference amplitude spectra at multiple orientations; The evaluation reference value is determined based on the amplitude minimum amplitude spectrum.

6. The method for evaluating the bonding quality of the cement sheath second interface according to claim 5, characterized in that: The determining the evaluation reference value based on the amplitude minimum amplitude spectrum includes: Determining two minimum frequencies adjacent to a first center frequency; wherein the first center frequency is the center frequency of the amplitude minimum spectrum; Determine the minimum amplitude values ​​corresponding to the two minimum frequencies respectively; An initial evaluation reference value is obtained based on the sum of the minimum amplitude values ​​corresponding to the two minimum frequencies; The evaluation reference value is obtained based on the initial evaluation reference value: Sum ref =k Sum0; where Sum ref is the evaluation reference value, Sum0 is the initial evaluation reference value, and k is a constant.

7. The method for evaluating the bonding quality of the cement sheath second interface according to claim 2, characterized in that: The obtaining of an azimuth evaluation value based on the evaluation azimuth amplitude spectrum includes: performing a flipping process on the evaluation azimuth amplitude spectrum to obtain a flipped evaluation azimuth amplitude spectrum; Determining a plurality of flip maxima and a plurality of frequency points corresponding to the flip maxima from the flip evaluation azimuth amplitude spectrum; Filtering two extreme frequency points adjacent to a second center frequency from a plurality of frequency points corresponding to flip maxima; wherein the second center frequency is the center frequency of the flip evaluation azimuth amplitude spectrum; Determining extreme amplitude values ​​corresponding to two extreme frequency points in the evaluation azimuth amplitude spectrum; The azimuth evaluation value is obtained based on the sum of the extreme amplitude values ​​corresponding to the two extreme frequency points.

8. The method for evaluating the bonding quality of the cement sheath second interface according to claim 2, characterized in that: The determining of the orientation evaluation result of the evaluation orientation based on the comparison result includes: If the orientation evaluation value is greater than the evaluation reference value, it is determined that the evaluation orientation has poor bonding; If the orientation evaluation value is less than or equal to the evaluation reference value, it is determined that the evaluation orientation is well bonded.

9. A cement sheath second interface bonding quality evaluation device, characterized in that: The cement sheath second interface bonding quality evaluation device comprises: An evaluation reference value determination module is used to determine an evaluation reference value of a reference depth point of the cement sheath based on the post-casing imaging logging data of the cement sheath; an azimuth evaluation result determination module, configured to determine an evaluation depth section of the cement sheath, and to perform a cementation evaluation on each evaluation depth point of the evaluation depth section in each evaluation azimuth in the circumferential direction of the cement sheath using the evaluation reference value and the post-casing imaging logging data, to obtain an azimuth evaluation result; wherein the evaluation depth section includes a plurality of evaluation depth points, and each evaluation depth point includes a plurality of evaluation azimuths in the circumferential direction of the cement sheath; The bonding quality evaluation result determination module is used to obtain the azimuth bonding imaging map of the second interface of the cement sheath based on the azimuth evaluation results of all evaluation orientations of all evaluation depth points in the circumferential direction of the cement sheath, and use the azimuth bonding imaging map of the second interface of the cement sheath to evaluate the bonding quality of the second interface of the cement sheath.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory, wherein: The processor executes the computer program to implement the steps of the method for evaluating the bonding quality of the second interface of the cement sheath according to any one of claims 1 to 8.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for evaluating the second interface bonding quality of the cement sheath are implemented as described in any one of claims 1 to 8.

12. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method for evaluating the second interface bonding quality of the cement sheath are implemented as described in any one of claims 1 to 8.

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