Method, device, equipment, medium and product for evaluating cementing quality of double casing well

Abstract

The present application relates to the technical field of well cementation evaluation, and particularly relates to a double casing well cementation quality evaluation method, device, equipment, medium and product, wherein the method comprises the following steps: performing logging on a cemented well section of a double casing well to obtain casing-cement composite mode wave data of the cemented well section; performing logging on a to-be-evaluated well section of the double casing well to obtain casing-cement composite mode wave data of the to-be-evaluated well section; comparing the casing-cement composite mode wave data of the to-be-evaluated well section with the casing-cement composite mode wave data of the cemented well section to evaluate the cementation quality of the to-be-evaluated well section of the double casing well; and the cementation quality of the double casing well can be comprehensively evaluated.

Description

Technical Field

[0001] This invention relates to the field of cementing evaluation technology, and in particular to a method, apparatus, equipment, medium and product for evaluating the cementing quality of double-casing wells. Background Technology

[0002] A double-casing well refers to a well where two casings are sequentially run in the same borehole, forming a structure with upper and lower casing layers. The first interface, second interface, third interface, and fourth interface refer to the contact interfaces between the first casing and the first cement sheath, the first cement sheath and the second casing, the second casing and the second cement sheath, and the second cement sheath and the formation, from the inside out, in a double-casing well. Related technologies cannot evaluate the occurrence of channeling at the first, second, third, and fourth interfaces of a double-casing well. There is a technical problem in this field of being unable to comprehensively assess the cementing quality of double-casing wells. Summary of the Invention

[0003] This invention provides a method, apparatus, equipment, medium, and product for evaluating the cementing quality of double-casing wells, solving the technical problem of the difficulty in comprehensively assessing the cementing quality of double-casing wells.

[0004] In a first aspect, the present invention provides a method for evaluating the cementing quality of a double-cased well, the method comprising: logging a cemented section of the double-cased well to obtain casing-cement composite mode wave data of the cemented section; logging a section of the double-cased well to be evaluated to obtain casing-cement composite mode wave data of the section to be evaluated; comparing the casing-cement composite mode wave data of the section to be evaluated with the casing-cement composite mode wave data of the cemented section to evaluate the cementing quality of the section to be evaluated in the double-cased well.

[0005] In some embodiments, the step of logging the section to be evaluated in a double-cased well to obtain the casing-cement composite mode wave data of the section to be evaluated includes: logging the section to be evaluated in the double-cased well to obtain logging data of the section to be evaluated; and calculating the casing-cement composite mode wave data of the section to be evaluated based on the logging data of the section to be evaluated.

[0006] In some embodiments, logging includes array acoustic logging.

[0007] In some embodiments, the casing-cement composite mode wave data includes: the amplitude, arrival time, propagation velocity, and / or phase velocity of the casing-cement composite mode wave.

[0008] In some embodiments, the step of comparing the casing-cement composite mode wave data of the section to be evaluated with the casing-cement composite mode wave data of the well section with good cementation to evaluate the cementing quality of the section to be evaluated in a double-cased well includes: comparing the phase velocity of the casing-cement composite mode wave of the section to be evaluated with the phase velocity of the casing-cement composite mode wave of the well section with good cementation to evaluate the interface where the channeling occurs in the section to be evaluated in the double-cased well; comparing the amplitude of the casing-cement composite mode wave of the section to be evaluated with the amplitude of the casing-cement composite mode wave of the well section with good cementation to evaluate the thickness of the channeling in the section to be evaluated in the double-cased well; and / or comparing the arrival time and propagation velocity of the casing-cement composite mode wave of the section to be evaluated with the arrival time and propagation velocity of the casing-cement composite mode wave of the well section with good cementation to evaluate the length of the channeling in the section to be evaluated in the double-cased well.

[0009] In some embodiments, the interface includes: a first interface, a second interface, a third interface, and a fourth interface; wherein, the first interface includes the contact interface between the first layer of casing and the first layer of cement sheath from the inside to the outside of the double-cased well; wherein, the second interface includes the contact interface between the first layer of cement sheath and the second layer of casing from the inside to the outside of the double-cased well; wherein, the third interface includes the contact interface between the second layer of casing and the second layer of cement sheath from the inside to the outside of the double-cased well; and wherein, the fourth interface includes the contact interface between the second layer of cement sheath and the formation from the inside to the outside of the double-cased well.

[0010] Secondly, the present invention provides a cementing quality evaluation device for double-cased wells. The device includes: a reference module for logging the cemented section of a double-cased well to obtain casing-cement composite mode wave data of the cemented section; an acquisition module for logging the section to be evaluated in the double-cased well to obtain casing-cement composite mode wave data of the section to be evaluated; and an evaluation module for comparing the casing-cement composite mode wave data of the section to be evaluated with the casing-cement composite mode wave data of the cemented section to evaluate the cementing quality of the section to be evaluated in the double-cased well.

[0011] Thirdly, the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of any of the above-described methods for evaluating the cementing quality of double-cased wells.

[0012] Fourthly, 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 any of the above-described methods for evaluating the cementing quality of double-casing wells.

[0013] Fifthly, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the steps of any of the above-described methods for evaluating the cementing quality of double-casing wells.

[0014] This invention provides a method, apparatus, equipment, medium, and product for evaluating the cementing quality of a double-cased well. The method includes: logging a well section with intact cementation in a double-cased well to obtain casing-cement composite wave data for the well section; logging a section of the double-cased well to be evaluated to obtain casing-cement composite wave data for the section to be evaluated; comparing the casing-cement composite wave data of the section to be evaluated with the casing-cement composite wave data of the well section with intact cementation to evaluate the cementing quality of the section to be evaluated in the double-cased well; and enabling a comprehensive assessment of the cementing quality of a double-cased well. Attached Figure Description

[0015] The invention will now be described in more detail with reference to embodiments and the accompanying drawings:

[0016] Figure 1 A flowchart illustrating a method for evaluating cementing quality in a double-casing well, provided in an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of the structure of a double-casing well cementing quality evaluation device provided in an embodiment of the present invention;

[0018] Figure 3 A schematic diagram of the waveforms of the first, second, third, and fourth interfaces of a double-casing cementing system, received by an array acoustic logging system as an application example of the present invention, showing the well-bonded cementation.

[0019] Figure 4 A waveform diagram showing channeling from the first to the fourth interface of a double-casing cementing system, received by an array acoustic logging system as an application example of the present invention.

[0020] Figure 5 A waveform diagram showing channeling at the first interface of a double-casing cementing well, received by an array acoustic logging system as an application example of the present invention.

[0021] Figure 6 A waveform diagram showing channeling at the second interface of a double-casing cementing well, received by an array acoustic logging system as an application example of the present invention.

[0022] Figure 7 A waveform diagram showing channeling at the third interface of a double-casing cementing well, received by an array acoustic logging system as an application example of the present invention.

[0023] Figure 8This is a waveform diagram of a groove appearing at the fourth interface of a double-casing cementing well, received by an array acoustic logging system as an application example of the present invention.

[0024] In the accompanying drawings, the same parts are referred to by the same reference numerals, and the drawings are not drawn to scale. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present invention and to fully understand and implement the process of how the present invention uses technical means to solve technical problems and achieve corresponding technical effects, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The embodiments of the present invention and the various features therein can be combined with each other without conflict, and the resulting technical solutions are all within the protection scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0028] A double-casing well refers to a well where two casings are sequentially run in the same borehole, forming a structure with upper and lower casing layers. The first interface, second interface, third interface, and fourth interface refer to the contact interfaces between the first casing and the first cement sheath, the first cement sheath and the second casing, the second casing and the second cement sheath, and the second cement sheath and the formation, from the inside out, in a double-casing well. Related technologies cannot evaluate the occurrence of channeling at the first, second, third, and fourth interfaces of a double-casing well. There is a technical problem in this field of being unable to comprehensively assess the cementing quality of double-casing wells.

[0029] To address the aforementioned technical problem of the difficulty in comprehensively evaluating the cementing quality of double-casing wells, this invention proposes a method, apparatus, equipment, medium, and product for evaluating the cementing quality of double-casing wells. The implementation details of this invention are described below for ease of understanding and are not essential for implementing this solution.

[0030] Example 1

[0031] Figure 1 This is a flowchart illustrating a method for evaluating the cementing quality of a double-casing well, as provided in an embodiment of this application. Figure 1 As shown in the technical solution of this embodiment, a method for evaluating the cementing quality of a double-cased well is provided. The method includes: logging the cemented section of the double-cased well to obtain the casing-cement composite mode wave data of the cemented section; logging the section to be evaluated in the double-cased well to obtain the casing-cement composite mode wave data of the section to be evaluated; comparing the casing-cement composite mode wave data of the section to be evaluated with the casing-cement composite mode wave data of the cemented section to evaluate the cementing quality of the section to be evaluated in the double-cased well.

[0032] The technical problem to be solved in this embodiment is how to comprehensively evaluate the cementing quality of double-casing wells.

[0033] In this embodiment, the technical solution first involves logging the well-cemented section of a double-cased well. Array acoustic logging is used to acquire casing-cement composite mode wave data for this section. This data includes wave amplitude, arrival time, propagation velocity, and phase velocity. These data reflect the acoustic characteristics under well-cemented conditions. Then, logging is performed on the section of the double-cased well to be evaluated, yielding corresponding casing-cement composite mode wave data. Finally, the data from the section to be evaluated is compared with the data from the well-cemented section. For example, under well-cemented conditions, the parameters of the casing-cement composite mode wave will be within a stable range. When cementing quality problems occur in the section to be evaluated, such as channeling, these parameters will change. This comparison reveals differences in cementing quality, thus enabling a comprehensive assessment of the cementing quality of the double-cased well.

[0034] The technical solution in this embodiment solves the problem of comprehensively evaluating the cementing quality of double-cased wells by first acquiring and comparing the casing-cement composite mode wave data of the well section with the section to be evaluated. This allows for a direct visual comparison of the differences between the section to be evaluated and the well section with intact cement. For example, if the phase velocity of the section to be evaluated changes significantly compared to the well section with intact cement, it may indicate that channeling has occurred at a certain interface. Moreover, by comparing the amplitude, arrival time, and propagation velocity, cementing quality can be evaluated from multiple dimensions. This not only determines whether channeling exists but also allows for quantitative analysis of the degree of channeling. Simultaneously, this comparison method can cover all interfaces of the entire double-cased well, including the first, second, third, and fourth interfaces from the inside out, improving the comprehensiveness of cementing quality evaluation and making the evaluation results more reliable, thus providing strong support for cementing quality control in oil and gas extraction projects.

[0035] Example 2

[0036] Based on the above embodiments, the step of logging the section to be evaluated in a double-cased well to obtain the casing-cement composite mode wave data of the section to be evaluated includes: logging the section to be evaluated in a double-cased well to obtain logging data of the section to be evaluated; and calculating the casing-cement composite mode wave data of the section to be evaluated based on the logging data of the section to be evaluated.

[0037] In this embodiment, well logging is performed on the section of a double-cased well to be evaluated. This well logging primarily refers to array acoustic logging. Array acoustic logging utilizes multiple acoustic sensors placed at different locations to acquire information such as the propagation time and amplitude changes of acoustic waves in the subsurface medium. This method yields logging data for the section to be evaluated, which includes various acoustic wave information such as casing waves, cement annular waves, and formation waves. Then, based on this logging data, the casing-cement composite mode wave data for the section to be evaluated is calculated. For example, in the acquired logging data, based on principles such as wave equations, the amplitude of the casing-cement composite mode wave is determined through analysis and calculation of different acoustic waves. This amplitude reflects the magnitude of the acoustic wave energy. The arrival time of the acoustic wave is determined using the Slow Time Correlation (STC) method. The propagation velocity is calculated, which is related to the propagation characteristics of acoustic waves in the medium. The phase velocity is calculated using the Slow Frequency Correlation (SFC) method. Through the calculation steps of this embodiment, the casing-cement composite mode wave data is extracted from the logging data.

[0038] The technical solution of this embodiment solves the problem of obtaining casing-cement composite mode wave data for the well section to be evaluated by acquiring logging data through array acoustic logging and then performing calculations based on this data. The method of this embodiment can accurately acquire relevant data for the well section to be evaluated, providing a basis for subsequent data comparison with well-cemented sections. For example, accurate casing-cement composite mode wave data can more precisely reflect the cementing quality of the well section to be evaluated. Calculated parameters such as amplitude, arrival time, propagation velocity, and phase velocity can be used to determine the existence and specific characteristics of channeling. Moreover, since the data in this embodiment is based on array acoustic logging, which itself has high accuracy and reliability, the acquired data can truly reflect the actual situation downhole, thereby improving the accuracy and practicality of the entire cementing quality evaluation method.

[0039] Example 3

[0040] Based on the above embodiments, well logging includes array acoustic logging.

[0041] In this embodiment, array acoustic logging is employed. Array acoustic logging is achieved by deploying multiple acoustic sensors at different locations downhole. These sensors can detect the propagation of sound waves in the subsurface medium. When logging double-cased wells, array acoustic logging technology is used for both cemented sections and sections requiring evaluation. For example, as sound waves propagate in the downhole medium, these sensors record various characteristics of the sound waves, such as wave train amplitude, arrival time, propagation speed, and phase velocity. This information can be transmitted to surface equipment for analysis. Furthermore, array acoustic logging can monitor the sound wave propagation at various interfaces of the double-cased well, including the first, second, third, and fourth interfaces. It can acquire information such as sound wave reflection and refraction at different interfaces, thereby providing detailed data support for subsequent cementing quality evaluation.

[0042] The technical solution in this embodiment solves the logging problem by using array acoustic logging. This logging method can provide rich acoustic information, laying the foundation for cementing quality evaluation. For example, because array acoustic logging can acquire acoustic information at different locations, it can comprehensively monitor the condition of each interface in complex structures such as double-casing wells. By analyzing the propagation characteristics of acoustic waves at different interfaces, potential cementing quality problems, such as channeling, can be discovered. Moreover, array acoustic logging has high accuracy and can accurately record various acoustic parameters, making the acquired data more reliable. This helps to more accurately evaluate cementing quality. Whether judging the cementing situation or analyzing information such as the length, thickness, and location of channeling, the high-quality data provided by array acoustic logging is indispensable, thereby improving the effectiveness of the entire double-casing well cementing quality evaluation method.

[0043] Example 4

[0044] Based on the above embodiments, the casing-cement composite mode wave data includes: the amplitude, arrival time, propagation velocity, and / or phase velocity of the casing-cement composite mode wave.

[0045] In this embodiment, the casing-cement composite mode wave data includes the amplitude, arrival time, propagation velocity, and phase velocity of the casing-cement composite mode wave. Amplitude refers to the amplitude of the sound wave train, reflecting the magnitude of the sound wave energy. For example, when a sound wave propagates at the casing-cement interface, if cross-channeling occurs, the sound wave energy may change, leading to a change in amplitude. Arrival time is calculated using the Slow Time Correlation (STC) method, representing the time it takes for the sound wave to reach the sensor. By analyzing the time of sound wave reception at different sensor locations, the propagation path and velocity changes of the sound wave in the downhole medium can be understood. Propagation velocity is related to the propagation characteristics of the sound wave in the medium, and it is affected by factors such as the density and elasticity of the medium. Phase velocity is calculated using the Slow Frequency Correlation (SFC) method, which is crucial for analyzing the phase changes of the sound wave. By integrating these parameters, the casing-cement composite mode wave data is constructed. When logging double-cased wells, these parameters must be obtained for both well sections with intact cementation and sections to be evaluated, in order to construct complete casing-cement composite mode wave data.

[0046] The technical solution of this embodiment solves the problem of constructing casing-cement composite model wave data by determining the amplitude, arrival time, propagation velocity, and phase velocity included in the casing-cement composite model wave data and using corresponding calculation methods to obtain these parameters. This comprehensively describes the propagation characteristics of acoustic waves in the casing-cement composite structure. For example, by analyzing changes in amplitude, it is possible to determine whether the acoustic wave energy is abnormal, and thus infer whether channeling exists. Arrival time information helps determine whether the acoustic wave propagation path is normal, while changes in propagation velocity and phase velocity reflect changes in the properties of the medium. These parameters work together to provide detailed data support for accurately evaluating the cementing quality of double-cased wells. Moreover, obtaining these parameters through standardized calculation methods makes the data comparable, making comparisons between different well sections and with theoretical models more convenient and accurate, thereby improving the reliability of cementing quality evaluation.

[0047] Example 5

[0048] Based on the above embodiments, the step of comparing the casing-cement composite mode wave data of the section to be evaluated with the casing-cement composite mode wave data of the well section with intact cementation to evaluate the cementing quality of the section to be evaluated in a double-cased well includes: comparing the phase velocity of the casing-cement composite mode wave of the section to be evaluated with the phase velocity of the casing-cement composite mode wave of the well section with intact cementation to evaluate the interface where the channeling occurs in the section to be evaluated in the double-cased well; comparing the amplitude of the casing-cement composite mode wave of the section to be evaluated with the amplitude of the casing-cement composite mode wave of the well section with intact cementation to evaluate the thickness of the channeling in the section to be evaluated in the double-cased well; and / or comparing the arrival time and propagation velocity of the casing-cement composite mode wave of the section to be evaluated with the arrival time and propagation velocity of the casing-cement composite mode wave of the well section with intact cementation to evaluate the length of the channeling in the section to be evaluated in the double-cased well.

[0049] In this embodiment, the cementing quality is evaluated by comparing the casing-cement composite wave data of the section to be evaluated with that of the well section with intact cementation. Specifically, the phase velocity of the casing-cement composite wave in the section to be evaluated is compared with that of the well section with intact cementation to evaluate the interface where the channeling occurs in the section to be evaluated in a double-cased well. For example, the phase velocities of the casing-cement composite wave decrease sequentially when channeling occurs at the first, second, third, and fourth interfaces of the double-cased well. By comparing the phase velocities, the interfaces where channeling may occur can be determined. Then, the amplitude of the casing-cement composite wave in the section to be evaluated is compared with that of the well section with intact cementation to evaluate the thickness of the channeling in the section to be evaluated in the double-cased well. When the channeling thickness is the same, as the channeling length increases, the amplitude of the casing-cement composite mode wave at the first, second, third, and fourth interfaces of the double-cased well increases. A comparison of amplitudes can provide a preliminary assessment of the channeling thickness. Simultaneously, comparing the arrival time and propagation velocity of the casing-cement composite mode wave in the section to be evaluated with those in a well-cemented section helps assess the length of the channeling in the double-cased well. When the channeling length is the same, as the channeling thickness increases, the arrival time of the casing-cement composite mode wave at the first, second, third, and fourth interfaces of the double-cased well decreases, while the propagation velocity increases. These changing patterns can be used to infer the length of the channeling.

[0050] The technical solution in this embodiment solves the problem of evaluating the cementing quality of the section to be evaluated in a double-cased well by comparing the phase velocity, amplitude, arrival time, and propagation velocity in the casing-cement composite mode wave data of the section to be evaluated and the well section with intact cementation. This evaluation method can analyze various aspects of cementing quality in detail. For example, by comparing phase velocities, the interface where cross-cutting may occur can be accurately located, which is crucial for subsequent maintenance and treatment. Amplitude comparison helps to understand the thickness of the cross-cutting, providing a basis for assessing the impact of cross-cutting on cementing quality. Comparison of arrival time and propagation velocity can further determine the length of the cross-cutting, thereby gaining a more comprehensive understanding of the characteristics of cross-cutting. This multi-parameter comparison method can comprehensively consider the influence of various factors on cementing quality, making the evaluation results more accurate and reliable. Moreover, by comparing with the well section with intact cementation, the changes in cementing quality can be seen intuitively, providing an effective technical means for cementing quality control in the oil and gas production process and ensuring the stable production of oil and gas wells.

[0051] Example 6

[0052] Based on the above embodiments, the interface includes: a first interface, a second interface, a third interface, and a fourth interface; wherein, the first interface includes the contact interface between the first layer of casing and the first layer of cement sheath from the inside to the outside of the double-cased well; wherein, the second interface includes the contact interface between the first layer of cement sheath and the second layer of casing from the inside to the outside of the double-cased well; wherein, the third interface includes the contact interface between the second layer of casing and the second layer of cement sheath from the inside to the outside of the double-cased well; wherein, the fourth interface includes the contact interface between the second layer of cement sheath and the formation from the inside to the outside of the double-cased well.

[0053] In this embodiment, the interfaces are defined as a first interface, a second interface, a third interface, and a fourth interface. Specifically, the first interface is the contact interface between the first layer of casing and the first layer of cement sheath in a double-cased well (from the inside out); the second interface is the contact interface between the first layer of cement sheath and the second layer of casing; the third interface is the contact interface between the second layer of casing and the second layer of cement sheath; and the fourth interface is the contact interface between the second layer of cement sheath and the formation. During cementing quality evaluation, each interface is distinguished by analyzing the casing-cement composite mode wave data. For example, the interface can be distinguished based on the phase velocity change pattern of the casing-cement composite mode wave when cross-flow occurs at different interfaces. When cross-flow occurs at the first interface, the phase velocity of the casing-cement composite mode wave will change accordingly, differing from the phase velocity changes when cross-flow occurs at other interfaces. This difference indicates that a problem has occurred at the first interface. Similarly, the second, third, and fourth interfaces can also be distinguished based on their unique phase velocity changes, as well as changes in parameters such as amplitude, arrival time, and propagation speed.

[0054] The technical solution in this embodiment solves the problem of distinguishing the interfaces of a double-cased well by defining each interface and combining the analysis of casing-cement composite mode wave data. This distinction method is crucial for accurately assessing the cementing quality of each interface. For example, during oil and gas extraction, if the cementing quality of a specific interface is problematic, such as channeling at the first interface, it may lead to safety issues such as oil and gas leaks. By accurately distinguishing the interfaces, targeted measures can be taken to address the problem. Moreover, by evaluating different interfaces separately, a more comprehensive understanding of the cementing quality of the double-cased well can be obtained. Simultaneously, this distinction method provides a clear framework for subsequent data analysis and quality evaluation, making the entire cementing quality evaluation process more orderly and accurate.

[0055] Example 7

[0056] Figure 2 This is a schematic diagram of the structure of a cementing quality evaluation device for double-casing wells provided in an embodiment of this application, as shown below. Figure 2 As shown in the technical solution of this embodiment, a cementing quality evaluation device for a double-cased well is provided. The device includes: a reference module, used to log the cemented section of the double-cased well to obtain the casing-cement composite mode wave data of the cemented section; an acquisition module, used to log the section to be evaluated of the double-cased well to obtain the casing-cement composite mode wave data of the section to be evaluated; and an evaluation module, used to compare the casing-cement composite mode wave data of the section to be evaluated with the casing-cement composite mode wave data of the cemented section to evaluate the cementing quality of the section to be evaluated in the double-cased well.

[0057] The technical problem to be solved in this embodiment is how to comprehensively evaluate the cementing quality of double-casing wells.

[0058] In this embodiment, the technical solution first involves logging the well-cemented section of a double-cased well. Array acoustic logging is used to acquire casing-cement composite mode wave data for this section. This data includes wave amplitude, arrival time, propagation velocity, and phase velocity. These data reflect the acoustic characteristics under well-cemented conditions. Then, logging is performed on the section of the double-cased well to be evaluated, yielding corresponding casing-cement composite mode wave data. Finally, the data from the section to be evaluated is compared with the data from the well-cemented section. For example, under well-cemented conditions, the parameters of the casing-cement composite mode wave will be within a stable range. When cementing quality problems occur in the section to be evaluated, such as channeling, these parameters will change. This comparison reveals differences in cementing quality, thus enabling a comprehensive assessment of the cementing quality of the double-cased well.

[0059] The technical solution in this embodiment solves the problem of comprehensively evaluating the cementing quality of double-cased wells by first acquiring and comparing the casing-cement composite mode wave data of the well section with the section to be evaluated. This allows for a direct visual comparison of the differences between the section to be evaluated and the well section with intact cement. For example, if the phase velocity of the section to be evaluated changes significantly compared to the well section with intact cement, it may indicate that channeling has occurred at a certain interface. Moreover, by comparing the amplitude, arrival time, and propagation velocity, cementing quality can be evaluated from multiple dimensions. This not only determines whether channeling exists but also allows for quantitative analysis of the degree of channeling. Simultaneously, this comparison device can cover all interfaces of the entire double-cased well, including the first, second, third, and fourth interfaces from the inside out, improving the comprehensiveness of cementing quality evaluation and making the evaluation results more reliable, thus providing strong support for cementing quality control in oil and gas extraction projects.

[0060] Based on the above embodiments, the step of logging the section to be evaluated in a double-cased well to obtain the casing-cement composite mode wave data of the section to be evaluated includes: logging the section to be evaluated in a double-cased well to obtain logging data of the section to be evaluated; and calculating the casing-cement composite mode wave data of the section to be evaluated based on the logging data of the section to be evaluated.

[0061] In this embodiment, well logging is performed on the section of a double-cased well to be evaluated. This well logging primarily refers to array acoustic logging. Array acoustic logging utilizes multiple acoustic sensors placed at different locations to acquire information such as the propagation time and amplitude changes of acoustic waves in the subsurface medium. This method yields logging data for the section to be evaluated, which includes various acoustic wave information such as casing waves, cement annular waves, and formation waves. Then, based on this logging data, the casing-cement composite mode wave data for the section to be evaluated is calculated. For example, in the acquired logging data, based on principles such as wave equations, the amplitude of the casing-cement composite mode wave is determined through analysis and calculation of different acoustic waves. This amplitude reflects the magnitude of the acoustic wave energy. The arrival time of the acoustic wave is determined using the Slow Time Correlation (STC) method. The propagation velocity is calculated, which is related to the propagation characteristics of acoustic waves in the medium. The phase velocity is calculated using the Slow Frequency Correlation (SFC) method. Through the calculation steps of this embodiment, the casing-cement composite mode wave data is extracted from the logging data.

[0062] The technical solution of this embodiment solves the problem of obtaining casing-cement composite mode wave data for the well section to be evaluated by acquiring logging data through array acoustic logging and then performing calculations based on this data. The device of this embodiment can accurately acquire relevant data for the well section to be evaluated, providing a basis for subsequent data comparison with well-cemented sections. For example, accurate casing-cement composite mode wave data can more precisely reflect the cementing quality of the well section to be evaluated. Calculated parameters such as amplitude, arrival time, propagation velocity, and phase velocity can be used to determine the existence and specific characteristics of channeling. Moreover, since the data in this embodiment is acquired based on array acoustic logging, which itself has high accuracy and reliability, the acquired data can truly reflect the actual situation downhole, thereby improving the accuracy and practicality of the entire cementing quality evaluation device.

[0063] Based on the above embodiments, well logging includes array acoustic logging.

[0064] In this embodiment, array acoustic logging is employed. Array acoustic logging is achieved by deploying multiple acoustic sensors at different locations downhole. These sensors can detect the propagation of sound waves in the subsurface medium. When logging double-cased wells, array acoustic logging technology is used for both cemented sections and sections requiring evaluation. For example, as sound waves propagate in the downhole medium, these sensors record various characteristics of the sound waves, such as wave train amplitude, arrival time, propagation speed, and phase velocity. This information can be transmitted to surface equipment for analysis. Furthermore, array acoustic logging can monitor the sound wave propagation at various interfaces of the double-cased well, including the first, second, third, and fourth interfaces. It can acquire information such as sound wave reflection and refraction at different interfaces, thereby providing detailed data support for subsequent cementing quality evaluation.

[0065] The technical solution in this embodiment solves the logging problem by using array acoustic logging. This logging method can provide rich acoustic information, laying the foundation for cementing quality evaluation. For example, because array acoustic logging can acquire acoustic information at different locations, it can comprehensively monitor the condition of each interface in complex structures such as double-casing wells. By analyzing the propagation characteristics of acoustic waves at different interfaces, potential cementing quality problems, such as channeling, can be discovered. Moreover, array acoustic logging has high accuracy and can accurately record various acoustic parameters, making the acquired data more reliable. This helps to more accurately evaluate cementing quality. Whether judging the cementing situation or analyzing information such as the length, thickness, and location of channeling, the high-quality data provided by array acoustic logging is indispensable, thereby improving the effectiveness of the entire double-casing well cementing quality evaluation device.

[0066] Based on the above embodiments, the casing-cement composite mode wave data includes: the amplitude, arrival time, propagation velocity, and / or phase velocity of the casing-cement composite mode wave.

[0067] In this embodiment, the casing-cement composite mode wave data includes the amplitude, arrival time, propagation velocity, and phase velocity of the casing-cement composite mode wave. Amplitude refers to the amplitude of the sound wave train, reflecting the magnitude of the sound wave energy. For example, when a sound wave propagates at the casing-cement interface, if cross-channeling occurs, the sound wave energy may change, leading to a change in amplitude. Arrival time is calculated using the Slow Time Correlation (STC) method, representing the time it takes for the sound wave to reach the sensor. By analyzing the time of sound wave reception at different sensor locations, the propagation path and velocity changes of the sound wave in the downhole medium can be understood. Propagation velocity is related to the propagation characteristics of the sound wave in the medium, and it is affected by factors such as the density and elasticity of the medium. Phase velocity is calculated using the Slow Frequency Correlation (SFC) method, which is crucial for analyzing the phase changes of the sound wave. By integrating these parameters, the casing-cement composite mode wave data is constructed. When logging double-cased wells, these parameters must be obtained for both well sections with intact cementation and sections to be evaluated, in order to construct complete casing-cement composite mode wave data.

[0068] The technical solution of this embodiment solves the problem of constructing casing-cement composite model wave data by determining the amplitude, arrival time, propagation velocity, and phase velocity included in the casing-cement composite model wave data and using a corresponding computing device to acquire these parameters. This comprehensively describes the propagation characteristics of acoustic waves in the casing-cement composite structure. For example, by analyzing changes in amplitude, it is possible to determine whether the acoustic wave energy is abnormal, and thus infer whether channeling exists. Arrival time information helps determine whether the acoustic wave propagation path is normal, while changes in propagation velocity and phase velocity reflect changes in the properties of the medium. These parameters work together to provide detailed data support for accurately evaluating the cementing quality of double-cased wells. Moreover, acquiring these parameters through standardized computing devices makes the data comparable, making comparisons between different well sections and with theoretical models more convenient and accurate, thereby improving the reliability of cementing quality evaluation.

[0069] Based on the above embodiments, the step of comparing the casing-cement composite mode wave data of the section to be evaluated with the casing-cement composite mode wave data of the well section with intact cementation to evaluate the cementing quality of the section to be evaluated in a double-cased well includes: comparing the phase velocity of the casing-cement composite mode wave of the section to be evaluated with the phase velocity of the casing-cement composite mode wave of the well section with intact cementation to evaluate the interface where the channeling occurs in the section to be evaluated in the double-cased well; comparing the amplitude of the casing-cement composite mode wave of the section to be evaluated with the amplitude of the casing-cement composite mode wave of the well section with intact cementation to evaluate the thickness of the channeling in the section to be evaluated in the double-cased well; and / or comparing the arrival time and propagation velocity of the casing-cement composite mode wave of the section to be evaluated with the arrival time and propagation velocity of the casing-cement composite mode wave of the well section with intact cementation to evaluate the length of the channeling in the section to be evaluated in the double-cased well.

[0070] In this embodiment, the cementing quality is evaluated by comparing the casing-cement composite wave data of the section to be evaluated with that of the well section with intact cementation. Specifically, the phase velocity of the casing-cement composite wave in the section to be evaluated is compared with that of the well section with intact cementation to evaluate the interface where the channeling occurs in the section to be evaluated in a double-cased well. For example, the phase velocities of the casing-cement composite wave decrease sequentially when channeling occurs at the first, second, third, and fourth interfaces of the double-cased well. By comparing the phase velocities, the interfaces where channeling may occur can be determined. Then, the amplitude of the casing-cement composite wave in the section to be evaluated is compared with that of the well section with intact cementation to evaluate the thickness of the channeling in the section to be evaluated in the double-cased well. When the channeling thickness is the same, as the channeling length increases, the amplitude of the casing-cement composite mode wave at the first, second, third, and fourth interfaces of the double-cased well increases. A comparison of amplitudes can provide a preliminary assessment of the channeling thickness. Simultaneously, comparing the arrival time and propagation velocity of the casing-cement composite mode wave in the section to be evaluated with those in a well-cemented section helps assess the length of the channeling in the double-cased well. When the channeling length is the same, as the channeling thickness increases, the arrival time of the casing-cement composite mode wave at the first, second, third, and fourth interfaces of the double-cased well decreases, while the propagation velocity increases. These changing patterns can be used to infer the length of the channeling.

[0071] The technical solution in this embodiment solves the problem of evaluating the cementing quality of the section to be evaluated in a double-cased well by comparing the phase velocity, amplitude, arrival time, and propagation velocity in the casing-cement composite mode wave data of the section to be evaluated and the well section with intact cementation. This evaluation method can analyze various aspects of cementing quality in detail. For example, by comparing phase velocities, the interface where cross-cutting may occur can be accurately located, which is crucial for subsequent maintenance and treatment. Amplitude comparison helps to understand the thickness of the cross-cutting, providing a basis for assessing the impact of cross-cutting on cementing quality. Comparison of arrival time and propagation velocity can further determine the length of the cross-cutting, thereby gaining a more comprehensive understanding of the characteristics of cross-cutting. This multi-parameter comparison device can comprehensively consider the influence of various factors on cementing quality, making the evaluation results more accurate and reliable. Moreover, by comparing with the well section with intact cementation, the changes in cementing quality can be seen intuitively, providing an effective technical means for cementing quality control in the oil and gas production process and ensuring the stable production of oil and gas wells.

[0072] Based on the above embodiments, the interface includes: a first interface, a second interface, a third interface, and a fourth interface; wherein, the first interface includes the contact interface between the first layer of casing and the first layer of cement sheath from the inside to the outside of the double-cased well; wherein, the second interface includes the contact interface between the first layer of cement sheath and the second layer of casing from the inside to the outside of the double-cased well; wherein, the third interface includes the contact interface between the second layer of casing and the second layer of cement sheath from the inside to the outside of the double-cased well; wherein, the fourth interface includes the contact interface between the second layer of cement sheath and the formation from the inside to the outside of the double-cased well.

[0073] In this embodiment, the interfaces are defined as a first interface, a second interface, a third interface, and a fourth interface. Specifically, the first interface is the contact interface between the first layer of casing and the first layer of cement sheath in a double-cased well (from the inside out); the second interface is the contact interface between the first layer of cement sheath and the second layer of casing; the third interface is the contact interface between the second layer of casing and the second layer of cement sheath; and the fourth interface is the contact interface between the second layer of cement sheath and the formation. During cementing quality evaluation, each interface is distinguished by analyzing the casing-cement composite mode wave data. For example, the interface can be distinguished based on the phase velocity change pattern of the casing-cement composite mode wave when cross-flow occurs at different interfaces. When cross-flow occurs at the first interface, the phase velocity of the casing-cement composite mode wave will change accordingly, differing from the phase velocity changes when cross-flow occurs at other interfaces. This difference indicates that a problem has occurred at the first interface. Similarly, the second, third, and fourth interfaces can also be distinguished based on their unique phase velocity changes, as well as changes in parameters such as amplitude, arrival time, and propagation speed.

[0074] The technical solution in this embodiment solves the problem of distinguishing the interfaces of a double-cased well by defining each interface and combining it with the analysis of casing-cement composite mode wave data. This distinction method is crucial for accurately assessing the cementing quality of each interface. For example, during oil and gas extraction, if the cementing quality of a specific interface is problematic, such as channeling at the first interface, it may lead to safety issues such as oil and gas leaks. By accurately distinguishing the interfaces, targeted measures can be taken to address the problem. Moreover, by evaluating different interfaces separately, a more comprehensive understanding of the cementing quality of the double-cased well can be obtained. Simultaneously, this distinction device provides a clear framework for subsequent data analysis and quality evaluation, making the entire cementing quality evaluation process more orderly and accurate.

[0075] Example 8

[0076] In the technical solution of this embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps of any of the above embodiments of the double-casing well cementing quality evaluation method.

[0077] In the technical solution of this embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, it implements the steps of any of the above embodiments of the double-casing well cementing quality evaluation method.

[0078] In the technical solution of this embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of any of the above embodiments of the double-casing well cementing quality evaluation method.

[0079] The processor may include, but is not limited to, one or more processors or microprocessors. Each processor may be implemented as an Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), controller, microcontroller, microprocessor, or other electronic component, for performing the methods in the above embodiments. The computer-readable storage medium may be implemented by any type of volatile or non-volatile storage device or a combination thereof, and may include, but is not limited to, random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, computer storage media (e.g., hard disk, floppy disk, solid-state drive, removable disk, CD-ROM, DVD-ROM, Blu-ray disc, etc.).

[0080] Computer-readable storage media may also store at least one computer-executable program / instruction, such as computer-readable instructions. Computer-readable storage media include, but are not limited to, volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory. Computer-readable storage media may include, for example, read-only memory (ROM), hard disk, flash memory, etc. For example, a non-transitory computer-readable storage medium may be connected to a computing device such as a computer, and then, when the computing device executes the computer-readable instructions stored on the computer-readable storage medium, the various methods described above can be performed.

[0081] In addition, the computer device may also include (but is not limited to) a data bus, an input / output (I / O) bus, a display, and input / output devices (e.g., a keyboard, mouse, speakers, etc.). The processor can communicate with external devices via the I / O bus through a wired or wireless network. In one embodiment, the at least one computer-executable instruction may also be compiled into or comprise a software product / computer program product, wherein one or more computer-executable instructions, when executed by the processor, perform the steps of the various functions and / or methods in the embodiments described herein.

[0082] Example 9

[0083] Based on the above embodiments, this embodiment provides an application example.

[0084] This application example provides a method for evaluating cementing quality in double-casing wells.

[0085] This technical solution mainly relates to the fields of geophysical logging technology and oil and gas extraction engineering technology. This invention relates to a method for evaluating the cementing quality of double-casing wells.

[0086] In the fields of geophysical logging technology and oil and gas extraction engineering, cementing quality assessment is a crucial step in ensuring stable production of oil and gas wells. Cementing refers to the process of injecting cement slurry around the wellbore after drilling to prevent oil and gas leakage, protect the oil and gas reservoir, and ensure wellbore stability. This process ensures a tight bond between the cement slurry and the wellbore and the oil and gas reservoir. The quality of cementing directly affects the production efficiency and safety of oil and gas wells. Relevant cementing quality assessment methods are primarily based on acoustic variable density logging. Acoustic variable density logging utilizes the significant difference in acoustic impedance between cement and mud to attenuate acoustic waves propagating along the casing axis, reflecting the bonding quality between cement and casing, and between casing and formation.

[0087] Existing cementing quality assessment methods can only evaluate the non-cementation of the first, second, third, and fourth interfaces of double-cased wells based on sonic variable density logging. A double-cased well refers to a well where two casings are run sequentially, forming an upper and lower casing structure. The first, second, third, and fourth interfaces refer to the contact interfaces between the first casing and the first cement sheath, the first cement sheath and the second casing, the second casing and the second cement sheath, and the second cement sheath and the formation, from the inside out. Related technologies cannot evaluate the presence of channeling at the first, second, third, and fourth interfaces of double-cased wells. Channeling refers to the space formed by flowing substances, such as water or oil, entering the interface. This phenomenon can lead to safety issues such as oil and gas leaks. Therefore, existing cementing quality assessment methods have significant limitations and cannot comprehensively evaluate the cementing quality of double-cased wells. There is a technical problem in this field that makes it difficult to comprehensively evaluate the cementing quality of double-cased wells.

[0088] Existing cementing quality evaluation methods can only assess the non-cementation of the first, second, third, and fourth interfaces of double-cased wells based on sonic variable density logging, and cannot evaluate the situation where cross-linking occurs at the first, second, third, and fourth interfaces of double-cased wells. To overcome the shortcomings of the above technologies, this invention provides a cementing quality evaluation method for double-cased wells based on array sonic logging. Compared with related technologies, this technical solution mainly solves the following problems:

[0089] (1) Technical problem: It is impossible to evaluate the situation where channeling occurs at the first, second, third, and fourth interfaces of a double-cased well. The relevant cementing quality evaluation methods can only evaluate the situation where the first, second, third, and fourth interfaces of a double-cased well are not cemented based on sonic variable density logging, which presents a technical problem that it is impossible to evaluate the situation where channeling occurs at the first, second, third, and fourth interfaces of a double-cased well.

[0090] (2) Technical problem of being unable to fully assess the cementing quality of double-casing wells. The relevant cementing quality evaluation methods have significant limitations, resulting in a technical problem that they cannot fully assess the cementing quality of double-casing wells.

[0091] A method for evaluating cementing quality in double-casing wells based on array acoustic logging includes:

[0092] (1) Numerical simulation of array acoustic logging response of cementing double-cased well, and obtaining the relationship between array acoustic logging response and the length, thickness and position of the channeling at the first, second, third and fourth interfaces of the double-cased well.

[0093] (2) By measuring the full wave train response obtained from the sonic logging model, the relationship between the array sonic logging response and the length, thickness and position of the channeling at the first, second, third and fourth interfaces of the double-cased well is verified.

[0094] In some implementations, the array acoustic logging response includes wave train amplitude, arrival time, propagation velocity, and phase velocity characteristics.

[0095] In some implementations, in (1), based on the wave equation, the full wave train response of array acoustic logging is numerically simulated when cross-channeling occurs at the first, second, third, and fourth interfaces of the cementing of a double-cased well.

[0096] In some implementations, in step (2), the numerical simulation results are verified by measuring the full wave train response obtained from the acoustic logging model, as follows:

[0097] The cementation of the first, second, third, and fourth interfaces is evaluated using the amplitude, arrival time, propagation speed, and phase velocity of the wave train. The arrival time is calculated using the Slowness Time Correlation (STC) method, and the phase velocity is calculated using the Slowness Frequency Correlation (SFC) method.

[0098] In some implementations, the phase velocity of the casing-cement composite mode wave decreases sequentially when cross-channeling occurs at the first, second, third, and fourth interfaces of the double-cased well.

[0099] In some implementations, when the channel thickness is the same, as the channel length increases, the amplitude of the casing-cement composite mode wave increases when channeling occurs at the first, second, third, and fourth interfaces of the double-cased well.

[0100] In some implementations, when the cross-cutting length is the same, as the cross-cutting thickness increases, the arrival time of the casing-cement composite mode wave decreases and the propagation speed increases when cross-cutting occurs at the first, second, third, and fourth interfaces of the double-cased well.

[0101] Compared with related technologies, the beneficial effects of the technical solution of the present invention are as follows:

[0102] (1) Comprehensiveness: The cementing quality evaluation method for double-cased wells based on array acoustic logging of this invention can not only evaluate the non-cementation of the first, second, third, and fourth interfaces of double-cased wells, but also evaluate the presence of channeling at the first, second, third, and fourth interfaces of double-cased wells. This greatly expands the scope of cementing quality evaluation, making the evaluation of cementing quality more comprehensive and accurate.

[0103] (2) Accuracy: The evaluation method of this invention uses multiple acoustic sensors placed at different locations to obtain the propagation time and amplitude changes of acoustic waves in the underground medium, thereby inferring the physical properties of the formation and wellbore. Compared with the prior art, this evaluation method of the present invention can provide higher evaluation accuracy, thus more accurately determining the quality of cementing.

[0104] (3) Practicality: Because the evaluation method of this invention can comprehensively and accurately evaluate the cementing quality of double-casing wells, the technical solution of this invention has significant practical value in the field of oil and gas extraction engineering. The technical solution of this invention can help oil companies better assess and manage the cementing quality of oil and gas wells, thereby improving the efficiency and safety of oil and gas extraction.

[0105] (4) Innovation: The evaluation method of this invention innovates upon related technologies by introducing new evaluation indicators and methods, thereby overcoming the limitations of related technologies. This not only improves the evaluation effect of cementing quality but also provides new ideas and technical support for the development of geophysical logging technology and oil and gas extraction engineering.

[0106] Figure 3 The waveforms of the first, second, third, and fourth interfaces of the double-casing cementing system, received by the array acoustic logging of the present invention, show the well-bonded cementation. Figure 4The image shows waveforms of channeling at the first, second, third, and fourth interfaces of a double-casing cementing system received by the array acoustic logging system according to the present invention. From left to right and top to bottom, these represent the first, second, third, and fourth interfaces, respectively. Figure 5 This is a waveform diagram of grooves appearing at the first interface of a double-casing cementing system, received by array acoustic logging. Figure 6 This is a waveform diagram of grooves appearing at the second interface of a double-casing cementing system, received by array acoustic logging. Figure 7 This is a waveform diagram of grooves appearing at the third interface of a double-casing cementing system, received by array acoustic logging. Figure 8 The waveform diagram shows the grooved pattern at the fourth interface of the double-casing cementing system, received by array acoustic logging.

[0107] Application Example 1: In this application example, a method for evaluating cementing quality in double-casing wells based on array acoustic logging will be described in detail.

[0108] Evaluation methods include:

[0109] (1) Numerical simulation of array acoustic logging response of cementing double-cased well to obtain the relationship between array acoustic logging response and the length, thickness and position of the channeling at the first, second, third and fourth interfaces of the double-cased well.

[0110] (2) Establish an acoustic logging model and use array acoustic logging technology to obtain acoustic data for a double-casing well with intact cementation and for a model with channeling at the first, second, third, and fourth interfaces. The acoustic data includes casing waves, cement annular waves, and formation waves.

[0111] (3) Based on the acquired acoustic wave data, calculate the amplitude, arrival time, propagation speed and phase velocity of the sleeve-cement composite mode wave.

[0112] (4) The cementation status of the first, second, third and fourth interfaces of the double-cased well is evaluated by using the amplitude, arrival time, propagation velocity and phase velocity of the casing-cement composite mode wave obtained by calculation.

[0113] Specifically, the phase velocity of the casing-cement composite mode wave decreases sequentially when cross-channeling occurs at the first, second, third, and fourth interfaces of a double-cased well.

[0114] Specifically, when the thickness of the channeling is the same, as the length of the channeling increases, the amplitude of the casing-cement composite mode wave increases when channeling occurs at the first, second, third, and fourth interfaces of the double-cased well.

[0115] Specifically, when the channeling length is the same, as the channeling thickness increases, the arrival time of the casing-cement composite mode wave decreases and the propagation speed increases when channeling occurs at the first, second, third, and fourth interfaces of the double-cased well.

[0116] The application method of the present invention will be further described.

[0117] Step 1: Perform array acoustic logging in the well section of the double-cased well to obtain data on the amplitude, arrival time, propagation velocity, and phase velocity of the casing-cement composite mode wave.

[0118] Step 2: Perform array sonic logging on the section of the double-cased well to be evaluated to obtain logging data for the double-cased well section.

[0119] Step 3: Based on the acquired logging data, calculate the amplitude, arrival time, propagation velocity, and phase velocity of the casing-cement composite mode wave.

[0120] Step 4: Compare the amplitude, arrival time, propagation velocity, and phase velocity of the wave in the casing-cement composite mode with those of the well-bonded section of the double-cased well.

[0121] Specifically, the interface where the channel is located is determined by the phase velocity of the sleeve-cement composite mode wave, the thickness of the channel is determined by the amplitude of the sleeve-cement composite mode wave, and the length of the channel is determined by the arrival time and propagation speed of the sleeve-cement composite mode wave.

[0122] The above are the specific steps of this application example. Through these steps, the cementing quality of double-cased wells can be comprehensively evaluated. This solves the problem that existing technologies can only evaluate the non-cementation of the first, second, third, and fourth interfaces of double-cased wells, and cannot evaluate the cross-flow situation at the first, second, third, and fourth interfaces of double-cased wells.

[0123] This invention discloses a method for evaluating the cementing quality of double-cased wells based on array acoustic logging, belonging to the field of geophysical logging engineering logging. This invention numerically simulates the array acoustic logging response of double-cased well cementing, and utilizes the wave train amplitude, arrival time, propagation velocity, and phase velocity characteristics of array acoustic logging to evaluate the cross-cutting length, thickness, and location of the first, second, third, and fourth interfaces of the double-cased well cementing. This invention solves the technical problem in related technologies that can only evaluate cases where the first, second, third, and fourth interfaces of a double-cased well are not cemented, but cannot evaluate cases where cross-cutting occurs at the first, second, third, and fourth interfaces of a double-cased well.

[0124] In the embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0125] It should be noted that, in this invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element limited by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0126] While the embodiments disclosed in this invention are as described above, the above content is merely for the purpose of facilitating understanding of this invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and changes in form and detail of the implementation without departing from the spirit and scope disclosed in this invention; however, the scope of patent protection of this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A method for evaluating the cementing quality of double-casing wells, characterized in that, The method includes: Well logging was performed on the cemented section of a double-cased well to obtain casing-cement composite mode wave data for the cemented section. Well logging was performed on the section of the double-cased well to be evaluated, and the casing-cement composite mode wave data of the section to be evaluated were obtained. The cementing quality of the casing-cement composite mode wave data of the section to be evaluated is evaluated by comparing it with that of the section with good cementation.

2. The method for evaluating cementing quality in double-casing wells according to claim 1, characterized in that, The step of logging the section to be evaluated in a double-cased well to obtain the casing-cement composite mode wave data of the section to be evaluated includes: Log the section of the double-cased well to be evaluated to obtain logging data for the section to be evaluated; Based on the logging data of the well section to be evaluated, the casing-cement composite mode wave data of the well section to be evaluated are calculated.

3. The method for evaluating cementing quality in double-casing wells according to claim 1, characterized in that, The logging includes array acoustic logging.

4. The method for evaluating the cementing quality of double-casing wells according to claim 1, characterized in that, The casing-cement composite mode wave data includes: the amplitude, arrival time, propagation speed, and / or phase velocity of the casing-cement composite mode wave.

5. The method for evaluating the cementing quality of double-casing wells according to claim 4, characterized in that, The step of comparing the casing-cement composite wave data of the section to be evaluated with the casing-cement composite wave data of the well section with good cementation to evaluate the cementing quality of the section to be evaluated in a double-cased well includes: The phase velocity of the casing-cement composite mode wave in the section to be evaluated is compared with the phase velocity of the casing-cement composite mode wave in the well-cemented section to evaluate the interface where the channeling occurs in the section to be evaluated in the double-cased well. The amplitude of the casing-cement composite mode wave in the section to be evaluated is compared with the amplitude of the casing-cement composite mode wave in the well-cemented section to evaluate the thickness of the channeling in the section to be evaluated in a double-cased well; and / or The arrival time and propagation velocity of the casing-cement composite mode wave in the section to be evaluated are compared with those of the well section with intact cementation to evaluate the length of the channeling in the section to be evaluated in the double-cased well.

6. The method for evaluating the cementing quality of double-casing wells according to claim 5, characterized in that, The interface includes: a first interface, a second interface, a third interface, and a fourth interface; The first interface includes the contact interface between the first layer of casing and the first layer of cement sheath from the inside to the outside of the double-cased well. The second interface includes the contact interface between the first cement sheath and the second casing layer from the inside to the outside of the double-cased well. The third interface includes the contact interface between the second casing and the second cement sheath from the inside to the outside of the double-cased well. The fourth interface includes the contact interface between the second cement sheath and the formation in a double-cased well.

7. A device for evaluating the cementing quality of double-casing wells, characterized in that, The device includes: The benchmark module is used to log the cemented section of a double-cased well to obtain the casing-cement composite mode wave data of the cemented section. The acquisition module is used to log the section of a double-cased well to be evaluated and obtain the casing-cement composite mode wave data of the section to be evaluated. The evaluation module is used to compare the casing-cement composite mode wave data of the section to be evaluated with the casing-cement composite mode wave data of the well section with good cementation to evaluate the cementing quality of the section to be evaluated in the double-cased well.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the double-casing well cementing quality evaluation method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the cementing quality evaluation method for double-casing wells as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the cementing quality evaluation method for double-casing wells as described in any one of claims 1 to 6.

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