A rapid formation cementation evaluation method, system, equipment, and storage medium based on first wave arrival time difference.

Abstract

This invention relates to the field of oil and gas exploration and development, specifically to a method, system, equipment, and storage medium for rapid formation cementation evaluation based on the first wave arrival time difference. The method includes obtaining the depth-arrival time curve and depth-relative acoustic amplitude curve of the cased well based on acoustic amplitude logging data; obtaining the array waveform-arrival time curve of the open hole well based on array acoustic logging data; establishing open hole and cased well models; calculating the arrival time of the open hole and cased well under different cementation conditions by real axis integration; and evaluating the cementation quality of the casing interface based on the difference in arrival times. This method solves the problem that traditional techniques struggle to clearly distinguish between formation wave and casing wave information, thus severely hindering the accurate evaluation of cementation quality in rapid formation sections.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration and development, specifically to a rapid formation cementation evaluation method, system, equipment, and storage medium based on the first wave arrival time difference. Background Technology

[0002] Cementing is a crucial part of oil and gas well drilling and completion. The process primarily involves filling the annular space between the outer wall of the casing and the wellbore, or the inner wall of the outer casing, with cement placed centrally in the wellbore. The purpose is twofold: firstly, to seal the formation and ensure the orderly and efficient development of oil, gas, and water; and secondly, to fix the metal casing and separate it from formation fluids, thereby extending the casing's lifespan. In practice, the cement bonding effect is often affected by factors such as temperature, pressure, wellbore size, and cement formulation, making complete consolidation of the annular space impossible. This results in incomplete sealing of the formation's oil and gas, leading to fluid cross-contamination between producing layers and shortening the well's development life and efficiency. Acoustic amplitude logging, which uses acoustic principles to measure the reflected wave energy at the casing-cement and cement-formation interfaces, is an effective method for evaluating cement cementing quality.

[0003] When the instrument performs acoustic amplitude logging centered in the casing, the travel time of each wave component is fixed. Therefore, a fixed recording time window is used to acquire the casing wave first wave signal. In sandstone and mudstone formations, the arrival time of the casing wave is much shorter than that of the formation wave, so the amplitude of the casing wave can be directly determined. However, in fast-moving formations such as carbonate rocks, the propagation speed of the formation wave is greater than that of the casing wave, which presents two problems for acoustic amplitude measurement: First, even if there is a free casing calibration point in the casing and the recording gate can be accurately established at the casing wave first wave position, when entering the fast formation measurement section, because the formation wave signal leads, the casing wave first wave acquired at the casing wave position is not a single casing wave component, but rather a superposition of the casing wave first wave component and the fast formation wave component. The amplitude of the acquired first wave signal still contains the formation wave component, and due to the phase relationship between the two, its amplitude also depends on the change in phase difference. The amplitude values ​​of the superimposed recorded signals cannot fully reflect the actual cement bonding situation; secondly, in the absence of a free casing calibration point, when calibrating at the point of maximum relative amplitude in a single well, it is difficult to acquire the first wave of the casing wave due to the leading formation wave. Often, the recording gate is set at the position of the leading formation wave's first wave, and what is detected is the amplitude change information of the formation wave's first wave. Based on the above problems, continuing to use the conventional CBL evaluation method in fast-moving formations will lead to erroneous conclusions. Summary of the Invention

[0004] To address the problems mentioned in the prior art, this invention proposes a rapid formation cementation evaluation method, system, equipment, and storage medium based on the arrival time difference of the first wave. Using numerical simulation, it can calculate the changes in the arrival time and amplitude of the first wave in rapid formations from well cemented to free casing models. By calculating the difference in arrival time between the casing wave first wave and the open hole wave first wave under different cementation conditions, the cement cementation quality of rapid formations can be judged.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a rapid formation cementation evaluation method based on the first wave arrival time difference, comprising the following steps: S1. Based on the acoustic amplitude logging data, obtain the well depth-time curve TL1 and the well depth-relative acoustic amplitude curve AL1 for the casing well; based on the array acoustic logging data, obtain the array waveform-time curve TL2 for the open hole well. S2. Based on the acoustic parameters of the fluid and formation in the well, establish an open-hole well model, calculate the acoustic waveform in the open-hole well model using the real axis integral method, and determine the arrival times of the first and second first waves. S3. Based on the velocity-density parameters of the fluid, casing, and cement in the well, a casing well model is established. The acoustic waveform in the casing well model is calculated using the real axis integration method to obtain the time-relative acoustic amplitude curve TL3. S4. Based on the arrival time of the first wave in S2 and the arrival time-relative acoustic amplitude curve TL3 in S3, the difference curve TL4 between the arrival time of the casing wave and the open-hole formation wave under different relative amplitudes is obtained. Based on the arrival time of the second first wave in S2 and the arrival time-relative acoustic amplitude curve TL3, the difference correction curve TL5 between the arrival time of the casing wave and the naked-hole formation wave under different relative amplitudes is obtained. S5. Based on the well depth-relative acoustic amplitude curve AL1 and the difference correction curve TL5 in S1, the well depth-to-time difference correction curve TL6 is obtained. Based on the well depth-to-time difference correction curve TL6, the array waveform-to-time curve TL2 of the open hole in S1 is corrected to the well depth-to-time curve TL7 of the open hole at the same scale; S6. Based on the difference between the well depth-time curve TL1 of the casing well in S1 and the well depth-time curve TL7 of the open hole well in S5, and the difference curve TL4 in S4, the cementation evaluation of the rapid formation is obtained.

[0006] As a further improvement of the present invention, the acoustic amplitude logging data in S1 is acquired by non-directional cement bonded logging acoustic amplitude logging and acoustic variable density logging. Array acoustic logging data is acquired by array waveform logging.

[0007] As a further improvement to the present invention, the calculation formula for the open-hole well model in S2 is as follows:

[0008] In the formula: n Indicates the ordinal number of the circumferential orientation; n This represents a monopole sound source, which is set to 0 here; r Indicates radial distance; k Here is the axial wave number; z This is the axial distance; ω Angular frequency; It is the sound source function; It is a type n-th order variant of the Bessel function; It is the acoustic amplitude coefficient inside the well; The acoustic amplitude coefficient inside the well The formula for calculation is:

[0009] In the formula: f It is the fluid inside the well; for Strata; M This is the coefficient matrix of the medium; A f The acoustic amplitude coefficient of the fluid flowing inward within the well; B for , D for , F for This represents the acoustic amplitude coefficient from within the stratum outwards; and The displacement and stress of the direct wave.

[0010] As a further improvement of the present invention, the casing well model in S3 includes a free casing model, a casing well model with poor I-interface cementation, a casing well model with relatively poor I-interface cementation, and a well-cemented model. The calculation formula for a well-bonded model is as follows:

[0011] In the formula: fl Represents the fluid inside the well; ca Representative sleeve; ce Represents cement; for Representative strata; r 0 represents the well wall, r 1 represents the radius of interface I. r 2 represents the radius of interface II; T The coefficient matrix representing the medium; Q Represents the acoustic amplitude coefficient of the casing, cement, and formation; and Displacement and stress representing the direct wave; The calculation formula for the casing well model with poor interfacial bonding is as follows:

[0012] In the formula: M This represents a matrix relating to the coupling stiffness coefficients; The calculation formula for the free sleeve model is as follows:

[0013] The calculation formula for the casing well model with relatively poor cementation at interface I is as follows:

[0014] In the formula: d This indicates the thickness of the fluid ring.

[0015] As a further improvement of the present invention, the source distance for the real axis integration method in S2 is 5ft, and the calculation frequency is based on the frequency of the measured array waveform. In S3, the source distance for the real-axis integration method is 5ft, and the calculation frequency is the center frequency of the measured casing well waveform.

[0016] As a further improvement of the present invention, the arrival time difference curve TL4 of the casing wave and the open-hole formation wave under different relative amplitudes in S4 can determine the arrival time range of the cementation superiority-inferiority difference based on the magnitude of the relative amplitude. As a further improvement of the present invention, if the difference between the arrival time of the well depth-arrival time curve TL7 obtained after correction in S6 and the arrival time of the well depth-arrival time curve TL1 is less than 30 μs, it can be identified as a fast formation.

[0017] A rapid formation cementation evaluation system based on first wave arrival time difference includes: The acquisition module is used to acquire the depth-time curve TL1 and the depth-relative acoustic amplitude curve AL1 of the cased well based on the acoustic amplitude logging data, and to acquire the array waveform-time curve TL of the open hole well based on the array acoustic logging data. The first module is used to establish an open-hole well model based on the acoustic parameters of the fluid and formation in the well. It uses the real axis integration method to calculate the acoustic waveform in the open-hole well model and determine the arrival times of the first and second first waves. The second module is used to establish a casing well model based on the velocity-density parameters of the fluid, casing, and cement in the well. It uses the real axis integration method to calculate the acoustic waveform in the casing well model and obtain the time-relative acoustic amplitude curve TL3. The first calculation module is used to obtain the difference curve TL4 between the arrival times of the casing wave and the open-hole formation wave under different relative amplitudes, based on the arrival time of the first wave in the first establishment module and the arrival time-relative acoustic amplitude curve TL3 in the second establishment module. Based on the arrival time of the second first wave in the first establishment module and the arrival time-relative acoustic amplitude curve TL3, the difference correction curve TL5 between the arrival time of the casing wave and the open-hole formation wave under different relative amplitudes is obtained. The second calculation module is used to obtain the well depth-to-time difference correction curve TL6 based on the well depth-relative acoustic amplitude curve AL1 and the difference correction curve TL5 in the acquisition module. Based on the well depth-to-time difference correction curve TL6, the array waveform-to-time curve TL2 of the open hole in S1 is corrected to the well depth-to-time curve TL7 of the open hole at the same scale; The evaluation module is used to compare the difference between the well depth-time curve TL1 of the casing well in the acquisition module and the well depth-time curve TL7 of the open hole well in the second calculation module with the difference curve TL4 in the first calculation module to obtain the cementation evaluation of the rapid formation.

[0018] A rapid formation consolidation evaluation device based on first-wave arrival time difference includes a processor and a memory, wherein the processor executes a computer program stored in the memory to implement the rapid formation consolidation evaluation method based on first-wave arrival time difference as described above.

[0019] A computer-readable storage medium for storing a computer program, wherein the computer program, when executed by a processor, implements the rapid formation cementation evaluation method based on the first wave to time difference as described above.

[0020] Compared with the prior art, the present invention achieves the following technical effects: This invention uses the real-axis integration method to calculate the arrival time of open-hole and casing wells under different cementing conditions. By comparing the arrival time difference between the two, the cementing quality of the casing interface can be evaluated. This solves the problem that traditional techniques have difficulty in clearly distinguishing formation wave and casing wave information, which seriously hinders the accurate evaluation of cementing quality in fast formation sections.

[0021] This invention integrates acoustic logging data from open-hole arrays and cased-hole acoustic amplitude logging data. A model is used to calculate the acoustic arrival times under open-hole conditions and different cementation states in cased-hole wells. The difference between the acoustic arrival times in the open-hole and cased-hole wells is used. When the arrival time of the cased-hole wave is equal to or greater than the arrival time of the formation wave, it indicates that the formation is a fast-forming formation. Furthermore, this invention can evaluate the cementation quality between the casing and the formation based on the magnitude of the arrival time difference, which not only improves the accuracy and reliability of cementing quality evaluation but also provides strong data support for subsequent production operations. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall process of the present invention; Figure 2This is a schematic diagram illustrating the simulation results of the time difference between the casing and the open-hole formation wave arrival in an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the effect of the first wave arrival time difference method for rapid formation cementing quality evaluation in Well X according to an embodiment of the present invention. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0024] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments: like Figure 1 As shown, the present invention provides a rapid formation cementation evaluation method based on the first wave arrival time difference, comprising the following steps: Step 1: Based on the acoustic waveforms at different depth points obtained from acoustic amplitude logging data, extract the relative amplitude of the first wave and the arrival time of the casing wave. In this embodiment, non-directional cement bonded logging acoustic amplitude logging and acoustic variable density logging are preferred to acquire the well depth-arrival time curve TL1 and the well depth-relative acoustic amplitude curve AL1 of the casing well. Array waveform logging data is acquired through array waveform logging. Based on the acoustic waveforms of the open hole well at different depth points obtained from the array acoustic logging data, extract the arrival time of the waveform (at the first depth point) to obtain the well depth-arrival time curve TL2.

[0025] Step 2: Based on the array acoustic logging, density logging, and caliper logging data within the depth range, obtain the actual data such as formation velocity, density, and caliper within the depth range, establish an open-hole well model, calculate the acoustic waveform of the open-hole well model using the real axis integration method, calculate the source distance of 5ft and the source distance based on the measured array logging data, and record the arrival times of the first and second waves.

[0026] In the established open-hole well model, the parameters of the fluid inside the well remain constant. The formation time difference curve obtained from the array waveform data is calculated using the following formula:

[0027] In the formula: n Indicates the ordinal number of the circumferential orientation; n This represents a monopole sound source, which is set to 0 here; r Indicates radial distance; k Here is the axial wave number; z This is the axial distance; ω Angular frequency; It is the sound source function; It is a type n-th order variant of the Bessel function; It is the acoustic amplitude coefficient inside the well; The acoustic amplitude coefficient in the well The formula for calculation is:

[0028] In the formula: f It is the fluid inside the well; for Strata; M This is the coefficient matrix of the medium; A f The acoustic amplitude coefficient of the fluid flowing inward within the well; B for , D for , F for This represents the acoustic amplitude coefficient from within the stratum outwards; and The displacement and stress of the direct wave.

[0029] Step 3: Based on the acoustic parameters of fluid, casing, and cement obtained from data such as casing specifications and cement specifications, establish a casing well model; use the real axis integration method to calculate the acoustic waveform of the casing well model, obtain the first wave amplitude and arrival time of the casing wave, normalize with the free casing section as 100%, and obtain the arrival time-relative acoustic amplitude curve TL3.

[0030] The established casing well models include a free casing model, a casing well model with poor I-interface cementation (represented by fluid ring thickness), a casing well model with relatively poor I-interface cementation (represented by shear coupling stiffness of the slip interface), and a well-cemented model; the calculation methods for acoustic amplitude coefficients of different cementation types in the casing well models are different.

[0031] The calculation formulas for different bonding conditions are as follows: The calculation formula for a well-bonded model is as follows:

[0032] In the formula: fl Represents the fluid inside the well; ca Representative sleeve; ce Represents cement; for Representative strata; r 0 represents the well wall, r 1 represents the radius of interface I. r 2 represents the radius of interface II; T The coefficient matrix representing the medium; Q Represents the acoustic amplitude coefficient of the casing, cement, and formation; and Displacement and stress representing the direct wave; The calculation formula for the casing well model with poor interfacial bonding is as follows:

[0033] In the formula: M This represents a matrix relating to the coupling stiffness coefficients; The calculation formula for the free sleeve model is as follows:

[0034] The calculation formula for the casing well model with relatively poor cementation at interface I is as follows:

[0035] In the formula: d This indicates the thickness of the fluid ring.

[0036] Step 4: Based on the theoretically calculated arrival time of the first wave and the arrival time-relative acoustic amplitude curve TL3 of the open hole with a source distance of 5ft, obtain the difference curve TL4 of the arrival time between the casing wave and the open hole formation wave under different relative amplitudes, and determine the arrival time range of cementation superiority and intermediate difference based on the magnitude of the relative amplitude.

[0037] Based on the theoretically calculated source distance and the measured open-hole source distance, the arrival time of the second first wave and the arrival time-relative acoustic amplitude curve TL3 are used to obtain the difference correction curve TL5 between the arrival time of the casing wave and the open-hole formation wave under different relative amplitudes. This curve is used to correct the arrival time of the measured source distance to 5ft.

[0038] Step 5: Based on the actual measured well depth-relative acoustic amplitude curve AL1 and the relative acoustic amplitude-first wave difference correction curve TL5, obtain the well depth-time difference correction curve TL6; subtract the correction curve TL6 from the measured array waveform time curve TL2 to obtain the well depth-time curve TL7 of the open hole well with a source distance of 5ft.

[0039] Step 6: When the arrival time of the well depth-arrival time curve TL7 obtained after correction is close to that of the well depth-arrival time curve TL1 (the difference between the two arrival times is less than 30μs), it can be identified as a fast formation; based on the difference between curve TL1 and curve TL7, the cementation status of the fast formation can be obtained by using the arrival time difference range of cementation quality and quality obtained by the difference curve TL4.

[0040] Figure 2This refers to the difference between the acoustic arrival time (AUT) of the formation and the acoustic arrival time of the formation under different cemented bonding conditions, calculated using real-axis integration. Specifically, in fast formations with 5.5-inch casing, the cemented bonding quality is rated as poor when the AUT difference between the casing and the formation is less than 3.75 μs; in fast formations with 7-inch casing, the AUT difference is rated as poor when it is less than 12.5 μs; and in fast formations with 9.625-inch casing, the AUT difference is rated as poor when it is less than 31.25 μs. However, the evaluation of the degree of cementation quality is slightly worse than that of 5.5-inch and 7-inch casings, reflecting that the effectiveness of this method is related to the casing size; the smaller the casing size, the better the application effect.

[0041] Figure 3 This demonstrates the effectiveness of using the first wave arrival time difference to evaluate the quality of rapid formation cementing in Well X. Well X has a casing size of 5.5", a casing wall thickness of 12.09 mm, and a cement density of 1.88 g / cm³. 3 . Figure 3 The first track shows the acoustic amplitude curve obtained from the casing well acoustic amplitude logging; the second track shows the measured relative acoustic amplitude value; the midline of the third track is the formation arrival time curve obtained from the array acoustic logging, and the solid line is the arrival time curve after correcting the formation measured from a 3m source distance to the same source distance as the acoustic amplitude measurement; the midline of the fourth track shows the casing wave-formation wave arrival time difference; the fifth track shows the measured waveform of the acoustic amplitude logging and the extracted first wave arrival time curve; the sixth track shows the measured waveform of the array acoustic logging and the extracted formation wave arrival time curve, and the first wave arrival time extracted from the acoustic amplitude variable density logging. Judging from the acoustic amplitude value, the acoustic amplitude value of this well section is generally greater than 15%, and in some areas greater than 30%, indicating that the cementation quality is generally average. Using this method, when the arrival time difference is greater than 3.75μs, it is judged as average or better cementation, and when the arrival time difference is greater than 12.5μs, it is judged as good cementation. Therefore, the cementation quality of this section is generally good.

[0042] Based on the same inventive concept, this embodiment of the invention also provides a rapid formation cementation evaluation system based on the first wave arrival time difference. Since the principle of this rapid formation cementation evaluation system based on the first wave arrival time difference is similar to that of the aforementioned rapid formation cementation evaluation method based on the first wave arrival time difference, the implementation of this rapid formation cementation evaluation system based on the first wave arrival time difference can refer to the implementation of the rapid formation cementation evaluation method based on the first wave arrival time difference, and the repeated parts will not be described again.

[0043] In practical implementation, the rapid formation cementation evaluation system based on the first wave to time difference provided in this embodiment of the invention specifically includes: The acquisition module is used to acquire the depth-time curve TL1 and the depth-relative acoustic amplitude curve AL1 of the cased well based on the acoustic amplitude logging data, and to acquire the array waveform-time curve TL of the open hole well based on the array acoustic logging data. The first module is used to establish an open-hole well model based on the acoustic parameters of the fluid and formation in the well. It uses the real axis integration method to calculate the acoustic waveform in the open-hole well model and determine the arrival times of the first and second first waves. The second module is used to establish a casing well model based on the velocity-density parameters of the fluid, casing, and cement in the well. It uses the real axis integration method to calculate the acoustic waveform in the casing well model and obtain the time-relative acoustic amplitude curve TL3. The first calculation module is used to obtain the difference curve TL4 between the arrival times of the casing wave and the open-hole formation wave under different relative amplitudes, based on the arrival time of the first wave in the first establishment module and the arrival time-relative acoustic amplitude curve TL3 in the second establishment module. Based on the arrival time of the second first wave in the first establishment module and the arrival time-relative acoustic amplitude curve TL3, the difference correction curve TL5 between the arrival time of the casing wave and the open-hole formation wave under different relative amplitudes is obtained. The second calculation module is used to obtain the well depth-to-time difference correction curve TL6 based on the well depth-relative acoustic amplitude curve AL1 and the difference correction curve TL5 in the acquisition module. Based on the well depth-to-time difference correction curve TL6, the array waveform-to-time curve TL2 of the open hole in S1 is corrected to the well depth-to-time curve TL7 of the open hole at the same scale; The evaluation module is used to compare the difference between the well depth-time curve TL1 of the casing well in the acquisition module and the well depth-time curve TL7 of the open hole well in the second calculation module with the difference curve TL4 in the first calculation module to obtain the cementation evaluation of the rapid formation.

[0044] Accordingly, embodiments of the present invention also provide a rapid formation cementation evaluation device based on first-wave arrival time difference, including a processor and a memory, wherein the processor executes a computer program stored in the memory to implement the rapid formation cementation evaluation method based on first-wave arrival time difference provided in embodiments of the present invention.

[0045] For more detailed information on the above methods, please refer to the relevant content disclosed in the foregoing embodiments, which will not be repeated here.

[0046] Accordingly, embodiments of the present invention also provide a computer-readable storage medium for storing a computer program, wherein the computer program, when executed by a processor, implements the above-described rapid formation cementation evaluation method based on first wave arrival time difference provided in embodiments of the present invention.

[0047] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems, devices, and storage media disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0048] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0049] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0050] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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 limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0051] The above provides a detailed description of the rapid formation cementation evaluation method, system, equipment, and storage medium based on the first wave arrival time difference provided by this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A rapid formation cementation evaluation method based on first-wave arrival time difference, characterized in that, Includes the following steps: S1. Based on the acoustic amplitude logging data, obtain the well depth-time curve TL1 and the well depth-relative acoustic amplitude curve AL1 for the casing well; based on the array acoustic logging data, obtain the array waveform-time curve TL2 for the open hole well. S2. Based on the acoustic parameters of the fluid and formation in the well, establish an open-hole well model, calculate the acoustic waveform in the open-hole well model using the real axis integral method, and determine the arrival times of the first and second first waves. S3. Based on the velocity-density parameters of the fluid, casing, and cement in the well, a casing well model is established. The acoustic waveform in the casing well model is calculated using the real axis integration method to obtain the time-relative acoustic amplitude curve TL3. S4. Based on the arrival time of the first wave in S2 and the arrival time-relative acoustic amplitude curve TL3 in S3, the difference curve TL4 between the arrival time of the casing wave and the open-hole formation wave under different relative amplitudes is obtained. Based on the arrival time of the second first wave in S2 and the arrival time-relative acoustic amplitude curve TL3, the difference correction curve TL5 between the arrival time of the casing wave and the naked-hole formation wave under different relative amplitudes is obtained. S5. Based on the well depth-relative acoustic amplitude curve AL1 and the difference correction curve TL5 in S1, the well depth-to-time difference correction curve TL6 is obtained. Based on the well depth-to-time difference correction curve TL6, the array waveform-to-time curve TL2 of the open hole in S1 is corrected to the well depth-to-time curve TL7 of the open hole at the same scale; S6. Based on the difference between the well depth-time curve TL1 of the casing well in S1 and the well depth-time curve TL7 of the open hole well in S5, and the difference curve TL4 in S4, the cementation evaluation of the rapid formation is obtained.

2. The rapid formation cementation evaluation method based on first-wave arrival time difference according to claim 1, characterized in that, The acoustic amplitude logging data in S1 is acquired by non-directional cement bonded logging acoustic amplitude logging and acoustic variable density logging. Array acoustic logging data is acquired by array waveform logging.

3. The rapid formation cementation evaluation method based on first-wave arrival time difference according to claim 1, characterized in that, The calculation formula for the open-hole well model in S2 is as follows: In the formula: n Indicates the ordinal number of the circumferential orientation; n This represents a monopole sound source, which is set to 0 here; r Indicates radial distance; k Here is the axial wave number; z This is the axial distance; ω Angular frequency; It is the sound source function; It is a type n-th order variant of the Bessel function; It is the acoustic amplitude coefficient inside the well; The acoustic amplitude coefficient inside the well The formula for calculation is: In the formula: f It is the fluid inside the well; for Strata; M This is the coefficient matrix of the medium; A f The acoustic amplitude coefficient of the fluid flowing inward within the well; B for , D for , F for This represents the acoustic amplitude coefficient from within the stratum outwards; and The displacement and stress of the direct wave.

4. The rapid formation cementation evaluation method based on first-wave arrival time difference according to claim 1, characterized in that, The casing well models in S3 include a free casing model, a casing well model with poor I-interface cementation, a casing well model with relatively poor I-interface cementation, and a well-cemented model. The calculation formula for a well-bonded model is as follows: In the formula: fl Represents the fluid inside the well; ca Representative sleeve; ce Represents cement; for Representative strata; r 0 represents the well wall, r 1 represents the radius of interface I. r 2 represents the radius of interface II; T The coefficient matrix representing the medium; Q Represents the acoustic amplitude coefficient of the casing, cement, and formation; and Displacement and stress representing the direct wave; The calculation formula for the casing well model with poor interfacial bonding is as follows: In the formula: M This represents a matrix relating to the coupling stiffness coefficients; The calculation formula for the free sleeve model is as follows: The calculation formula for the casing well model with relatively poor cementation at interface I is as follows: In the formula: d This indicates the thickness of the fluid ring.

5. A rapid formation cementation evaluation method based on first-wave arrival time difference as described in claim 3 or 4, characterized in that, The source distance calculated by the real axis integration method in S2 is 5ft, and the calculation frequency is based on the frequency of the measured array waveform. In S3, the source distance for the real-axis integration method is 5ft, and the calculation frequency is the center frequency of the measured casing well waveform.

6. The rapid formation cementation evaluation method based on first-wave arrival time difference according to claim 1, characterized in that, The arrival time difference curve TL4 between the casing wave and the open-hole formation wave at different relative amplitudes in S4 can determine the arrival time range of the cementation difference based on the magnitude of the relative amplitude.

7. The rapid formation cementation evaluation method based on first-wave arrival time difference according to claim 1, characterized in that, If the difference between the arrival time of the well depth-arrival time curve TL7 obtained after correction in S6 and the arrival time of the well depth-arrival time curve TL1 is less than 30 μs, it can be identified as a fast formation.

8. A rapid formation cementation evaluation system based on first-wave arrival time difference, characterized in that, include: The acquisition module is used to acquire the depth-time curve TL1 and the depth-relative acoustic amplitude curve AL1 of the cased well based on the acoustic amplitude logging data, and to acquire the array waveform-time curve TL of the open hole well based on the array acoustic logging data. The first module is used to establish an open-hole well model based on the acoustic parameters of the fluid and formation in the well. It uses the real axis integration method to calculate the acoustic waveform in the open-hole well model and determine the arrival times of the first and second first waves. The second module is used to establish a casing well model based on the velocity-density parameters of the fluid, casing, and cement in the well. It uses the real axis integration method to calculate the acoustic waveform in the casing well model and obtain the time-relative acoustic amplitude curve TL3. The first calculation module is used to obtain the difference curve TL4 between the arrival times of the casing wave and the open-hole formation wave under different relative amplitudes, based on the arrival time of the first wave in the first establishment module and the arrival time-relative acoustic amplitude curve TL3 in the second establishment module. Based on the arrival time of the second first wave in the first establishment module and the arrival time-relative acoustic amplitude curve TL3, the difference correction curve TL5 between the arrival time of the casing wave and the open-hole formation wave under different relative amplitudes is obtained. The second calculation module is used to obtain the well depth-to-time difference correction curve TL6 based on the well depth-relative acoustic amplitude curve AL1 and the difference correction curve TL5 in the acquisition module. Based on the well depth-to-time difference correction curve TL6, the array waveform-to-time curve TL2 of the open hole in S1 is corrected to the well depth-to-time curve TL7 of the open hole at the same scale; The evaluation module is used to compare the difference between the well depth-time curve TL1 of the casing well in the acquisition module and the well depth-time curve TL7 of the open hole well in the second calculation module with the difference curve TL4 in the first calculation module to obtain the cementation evaluation of the rapid formation.

9. A rapid formation cementation evaluation device based on the first wave arrival time difference, characterized in that, It includes a processor and a memory, wherein the processor executes a computer program stored in the memory to implement the rapid formation cementation evaluation method based on the first wave to time difference as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, Used to store a computer program, wherein the computer program, when executed by a processor, implements the rapid formation cementation evaluation method based on first-wave arrival time difference as described in any one of claims 1 to 7.

Images