A cementing quality detection device and a cementing quality detection method
By using a cementing quality inspection device with a robotic arm in contact with the inner wall of the casing in PVC casing wells, the signal propagation path is redefined as a casing structure vibration propagation model, which solves the problem of poor detection accuracy of traditional sonic logging methods in PVC casing wells and realizes accurate detection of cement sheath bonding status.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING RESEARCH INSTITUTE OF CHEMICAL ENGINEERING AND METALLURGY
- Filing Date
- 2026-06-04
- Publication Date
- 2026-07-21
AI Technical Summary
Traditional acoustic logging methods are difficult to effectively detect cementing quality in PVC casing wells because the low acoustic impedance of PVC casing leads to low energy coupling efficiency, poor signal-to-noise ratio of received signals, and difficulty in obtaining stable cement sheath response information.
The cementing quality inspection equipment includes a detector body, a robotic arm, a support mechanism, and a transducer assembly. The robotic arm contacts the inner wall of the casing to transmit and receive waveform signals. The signal propagation path is redefined as the casing structure vibration propagation model, and the elastic wave response is used for detection.
It improves the accuracy of cementing quality detection and can effectively extract target reflected waves in scenarios where traditional sonic logging is not applicable, thus enabling accurate evaluation of the cement sheath bonding state.
Smart Images
Figure CN122428895A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of in-situ leaching uranium mining technology, and in particular to a cementing quality testing device and a cementing quality testing method. Background Technology
[0002] In the field of in-situ leaching uranium production, non-metallic casings such as PVC are increasingly being used. PVC materials, with their low density, low elastic modulus, and low acoustic impedance, significantly alter traditional acoustic logging conditions. In PVC-cased wells, traditional acoustic-based CBL and VDL cementing quality inspection methods are difficult to apply because the acoustic waves propagating in the well fluid are insufficient to effectively excite casing vibration; most of the energy propagates along the well fluid or attenuates within the casing, resulting in a significant reduction in the effective energy reaching the cement sheath. Therefore, cementing quality assessment is a crucial step in in-situ leaching uranium production and wellbore integrity evaluation in underground engineering. Its main purpose is to detect the bonding state between the casing and the cement sheath, and between the cement sheath and the formation.
[0003] Currently, existing cementing quality inspection typically employs acoustic cementing logging instruments combined with acoustic logging methods. These instruments usually include a source transducer and a receiver transducer. The sound source excites elastic wave signals in the well fluid, which propagate through the fluid to the casing and then couple into the cement sheath and formation. The cement sheath bonding quality is then evaluated by analyzing the amplitude, waveform, and propagation characteristics of the received signal. However, this method relies heavily on the excellent elastic waveguide properties of metal casing to allow acoustic energy to propagate along the casing and couple with the cement sheath. PVC casing, due to its low acoustic impedance and weak waveguide capability, suffers from extremely low energy coupling efficiency, resulting in poor signal-to-noise ratio and indistinct characteristics in the received signal. Furthermore, traditional non-contact excitation and reception modes primarily receive casing propagation waves or well fluid waves, making it difficult to obtain stable cement sheath response information and thus hindering the accurate acquisition of effective acoustic waves. Summary of the Invention
[0004] In view of this, this application provides a cementing quality testing device and a cementing quality testing method, the main purpose of which is to solve the problem of poor accuracy in existing cementing quality testing.
[0005] According to one aspect of this application, a cementing quality testing device is provided, comprising: The detector body, several robotic arms, a support mechanism, and several transducer assemblies; The robotic arm is arranged on the detector body according to a preset detection array. One end of the robotic arm is hinged to the detector body via a rotating mechanism, and the other end of the robotic arm is connected to the transducer assembly. Each robotic arm can be adapted to casing wells of different diameters by telescopic extension. The transducer assembly is connected to the robotic arm via the support mechanism, and in the extended state of the robotic arm, it contacts the inner wall of the casing well for transmitting and receiving waveform signals. The detector body is used to mount a power module, a processing module, and several wires to process the waveform signal.
[0006] Furthermore, the transducer assembly includes an excitation module, a receiving module, a signal acquisition module, and a control module, which are electrically connected to the power supply module in sequence. The excitation module is used to transmit waveform signals, the receiving module is used to convert electrical signals of mechanical vibrations, the signal acquisition module is used to amplify signals and perform digital-to-analog conversion, and the control module is used to control the signal transmission frequency and the acquisition frequency.
[0007] Furthermore, the support mechanism includes any one of the following: a stabilizing loading mechanism, a sliding telescopic radial probe structure, a radial telescopic rod structure, a flexible support arm structure, and a multi-segment folding support structure. The stabilizing loading mechanism includes any one of the following: a spring loading mechanism, an airbag expansion loading structure, a rubber elastic support structure, a roller clamping structure, an adjustable preload mechanism, and a magnetic or mechanical locking loading structure, so that the transducer assembly is pressed against the inner wall of the casing well after pressure is applied by the stabilizing loading mechanism.
[0008] Furthermore, the detector body has a cylindrical structure, and the transducer assembly is driven through the well shaft when the robotic arm is in the retracted state.
[0009] Furthermore, the waveform signal includes any one of compression wave, shear wave, structured guided wave, surface wave, and elastic wave.
[0010] Furthermore, the preset detection array arrangement includes any one of the following: circumferential uniform array arrangement, spiral distribution array arrangement, and axial multi-layer array arrangement.
[0011] According to another aspect of this application, a method for detecting cementing quality is provided, applied to the cementing quality detection equipment, comprising: Acquire waveform signals, which are collected by the transducer assembly after the cementing quality testing equipment is fixed to the inner wall of the casing well by a robotic arm; Based on the theoretical arrival time of the waveform signal, the signal is divided into time windows, and the target reflected wave corresponding to the time window is determined. Based on the characteristic parameters of the target reflected wave, a quality evaluation index is determined, and the cementing quality detection results are generated.
[0012] Furthermore, the process of dividing the signal based on the theoretical arrival time of the waveform signal to obtain a time window includes: Multiple propagation paths of the waveform signal are determined, and the theoretical arrival time is calculated based on the propagation speed corresponding to the propagation path. Based on the aforementioned theory, a corresponding time window is established upon reaching the specified time.
[0013] Further, determining the target reflected wave corresponding to the time window includes: The waveform signal is superimposed and enhanced according to the time window to obtain the superimposed target wave signal; The energy value corresponding to each time window is calculated based on the target wave signal, and the target reflected wave is determined based on the time window corresponding to the largest energy value.
[0014] Furthermore, after acquiring the waveform signal, the method further includes: The waveform signal is preprocessed to obtain the waveform signal to be divided. The preprocessing includes at least one of DC component removal processing, bandpass filtering processing, amplitude normalization processing, and multi-channel signal time synchronization correction.
[0015] By employing the above technical solutions, the technical solutions provided in the embodiments of this application have at least the following advantages: This application provides a cementing quality testing device and a cementing quality testing method. Compared with the prior art, the device in this application includes: a detector body, several robotic arms, a support mechanism, and several transducer assemblies; wherein, the robotic arms are arranged on the detector body according to a preset detection array, one end of each robotic arm is hinged to the detector body via a rotating mechanism, and the other end of each robotic arm is connected to the transducer assembly; each robotic arm is adapted to casing wells of different diameters by telescopic extension; the transducer assembly is connected to the robotic arm via the support mechanism, and in the extended state of the robotic arm, it contacts the inner wall of the casing well for transmitting and receiving waveform signals; the detection... The main body of the detector is used to load a power module, a processing module, and several wires to process the waveform signal. By limiting the received signal to the elastic wave response generated by the mechanical coupling excitation of the casing wall, and redefining the signal propagation path based on this coupling condition, the detection problem is transformed from the traditional well fluid acoustic wave propagation model to the casing structure vibration propagation model. A new interpretation basis is constructed from the signal source level. Through time window selection and wave field decomposition methods based on propagation time difference and array response characteristics, the effective extraction of target reflected waves is achieved. By calculating the evaluation characteristics of the separated target waveband, detection of scenarios that cannot be applied by traditional acoustic logging is realized, greatly improving the detection accuracy of cementing quality.
[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description
[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This illustration shows a structural schematic diagram of a cementing quality testing device provided in an embodiment of this application; Figure 2 This illustration shows a schematic diagram of a robotic arm in an deployed state according to an embodiment of this application; Figure 3 This illustration shows a schematic diagram of a robotic arm in a retracted state according to an embodiment of this application. Figure 4 This illustration shows a working state effect diagram provided by an embodiment of this application; Figure 5 This illustration shows a schematic diagram of the working principle provided in an embodiment of this application; Figure 6 A schematic diagram of a cementing quality detection method provided in an embodiment of this application is shown; Figure 7 This illustration shows a schematic diagram of a well logging workflow provided in an embodiment of this application; Figure 8 This illustration shows a schematic diagram of the propagation path of various waveforms provided in an embodiment of this application; Figure 9 This illustration shows a waveform diagram provided in an embodiment of this application; Figure 10 This illustration shows a schematic diagram of a quality assessment curve provided in an embodiment of this application; Figure 11 This illustration shows a time window diagram provided in an embodiment of this application; Figure 12 The diagram shows the effect of array signal superposition and wave field separation processing provided in an embodiment of this application. Detailed Implementation
[0018] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application 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 this application 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 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.
[0020] This application provides a cementing quality testing device, such as... Figure 1 As shown, the device includes: a detector body 1, several robotic arms 2, a support mechanism 3, and several transducer assemblies 4; The robotic arm 2 is arranged on the detector body 1 according to a preset detection array. One end of the robotic arm 2 is hinged to the detector body 1 via a rotating mechanism 5, and the other end of the robotic arm 2 is connected to the transducer assembly 4. Each robotic arm 2 can be adapted to casing wells of different diameters by telescopic extension. The transducer assembly 4 is connected to the robotic arm 2 via the support mechanism 3. When the robotic arm 2 is in the extended state, it contacts the inner wall of the casing well and is used to transmit and receive waveform signals. The detector body 1 is used to mount a power module, a processing module, and several wires to process the waveform signal.
[0021] In this embodiment, the detector body serves as the mounting base for the cementing quality inspection equipment. Since the diameter of the body is smaller than the inner wall diameter of the casing well, and because the robotic arm is arranged in a preset detection array on the detector body, the difference between the detector diameter and the inner wall diameter should be greater than a preset threshold to ensure that the detector body carries the robotic arm into the well. This allows for sufficient space for the robotic arm to deploy. In this embodiment, the casing can be PVC casing, but other low acoustic impedance non-metallic casings, such as composite material casings or fiberglass casings, are also applicable. This embodiment does not impose specific limitations.
[0022] In one specific embodiment, the preset detection array arrangement includes any one of the following: circumferential uniform array arrangement, spiral distribution array arrangement, and axial multi-layer array arrangement. The circumferential uniform array arrangement is suitable for high-precision circumferential defect identification, the spiral distribution array arrangement balances axial and circumferential resolution, and the axial multi-layer array arrangement is suitable for long-distance segmented defect localization. Each array arrangement method uses a processing module to calibrate the extension and retraction of the robotic arm and the transducer tilt angle in real time, ensuring the spatiotemporal consistency and geometric fidelity of waveform signal acquisition. In a specific example, the robotic arms are arranged at uniform intervals along the circumference of the detector body, with a minimum of three, preferably four or more. At this time, one end of the robotic arm is hinged to the detector body via a rotating mechanism, i.e., a rotational connection is formed between the robotic arm and the detector body through a rotating shaft connection mechanism, allowing the robotic arm to swing radially around the rotating shaft. Simultaneously, the other end of the robotic arm is connected to the transducer assembly. Each robotic arm adapts to casing wells of different diameters through extension and retraction; that is, robotic arm extension refers to the robotic arm opening outwards and contacting the inner wall of the casing for detection, such as... Figure 2 The robotic arm is shown in its extended state. The retracted state refers to its position close to the outer wall of the detector body, used for lowering into the wellbore. Figure 3 The robotic arm is shown in its retracted state.
[0023] It should be noted that, in order to maintain a constant positive pressure when the transducer assembly contacts the inner wall of the casing, the transducer assembly is connected to the robotic arm through a stabilizing loading mechanism. At this time, with the robotic arm extended, the transducer assembly contacts the inner wall of the casing well for transmitting and receiving waveform signals, such as... Figure 4 As shown. In a specific example, the transducer assembly can be an elastic wave transducer assembly, installed at the end of the robotic arm away from the instrument body, used to excite and receive elastic wave signals. When the elastic wave transducer assembly is in direct contact with the inner wall of the casing, the excited elastic wave can be directly coupled through the casing wall into the cement sheath and formation, so as to collect the corresponding wave signal, such as... Figure 5 As shown.
[0024] In one embodiment of this application, the support mechanism includes any one of the following: a stabilizing loading mechanism, a sliding telescopic radial probe structure, a radial telescopic rod structure, a flexible support arm structure, and a multi-segment folding support structure, to ensure that the transducer is stably installed at one end of the robotic arm. The stabilizing loading mechanism is a mechanical structure in which a pre-compressed spring and a displacement sensor work together, disposed between the robotic arm and the transducer assembly, to provide radial outward thrust. When the robotic arm is in a free state, the stabilizing loading mechanism drives the robotic arm to rotate outward, causing the transducer assembly installed at the end of the robotic arm to press against the inner wall of the sleeve, thereby forming a stable contact coupling.
[0025] The detector body in this embodiment is used to load a power module, a processing module, and several wires to process the waveform signal. Specifically, the processing module inside the detector body has signal processing function so as to directly perform cementing quality detection.
[0026] In one embodiment of this application, the transducer assembly includes an excitation module, a receiving module, a signal acquisition module, and a control module, which are electrically connected to the power supply module in sequence. The excitation module transmits waveform signals, the receiving module converts mechanical vibrations into electrical signals, the signal acquisition module amplifies the signals and performs digital-to-analog conversion, and the control module controls the signal transmission frequency and acquisition frequency. By synchronously exciting and acquiring signals through the transducer assembly, timing accuracy can be greatly ensured.
[0027] In one embodiment of this application, in order to stably fit the transducer assembly against the inner wall, the stabilizing loading mechanism includes any one of the following: a spring loading mechanism, an airbag expansion loading structure, a rubber elastic support structure, a roller pressing structure, an adjustable preload mechanism, and a magnetic or mechanical locking loading structure, so that the transducer assembly is pressed against the inner wall of the casing well after pressure is applied by the stabilizing loading mechanism.
[0028] In one embodiment of this application, to facilitate downhole detection, the detector body is a cylindrical structure, and the transducer assembly is driven through the wellbore by the retracted robotic arm. After reaching the target detection depth, the robotic arm extends under spring pressure to allow the transducer to form contact coupling with the inner wall.
[0029] In one embodiment of this application, the waveform signal includes any one of compression wave, shear wave, structural guided wave, surface wave, and elastic wave. Among them, elastic wave is the preferred signal type for cementing quality evaluation due to its high sensitivity and strong penetration at the cementing interface. Its propagation characteristics at the cement sheath and casing, and cement sheath and formation interfaces can accurately reflect the cementing integrity and defect distribution.
[0030] In one embodiment of this application, in order to excite and receive elastic waves in different circumferential directions of the sleeve, the preset detection array arrangement includes any one of the following: circumferential uniform array arrangement, spiral distribution array arrangement, and axial multi-layer array arrangement.
[0031] In one specific embodiment, multiple robotic arms and their corresponding elastic wave transducer assemblies are arrayed along the circumference of the instrument body to form a circumferential detection array. The elastic wave signals obtained by the transducers in different orientations can be used to identify the circumferential non-uniform consolidation state of the cement ring.
[0032] In some embodiments, the deployment of the robotic arm can be achieved by a spring loading mechanism, or by a motor-driven deployment structure, an electromagnetic-driven deployment structure, a hydraulic or pneumatic drive mechanism, a shape memory alloy drive structure, or a passive deployment structure triggered by changes in well diameter. All of the above methods can enable the transducer to form contact coupling with the inner wall of the PVC casing, thereby achieving the purpose of elastic wave detection.
[0033] In some embodiments, the pressure of the robotic arm contacting the inner wall after it is extended can be achieved based on a spring loading mechanism or a hydraulic or pneumatic drive mechanism. Therefore, in addition to adjusting the spring stiffness, the pressure generated by the contact can also be adjusted using a displacement limiting structure, an active pressure control system, and a feedback control loading mechanism. These can be set based on different loading mechanisms or connection structures to ensure the stability of the contact during the detection process.
[0034] This application provides a cementing quality inspection device, including: a detector body, several robotic arms, a support mechanism, and several transducer assemblies; wherein, the robotic arms are arranged on the detector body according to a preset detection array, one end of each robotic arm is hinged to the detector body via a rotating mechanism, and the other end of each robotic arm is connected to the transducer assembly; each robotic arm is telescopically adapted to casing wells of different diameters; the transducer assembly is connected to the robotic arm via the support mechanism, and in the extended state of the robotic arm, it contacts the inner wall of the casing well for transmitting and receiving waveform signals; the detector body is used to mount a power supply module. The system comprises a block, a processing module, and several wires to process the waveform signal. By limiting the received signal to the elastic wave response generated by the mechanical coupling excitation of the casing wall, and redefining the signal propagation path based on this coupling condition, the detection problem is transformed from the traditional well fluid acoustic wave propagation model to the casing structure vibration propagation model. A new interpretive basis is constructed from the signal source level. Through time window selection and wave field decomposition methods based on propagation time difference and array response characteristics, the effective extraction of target reflected waves is achieved. By calculating the evaluation features of the separated target wavebands, detection of scenarios that cannot be applied by traditional acoustic logging is realized, greatly improving the accuracy of cementing quality detection.
[0035] Furthermore, as a response to the above Figure 1 The implementation of the method shown in this application provides a method for detecting cementing quality, such as... Figure 6 As shown, the method includes: 201. Obtain the waveform signal; 202. Based on the theoretical arrival time of the waveform signal, the signal is divided into time windows, and the target reflected wave corresponding to the time window is determined; 203. Determine the quality evaluation index based on the characteristic parameters of the target reflected wave, and generate the cementing quality detection results.
[0036] In this embodiment, the detector body, which serves as the current execution subject, is applied in the cementing quality testing equipment of the casing. The cementing quality testing equipment also includes a robotic arm, a support mechanism, and several transducer assemblies. The waveform signal is collected by the transducer assemblies after the cementing quality testing equipment is fixed to the inner wall of the casing well by the robotic arm.
[0037] In one specific embodiment, the cementing quality inspection equipment is lowered into the casing well with its robotic arm retracted. After reaching the target layer, the robotic arm automatically extends under the action of a spring-loaded support mechanism, and the transducer forms contact coupling with the inner wall of the casing. The transducer then excites and receives elastic wave signals, obtaining waveform signals. Subsequently, signal analysis is performed on the waveform signals, and the cement sheath consolidation quality is evaluated based on wave propagation characteristics. This process continues until the cementing quality inspection equipment completes the target layer measurement. Then, the robotic arm automatically retracts under the action of the spring-loaded mechanism. Figure 7 The workflow diagram shown.
[0038] In a specific example, measurements are taken at the target formation downhole using cementing quality testing equipment. The transducer forms a mechanical contact coupling with the inner wall of the PVC casing, allowing elastic wave signals to be emitted towards the casing wall via ceramic piezoelectric and mechanical vibration / impact methods. After propagating through the casing wall, the elastic waves couple outwards into the cement sheath and formation. Simultaneously, multiple propagation paths are formed within the casing structure, including direct propagation waves, casing circumferential propagation waves, casing-cement interface reflection waves, and cement sheath and formation reflection waves, such as... Figure 8 The diagram shows the propagation path of the elastic wave in the PVC casing-cement sheath-formation system. The array receiving transducer receives the original wave train signal formed by the above superposition, as shown... Figure 9 As shown.
[0039] It should be noted that after obtaining the waveform signal, the signal analysis process begins by dividing the signal into time windows based on the theoretical arrival time of the waveform signal. A time window refers to the period during which the signal undergoes regular changes, allowing for the segmentation of the waveform signal and the determination of the target reflected wave corresponding to the time window. The target reflected wave is the waveform signal obtained after propagation through the casing and reflection, which is then divided into time windows. Based on the characteristic parameters of this target reflected wave, a quality evaluation index is determined, generating the cementing quality detection results.
[0040] In one specific embodiment, the target reflector can be determined by array weighting or single-channel time window analysis, and the evaluation parameters can be calculated using quality evaluation parameters or machine learning models.
[0041] In one specific embodiment, when generating cementing quality detection results by determining the quality evaluation index based on the characteristic parameters of the target reflected wave, characteristic parameters can be calculated for the extracted target waveband, including but not limited to: energy characteristics, amplitude attenuation characteristics, and spectral distribution characteristics. For example, the consolidation quality index can include: energy characteristics, amplitude attenuation coefficient, dominant frequency characteristics, and frequency band energy ratio. The energy characteristics can be expressed as: .
[0042] The amplitude attenuation coefficient can be expressed as: ; in: For the target wave peak value, To reach the peak value directly. The main frequency characteristic, calculated using FFT, can be represented as: ; The calculation of clock speed can be expressed as: ; The bandwidth energy ratio can be expressed as: Used to identify coupling attenuation.
[0043] The final evaluation formula can be expressed as: ; in, The energy of the reflected wave from the target. This represents the total signal energy. The cement ring bonding state is classified and evaluated based on the magnitude of the evaluation parameters.
[0044] In a specific example, based on the continuous calculation results along the well depth using evaluation parameters, a cement sheath consolidation quality curve is generated, such as... Figure 10 As shown, the cementing quality curve generation process includes: continuously acquiring array signals along the well depth, repeatedly calculating energy characteristics for each depth; amplitude attenuation characteristics and spectral distribution characteristics, and repeatedly calculating the evaluation value corresponding to the depth. Arranged in depth order to form a continuous function, and using cubic spline interpolation to generate a continuous curve, it can be expressed as: ; The final output is a continuous cementing quality profile, enabling the identification of well cemented zones, micro-annulus zones, and debonding or void zones.
[0045] In another embodiment of this application, for further definition and explanation, the step of dividing the signal based on the theoretical arrival time of the waveform signal to obtain a time window includes: Multiple propagation paths of the waveform signal are determined, and the theoretical arrival time is calculated based on the propagation speed corresponding to the propagation path. Based on the aforementioned theory, a corresponding time window is established upon reaching the specified time.
[0046] In order to achieve windowing of waveform signals to meet the needs of different propagation wave extraction and thus improve the accuracy of cementing quality detection, when dividing the signal, multiple propagation paths of the waveform signal are first determined, and the theoretical arrival time is calculated based on the propagation speed corresponding to the propagation path.
[0047] In a specific embodiment, in the PVC casing-cement sheath-formation system, the elastic wave mainly includes the following propagation paths. Different paths have different propagation distances and propagation speeds, and therefore, they are distinguishable arrival times on the time axis.
[0048] For a direct-propagation wave through the casing, the propagation path can be: excitation point - along the casing axis - receiving point. When calculating the theoretical time of arrival, this can be expressed as: ; in, The axial distance between the excitation point and the receiving point. The longitudinal wave velocity of the bushing is characterized by the earliest arrival, phase consistency of multiple signals, and concentrated energy.
[0049] For a wave propagating around a sleeve, the propagation path can be: it travels around the circumference of the sleeve and reaches the receiver. The corresponding propagation length can be approximated as: When calculating the theoretical arrival time, it can be expressed as: ; in, The outer diameter of the casing is used to describe the characteristics of the wave propagating around the casing, which is later than the direct wave, has a significant phase delay, and exhibits decreased coherence between multiple channels.
[0050] For the reflected wave at the casing-cement interface, the propagation path can be: casing-cement interface-reflection-casing-receiver, and the corresponding approximate path is expressed as: ; in, Given the casing wall thickness and the equivalent coupling distance, the theoretical arrival time can be expressed as: ; Among its characteristics, the energy is controlled by the cementation state, and it is the main target wave for evaluation.
[0051] For the cement sheath and formation reflected waves, the propagation path can be: casing-cement-formation-reflection-return, and the corresponding propagation time can be expressed as: ; in, The thickness of the cement ring. This is the equivalent penetration depth of the formation. For the longitudinal wave velocity of cement, The longitudinal wave velocity of the formation is characterized by the cement sheath and the formation reflected wave arriving latest, having a lower frequency, and being most sensitive to the consolidation quality.
[0052] It should be noted that after obtaining the theoretical arrival time of each wave, a corresponding time window is established based on the theoretical arrival time. Specifically, according to the difference in propagation speed of elastic waves in PVC sleeves and cement rings, the theoretical arrival time of different propagation paths is calculated, and a time window function is established to segment the signal: ; in, For the first propagation path length, To correspond to the propagation speed, Based on the theoretical arrival time, in this embodiment, the signal can be divided into: a direct wave time window, a surrounding propagation wave time window, and a cement ring reflection wave time window, so as to achieve preliminary separation of different propagation components by intercepting the time windows, such as... Figure 11 As shown.
[0053] In another embodiment of this application, for further definition and explanation, the step of determining the target reflected wave corresponding to the time window includes: The waveform signal is superimposed and enhanced according to the time window to obtain the superimposed target wave signal; The energy value corresponding to each time window is calculated based on the target wave signal, and the target reflected wave is determined based on the time window corresponding to the largest energy value.
[0054] To achieve accurate extraction of the target wave and improve the accuracy of cementing quality inspection, the extraction of the target reflected wave involves first superimposing and enhancing the waveform signal according to a time window to obtain the superimposed target wave signal. For example, array signal processing, coherent superposition, time-delay superposition, or adaptive beamforming methods can be used to enhance the target wave.
[0055] In one specific embodiment, the spatial consistency characteristics of the array received signals are utilized to perform superposition and wavefield enhancement processing on multiple channels: ; in, For the first One receiving channel signal, These are weighting coefficients. This refers to the number of channels in the receiving array. By superimposing the arrays, non-uniform propagation waves are suppressed, increasing the signal energy from the direction of reflection from the cement ring, thus enhancing the target wave signal. Figure 12 As shown.
[0056] Furthermore, after obtaining the target wave signal, the energy value corresponding to each time window can be calculated based on the target wave signal, and the target reflected wave can be determined based on the time window corresponding to the largest energy value. In a specific embodiment, the target wave signal after array superposition... Calculate the short-time energy function: ; in, Let be the length of the sliding window. At this point, search for a local maximum energy value within the theoretical time window of the cement ring reflected wave, and define the interval corresponding to this energy peak as the target band: The signal within that time window is output as the target reflected wave.
[0057] In another embodiment of this application, for further definition and explanation, after acquiring the waveform signal, the method further includes: The waveform signal is preprocessed to obtain the waveform signal to be divided. The preprocessing includes at least one of DC component removal processing, bandpass filtering processing, amplitude normalization processing, and multi-channel signal time synchronization correction.
[0058] To ensure the validity of the waveform signal, the acquired raw signal is preprocessed, which may include at least one of the following: DC component removal processing, bandpass filtering processing, amplitude normalization processing, and multi-channel signal time synchronization correction, in order to improve the signal-to-noise ratio and unify the signal reference between different receiving channels. The bandpass filtering frequency range can be adjusted according to the sleeve size and excitation frequency; this application embodiment does not impose specific limitations.
[0059] This application provides a method for detecting cementing quality. Compared with the prior art, this application acquires waveform signals; divides the signals based on the theoretical arrival time of the waveform signals to obtain time windows, and determines the target reflected wave corresponding to the time window; determines the quality evaluation index based on the characteristic parameters of the target reflected wave, and generates the detection result of cementing quality. By limiting the received signal to the elastic wave response generated by the mechanical coupling excitation of the casing wall, and redefining the signal propagation path based on this coupling condition, the detection problem is transformed from the traditional well fluid acoustic wave propagation model to the casing structure vibration propagation model, constructing a new interpretation basis from the signal source level. Through the time window selection and wave field decomposition method based on the propagation time difference and array response characteristics, the target reflected wave is effectively extracted. By calculating the evaluation characteristics of the separated target waveband, detection of scenarios that cannot be applied by traditional acoustic logging is achieved, greatly improving the accuracy of cementing quality detection.
[0060] Obviously, those skilled in the art should understand that the modules or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.
[0061] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.
Claims
1. A cementing quality testing device, characterized in that, include: The detector body, several robotic arms, a support mechanism, and several transducer assemblies; The robotic arm is arranged on the detector body according to a preset detection array. One end of the robotic arm is hinged to the detector body via a rotating mechanism, and the other end of the robotic arm is connected to the transducer assembly. Each robotic arm can be adapted to casing wells of different diameters by telescopic extension. The transducer assembly is connected to the robotic arm via the support mechanism, and in the extended state of the robotic arm, it contacts the inner wall of the casing well for transmitting and receiving waveform signals. The detector body is used to mount a power module, a processing module, and several wires to process the waveform signal.
2. The cementing quality testing equipment according to claim 1, characterized in that, The transducer assembly includes an excitation module, a receiving module, a signal acquisition module, and a control module, which are electrically connected to the power supply module in sequence. The excitation module is used to transmit waveform signals, the receiving module is used to convert electrical signals of mechanical vibrations, the signal acquisition module is used to amplify signals and perform digital-to-analog conversion, and the control module is used to control the signal transmission frequency and the acquisition frequency.
3. The cementing quality testing equipment according to claim 1, characterized in that, The support mechanism includes any one of the following: a stabilizing loading mechanism, a sliding telescopic radial probe structure, a radial telescopic rod structure, a flexible support arm structure, and a multi-segment folding support structure. The stabilizing loading mechanism includes any one of the following: a spring loading mechanism, an airbag expansion loading structure, a rubber elastic support structure, a roller pressing structure, an adjustable preload mechanism, and a magnetic or mechanical locking loading structure. The stabilizing loading mechanism applies pressure to press the transducer assembly against the inner wall of the casing well.
4. The cementing quality testing equipment according to claim 1, characterized in that, The detector body is a cylindrical structure, and the transducer assembly is driven through the well shaft when the robotic arm is retracted.
5. The cementing quality testing equipment according to claim 1, characterized in that, The waveform signal includes any one of compression wave, shear wave, structured guided wave, surface wave, and elastic wave.
6. The cementing quality testing equipment according to claim 1, characterized in that, The preset detection array arrangement includes any one of the following: circumferential uniform array arrangement, spiral distribution array arrangement, and axial multi-layer array arrangement.
7. A method for detecting cementing quality, characterized in that, The cementing quality testing equipment as described in any one of claims 1-6 includes: Acquire waveform signals, which are collected by the transducer assembly after the cementing quality testing equipment is fixed to the inner wall of the casing well by a robotic arm; Based on the theoretical arrival time of the waveform signal, the signal is divided into time windows, and the target reflected wave corresponding to the time window is determined. Based on the characteristic parameters of the target reflected wave, a quality evaluation index is determined, and the cementing quality detection results are generated.
8. The method according to claim 7, characterized in that, The process of dividing the signal based on the theoretical arrival time of the waveform signal to obtain a time window includes: Multiple propagation paths of the waveform signal are determined, and the theoretical arrival time is calculated based on the propagation speed corresponding to the propagation path. Based on the aforementioned theory, a corresponding time window is established upon reaching the specified time.
9. The method according to claim 8, characterized in that, Determining the target reflected wave corresponding to the time window includes: The waveform signal is superimposed and enhanced according to the time window to obtain the superimposed target wave signal; The energy value corresponding to each time window is calculated based on the target wave signal, and the target reflected wave is determined based on the time window corresponding to the largest energy value.
10. The method according to claim 7, characterized in that, After acquiring the waveform signal, the method further includes: The waveform signal is preprocessed to obtain the waveform signal to be divided. The preprocessing includes at least one of DC component removal processing, bandpass filtering processing, amplitude normalization processing, and multi-channel signal time synchronization correction.