A current injection type rescue well detection signal processing method, device, equipment and medium

Abstract

This invention relates to the field of rescue well detection, and discloses a current-injection type rescue well detection signal processing method, apparatus, equipment, and medium. For any one of multiple probes in a rescue well, multiple component signals of a secondary magnetic field signal are acquired by the probe. For any component signal acquired by the probe, the component signal is divided into multiple segmented signals, and each segmented signal is arranged into a target matrix. A piecewise fast Fourier transform and frequency domain reconstruction are performed on the target matrix to obtain the processed component signal. The corresponding frequency band component signal is extracted from the processed component signal according to a set frequency. Each frequency band component signal is used as a whole to locate the accident well. This invention introduces a piecewise fast Fourier transform processing strategy, significantly reducing the storage resource consumption of a single operation, avoiding processing delays and accuracy loss due to excessive data volume, achieving fast and high-precision processing of downhole signals, and ensuring the positioning accuracy of the accident well.

Description

Technical Field

[0001] This invention relates to the field of rescue well detection, and in particular to a current injection-type rescue well detection signal processing method, apparatus, equipment, and medium. Background Technology

[0002] In oil and gas drilling projects, blowouts and overflows can not only cause significant losses of oil and gas resources, but also lead to severe environmental pollution, equipment damage, and even casualties. During the drilling of deep wells and wells with complex structures, if a blowout occurs out of control, rescue operations must be implemented quickly to minimize losses.

[0003] Among these, the detection of rescue wells is the ultimate means of handling blowouts. The core challenge lies in whether the rescue well and the accident well can be efficiently and accurately connected underground, which directly depends on the ability to accurately measure the distance and orientation between them. To achieve efficient detection and precise positioning of the rescue well, not only is sufficient information collected, but also high-quality target signals are required. This places high demands on the accuracy of downhole signal acquisition and processing capabilities.

[0004] However, the relevant technologies are not capable enough of processing downhole signals, which may lead to insufficient positioning accuracy of the accident well. Summary of the Invention

[0005] This invention provides a current injection-based rescue well detection signal processing method, apparatus, equipment, and medium to address the shortcomings of related technologies in processing downhole signals, which may lead to insufficient positioning accuracy of accident wells. It enables rapid and high-precision processing of downhole signals, ensuring the positioning accuracy of accident wells.

[0006] In a first aspect, the present invention provides a method for processing signals from current-injection type rescue well detection, comprising:

[0007] For any one of the multiple probes in the rescue well, multiple components of the secondary magnetic field signal are collected through the probe; wherein, the secondary magnetic field signal is generated by the metal casing in the accident well according to the alternating current of a set frequency emitted by the rescue well; For any component signal acquired by the probe, the component signal is divided into multiple segment signals, each segment signal is arranged into a target matrix, and the target matrix is ​​subjected to segmented fast Fourier transform and frequency domain reconstruction to obtain the processed component signal; the corresponding frequency band component signal is extracted from the processed component signal according to the set frequency; wherein, each frequency band component signal is used as a whole to locate the accident well.

[0008] Optionally, dividing the component signal into multiple segmented signals includes: According to the set segment length, the component signal is divided into multiple segment signals, and the signal length of each segment signal is equal to the set segment length; The step of arranging each of the segmented signals into a target matrix includes: Based on the order of the preceding and following positions of each segment signal in the component signal, the row order corresponding to each segment signal is set; wherein, the smaller the order of the preceding and following positions of the segment signal in the component signal, the smaller the row order corresponding to the segment signal; Each segmented signal is arranged into the target matrix according to the row order corresponding to each segmented signal.

[0009] Optionally, performing piecewise fast Fourier transform and frequency domain reconstruction on the target matrix to obtain the processed component signals includes: Perform a Fast Fourier Transform on each column of data in the target matrix to obtain the first transform matrix; Multiply each row of data in the first transformation matrix by the modulation factor to obtain the modulated matrix; Perform a Fast Fourier Transform on each row of data in the modulated matrix to obtain a second transformed matrix; The transpose and concatenation of the second transformed matrix yields the processed component signal.

[0010] Optionally, the step of transposing and concatenating the second transformed matrix to obtain the processed component signal includes: According to the row order of each row of data in the second transformed matrix, each row of data in the second transformed matrix is ​​concatenated in turn to obtain the final frequency domain sequence, which is used as the processed component signal.

[0011] Optionally, the multiple component signals of the secondary magnetic field signal are respectively x Component magnetic field signal, y Component magnetic field signal and z Component magnetic field signal; Each probe includes three signal acquisition channels, each used for acquiring signals. x Component magnetic field signal, y Component magnetic field signal and z Component magnetic field signal; The processed component signal is the processed... x Component magnetic field signal, after processing y Component magnetic field signal or after processing z Component magnetic field signal; The frequency band component signal is a frequency band. x Component magnetic field signal, frequency band y Component magnetic field signal or frequency bandz Component magnetic field signal.

[0012] Optionally, after extracting the corresponding frequency band component signal from the processed component signal according to the set frequency, the method further includes: Obtaining gravitational acceleration x Quantity, y Components and z Quantity; According to the aforementioned gravitational acceleration x Quantity, y Components and z Components, each of the frequency bands x Component magnetic field signal, each of the frequency bands y Component magnetic field signals and each of the frequency bands z The relative orientation and relative distance between the accident well and the rescue well are deduced from the component magnetic field signal.

[0013] Optionally, after performing a Fast Fourier Transform on each column of data in the target matrix to obtain a first transform matrix, the method further includes: The first transformation matrix, the modulated matrix, the second transformation matrix, the processed component signal, and the frequency band component signal are stored in the target space; The relative orientation and relative distance between the accident well and the rescue well obtained by reverse calculation are stored in the target space and sent to ground equipment.

[0014] In a second aspect, the present invention provides a current injection type rescue well detection signal processing device, comprising: The acquisition unit is used to acquire multiple component signals of a secondary magnetic field signal through any one of the multiple probes in the rescue well; wherein, the secondary magnetic field signal is generated by the metal casing in the accident well according to the alternating current of a set frequency emitted by the rescue well. The segmentation unit is used to segment any component signal acquired by the probe into multiple segment signals; An arrangement unit is used to arrange each of the segmented signals into a target matrix; The processing unit is used to perform piecewise fast Fourier transform and frequency domain reconstruction on the target matrix to obtain the processed component signals; An extraction unit is used to extract the corresponding frequency band component signal from the processed component signal according to the set frequency; wherein each frequency band component signal is used as a whole to locate the accident well.

[0015] Thirdly, the present invention provides a computer device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the current injection rescue well detection signal processing method of the first aspect or any corresponding embodiment described above.

[0016] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the current injection rescue well detection signal processing method of the first aspect or any corresponding embodiment described above.

[0017] This invention provides a current-injection-based rescue well detection signal processing method, apparatus, equipment, and medium. For any one of multiple probes in a rescue well, the probe acquires multiple component signals of a secondary magnetic field signal. The secondary magnetic field signal is generated by an alternating current at a set frequency emitted by the metal casing of the accident well. For any component signal acquired by the probe, the component signal is divided into multiple segments. Each segment is arranged into a target matrix, and the target matrix is ​​subjected to a piecewise fast Fourier transform and frequency domain reconstruction to obtain the processed component signal. The corresponding frequency band component signal is extracted from the processed component signal according to a set frequency. Each frequency band component signal is used as a whole to locate the accident well. This invention introduces a piecewise fast Fourier transform processing strategy, significantly reducing the storage resource consumption of a single operation, avoiding processing delays and accuracy loss due to excessive data volume, achieving fast and high-precision processing of downhole signals, and ensuring the positioning accuracy of the accident well. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A flowchart of a current injection-type rescue well detection signal processing method provided in an embodiment of the present invention; Figure 2 A schematic diagram of current injection detection provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a piecewise fast Fourier transform processing flow provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of multi-component signal acquisition provided in an embodiment of the present invention; Figure 5A schematic diagram of a 17Hz original signal provided in an embodiment of the present invention; Figure 6 A schematic diagram of a 37Hz original signal provided in an embodiment of the present invention; Figure 7 A schematic diagram of a 57Hz original signal provided in an embodiment of the present invention; Figure 8 This is a schematic diagram illustrating the processing result of a 17Hz original signal provided in an embodiment of the present invention; Figure 9 This is a schematic diagram illustrating the processing result of a 37Hz original signal provided in an embodiment of the present invention; Figure 10 This is a schematic diagram illustrating the processing result of a 57Hz original signal provided in an embodiment of the present invention; Figure 11 This is a schematic diagram of the structure of a current injection type rescue well detection signal processing device provided in an embodiment of the present invention; Figure 12 This is a schematic diagram of the structure of a computer device provided in an embodiment of the present invention. Detailed Implementation

[0020] Currently, the electromagnetic methods used for rescue well detection and location mainly include two types: static magnetic detection and active electromagnetic detection. Static magnetic detection utilizes fluxgate sensors in measurement-while-drilling tools to detect disturbances to the geomagnetic field caused by the casing of the accident well, thereby estimating the well's location. It requires no artificial excitation source and has a relatively simple structure, but its detection range is short, it is easily affected by geomagnetic fluctuations and environmental interference, and its detection accuracy is limited; it is typically used only as an auxiliary method in short-range detection. Active electromagnetic detection mainly includes two types: transient electromagnetic methods and current injection methods. Transient electromagnetic methods use a transmitting coil to apply transient pulse excitation, and a receiving coil to collect the diffusion characteristics of the secondary induced field to determine the target casing's location. This technology does not require a high-power power supply and the cable is easy to set up and down, but its detection range is severely limited due to the weak secondary field signal. In contrast, current injection methods inject low-frequency alternating current into the formation through downhole electrodes. The metal casing of the accident well converges the current and excites a detectable secondary magnetic field signal, thereby achieving the detection and location of the accident well. It offers high positioning accuracy and long detection distance, demonstrating significant technical advantages in rescue well detection.

[0021] To achieve efficient detection and precise positioning of rescue wells, not only is sufficient information acquisition necessary, but high-quality target signals are also crucial. This places extremely high demands on the accuracy of downhole signal acquisition, processing capabilities, and transmission efficiency. However, in current injection mode, the low-frequency signals injected into the formation propagate in a quasi-static field form. Long-distance detection signals are weak in energy and easily mixed with environmental noise and power frequency interference, resulting in an extremely low signal-to-noise ratio. Furthermore, the harsh electromagnetic environment downhole causes severe background interference with a large dynamic range. How to extract weak but effective signals from strong interference and achieve efficient transmission has become a core challenge restricting the improvement of detection capabilities.

[0022] To address the aforementioned issues, related technologies still face numerous limitations in noise suppression. Hardware filtering methods, by setting up analog filtering circuits at the acquisition front end to filter out some power frequency and high-frequency interference, suffer from severe performance drift due to the high temperature and pressure environment downhole, and are ineffective at suppressing strong interference overlapping with the target signal frequency. Software-level processing methods, such as digital filtering, adaptive filtering, wavelet transform denoising, and empirical mode decomposition, can improve the signal-to-noise ratio to some extent, but their implementation is highly dependent on computing resources. Considering the extremely limited processing capabilities and storage resources of downhole tools, deploying complex algorithms downhole makes it difficult to balance processing accuracy and real-time performance; uploading all raw data to the surface for processing would result in excessive data volume, consuming limited bandwidth and severely impacting the real-time performance and reliability of data transmission. Compressing the data to alleviate transmission pressure inevitably leads to the loss of some signal details, thus affecting positioning accuracy. Therefore, how to achieve high-fidelity acquisition, efficient denoising, and reliable real-time transmission of weak signals under resource-constrained downhole conditions has become a key issue in the precise positioning technology of current injection rescue wells.

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0024] The following is combined Figures 1-10 The present invention describes a current injection-based rescue well detection signal processing method.

[0025] like Figure 1 As shown, this embodiment proposes a first method for processing signals from current injection-type rescue well detection. This method may include the following steps: S101. For any one of the multiple probes in the rescue well, collect multiple component signals of the secondary magnetic field signal through the probe; wherein, the secondary magnetic field signal is generated by the alternating current of the metal casing in the accident well according to the set frequency emitted by the rescue well.

[0026] like Figure 2 As shown, the current injection detection system in this embodiment can be composed of a surface loop electrode, a downhole transmitting electrode, a downhole receiving tool, and a cable. The receiving tool has a built-in alternating magnetic sensor and an accelerometer. During the detection process, the downhole transmitting electrode injects a low-frequency alternating current into the formation, which diffuses quasi-statically within the formation. Due to the low conductivity of the target well's metal casing (approximately 10), the current is effectively absorbed. 6 ~10 7 The current (S / m) is much higher than the surrounding strata, and the current flow is affected by the "short-circuit effect," converging along the casing surface and thus exciting a secondary alternating magnetic field. An alternating magnetic sensor inside the rescue well collects this magnetic field signal and can calculate the distance between the target well and the rescue well. Simultaneously, an accelerometer is used to measure geomagnetic field information to determine the relative orientation of the two wells, thereby achieving precise detection of the target well's location within the rescue well. In current-injection rescue well detection, the target signal typically manifests as a weak magnetic field response at a specific frequency.

[0027] It should be noted that, considering the complex environment and severe noise interference in the well, the acquired signals need to be processed to extract the effective magnetic field information corresponding to the excitation frequency.

[0028] Specifically, there can be four probes, each of which can acquire the x-component, y-component, and z-component signals of the secondary magnetic field signal.

[0029] S102. For any component signal acquired by the probe, the component signal is divided into multiple segment signals.

[0030] Specifically, in this embodiment, any component signal acquired by any probe can be divided into multiple continuous and non-overlapping segment signals.

[0031] Optionally, step S102 includes: The component signal is divided into multiple segment signals according to the set segment length, and the signal length of each segment signal is equal to the set segment length.

[0032] Specifically, in this embodiment, the component signal can be divided into multiple segments of equal length, continuous and non-overlapping, with each segment having a predetermined segment length. The specific value of the predetermined segment length can be set by a technician according to the actual situation; this embodiment does not impose a limitation. For example, the predetermined segment length can be 256.

[0033] S103. Arrange each segmented signal into a target matrix.

[0034] Specifically, this embodiment can construct a target matrix composed of each segmented signal based on each segmented signal.

[0035] Optionally, step S103 includes: Based on the order of each segment signal's position in the component signal, the row order corresponding to each segment signal is set; where, the smaller the order of the segment signal's position in the component signal, the smaller the row order corresponding to the segment signal. Arrange each segment signal into a target matrix according to the row order of each segment signal.

[0036] Specifically, in this embodiment, the first segment of the component signal can be placed in the first row of the matrix to be constructed, the second segment of the component signal can be placed in the second row of the matrix to be constructed, and so on, until the last segment of the component signal is placed in the last row of the matrix to be constructed, thus obtaining the target matrix. See also Figure 3 Any component signal acquired by any probe can be represented as a signal of length . N Timing signals x [ n First, you can x [ n [Split into] P There are segmented signals, and the signal length of each segment is... L ,Will P The segmented signals are used as row data and arranged sequentially to form the target matrix.

[0037] S104. Perform piecewise fast Fourier transform and frequency domain reconstruction on the target matrix to obtain the processed component signals.

[0038] Specifically, in this embodiment, after obtaining the target matrix, a piecewise fast Fourier transform and frequency domain reconstruction are performed on the target matrix, and the result obtained after processing is determined as the processed component signal.

[0039] Optionally, step S104 includes: Perform a Fast Fourier Transform on each column of data in the target matrix to obtain the first transformation matrix; Multiply each row of data in the first transformation matrix by the modulation factor to obtain the modulated matrix; Perform a Fast Fourier Transform on each row of data in the modulated matrix to obtain the second transformed matrix; The transpose of the transformed matrix is ​​then concatenated to obtain the processed component signals.

[0040] Optionally, the transpose and concatenation of the second transformed matrix to obtain the processed component signals include: According to the row order of each row of data in the second transformed matrix, each row of data in the second transformed matrix is ​​concatenated in turn to obtain the final frequency domain sequence, which is used as the processed component signal.

[0041] It should be noted that, to ensure the quality of the detected signal, a high sampling frequency is required. When using a multi-component array antenna for reception, the data volume is enormous. Taking a 4-element receiving antenna as an example, each probe acquiring 3 components requires 3 channels, resulting in a total of 12 channels for the entire acquisition process. This leads to problems such as excessive data volume failing to meet storage requirements and serial computation failing to meet efficiency requirements during power spectrum estimation. To address these issues, this embodiment designs a piecewise fast Fourier transform algorithm to achieve efficient processing and extraction of fixed-frequency signals. The implementation process is as follows: Figure 3 As shown.

[0042] See Figure 3 Any component signal acquired by any probe can be represented as a signal of length . N Timing signals x [ n First, you can x [ n [Split into] P There are segmented signals, and the signal length of each segment is... L ,Will P The segmented signals are arranged into a target matrix. x [ p , l Next, in this embodiment, a Fast Fourier Transform (FFT) can be performed on each column of data in the target matrix. L Second-rate P Point FFT yields the first transformation matrix. X 1[ p , l ] Then, in this embodiment, the first transformation matrix can be... X 1[ p , l Multiplying each row of data in the matrix by the modulation factor yields the modulated matrix. X 2[ b , l This embodiment can modulate the matrix. X 2[ b , l Perform an FFT on each row of data in the matrix to obtain the second transformed matrix. X [ b , a ] Then, this embodiment can process the second transformed matrix. X [ b ,a The transpose and concatenation are performed to obtain the processed component signals. X [ k ].

[0043] in, N Represents the length of the original signal, n The first representing the original signal n One element; K Represents the length of the processed signal, k Represents the processed signal's first... n One element; P This represents the number of segments into which the signal is divided. L This represents the length of each segment of the signal after segmentation. p Represents any sequence number. l Represents any element of the corresponding segment; b This indicates the row number after performing the FFT transformation column-wise; a This indicates the column number after performing the FFT transformation row by row; k This represents the element number of the concatenated sequence after all operations are completed.

[0044] S105. Extract the corresponding frequency band component signal from the processed component signal according to the set frequency; wherein, each frequency band component signal is used as a whole to locate the accident well.

[0045] The set frequency is the frequency of the low-frequency alternating current emitted by the rescue well.

[0046] Specifically, this embodiment can extract the frequency band component signal with a set frequency from the processed component signal.

[0047] Optionally, the multiple component signals of the secondary magnetic field signal are respectively x Component magnetic field signal, y Component magnetic field signal and z Component magnetic field signal; Each probe includes three signal acquisition channels, each used for acquiring signals. x Component magnetic field signal, y Component magnetic field signal and z Component magnetic field signal; The processed component signal is the processed x Component magnetic field signal, after processing y Component magnetic field signal or after processing z Component magnetic field signal; Frequency band component signal is frequency band x Component magnetic field signal, frequency band y Component magnetic field signal or frequency band z Component magnetic field signal.

[0048] It is understood that for any component signal acquired by any probe, this embodiment can process that component signal to obtain the corresponding frequency band component signal. Then, this embodiment can determine the location and distance of the accident well relative to the rescue well based on all the obtained frequency band component signals.

[0049] It should be noted that after obtaining the signal components of each frequency band, this embodiment achieves the extraction of the signal at the target frequency. The innovation of this process lies in the fact that while directly performing an FFT on the entire signal is theoretically feasible, its practical operability is very low. The confined space downhole limits the space available for circuit installation, and the harsh environment of high temperature and high pressure also affects circuit performance. Therefore, directly performing an FFT on the entire signal is not only computationally intensive but also requires significant data storage space, making it difficult to implement. Segmented FFT processing achieves ideal processing results while saving computational and storage space, enabling effective extraction of the target signal.

[0050] Optionally, in other current-injection rescue well detection signal processing methods proposed in this embodiment, the method may further include the following after step S105: Obtaining gravitational acceleration x Quantity, y Components and z Quantity; Based on gravitational acceleration x Quantity, y Components and z Components, each frequency band x Component magnetic field signal, each frequency band y Component magnetic field signals and each frequency band z The component magnetic field signal is used to infer the relative orientation and relative distance between the accident well and the rescue well.

[0051] Specifically, this embodiment can be based on the obtained gravitational acceleration. x Component velocity, y Component velocity and z The component velocities, and based on the component signals of each frequency band, the relative orientation and relative distance between the accident well and the rescue well are deduced.

[0052] The current-injection-based rescue well detection signal processing method proposed in this embodiment involves collecting multiple component signals of a secondary magnetic field signal from any one of multiple probes in the rescue well. The secondary magnetic field signal is generated by the alternating current emitted by the metal casing of the accident well at a set frequency from the rescue well. For any component signal collected by the probe, the component signal is divided into multiple segments, and each segment is arranged into a target matrix. The target matrix is ​​then subjected to a piecewise fast Fourier transform and frequency domain reconstruction to obtain the processed component signal. The corresponding frequency band component signal is extracted from the processed component signal according to a set frequency. Each frequency band component signal is used as a whole to locate the accident well. This embodiment introduces a piecewise fast Fourier transform processing strategy, significantly reducing the storage resource consumption of a single operation, avoiding processing delays and accuracy loss due to excessive data volume, achieving fast and high-precision processing of downhole signals, and ensuring the positioning accuracy of the accident well.

[0053] It should be noted that the distance and azimuth information of the accident well are included in the detection signal. By using the measured signal for inversion and calculation, the distance and azimuth between the two wells can be obtained. This is the general process in rescue well detection. The innovation of this embodiment is not mainly reflected in the process of inferring distance and azimuth from the signal, but in the signal processing. During the detection process, a low-frequency AC signal at a specific frequency is transmitted. At the receiving end, only by separating and extracting the signal at this target frequency from all received signals can effective information containing the target distance and azimuth be obtained. This is necessary for further analysis of the distance and azimuth. Without processing, a large amount of power frequency signal and environmental noise will be mixed with the effective signal, affecting the interpretation effect.

[0054] based on Figure 1 This embodiment proposes a second signal processing method for current injection rescue well detection. In current injection rescue well detection, the target signal usually manifests as a weak magnetic field response at a specific frequency. Considering the complex downhole environment and severe noise interference, it is necessary to process the acquired signal to extract the effective magnetic field information corresponding to the excitation frequency. To this end, this embodiment can introduce power spectral density estimation to achieve adaptive separation of the target frequency signal. Power spectral density describes the distribution characteristics of signal power on the frequency axis and can effectively distinguish deterministic signals from broadband noise. The calculation process is shown in equation (1).

[0055] ----------Formula (1); in, x ( t ) represents the collected signal. S xx ( f ) represents the power spectral density. X ( f ) =F { x ( t )} represents the Fourier transform of the signal. Specifically, the power spectral density of the acquired time-domain signal is first calculated; based on this, the target frequency can be located and its amplitude and phase information extracted by identifying the energy peak at the frequency of the injected current in the power spectrum. This process does not rely on a priori noise models and can achieve robust separation of the target signal under low signal-to-noise ratio conditions, providing high-quality input data for subsequent positioning calculations.

[0056] To ensure signal quality, a high sampling frequency is required, resulting in a massive amount of data when using a multi-component array antenna. Taking a 4-element receiving antenna as an example, each probe acquiring 3 components requires 3 channels, totaling 12 channels for the entire acquisition process. This leads to problems such as excessive data volume failing to meet storage requirements and serial computation failing to meet efficiency requirements during power spectrum estimation. To address these issues, a piecewise Fast Fourier Transform (FFT) algorithm is designed to achieve efficient processing and extraction of signals at fixed frequencies.

[0057] like Figure 3 and Figure 4 As shown, for a length of N time-domain sequence x [ n The frequency domain sequence can be obtained by performing a discrete Fourier transform on it according to equation (2). X [ k The basic method is as follows: ----------Formula (2); The basic idea of ​​piecewise FFT is to process the original time-domain sequence... x [ n Divided into P Segment (each segment is [length]) L = N / P ), and after segmentation P Perform FFT on each segment of the sequence, hoping to utilize this P The segment FFT transform results reconstruct the complete frequency domain sequence. X [ k First, through equation transformation, it can be seen that the segmented time-domain sequence becomes... x [ p , l ], of which 0 p <P 0 l<L Accordingly, time-domain sequence indexing n Become pL + l Thus, we obtain equation (3); ----------Formula (3); Similarly, for k The data is segmented, and the value of each frequency point is obtained by the combined effect of all segmented time-domain data. Therefore, the frequency domain sequence index... k Become aP + b Then equation (3) can be transformed into equation (4); ----------Formula (4); In this process, firstly, the segments are processed according to formula (5). x [ p , l Perform FFT transformation column by column to obtain X 1[ b , l ]; ----------Formula (5); Then, according to equation (6) X 1[ b , l Multiply by the modulation factor to obtain X 2[ b , l ]: ----------Formula (6); Further performing an FFT operation on each row, as shown in equation (7), yields... X [ b , a ]; ----------Formula (7); Then perform matrix transpose to obtain X [ a , b The final frequency domain sequence result is obtained by concatenating vectors. X [ k ].

[0058] A segmented design and supporting multi-channel acquisition scheme. For example... Figure 4 As shown, taking a 4-element receiving antenna as an example, a set of circuit boards needs to be matched for each element. Each set of circuit boards includes two modules. One module includes two sub-modules, AD7981 and DSP33EV, for data acquisition and preprocessing. The other module includes two sub-modules, DSP33FJ and FLASH, for segmented processing and storage.

[0059] Specifically, in this embodiment, the first board can be used for data acquisition and preprocessing. The acquired signal is divided into 256 segments, each segment being 256 characters long, resulting in a 256-character signal format. A 256-dimensional matrix is ​​used. During data acquisition, a DSP33EV is used to control the matrix and perform an FFT row-wise. The processed result is then transmitted to a second board and stored in the FLASH memory. Next, the stored data is read column-wise from the FLASH memory, and an FFT is performed column-wise, with the result also stored in the FLASH memory. After all FFT processing is complete, the corresponding portions are used to calculate the component values ​​of the target frequency band. The processing flow is the same for each board. Finally, the... H X , H Y , H Z and G X , G Y , G Z Once the information is transmitted to the transmission board, the detection distance and orientation can be calculated. H X , H Y , H Z Frequency bands x Component signals, frequency bands y Component signals and frequency bands z component signal, G X , G Y , G Z These are the accelerations due to gravity. x Component velocity, y Component velocity and z Component velocity.

[0060] in, H X To extract the magnetic field at the target frequency point after processing the acquired raw magnetic field x-component signal. x Quantity; H Y To obtain the original magnetic field y After component signal processing, the magnetic field at the target frequency point is extracted. y Quantity; H Z To obtain the original magnetic field z After component signal processing, the magnetic field at the target frequency point is extracted. z Quantity.

[0061] Among them, see Figure 4 This embodiment is designed to process 12 channels of signals simultaneously. These 12 channels specifically correspond to: 4 probes, each probe having a magnetic signal from an alternating magnetic field. H X , H Y , H Z Three components. After all FFTs are completed, the transmission board contains signals from multiple frequency points across 12 channels. The corresponding part refers to: if the transmitted signal is 17 Hz, then the 17 Hz signal is extracted for subsequent interpretation; if the transmitted signal is 27 Hz, then the 27 Hz signal is extracted for subsequent interpretation; and for each probe... H X , H Y , H Z All components were extracted.

[0062] This embodiment aims to address the challenge of balancing signal processing and transmission efficiency in downhole environments with limited resources. Based on existing technologies, this embodiment improves upon existing ones by introducing power spectral density estimation to achieve adaptive separation of the target frequency signal. Simultaneously, a piecewise fast Fourier transform processing strategy is designed to enhance signal processing efficiency and avoid the adverse effects of excessive data volume on transmission efficiency and processing accuracy. Furthermore, a multi-channel signal transmission protocol is designed to achieve low-noise, high-speed signal acquisition, thus providing reliable technical support for high-precision positioning of rescue wells.

[0063] This embodiment aims to utilize segmented power spectral density estimation to achieve adaptive and rapid separation of multi-frequency detection signals, thereby improving the detection signal-to-noise ratio and enabling low-noise, high-speed transmission of rescue well detection signals.

[0064] Compared with related technologies, this embodiment achieves at least the following technical effects: 1. By employing the power spectral density estimation method, adaptive extraction of the target frequency signal is achieved, effectively suppressing power frequency interference and broadband noise, significantly improving signal fidelity under low signal-to-noise ratio conditions, and providing reliable data support for accurate positioning; 2. By introducing a segmented fast Fourier transform processing strategy, the storage resource consumption of a single operation is significantly reduced, avoiding the processing delay and accuracy loss caused by excessive data volume in traditional methods, and realizing fast and high-precision processing of downhole signals.

[0065] 3. Design a data acquisition and transmission protocol that adapts to the needs of multi-component detection, and support the parallel processing of multi-channel signals and low-noise transmission. This not only improves the overall detection efficiency, but also lays a good data foundation for accurate detection and positioning.

[0066] To verify the application effect of segmented FFT, this embodiment acquired raw signals at 17 Hz, 37 Hz, and 57 Hz, as follows: Figure 5 , Figure 6 and Figure 7 As shown. These signals were processed using both the global power spectral density estimation method and the piecewise FFT-based estimation method, and the results are shown below. Figure 8 , 9 As shown in Figure 10, it can be seen that the results of direct FFT processing and piecewise FFT processing are highly consistent, both showing large amplitude values ​​at the excitation frequency, proving the feasibility of using piecewise FFT.

[0067] like Figure 11 As shown, this embodiment proposes a current injection type rescue well detection signal processing device, which may include: The acquisition unit 101 is used to acquire multiple component signals of the secondary magnetic field signal through any one of the multiple probes in the rescue well; wherein, the secondary magnetic field signal is generated by the metal casing in the accident well according to the alternating current of the set frequency emitted by the rescue well. The segmentation unit 102 is used to segment any component signal acquired by the probe into multiple segment signals. Arrangement unit 103 is used to arrange each segmented signal into a target matrix; Processing unit 104 is used to perform piecewise fast Fourier transform and frequency domain reconstruction on the target matrix to obtain the processed component signal; The extraction unit 105 is used to extract the corresponding frequency band component signal from the processed component signal according to the set frequency; wherein, each frequency band component signal is used as a whole to locate the accident well.

[0068] It should be noted that the processing procedures and beneficial effects of the acquisition unit 101, the segmentation unit 102, the arrangement unit 103, the processing unit 104, and the extraction unit 105 can be referred to respectively. Figure 1 Steps S101 to S105 are not described in detail here.

[0069] Optionally, the segmentation unit 102 is also used for: The component signal is divided into multiple segment signals according to the set segment length, and the signal length of each segment signal is equal to the set segment length. Arrangement unit 103 is also used for: Based on the order of each segment signal's position in the component signal, the row order corresponding to each segment signal is set; where, the smaller the order of the segment signal's position in the component signal, the smaller the row order corresponding to the segment signal. Arrange each segment signal into a target matrix according to the row order of each segment signal.

[0070] Optionally, the processing unit 104 is also used for: Perform a Fast Fourier Transform on each column of data in the target matrix to obtain the first transformation matrix; Multiply each row of data in the first transformation matrix by the modulation factor to obtain the modulated matrix; Perform a Fast Fourier Transform on each row of data in the modulated matrix to obtain the second transformed matrix; The transpose of the transformed matrix is ​​then concatenated to obtain the processed component signals.

[0071] Optionally, the processing unit 104 is also used for: According to the row order of each row of data in the second transformed matrix, each row of data in the second transformed matrix is ​​concatenated in turn to obtain the final frequency domain sequence, which is used as the processed component signal.

[0072] Optionally, the multiple component signals of the secondary magnetic field signal are respectively x Component magnetic field signal, y Component magnetic field signal and z Component magnetic field signal; Each probe includes three signal acquisition channels, each used for acquiring signals. x Component magnetic field signal, y Component magnetic field signal and z Component magnetic field signal; The processed component signal is the processed x Component magnetic field signal, after processing y Component magnetic field signal or after processing z Component magnetic field signal; Frequency band component signal is frequency band x Component magnetic field signal, frequency band y Component magnetic field signal or frequency band z Component magnetic field signal.

[0073] Optionally, the above-mentioned device further includes: The reverse-engineering unit is used to obtain the gravitational acceleration after extracting the corresponding frequency band component signal from the processed component signal according to a set frequency. x Component velocity, y Component velocity and z Component velocity; based on gravitational acceleration x Quantity, y Components and z Components, each frequency band x Component magnetic field signal, each frequency band y Component magnetic field signals and each frequency bandz The component magnetic field signal is used to infer the relative orientation and relative distance between the accident well and the rescue well.

[0074] Optionally, the above-mentioned device further includes: The storage unit is used to perform a fast Fourier transform on each column of data in the target matrix to obtain a first transform matrix, and then store the first transform matrix, the modulated matrix, the second transform matrix, the processed component signal, and the frequency band component signal in the target space; store the relative azimuth and relative distance between the accident well and the rescue well obtained by reverse calculation in the target space, and send them to the ground equipment.

[0075] The current-injection type rescue well detection signal processing device proposed in this embodiment collects multiple component signals of a secondary magnetic field signal from any one of multiple probes in the rescue well. The secondary magnetic field signal is generated by the alternating current emitted by the metal casing of the accident well at a set frequency. For any component signal collected by the probe, the component signal is divided into multiple segments, and each segment is arranged into a target matrix. The target matrix is ​​then subjected to piecewise fast Fourier transform and frequency domain reconstruction to obtain the processed component signal. The corresponding frequency band component signal is extracted from the processed component signal according to a set frequency. Each frequency band component signal is used as a whole to locate the accident well. This embodiment introduces a piecewise fast Fourier transform processing strategy, significantly reducing the storage resource consumption of a single operation, avoiding processing delays and accuracy loss due to excessive data volume, achieving fast and high-precision processing of downhole signals, and ensuring the positioning accuracy of the accident well.

[0076] In this embodiment, the current injection type rescue well detection signal processing device is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0077] This invention also provides a computer device having the above-described features. Figure 11 The image shows a current-injection type rescue well detection signal processing device.

[0078] Please see Figure 12The present invention provides a schematic diagram of the structure of a computer device according to an optional embodiment. The computer device includes one or more processors 10, a memory 20, and interfaces for connecting the various components, including high-speed interfaces and low-speed interfaces. The various components are interconnected via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, multiple processors and / or multiple buses can be used with multiple memories, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 12 Take a processor 10 as an example.

[0079] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0080] The memory 20 stores instructions executable by at least one processor 10 to cause at least one processor 10 to perform the method shown in the above embodiments.

[0081] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function. The data storage area may store data created based on the use of the computer device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, which can be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0082] Memory 20 may include volatile memory, such as random access memory. Memory may also include non-volatile memory, such as flash memory, hard disk, or solid-state drive. Memory 20 may also include combinations of the above types of memory.

[0083] The computer device also includes a communication interface 30 for communicating with other devices or communication networks.

[0084] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for processing signals from current-injection type rescue well detection, characterized in that, include: For any one of the multiple probes in the rescue well, multiple components of the secondary magnetic field signal are collected through the probe; wherein, the secondary magnetic field signal is generated by the metal casing in the accident well based on the alternating current of a set frequency emitted by the rescue well; For any component signal acquired by the probe, the component signal is divided into multiple segment signals, each segment signal is arranged into a target matrix, and the target matrix is ​​subjected to segmented fast Fourier transform and frequency domain reconstruction to obtain the processed component signal; the corresponding frequency band component signal is extracted from the processed component signal according to the set frequency; wherein, each frequency band component signal is used as a whole to locate the accident well.

2. The method according to claim 1, characterized in that, The step of dividing the component signal into multiple segmented signals includes: According to the set segment length, the component signal is divided into multiple segment signals, and the signal length of each segment signal is equal to the set segment length; The step of arranging each of the segmented signals into a target matrix includes: Based on the order of the preceding and following positions of each segment signal in the component signal, the row order corresponding to each segment signal is set; wherein, the smaller the order of the preceding and following positions of the segment signal in the component signal, the smaller the row order corresponding to the segment signal; Each segmented signal is arranged into the target matrix according to the row order corresponding to each segmented signal.

3. The method according to claim 2, characterized in that, The step of performing piecewise fast Fourier transform and frequency domain reconstruction on the target matrix to obtain the processed component signals includes: Perform a Fast Fourier Transform on each column of data in the target matrix to obtain the first transform matrix; Multiply each row of data in the first transformation matrix by the modulation factor to obtain the modulated matrix; Perform a Fast Fourier Transform on each row of data in the modulated matrix to obtain a second transformed matrix; The transpose and concatenation of the second transformed matrix yields the processed component signal.

4. The method according to claim 3, characterized in that, The step of transposing and concatenating the second transformed matrix to obtain the processed component signal includes: According to the row order of each row of data in the second transformed matrix, each row of data in the second transformed matrix is ​​concatenated in turn to obtain the final frequency domain sequence, which is used as the processed component signal.

5. The method according to any one of claims 1 to 4, characterized in that, The multiple component signals of the secondary magnetic field signal are respectively x Component magnetic field signal, y Component magnetic field signal and z Component magnetic field signal; Each probe includes three signal acquisition channels, each used for acquiring signals. x Component magnetic field signal, y Component magnetic field signal and z Component magnetic field signal; The processed component signal is the processed... x Component magnetic field signal, after processing y Component magnetic field signal or after processing z Component magnetic field signal; The frequency band component signal is a frequency band. x Component magnetic field signal, frequency band y Component magnetic field signal or frequency band z Component magnetic field signal.

6. The method according to claim 5, characterized in that, After extracting the corresponding frequency band component signal from the processed component signal according to the set frequency, the method further includes: Obtaining gravitational acceleration x Quantity, y Components and z Quantity; According to the aforementioned gravitational acceleration x Quantity, y Components and z Components, each of the frequency bands x Component magnetic field signal, each of the frequency bands y Component magnetic field signals and each of the frequency bands z The relative orientation and relative distance between the accident well and the rescue well are deduced from the component magnetic field signal.

7. The method according to claim 6, characterized in that, After performing a Fast Fourier Transform on each column of data in the target matrix to obtain a first transform matrix, the method further includes: The first transformation matrix, the modulated matrix, the second transformation matrix, the processed component signal, and the frequency band component signal are stored in the target space; The relative orientation and relative distance between the accident well and the rescue well obtained by reverse calculation are stored in the target space and sent to ground equipment.

8. A current-injection type rescue well detection signal processing device, characterized in that, include: The acquisition unit is used to acquire multiple component signals of a secondary magnetic field signal through any one of the multiple probes in the rescue well; wherein, the secondary magnetic field signal is generated by the metal casing in the accident well according to the alternating current of a set frequency emitted by the rescue well. The segmentation unit is used to segment any component signal acquired by the probe into multiple segmented signals. An arrangement unit is used to arrange each of the segmented signals into a target matrix; The processing unit is used to perform piecewise fast Fourier transform and frequency domain reconstruction on the target matrix to obtain the processed component signals; An extraction unit is used to extract the corresponding frequency band component signal from the processed component signal according to the set frequency; wherein each frequency band component signal is used as a whole to locate the accident well.

9. A computer device, characterized in that, include: The system includes a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to perform the current injection-type rescue well detection signal processing method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to execute the current injection rescue well detection signal processing method according to any one of claims 1 to 7.

Images