Method and device for identifying coupling signal and medium

Abstract

The invention discloses a method and device for identifying a coupling signal and a medium, and is suitable for the technical field of oil-gas exploration. And comparing the acquired induced electromotive force of the current period with the induced electromotive force of the previous period, and if the induced electromotive force of the current period is different from the induced electromotive force of the previous period, processing the induced electromotive force of the current period according to a waveform time analysis algorithm and an automatic threshold gain algorithm so as to determine a coupling signal corresponding to the induced electromotive force of the current period. According to the method, induced electromotive force collected by a sensor is received, a current period is correspondingly compared with a previous period, if the current period is different from the previous period, it is determined that the induced electromotive force of the current period is changed, the authenticity of the casing coupling is guaranteed according to a waveform time analysis algorithm, and noise interference is filtered out through a threshold automatic gain algorithm; and the position of the casing coupling can be distinguished, so that the detection of the seamless casing coupling can be realized. The problem of magnetization interference of the seamless sleeve is solved, and the signal detectability and accuracy are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploration, and particularly to a method, device and medium for identifying collar signals. Background Art

[0002] Sector acoustic wave instruments are the main means for evaluating cementing quality. The magnetic positioning signals of casing collars measured by such instruments, as the basis for perforating, depth calibration, and positioning, directly affect the production of oil wells and may even cause misperforation due to depth errors. Therefore, the accuracy of measuring collar signals is crucial.

[0003] With the popularization and application of sidetracking well technology, seamless casing collar connection methods have emerged in cemented casings. It has advantages such as high connection strength, good sealing performance, and strong composite load capacity. Therefore, it has been widely used in oil and gas wells in domestic and foreign oil fields. Since the wall thickness at the connection interface of the special threaded casing collar used is basically the same as the inner and outer diameters of the pipe body, when measured by electromagnetic principles, the change in magnetic flux is small when the instrument passes through the collar. Coupled with the influence of various factors such as casing magnetization and downhole interference, the measured casing collar signals are submerged in interference signals and cannot be identified. In particular, the single and double peaks of the collar cannot be distinguished, causing many difficulties in the calculation of perforating depth positioning and directly affecting the accuracy of perforating.

[0004] Therefore, how to avoid the interference of collar signals to improve the accuracy of perforating depth positioning is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a method, device and medium for identifying collar signals. By ensuring the authenticity of the casing collar according to the waveform time analysis algorithm, filtering out noise interference using the threshold automatic gain algorithm, and distinguishing the position of the casing collar, the detection of seamless casing collars can be achieved. The problem of seamless casing magnetization interference is solved, and the detectability and accuracy of the signal are improved.

[0006] To solve the above technical problems, the present invention provides a method for identifying collar signals, including:

[0007] Collect the induced electromotive force of the current cycle and the induced electromotive force of the previous cycle emitted by the receiving sensor, where the induced electromotive force is the electromotive force obtained by the excitation circuit exciting the transmitting sensor for the receiving sensor to receive;

[0008] Compare the induced electromotive force corresponding to the current cycle with that of the previous cycle;

[0009] If they are different, process the induced electromotive force of the current cycle according to the waveform time analysis algorithm and the threshold automatic gain algorithm to determine the collar signal corresponding to the induced electromotive force of the current cycle.

[0010] Preferably, processing the induced electromotive force of the current cycle according to the waveform time analysis algorithm and the threshold automatic gain algorithm to determine the collar signal corresponding to the induced electromotive force of the current cycle includes:

[0011] Processing the induced electromotive force of the current cycle according to the waveform time analysis algorithm to obtain a first induced electromotive force;

[0012] Processing the first induced electromotive force according to the threshold automatic gain algorithm to obtain a threshold voltage corresponding to the first induced electromotive force;

[0013] When the first induced electromotive force is greater than the threshold voltage, it is determined that the induced electromotive force is the collar signal.

[0014] Preferably, processing the induced electromotive force of the current cycle according to the waveform time analysis algorithm to obtain a first induced electromotive force includes:

[0015] Dividing the signal of the induced electromotive force of the current cycle into N equal - part signals according to the sampling time interval;

[0016] Sampling the N equal - part signals point by point;

[0017] Adding the point - by - point sampled signals to synchronously restore to the induced electromotive force of the current cycle;

[0018] Obtaining the first time when the excitation wave emitted by the transmitting sensor propagates along the casing to the receiving sensor;

[0019] Determining the signal opening time of the induced electromotive force of the current cycle according to the first time;

[0020] Intercepting the corresponding N equal - part signals of the induced electromotive force of the current cycle according to the signal opening time to obtain the corresponding first induced electromotive force.

[0021] Preferably, processing the first induced electromotive force according to the threshold automatic gain algorithm to obtain a threshold voltage corresponding to the first induced electromotive force includes:

[0022] Obtaining the number of samples corresponding to the first induced electromotive force;

[0023] Selecting the maximum sampled data from the number of samples;

[0024] Determining the average value of the sampled data corresponding to the number of samples;

[0025] Determining the threshold voltage according to the relationship between the average value of the sampled data, the maximum sampled data and the threshold voltage coefficient.

[0026] Preferably, it further includes:

[0027] When the induced electromotive force in the current period is the same as that in the previous period, return to the step of collecting the induced electromotive force in the current period and the induced electromotive force in the previous period emitted by the acquisition receiving sensor to obtain the induced electromotive force in the next period.

[0028] Preferably, before processing the induced electromotive force in the current period according to the waveform time analysis algorithm to obtain the first induced electromotive force, it further includes:

[0029] Perform differential amplification processing on the induced electromotive force in the current period to obtain the processed induced electromotive force in the current period;

[0030] Perform low-pass filtering processing on the processed induced electromotive force in the current period to obtain the filtered induced electromotive force in the current period, and enter the step of processing the induced electromotive force in the current period according to the waveform time analysis algorithm to obtain the first induced electromotive force;

[0031] Correspondingly, after processing the induced electromotive force in the current period according to the waveform time analysis algorithm to obtain the first induced electromotive force, and before processing the first induced electromotive force according to the threshold automatic gain algorithm to obtain the threshold voltage corresponding to the first induced electromotive force, it further includes:

[0032] Perform phase-sensitive demodulation processing on the first induced electromotive force to obtain the processed first induced electromotive force, and enter the step of processing the first induced electromotive force according to the threshold automatic gain algorithm to obtain the threshold voltage corresponding to the first induced electromotive force.

[0033] Preferably, the determination process of the induced electromotive force includes:

[0034] Obtain an excitation signal source generated by the CPU, where the excitation signal source is a positive and negative pulse low-frequency signal;

[0035] Amplify the excitation signal source by adopting a three-group pulse phase-shifted push-pull amplification method so that the receiving sensor can receive the induced electromotive force.

[0036] To solve the above technical problems, the present invention further provides a device for identifying a collar signal, including:

[0037] An acquisition module, configured to acquire the induced electromotive force in the current period and the induced electromotive force in the previous period emitted by the receiving sensor, where the induced electromotive force is excited by an excitation circuit to the emission sensor so that the receiving sensor can receive the electromotive force;

[0038] A comparison module, configured to compare the induced electromotive force in the current cycle with that in the previous cycle, and if they are different, enter the processing module;

[0039] The processing module is configured to process the induced electromotive force in the current cycle according to a waveform time analysis algorithm and a threshold automatic gain algorithm to determine the collar signal corresponding to the induced electromotive force in the current cycle.

[0040] To solve the above technical problems, the present invention also provides a device for identifying a collar signal, including:

[0041] A memory, configured to store a computer program;

[0042] A processor, configured to implement the steps of the method for identifying a collar signal as described above when executing the computer program.

[0043] To solve the above technical problems, the present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method for identifying a collar signal as described above are implemented.

[0044] A method for identifying a collar signal provided by the present invention includes: collecting the induced electromotive force in the current cycle and the induced electromotive force in the previous cycle emitted by a receiving sensor, where the induced electromotive force is the electromotive force excited by an excitation circuit to the transmitting sensor for the receiving sensor to receive; comparing the induced electromotive force in the current cycle with that in the previous cycle; if they are different, processing the induced electromotive force in the current cycle according to a waveform time analysis algorithm and a threshold automatic gain algorithm to determine the collar signal corresponding to the induced electromotive force in the current cycle. Through the induced electromotive force collected by the receiving sensor, by comparing the current cycle with the previous cycle, if they are different, it is determined that the induced electromotive force in the current cycle has changed. According to the waveform time analysis algorithm, the authenticity of the casing collar is ensured, and the threshold automatic gain algorithm is used to filter out noise interference and distinguish the position of the casing collar, so as to realize the detection of seamless casing collars. The problem of magnetization interference of seamless casings is solved, and the detectability and accuracy of signals are improved.

[0045] In addition, the present invention also provides a device and a medium for identifying a collar signal, which have the same beneficial effects as the method for identifying a collar signal as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] To more clearly illustrate the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0047] Figure 1 It is a schematic structural diagram of a measurement circuit based on a sector acoustic wave instrument provided by an embodiment of the present invention;

[0048] Figure 2 It is a flowchart of a method for identifying collar signals provided by an embodiment of the present invention;

[0049] Figure 3 It is a structural diagram of a device for identifying collar signals provided by an embodiment of the present invention;

[0050] Figure 4 It is a structural diagram of another device for identifying collar signals provided by an embodiment of the present invention;

[0051] Figure 5 It is a schematic application diagram of an existing method for identifying collar signals;

[0052] Figure 6 It is a schematic application diagram of a method for identifying collar signals provided by an embodiment of the present invention. Specific embodiments

[0053] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0054] The core of the present invention is to provide a method, device, and medium for identifying collar signals. By ensuring the authenticity of the casing collar according to the waveform time analysis algorithm, and using the threshold automatic gain algorithm to filter out noise interference and distinguish the position of the casing collar, the detection of seamless casing collars can be achieved. It solves the problem of magnetization interference in seamless casings and improves the detectability and accuracy of signals.

[0055] To enable those skilled in the art to better understand the solution of the present invention, the following will further elaborate on the present invention in detail with reference to the drawings and specific embodiments.

[0056] It should be noted that the existing instrument for magnetic positioning uses the electromagnetic principle and measures with a probe composed of two permanent magnets and a coil. During well logging, when the instrument moves through a collar in the casing, the magnetic flux passing through the induction coil changes, generating an induced electromotive force. The coil outputs a collar signal, which serves as a marker for depth positioning. The method for identifying the collar signal provided by the embodiments of the present invention is based on the measurement circuit of a sector acoustic wave instrument. Figure 1 FIG. Figure 1 is a schematic structural diagram of a measurement circuit based on a sector acoustic wave instrument provided by an embodiment of the present invention. As Figure 1 shown, a central processing unit (CPU) processing circuit 3 receives commands from a host computer, generates an excitation signal source, and sends it to a signal excitation circuit 2. The signal excitation circuit 2 generates a high-voltage excitation pulse signal to excite a transmitting sensor 1. A receiving sensor 4 receives a feedback signal, and through a signal processing circuit 5, signal interference is removed, and interference signals are filtered to achieve precise positioning of the casing collar. The analog-to-digital (A / D) signal acquisition circuit 6 acquires A / D signals, which are processed by the CPU processing circuit 3 using a threshold automatic gain operation to identify the original signal of the casing collar. The identified collar signal forms a standard collar signal through D / A simulation and is sent to the data bus through a sending circuit. The host computer obtains the seamless casing collar position information through the data bus.

[0057] Figure 2 FIG. Figure 2 is a flowchart of a method for identifying a collar signal provided by an embodiment of the present invention. As Figure 2 shown, the method includes:

[0058] S11: Acquire the induced electromotive force of the current cycle and the induced electromotive force of the previous cycle emitted by the receiving sensor;

[0059] wherein, the induced electromotive force is the electromotive force obtained by the excitation circuit exciting the transmitting sensor for the receiving sensor to receive;

[0060] S12: Determine whether the induced electromotive forces corresponding to the current cycle and the previous cycle are the same. If they are different, proceed to step S13; if they are the same, proceed to step S14;

[0061] S13: Process the induced electromotive force of the current cycle according to the waveform time analysis algorithm and the threshold automatic gain algorithm to determine the collar signal corresponding to the induced electromotive force of the current cycle.

[0062] S14: Return to step S11 to obtain the induced electromotive force of the next cycle.

[0063] Specifically, the CPU processing circuit includes an excitation signal source, an A / D signal acquisition circuit, and a coded signal transmission circuit; the excitation signal source is generated by the CPU and sent to the signal excitation circuit. The excitation source signal is a positive and negative pulse low-frequency signal, which generates a high-voltage excitation pulse signal through the signal excitation circuit to excite the transmitting sensor; the low-frequency electromagnetic wave emitted by the transmitting sensor is transmitted along the casing, and the receiving sensor detects and samples the wave passing through the casing, and the sampled signal is connected to the signal processing circuit.

[0064] Sample the induced electromotive force emitted by the receiving sensor. To determine how the current induced electromotive force changes, it is more straightforward to obtain the induced electromotive forces of different sampling periods, that is, to obtain the induced electromotive force of the current period and the induced electromotive force of the previous period. Regarding how the induced electromotive force is generated by the receiving sensor, the transmitting sensor needs to emit a signal and feedback it to the receiving sensor.

[0065] As an embodiment, the process of determining the induced electromotive force includes:

[0066] Obtain the excitation signal source generated by the CPU, where the excitation signal source is a positive and negative pulse low-frequency signal;

[0067] Amplify the excitation signal source by using a three-group pulse phase-shifted push-pull amplification method so that the receiving sensor can receive the induced electromotive force.

[0068] Specifically, the excitation signal source is generated by the CPU and sent to the signal excitation circuit. The excitation source signal is a positive and negative pulse low-frequency signal, which generates a high-voltage excitation pulse signal through the signal excitation circuit to excite the transmitting sensor; the positive and negative pulse low-frequency signals of the excitation source adopt a three-group pulse phase-shifted push-pull amplification method. Compared with the single-pulse method, this method forms a larger induced current in the casing and can generate a stronger induced electromotive force. The low-frequency electromagnetic wave emitted by the transmitting sensor is transmitted along the casing, and the receiving sensor detects and samples the wave passing through the casing, and the sampled signal is connected to the signal processing circuit; the receiving sensor receives the feedback signal, which successively passes through the signal processing circuit and the A / D signal acquisition circuit and enters the CPU processing circuit.

[0069] The three-group pulse phase-shifted push-pull amplification method uses a push-pull amplifier. According to the number of amplification elements in the power amplifier output stage, it can be divided into a single-ended amplifier and a push-pull amplifier. The output stage of the push-pull amplifier has two "arms" (two groups of amplification elements). When the current in one "arm" increases, the current in the other "arm" decreases, and their states alternate. For the load, it seems that one "arm" is pushing and the other "arm" is pulling, jointly completing the current output task. Although class A amplifiers can use push-pull amplification, it is more common to use push-pull amplification to form class B or class AB amplifiers. In this embodiment, no specific limitation is made on the specific push-pull amplifier, and it can be set according to the actual situation.

[0070] Compare whether the induced electromotive forces corresponding to two cycles are the same. If they are different, it is determined that the current induced electromotive force has changed, whether it has decreased or increased. If they are the same, it is determined that the current induced electromotive force has not changed, and the induced electromotive force of the next cycle is collected continuously.

[0071] As an embodiment, it further includes:

[0072] When the induced electromotive force of the current cycle is the same as that of the previous cycle, return to the step of collecting the induced electromotive force of the current cycle and the induced electromotive force of the previous cycle emitted by the receiving sensor to obtain the induced electromotive force of the next cycle.

[0073] If the induced electromotive forces of two cycles are the same, it is determined that there is no change, save the induced electromotive force of the current cycle, and continue to return to step S11 to collect the induced electromotive force of the next cycle for comparison.

[0074] In step S13, only for the changed induced electromotive force, the induced electromotive force of the current cycle is processed according to the waveform time analysis algorithm and the threshold automatic gain algorithm to obtain the corresponding collar signal. Generally speaking, the two algorithms are used to filter the signal of the induced electromotive force and reduce the noise interference. The waveform time analysis algorithm is mainly for intercepting the signal, so as to intercept the useful signal to a certain extent. The threshold automatic gain algorithm is to generate a threshold comparison in combination with the signal itself according to the intercepted signal. It should be noted that for the threshold automatic gain algorithm, the threshold can be the same or different each time, mainly determined according to the change of the intercepted signal. As a preferred embodiment, the waveform time analysis algorithm and the threshold automatic gain algorithm need to perform the waveform time analysis algorithm first, and then the threshold automatic gain algorithm, so that the signal waveform processed later is smaller, the processing time is faster, and at the same time, because the intercepted signal after the waveform time analysis algorithm has fewer interference factors, the final signal judgment is more accurate.

[0075] A method for identifying collar signals provided by an embodiment of the present invention includes: collecting the induced electromotive force of the current cycle and the induced electromotive force of the previous cycle emitted by a receiving sensor, where the induced electromotive force is the electromotive force excited by an excitation circuit to excite a transmitting sensor for the receiving sensor to receive; comparing the induced electromotive forces corresponding to the current cycle and the previous cycle; if they are different, processing the induced electromotive force of the current cycle according to a waveform time analysis algorithm and a threshold automatic gain algorithm to determine the collar signal corresponding to the induced electromotive force of the current cycle. This method collects the induced electromotive force through a receiving sensor, compares the current cycle with the previous cycle. If they are different, it is determined that the induced electromotive force of the current cycle has changed. The authenticity of the casing collar is ensured according to the waveform time analysis algorithm, and the threshold automatic gain algorithm is used to filter out noise interference and distinguish the position of the casing collar, thus realizing the detection of seamless casing collars. It solves the problem of magnetization interference of seamless casings and improves the detectability and accuracy of signals.

[0076] Based on the above embodiment, processing the induced electromotive force of the current cycle according to a waveform time analysis algorithm and a threshold automatic gain algorithm in step S13 to determine the collar signal corresponding to the induced electromotive force of the current cycle includes:

[0077] Processing the induced electromotive force of the current cycle according to a waveform time analysis algorithm to obtain a first induced electromotive force;

[0078] Processing the first induced electromotive force according to a threshold automatic gain algorithm to obtain the threshold voltage corresponding to the first induced electromotive force;

[0079] When the first induced electromotive force is greater than the threshold voltage, it is determined that the induced electromotive force is a collar signal.

[0080] Specifically, the induced electromotive force of the current cycle is intercepted and processed according to a waveform time analysis algorithm to obtain a first induced electromotive force, and then the first induced electromotive force is processed according to a threshold automatic gain algorithm to obtain the corresponding threshold voltage.

[0081] Comparing the first induced electromotive force with the threshold voltage to determine the corresponding collar signal. If the first induced electromotive force is greater than the threshold voltage, it is determined that the collar signal has arrived.

[0082] In addition, the threshold automatic gain algorithm can be performed first to determine whether the collar signal has arrived, and then the waveform time analysis algorithm is performed for filtering to obtain the filtered collar signal.

[0083] As an embodiment, processing the induced electromotive force of the current cycle according to a waveform time analysis algorithm to obtain a first induced electromotive force includes:

[0084] Dividing the signal of the induced electromotive force of the current cycle into N equal parts of signals according to the sampling time interval;

[0085] Sample the signal divided into N equal parts point by point;

[0086] Sum up the signals after point-by-point sampling to synchronously restore to the induced electromotive force of the current cycle;

[0087] Obtain the first time when the excitation wave emitted by the transmitting sensor propagates along the casing to the receiving sensor;

[0088] Determine the signal opening time of the induced electromotive force of the current cycle according to the first time;

[0089] Intercept the corresponding N-equal-part signals of the induced electromotive force of the current cycle according to the signal opening time to obtain the corresponding first induced electromotive force.

[0090] Specifically, to obtain the first induced electromotive force, filter out the formation interference signals caused by casing magnetization and signal propagation. The algorithm is as follows:

[0091] Receive the signal corresponding to the induced electromotive force of the current cycle as:

[0092] S(t) = Vcos(w 0 t + φ);

[0093] where S(t) is the induced electromotive force, V is the signal amplitude, φ is the phase angle, t is the sampling time, and w 0 is a constant.

[0094] Divide the signal of the induced electromotive force of the current cycle into N equal-part signals according to the sampling time interval. The formula is as follows:

[0095] S(t) = {s1(Δt), s2(Δt), s3(Δt)……sn(Δt)};

[0096] where Δt is the sampling time interval;

[0097] Select an interval as the sampling time according to the characteristics of waveform propagation and amplitude change sensitivity, sample the signal divided into N equal parts point by point, and then perform synchronous summation to realize waveform synchronous restoration in noise. The specific formula is as follows:

[0098]

[0099] where, if n = 5, perform 5-point mean filtering.

[0100] Obtain the first time T when the excitation wave emitted by the transmitting sensor propagates along the casing to the receiving sensor. The formula is as follows:

[0101] T = S / V;

[0102] where S is the signal propagation distance and V is the signal wave propagation speed.

[0103] The CPU processor calculates the signal opening time according to the time length of T, and the specific formula is as follows:

[0104] S(n) = {x(n); t; k};

[0105] Among them, x(n) indicates that the signal sampling time is directly proportional to t, t = T + Δt, k is the switching conversion frequency, the selection of the signal channel switching frequency k is consistent with the emission excitation source frequency, and the switching time is related to the magnitude of t.

[0106] According to the signal opening time, the corresponding first induced electromotive force is obtained after intercepting the corresponding N equal parts of the signal from the induced electromotive force in the current cycle. For example, the waveform of the induced electromotive force in the current cycle is divided into 5 equal parts of signals, and the corresponding times are (0 - 1 - 2 - 3 - 4 - 5) s respectively. Among them, the signal opening time is 2 s, then the waveform after 2 s is intercepted, that is, the waveform signal corresponding to (2 - 3 - 4 - 5), and the first induced electromotive force is obtained. The waveform time analysis algorithm has the characteristics of high output sensitivity and strong noise suppression ability.

[0107] On the basis of the above embodiments, as an embodiment, the first induced electromotive force is processed according to the threshold automatic gain algorithm to obtain the threshold voltage corresponding to the first induced electromotive force, including:

[0108] Obtain the number of samples corresponding to the first induced electromotive force;

[0109] Select the maximum sampling data from the number of samples;

[0110] Determine the average value of the sampling data corresponding to the number of samples;

[0111] Determine the threshold voltage according to the relationship between the average sampling data, the maximum sampling data and the threshold voltage coefficient.

[0112] The digital A / D signal is processed by the CPU processing circuit and uses the threshold automatic gain operation to identify the original signal of the casing collar signal. The determination process of its threshold voltage is as follows:

[0113] Obtain the number of samples corresponding to the first induced electromotive force, and the formula is as follows:

[0114] x = {x 1 , x 2 , x 3 , x 4 , … x n};

[0115] Among them, x is the digital A / D sampling signal corresponding to the first induced electromotive force, and n is the number of sampling data greater than 1;

[0116] Select the maximum sampling data from the number of samplings. The formula is as follows:

[0117] x max = max{x 1 , x 2 , x 3 , x 4 , … x n};

[0118] Among them, x max is the maximum value among n data, and x is the sampling data;

[0119] Determine the average value of the sampling data corresponding to the number of samplings. The formula is as follows:

[0120]

[0121] Its average value can be used as the amplitude average value or the amplitude threshold voltage value of the noise.

[0122] Determine the threshold voltage according to the relationship between the average value of the sampling data, the maximum sampling data, and the threshold voltage coefficient. The formula is as follows:

[0123] w = x av + p * x max ;

[0124] Among them, w is the threshold voltage, and p is the threshold voltage coefficient.

[0125] The selection of the threshold value in this embodiment can filter out noise interference. The value lower than the threshold voltage is regarded as the noise value and is regarded as the signal baseline zero value in the calculation. After the signal A / D sampling voltage is greater than the threshold voltage within the sampling interval, a trigger flag is generated, and at the same time, the trigger flag triggers the processing circuit to generate a collar signal.

[0126] The identification process of the collar signal provided in this embodiment ensures the authenticity of the casing collar according to the waveform time analysis algorithm, filters out noise interference by using the threshold automatic gain algorithm, and distinguishes the position of the casing collar, thereby realizing the detection of seamless casing collars.

[0127] On the basis of the above embodiment, as an embodiment, before processing the induced electromotive force of the current cycle according to the waveform time analysis algorithm to obtain the first induced electromotive force, it further includes:

[0128] Perform differential amplification processing on the induced electromotive force of the current cycle to obtain the processed induced electromotive force of the current cycle;

[0129] Perform low-pass filtering processing on the processed induced electromotive force of the current cycle to obtain the filtered induced electromotive force of the current cycle, and enter the step of processing the induced electromotive force of the current cycle according to the waveform time analysis algorithm to obtain the first induced electromotive force;

[0130] Correspondingly, after processing the induced electromotive force of the current cycle according to the waveform time analysis algorithm to obtain the first induced electromotive force, and before processing the first induced electromotive force according to the threshold automatic gain algorithm to obtain the threshold voltage corresponding to the first induced electromotive force, the following steps are further included:

[0131] Perform phase-sensitive detection processing on the first induced electromotive force to obtain the processed first induced electromotive force, and enter the step of processing the first induced electromotive force according to the threshold automatic gain algorithm to obtain the threshold voltage corresponding to the first induced electromotive force.

[0132] Specifically, the noise processing circuit includes a signal processing circuit, and the signal processing circuit includes a signal differential amplification circuit and a low-frequency signal filtering circuit; the input end of the signal processing circuit is connected to the receiving sensor, and the output end is connected to the A / D signal acquisition circuit in the CPU processing circuit; the signal differential amplification circuit is connected to the receiving sensor, and the differential amplification circuit that amplifies the signal of the receiving sensor by 50 times uses a differential operational amplifier, which is conducive to the amplification of small signals and has a high signal-to-noise ratio. The signal amplified by the signal differential amplification circuit is connected to the low-frequency signal filtering circuit, and the low-frequency signal filtering circuit uses a second-order low-pass filter to filter out the high-frequency interference of the signal.

[0133] It should be noted that for the low-pass sampling at the beginning of the filtering process, high-pass can also be used, and the level of filtering is not limited here and can be set according to the actual situation.

[0134] Correspondingly, a phase-sensitive detection circuit is further included. There are two problems with envelope detection: one is that the main process of demodulation is to perform half-wave or full-wave rectification on the amplitude-modulated signal, and the phase of the modulation signal cannot be identified from the output of the detector. Second, the envelope detection circuit itself does not have the ability to distinguish signals with different carrier frequencies. For signals with different carrier frequencies, it rectifies them in the same way to restore the modulation signal, which means it does not have the ability to identify signals. In order to enable the detection circuit to have the ability to discriminate the phase and frequency of signals and improve the anti-interference ability, a phase-sensitive detection circuit needs to be used.

[0135] The phase-sensitive detection processing provided in this embodiment is to improve the anti-interference ability to obtain the first induced electromotive force.

[0136] The above describes in detail each embodiment corresponding to the method for identifying the collar signal. On this basis, the present invention also discloses a device for identifying the collar signal corresponding to the above method, Figure 3 which is a structural diagram of a device for identifying the collar signal provided by an embodiment of the present invention. As Figure 3 shown, the device for identifying the collar signal includes:

[0137] The acquisition module 11 is configured to acquire the induced electromotive force of the current cycle and the induced electromotive force of the previous cycle emitted by the receiving sensor, wherein the induced electromotive force is the electromotive force obtained by the excitation circuit exciting the transmitting sensor for the receiving sensor to receive;

[0138] The comparison module 12 is configured to compare the induced electromotive force corresponding to the current cycle with that of the previous cycle. If they are different, it enters the processing module 13;

[0139] The processing module 13 is configured to process the induced electromotive force of the current cycle according to the waveform time analysis algorithm and the threshold automatic gain algorithm to determine the collar signal corresponding to the induced electromotive force of the current cycle.

[0140] Since the embodiments of the device part correspond to the above embodiments, the embodiments of the device part are described with reference to the embodiments of the above method part and will not be elaborated here.

[0141] For the introduction of a device for identifying collar signals provided by the present invention, please refer to the above method embodiments. The present invention will not be elaborated here, and it has the same beneficial effects as the above method for identifying collar signals.

[0142] Figure 4 It is a structural diagram of another device for identifying collar signals provided by an embodiment of the present invention. As Figure 4 shown, the device includes:

[0143] The memory 21 is configured to store computer programs;

[0144] The processor 22 is configured to implement the steps of the method for identifying collar signals when executing the computer program.

[0145] The device for identifying collar signals provided in this embodiment may include but is not limited to smart phones, tablet computers, laptop computers, or desktop computers, etc.

[0146] Among them, the processor 22 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 22 may be implemented in at least one hardware form of a Digital Signal Processor (DSP), a Field-Programmable Gate Array (FPGA), or a Programmable Logic Array (PLA). The processor 22 may also include a main processor and a coprocessor. The main processor is a processor used to process data in the wake state, also known as the CPU; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 22 may be integrated with a Graphics Processing Unit (GPU), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 22 may further include an Artificial Intelligence (AI) processor, and the AI processor is used to process computational operations related to machine learning.

[0147] The memory 21 may include one or more computer-readable storage media, and the computer-readable storage media may be non-transitory. The memory 21 may further include high-speed random access memory and non-volatile memory, such as one or more disk storage devices and flash storage devices. In this embodiment, the memory 21 is at least used to store the following computer program 211. After the computer program is loaded and executed by the processor 22, it can implement the relevant steps of the method for identifying collar signals disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 21 may further include an operating system 212 and data 213, etc., and the storage method may be transient storage or permanent storage. Among them, the operating system 212 may include Windows, Unix, Linux, etc. The data 213 may include, but is not limited to, the data involved in the method for identifying collar signals, etc.

[0148] In some embodiments, the device for identifying collar signals may further include a display screen 23, an input / output interface 24, a communication interface 25, a power supply 26, and a communication bus 27.

[0149] Those skilled in the art can understand that Figure 4 the structure shown in

[0150] does not constitute a limitation on the device for identifying collar signals, and it may include more or fewer components than those shown in the figure.

[0151] For the introduction of a device for identifying collar signals provided by the present invention, please refer to the above method embodiments. The present invention will not be elaborated herein, and it has the same beneficial effects as the above method for identifying collar signals.

[0152] Furthermore, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor 22, the steps of the method for identifying collar signals as described above are implemented.

[0153] It can be understood that if the methods in the above embodiments are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0154] For the introduction of a computer-readable storage medium provided by the present invention, please refer to the above method embodiments. The present invention will not be elaborated herein, and it has the same beneficial effects as the above method for identifying collar signals.

[0155] Figure 5 It is a schematic diagram of an application of an existing method for identifying collar signals. As Figure 5 shown, the original instrument measures well logging data in a sidetracked seamless casing well at a speed of about 600 meters per hour. The upper part 31 of the figure is the GR curve, and the lower part 32 is the magnetic positioning curve. Changing the speed has little effect on the signal. Generally, the recognition accuracy of the casing collar signal is poor, the curve noise interference is large, and the magnetic positioning collar signal is completely submerged in the interference signal, making it difficult to distinguish the standard collar position information.

[0156] Figure 6 It is a schematic diagram of an application of a method for identifying collar signals provided by an embodiment of the present invention. As Figure 6 shown, based on the well logging data measured by the method of using a sector acoustic wave instrument to measure seamless casing collars, the upper part 31 of the figure is the GR curve, and the lower part 32 is the magnetic positioning curve. It can be seen from the figure that in the curve, the noise interference signal is small, the magnetic positioning collar signal is obvious, and the standard collar position information can be accurately distinguished, which can meet the requirements of perforation positioning and ensure the accuracy of perforation.

[0157] During the logging process of a sidetrack well, when the sector acoustic instrument passes through a seamless casing collar, the transmitting sensor emits an excitation pulse signal, generating an induced electromotive force on the casing collar. At the same time, the induced electromotive force of the receiving sensor changes. The position of the casing collar is identified by the change in the induced electromotive force, and the detection of the seamless casing collar can be achieved through analysis and calculation.

[0158] The above has introduced in detail a method for identifying a collar signal, a device for identifying a collar signal, and a medium provided by the present invention. The various embodiments in the specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0159] It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

Claims

1. A method for identifying a collar signal, characterized in that: include: Collecting the induced electromotive force of the current cycle and the induced electromotive force of the previous cycle emitted by the receiving sensor, wherein the induced electromotive force is excited by the excitation circuit to excite the transmitting sensor so that the receiving sensor receives the obtained electromotive force; Comparing the induced electromotive force corresponding to the current cycle with that corresponding to the previous cycle; If they are different, the induced electromotive force of the current cycle is processed according to a waveform time analysis algorithm and a threshold automatic gain algorithm to determine the coupling signal corresponding to the induced electromotive force of the current cycle.

2. The method for identifying a collar signal according to claim 1, characterized in that: The step of processing the induced electromotive force of the current cycle according to the waveform time analysis algorithm and the threshold automatic gain algorithm to determine the coupling signal corresponding to the induced electromotive force of the current cycle includes: Processing the induced electromotive force of the current cycle according to the waveform time analysis algorithm to obtain a first induced electromotive force; Processing the first induced electromotive force according to the threshold automatic gain algorithm to obtain a threshold voltage corresponding to the first induced electromotive force; When the first induced electromotive force is greater than the threshold voltage, the induced electromotive force is determined to be the coupling signal.

3. The method for identifying a collar signal according to claim 2, characterized in that: The step of processing the induced electromotive force of the current cycle according to the waveform time analysis algorithm to obtain the first induced electromotive force includes: Dividing the signal of the induced electromotive force of the current cycle into N equal parts according to the sampling time interval; Sampling the N equally divided signals point by point; Accumulating the sampled point-by-point signals to synchronously restore them to the induced electromotive force of the current cycle; Acquire the first time when the excitation wave emitted by the transmitting sensor propagates along the casing to the receiving sensor; Determine the signal door opening time of the induced electromotive force of the current cycle according to the first time; The first induced electromotive force corresponding to the N-divided signal of the induced electromotive force of the current cycle is intercepted according to the signal opening time.

4. The method for identifying a collar signal according to claim 3, characterized in that: The step of processing the first induced electromotive force according to the threshold automatic gain algorithm to obtain a threshold voltage corresponding to the first induced electromotive force includes: Obtaining the number of samples corresponding to the first induced electromotive force; Selecting the maximum sampling data from the number of samples; Determine the average value of the sampling data corresponding to the number of samples; The threshold voltage is determined according to a relationship among the sampling data average, the maximum sampling data and a threshold voltage coefficient.

5. The method for identifying a collar signal according to claim 1, characterized in that: Also includes: When the induced electromotive force of the current cycle is the same as the induced electromotive force of the previous cycle, the process returns to the step of collecting and receiving the induced electromotive force of the current cycle and the induced electromotive force of the previous cycle emitted by the sensor to obtain the induced electromotive force of the next cycle.

6. The method for identifying a collar signal according to claim 3, characterized in that: Before the induced electromotive force of the current cycle is processed according to the waveform time analysis algorithm to obtain the first induced electromotive force, the method further includes: Performing differential amplification processing on the induced electromotive force of the current cycle to obtain the processed induced electromotive force of the current cycle; The processed induced electromotive force of the current cycle is subjected to low-pass filtering to obtain the filtered induced electromotive force of the current cycle, and the step of processing the induced electromotive force of the current cycle according to the waveform time analysis algorithm to obtain the first induced electromotive force is entered; Correspondingly, after the induced electromotive force of the current cycle is processed according to the waveform time analysis algorithm to obtain the first induced electromotive force, and before the first induced electromotive force is processed according to the threshold automatic gain algorithm to obtain the threshold voltage corresponding to the first induced electromotive force, it also includes: The first induced electromotive force is subjected to phase-sensitive detection processing to obtain the processed first induced electromotive force, and the step of processing the first induced electromotive force according to the threshold automatic gain algorithm to obtain a threshold voltage corresponding to the first induced electromotive force is entered.

7. The method for identifying a collar signal according to claim 3 or 6, characterized in that: The process of determining the induced electromotive force includes: Acquire an excitation signal source generated by a CPU, wherein the excitation signal source is a positive and negative pulse low-frequency signal; The excitation signal source is amplified by using three groups of pulse phase-shift push-pull amplification methods so that the receiving sensor can receive and obtain the induced electromotive force.

8. A device for identifying a coupling signal, characterized in that: include: A collection module, used for collecting the induced electromotive force of the current cycle and the induced electromotive force of the previous cycle emitted by the receiving sensor, wherein the induced electromotive force is excited by the excitation circuit to excite the transmitting sensor so that the receiving sensor receives the obtained electromotive force; A comparison module, used for comparing the induced electromotive force corresponding to the current cycle with that of the previous cycle, and if they are different, entering the processing module; The processing module is used to process the induced electromotive force of the current cycle according to a waveform time analysis algorithm and a threshold automatic gain algorithm to determine the coupling signal corresponding to the induced electromotive force of the current cycle.

9. A device for identifying a coupling signal, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of the method for identifying a collar signal according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for identifying a collar signal according to any one of claims 1 to 7 are implemented.

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