A well logging signal demodulation method and device, computer equipment and storage medium

Abstract

The present disclosure relates to the technical field of well logging, and particularly relates to a well logging signal demodulation method and device, computer equipment and a storage medium. The method comprises: in response to receiving a to-be-demodulated signal, determining a first time domain function and a power spectrum image corresponding to the to-be-demodulated signal; determining a target harmonic for demodulating the signal according to the power spectrum image; processing a plurality of second time domain functions and the first time domain function according to the target harmonic to obtain a plurality of filter functions and a to-be-processed function; and demodulating the to-be-demodulated signal according to the plurality of filter functions and the to-be-processed function to obtain a plurality of symbols. According to the present disclosure, the frequency band of the to-be-demodulated signal demodulated by the target harmonic determined by the power spectrum image is least interfered, and the obtained symbols are more accurate.

Description

Technical Field

[0001] This disclosure relates to the field of well logging technology, and in particular to a well logging signal demodulation method, apparatus, computer equipment, and storage medium. Background Technology

[0002] Currently, in the use of oil well logging instruments, Manchester code is mostly used for modulation and demodulation of the acquired signals. During demodulation, only filters are used to remove high-frequency signals, and the fundamental frequency signal is used for detection and demodulation. However, due to the highly complex environment downhole, the fundamental frequency signal is often more susceptible to interference than the high-frequency signal. If, under such circumstances, the fundamental frequency is still used to demodulate the low-frequency signal, accurate code elements cannot be obtained.

[0003] Determining the appropriate waveform for demodulation to improve signal demodulation accuracy is a problem that urgently needs to be solved in the current technology. Summary of the Invention

[0004] To address the problems in the prior art, this disclosure provides a well logging signal demodulation method, apparatus, computer equipment, and storage medium. By using power spectrum images, the frequency band of the signal to be demodulated is determined to have the least interference, resulting in more accurate demodulated symbols.

[0005] To solve the above-mentioned technical problems, the specific technical solution of this disclosure is as follows:

[0006] On the one hand, embodiments of this disclosure provide a well logging signal demodulation method, including,

[0007] In response to receiving a signal to be demodulated, a first time-domain function and a power spectrum image corresponding to the signal to be demodulated are determined;

[0008] Based on the power spectrum image, the target harmonic for demodulating the signal is determined;

[0009] Based on the target harmonic, multiple preset second time-domain functions and the first time-domain function are processed to obtain multiple filter functions and a function to be processed; and

[0010] Based on the multiple filtering functions and the function to be processed, the signal to be demodulated is demodulated to obtain multiple symbols.

[0011] Furthermore, determining the target harmonic for demodulation based on the power spectrum image further includes:

[0012] Based on the power spectrum image, determine the energy values ​​corresponding to multiple frequency bands to obtain multiple energy values;

[0013] For each frequency band, determine at least one energy difference between the frequency band and at least one target frequency band; and

[0014] The target harmonic is determined based on the frequency band corresponding to the at least one energy difference that meets the preset conditions.

[0015] Furthermore, based on the target harmonic, multiple preset second time-domain functions are processed to obtain multiple filter functions, which further include:

[0016] Perform a Fourier transform on each second time-domain function to obtain multiple first Fourier series expansions;

[0017] Based on the target harmonic, determine multiple first zero-setting terms in each first Fourier series expansion; and

[0018] By determining that the coefficients of the plurality of first zero-set terms in each first Fourier series expansion are zero, a plurality of filter functions are obtained.

[0019] Furthermore, when there are two of the plurality of second time-domain functions, the plurality of second time-domain functions further include:

[0020]

[0021]

[0022] Among them, the and stated These are the second time-domain functions, For time, and It is a periodicity.

[0023] Furthermore, based on the target harmonic, the first time-domain function is processed to obtain the function to be processed, including:

[0024] Perform a Fourier transform on the first time-domain function to obtain the second Fourier series expansion;

[0025] Based on the target harmonic, determine multiple second zero-setting terms in the second Fourier series expansion;

[0026] Determine that the coefficients of the plurality of second zero-set terms in the second Fourier series expansion are zero, thus obtaining the function to be processed; and

[0027] Perform an inverse Fourier transform on the function to be processed to obtain the function to be processed.

[0028] Furthermore, demodulating the signal to be demodulated to obtain multiple symbols based on the plurality of filtering functions and the function to be processed further includes:

[0029] Perform convolution operations on the function to be processed and each filter function to obtain multiple target functions;

[0030] Based on the objective function, multiple objective values ​​are determined for each time step; and

[0031] For each time step, multiple target values ​​are considered to obtain the corresponding code symbol for each time step.

[0032] Based on the symbols corresponding to each time moment, multiple symbols corresponding to the signal to be demodulated are obtained.

[0033] Furthermore, when there are two target values ​​among the plurality of targets, the decision further includes:

[0034]

[0035]

[0036]

[0037]

[0038] Among them, the The value is a positive integer. For the period, the and stated These are the objective functions, respectively. The codewords at the corresponding time, and the... .

[0039] On the other hand, embodiments of this disclosure also provide a logging signal demodulation device, including,

[0040] The first determining unit is configured to determine, in response to receiving the signal to be demodulated, a first time-domain function and a power spectrum image corresponding to the signal to be demodulated.

[0041] The second determining unit is used to determine the target harmonic for demodulating the signal based on the power spectrum image.

[0042] The processing module is configured to process a plurality of preset second time-domain functions and a first time-domain function according to the target harmonic to obtain a plurality of filter functions and a function to be processed; and

[0043] The third determining unit is used to demodulate the signal to be demodulated according to the plurality of filtering functions and the function to be processed, to obtain a plurality of symbols.

[0044] On the other hand, this disclosure also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method.

[0045] On the other hand, embodiments of this disclosure also provide a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the above-described method.

[0046] Using embodiments of this disclosure, the target frequency band with the least interference is first determined based on the power spectrum image of the signal to be demodulated. Then, multiple filtering functions are constructed based on the target harmonics corresponding to the target frequency band. The signal to be demodulated is then demodulated using these multiple filtering functions and the processing function corresponding to the signal to be demodulated, thereby improving the accuracy of the demodulated symbols. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 The figure shown is a schematic diagram of an implementation system for a well logging signal demodulation method according to an embodiment of this disclosure;

[0049] Figure 2 The diagram shown is a flowchart of a well logging signal demodulation method according to an embodiment of this disclosure;

[0050] Figure 3A The diagram shown is a flowchart of a well logging signal demodulation method according to another embodiment of this disclosure;

[0051] Figure 3B The diagram shown is a flowchart of a well logging signal demodulation method according to another embodiment of this disclosure;

[0052] Figure 4 The diagram shown is a schematic representation of an ideal power spectrum according to an embodiment of this disclosure;

[0053] Figure 5 The diagram shown is a schematic representation of well logging signal demodulation according to another embodiment of this disclosure;

[0054] Figure 6 The diagram shown is a structural schematic of a well logging signal demodulation device according to an embodiment of this disclosure;

[0055] Figure 7 This is a schematic diagram of the structure of a computer device according to an embodiment of the present disclosure.

[0056] [Explanation of Labels in the Attached Image]

[0057] 101. Data Acquisition Terminal;

[0058] 102. Server;

[0059] 301. Signal to be demodulated;

[0060] 302. Target harmonics;

[0061] 303. First time-domain function;

[0062] 310. Multiple second-time domain functions;

[0063] 311. Second time-domain function;

[0064] 312. Second time-domain function;

[0065] 320. Multiple filter functions;

[0066] 321. Filtering function;

[0067] 322. Filtering function;

[0068] 330. Functions to be processed;

[0069] 340. Multiple objective functions;

[0070] 341. Objective function;

[0071] 342. Objective function;

[0072] 350, multiple code elements;

[0073] 351, code element;

[0074] 352, code element;

[0075] 501. Diagram of the signal to be demodulated;

[0076] 502. Encoded function graph;

[0077] 503. First time-domain function graph;

[0078] 504. Harmonic component diagram;

[0079] 505, Code element diagram;

[0080] 610. First Determined Unit;

[0081] 620. Second Determined Unit;

[0082] 630. Processing Unit;

[0083] 640. The third unit to be determined;

[0084] 702. Computer equipment;

[0085] 704. Processing equipment;

[0086] 706. Storage resources;

[0087] 708. Drive mechanism;

[0088] 710. Input / Output Module;

[0089] 712. Input devices;

[0090] 714. Output devices;

[0091] 716. Presentation equipment;

[0092] 718. Graphical User Interface;

[0093] 720. Network interface;

[0094] 722. Communication link;

[0095] 724. Communication bus. Detailed Implementation

[0096] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this disclosure.

[0097] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0098] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0099] like Figure 1 The diagram illustrates an implementation system for a well logging signal demodulation method according to an embodiment of this disclosure. The system may include a data acquisition terminal 101 and a server 102. The data acquisition terminal 101 and the server 102 communicate via a network, which may include a Local Area Network (LAN), a Wide Area Network (WAN), the Internet, or a combination thereof, and is connected to a website, user equipment (e.g., a computing device), and a backend system. The server 102 can demodulate the signal to be demodulated obtained from the data acquisition terminal 101, determine multiple symbols or target information corresponding to the signal, and then send these symbols or target information to the data acquisition terminal 101 via the network. The data acquisition terminal 101 displays the symbols or target information provided by the server 102 so that the user corresponding to the data acquisition terminal 101 can view it on the data acquisition terminal 101. Optionally, the server 102 may be a node in a cloud computing system (not shown in the diagram), or each server 102 may be a separate cloud computing system, including multiple computers interconnected by a network and operating as a distributed processing system.

[0100] In an optional embodiment, the acquisition terminal 101 may include downhole instruments and surface electronic devices. The downhole instruments may be, for example, any sensor capable of acquiring signals. The surface electronic devices and the downhole instruments communicate via a network to receive signals. The surface electronic devices are not limited to smartphones, acquisition devices, desktop computers, tablets, laptops, smart speakers, digital assistants, augmented reality (AR) / virtual reality (VR) devices, smart wearable devices, and other similar electronic devices. Optionally, the operating system running on the electronic devices may include, but is not limited to, Android, iOS, Linux, Windows, etc.

[0101] In addition, it should be noted that, Figure 1 The example shown is merely one application environment provided by this disclosure. In practical applications, it may include multiple acquisition terminals 101, and this specification does not impose any restrictions.

[0102] like Figure 2The diagram shows a flowchart of a well logging signal demodulation method according to an embodiment of this disclosure. Addressing the problems existing in the prior art, this disclosure provides a well logging signal demodulation method that determines a suitable wave for demodulation, improving the accuracy of the demodulated symbols. The well logging signal demodulation process is described in this figure, but based on conventional or non-inventive methods, it may include more or fewer operational steps. The order of steps listed in the embodiment is merely one possible execution order among many steps and does not represent the only possible execution order. In actual system or device products, the methods shown in the embodiment or the accompanying drawings can be executed sequentially or in parallel. Specifically, as shown... Figure 2 As shown, the method may include:

[0103] S210, in response to receiving the signal to be demodulated, determine the first time-domain function and power spectrum image corresponding to the signal to be demodulated;

[0104] S220, based on the power spectrum image, determine the target harmonic for demodulation;

[0105] S230, based on the target harmonic, processes multiple preset second time-domain functions and first time-domain functions to obtain multiple filter functions and functions to be processed;

[0106] S240 demodulates the signal to be demodulated based on multiple filtering functions and the function to be processed, and obtains multiple symbols.

[0107] The method of this disclosure first determines the target frequency band with the least interference based on the power spectrum image of the signal to be demodulated. Then, based on the target harmonics corresponding to the target frequency band, multiple filter functions are constructed. The signal to be demodulated is then demodulated using these multiple filter functions and the processing function corresponding to the signal to be demodulated, thereby improving the accuracy of the demodulated symbols.

[0108] According to embodiments of this disclosure, the signal to be demodulated includes signals acquired by downhole instruments. Upon receiving the signal to be demodulated, a signal coding model is used to encode the signal to obtain a coded function, which is then transmitted back to the surface electronic equipment. The surface electronic equipment processes the received signal to obtain a first time-domain function. The signal coding model can be any model capable of encoding signals, such as the Manchester coding model. Based on the received signal to be demodulated, the frequency of the signal is processed to determine a power spectrum image.

[0109] By integrating the power across different frequency bands, the energy value carried by each frequency band is determined. Based on the energy value of each frequency band, the degree of interference on the signal to be demodulated within that band is determined. Comparing the degree of interference in each frequency band, the target frequency band for demodulation is determined. Then, based on this target frequency band, the target harmonic is determined. For example, based on the energy, among the frequency bands 0Hz-40Hz, 40Hz-80Hz, 80Hz-120Hz, and 120Hz-160Hz, the 40Hz-80Hz band experiences the least interference; therefore, 40Hz-80Hz is determined as the target frequency band. Since fundamental harmonics are used for demodulation in signal demodulation, and the frequency domain distribution is divided into several odd harmonic components, the target frequency band 40Hz-80Hz corresponds to the third harmonic component; therefore, the target harmonic is determined as the third harmonic. Thus, based on the power spectrum image of the signal to be demodulated, the target frequency band with the least interference is determined, and consequently, the most suitable target harmonic for demodulation is identified.

[0110] Before demodulating the signal to be demodulated, a time-domain function for generating the filtering function is pre-set. In this disclosure, this time-domain function is referred to as the second time-domain function. After determining the target harmonic, multiple second time-domain functions are processed according to the order value of the target harmonic to obtain multiple filtering functions. These filtering functions are used to construct filters, and multiple filtering functions construct multiple filters. Based on the order value of the target harmonic, the first time-domain function is processed to obtain the function to be processed.

[0111] The function to be processed is input into multiple filters to obtain multiple objective functions. The value at each time step is then substituted into each objective function to obtain multiple target values ​​corresponding to each time step. A decision is made based on the multiple target values ​​at each time step to obtain the corresponding symbol. The determined symbols are then concatenated according to their corresponding time order to obtain a symbol diagram for subsequent processing.

[0112] According to another embodiment of this disclosure, the plurality of second time-domain functions may further include:

[0113] Formula (1)

[0114] Formula (2)

[0115] in, and These are the second time-domain functions, For time, and It is a periodicity.

[0116] According to another embodiment of this disclosure, in order to achieve higher demodulation accuracy, processing a plurality of preset second time-domain functions based on the target harmonic to obtain a plurality of filter functions further includes: performing a Fourier transform on each second time-domain function to obtain a plurality of first Fourier series expansions; determining a plurality of first zero-set terms in each first Fourier series expansion based on the target harmonic; and determining that the coefficients of the plurality of first zero-set terms in each first Fourier series expansion are zero, thereby obtaining a plurality of filter functions.

[0117] Determining the first zero-set term can be, for example, by identifying, for each of the multiple first Fourier series expansions, the term other than the term corresponding to the order value of the target harmonic as the first zero-set term.

[0118] For example, if the order of the target harmonic is determined to be 3 (i.e., the 3rd harmonic), then the terms in the first Fourier series expansion other than the third term (n=3) are determined to be the first zero-term terms. The second time-domain function in formula (1) and formula (2) will be used as an example for further explanation. Fourier transforms are performed on formula (1) and formula (2) respectively to obtain the first Fourier series expansion as shown in formula (6) (formula (3)-formula (6) are examples of the derivation process), and the first Fourier series expansion as shown in formula (10) (formula (7)-formula (10) are examples of the derivation process).

[0119] Formula (3)

[0120] in,

[0121] Formula (4)

[0122] Formula (5)

[0123] Therefore, when hour,

[0124] Formula (6)

[0125] Formula (7)

[0126] in,

[0127] Formula (8)

[0128] Formula (9)

[0129] Therefore, when hour,

[0130] Formula (10)

[0131] After determining multiple first Fourier series expansions as shown in formulas (6) and (10), the terms corresponding to n other than n=3 are determined as the first zero-set terms. Then, the coefficients of the first zero-set terms are set to 0, resulting in multiple filter functions as shown in formula (11). And in formula (12) .

[0132] Formula (11)

[0133] Formula (12)

[0134] It should be noted that currently, in the process of fundamental frequency demodulation, the second time-domain function is often directly used to construct the filter without processing or transformation. However, this disclosure determines the corresponding higher harmonic components for multiple preset second time-domain functions and uses these higher harmonic components to construct the filter. This further improves the accuracy in the signal demodulation process.

[0135] According to another embodiment of this disclosure, processing the first time-domain function according to the target harmonic to obtain the function to be processed further includes: performing a Fourier transform on the first time-domain function to obtain a second Fourier series expansion; determining a plurality of second zero-set terms in the second Fourier series expansion according to the target harmonic; determining that the coefficients of the plurality of second zero-set terms in the second Fourier series expansion are zero to obtain a pre-processing function; and performing an inverse Fourier transform on the pre-processing function to obtain the function to be processed.

[0136] For example, the first time-domain function is ,against Perform a Fourier transform by following the derivation process of formulas (3) to (6) above, and obtain the result. The corresponding second Fourier series expansion. Given that the order of the target harmonic is 3, all terms in the second Fourier series expansion except the third term (n=3) are designated as second zero-set terms. The coefficients of multiple second zero-set terms are set to zero (as in the process of converting formula (6) to formula (11) or formula (10) to formula (12) above), resulting in the function to be processed. .against Perform an inverse Fourier transform to obtain the result. Corresponding function to be processed The Fourier transform and the inverse Fourier transform are inverse transforms of each other.

[0137] According to another embodiment of this disclosure, demodulating the signal to be demodulated based on multiple filtering functions and a function to be processed to obtain multiple symbols further includes: performing a convolution operation on the function to be processed and each filtering function to obtain multiple target functions; determining multiple target values ​​for each time step based on the target functions; making a decision on the multiple target values ​​for each time step to obtain symbols corresponding to each time step; and obtaining multiple symbols corresponding to the signal to be demodulated based on the symbols corresponding to each time step.

[0138] For example, if the order of the target harmonic is determined to be 3, and there are two second time-domain functions, then the function to be processed as determined above... and multiple filter functions and By performing convolution operations separately, multiple objective functions are obtained, as shown in formulas (13) and (14) below. and .

[0139] Formula (13)

[0140] Formula (14)

[0141] in, For convolution operations, and These are the objective functions.

[0142] Substitute the n value corresponding to each time step into the objective function. and In this process, two target values ​​are obtained corresponding to each time step (each value of n). A decision is made based on these two target values ​​to determine the symbol corresponding to each time step. This determines the symbol diagram for subsequent processing.

[0143] According to another embodiment of this disclosure, when there are two target values, the decision includes the following formulas (15), (16), (17) and (18).

[0144]

[0145]

[0146]

[0147]

[0148]

[0149]

[0150]

[0151]

[0152] in, It is a positive integer. For a period of time, and These are the objective functions, For the corresponding code elements, and This is the code for the next time step at the corresponding time step.

[0153] For each time moment (each Two target values ​​can be obtained, and the larger of the two target values ​​is determined as the first target value. It is then determined whether the first target value is greater than zero. Then, the judgments shown in formulas (15), (16), (17), and (18) are performed to determine the value relative to the target value at that time. Corresponding code element ( ) and the next moment after that moment +1 corresponds to the code element ( ).

[0154] It should be noted that in making the judgment, this disclosure uses the midpoint of a cycle as the judgment point. ), to accommodate the filtering function in this disclosure, instead of the previously used boundary points of one period ( ).

[0155] According to another embodiment of this disclosure, in order to improve the accuracy of the demodulated symbols, when there are two target values, only one is considered during the decision-making process. The decision is to take either an odd-order term or an even-order term. In other words, Only take odd numbers or Only even numbers are considered.

[0156] In only When determining whether to use an odd-order or even-order term, only one corresponding symbol can be generated for each time step. However, if the decision applies to all... If both are judged, two corresponding code elements will be generated for a given moment, resulting in inaccurate generated code elements.

[0157] like Figure 3A The diagram shown is a flowchart of a well logging signal demodulation method according to another embodiment of this disclosure.

[0158] According to another embodiment of this disclosure, as shown in 3A, after receiving the demodulated signal 301, the demodulated signal 301 is encoded using the Manchester coding model to obtain a coded function, which is then returned. The signal corresponding to the received, interfered coded function is processed to obtain a first time-domain function 303. For the demodulated signal 301, the energy value of each frequency band is determined. Based on the energy value of each frequency band, interference analysis is performed to obtain the target harmonic 302.

[0159] A Fourier transform is performed on the first time-domain function 303 to obtain the second Fourier series expansion. Terms that do not correspond to the order of the target harmonic 302 are identified as second zero-set terms. The coefficients of these second zero-set terms are all set to zero, resulting in the function to be processed 330. Similarly, the same operation is performed on each of the multiple second time-domain functions 310 to obtain multiple filter functions 320.

[0160] A convolution operation is performed on the function to be processed 330 and multiple filter functions 320 to obtain multiple objective functions 340. Using these multiple objective functions 340, the target value corresponding to each time step is determined. Then, a decision is made for each target value to determine multiple symbols 350.

[0161] According to another embodiment of this disclosure, in order to more accurately determine the target harmonic for demodulation, determining the target harmonic for demodulation based on the power spectrum image further includes: determining energy values ​​corresponding to multiple frequency bands based on the power spectrum image to obtain multiple energy values; for each frequency band, determining at least one energy difference between the frequency band and at least one target frequency band; and determining the target harmonic based on the frequency band corresponding to at least one energy difference that satisfies a preset condition.

[0162] In the absence of interference, an ideal power spectrum image would look like this: Figure 4 As shown in Table 1 below, the energy distribution of different frequency bands is obtained by determining the energy of each frequency band based on the ideal power spectrum image.

[0163] Table 1

[0164]

[0165] As shown in Table 1, the 3rd harmonic is 10.9 dBm lower than the fundamental frequency, the 5th harmonic is 4.52 dBm lower than the 3rd harmonic, the 5th harmonic is 15.42 dBm lower than the fundamental frequency, the 7th harmonic is 2.94 dBm lower than the 5th harmonic, the 7th harmonic is 7.46 dBm lower than the 3rd harmonic, and the 7th harmonic is 19.36 dBm lower than the fundamental frequency. Based on this, the preset conditions are determined. Since the preset conditions of this disclosure are determined based on an ideal power spectrum image, the rationality of the determined preset conditions is guaranteed. This allows for the determination of the most suitable target harmonic from multiple harmonics for demodulating the signal, thereby improving the accuracy of the demodulated symbols.

[0166] For each frequency band, all frequency bands smaller than that frequency band are identified as target frequency bands. For example, for a frequency band of 40Hz-80Hz (3rd harmonic), the target frequency band is 0Hz-40Hz (fundamental frequency); for a frequency band of 80Hz-120Hz (5th harmonic), the target frequency bands are 0Hz-40Hz (fundamental frequency) and 40Hz-80Hz (3rd harmonic); for a frequency band of 120Hz-160Hz (7th harmonic), the target frequency bands are 0Hz-40Hz (fundamental frequency), 40Hz-80Hz (3rd harmonic), and 80Hz-120Hz (5th harmonic).

[0167] Determining a target harmonic based on a frequency band corresponding to at least one energy difference that satisfies a preset condition may include, for example, determining a corresponding threshold based on a frequency band and a target frequency band, and determining that the frequency band satisfies a preset condition when the energy difference between the frequency band and each target frequency band is greater than the corresponding threshold, and determining the harmonic corresponding to the frequency band as the target harmonic.

[0168] With a frequency range of 40Hz-80Hz (3rd harmonic) and a target frequency range of 0Hz-40Hz (fundamental frequency), the corresponding threshold is 10.9 dBm.

[0169] When the frequency range is 80Hz-120Hz (5th harmonic) and the target frequency range is 40Hz-80Hz (3rd harmonic), the corresponding threshold is 4.52 dBm; when the frequency range is 80Hz-120Hz (5th harmonic) and the target frequency range is 0Hz-40Hz (fundamental frequency), the corresponding threshold is 15.42 dBm.

[0170] The threshold value is 2.94 dBm when the frequency range is 120Hz-160Hz (7th harmonic) and the target frequency range is 80Hz-120Hz (5th harmonic); the threshold value is 7.46 dBm when the frequency range is 120Hz-160Hz (7th harmonic) and the target frequency range is 40Hz-80Hz (3rd harmonic); and the threshold value is 19.36 dBm when the frequency range is 120Hz-160Hz (7th harmonic) and the target frequency range is 0Hz-40Hz (fundamental frequency).

[0171] For example, targeting the frequency band 40Hz-80Hz (3rd harmonic) and the target frequency band 0Hz-40Hz (fundamental frequency). The energy value of the 40Hz-80Hz band is determined to be 19 dBm, and the energy value of the target frequency band 0Hz-40Hz is determined to be 32 dBm, resulting in an energy difference of 13 dBm. The threshold value corresponding to both the 40Hz-80Hz band (3rd harmonic) and the target frequency band 0Hz-40Hz (fundamental frequency) is 10.9 dBm. Comparing the energy difference of 13 dBm with the corresponding threshold value of 10.9 dBm, if the energy difference is greater than the threshold, then the 40Hz-80Hz band (3rd harmonic) meets the preset condition, and the 3rd harmonic is identified as the target harmonic. It is important to note that the energy difference must be a number greater than or equal to zero.

[0172] To illustrate the situation where multiple target frequency bands exist, consider the frequency band 80Hz-120Hz (5th harmonic), with target frequency bands of 0Hz-40Hz (fundamental frequency) and 40Hz-80Hz (3rd harmonic). Similarly, if the energy value of the 80Hz-120Hz (5th harmonic) frequency band is determined to be 14, the energy value of the target frequency band 40Hz-80Hz is 19 dBm, and the energy value of the target frequency band 0Hz-40Hz is 32 dBm, then the energy difference between the 80Hz-120Hz frequency band and the target frequency band 40Hz-80Hz is 18 dBm, and the energy difference between the 80Hz-120Hz frequency band and the target frequency band 40Hz-80Hz is 5 dBm. The threshold values ​​for the frequency band 80Hz-120Hz (5th harmonic) and the target frequency band 0Hz-40Hz (fundamental frequency) are 15.42 dBm, and the threshold values ​​for the frequency band 80Hz-120Hz (5th harmonic) and the target frequency band 40Hz-80Hz (fundamental frequency) are 4.52 dBm. That is, we compare 18 dBm with the threshold value of 15.42 dBm, and compare 5 dBm with 4.52 dBm. Based on the above comparisons, it can be seen that the energy difference between the frequency band 80Hz-120Hz (5th harmonic) and the target frequency band is greater than the corresponding threshold values. Therefore, the frequency band 80Hz-120Hz (5th harmonic) meets the preset conditions, and the 5th harmonic is determined to be the target harmonic. It should be noted that this target harmonic is not the fundamental frequency (1st harmonic).

[0173] Figure 3B The flowchart shown is a well logging signal demodulation method according to another embodiment of this disclosure.

[0174] According to another embodiment of this disclosure, when there are two second time-domain functions, the flowchart of the well logging signal demodulation method of this embodiment can be shown as 3B. After determining the target harmonic 302, a Fourier transform is performed on the second time-domain function 311 to obtain the first Fourier series expansion. The terms that do not correspond to the order of the target harmonic 302 are identified as the first zero-set terms. The coefficients of the first zero-set terms are all set to zero to obtain the filter function 321. Similarly, the same operation is performed on the second time-domain function 312 to obtain the filter function 322.

[0175] A convolution operation is performed on the function to be processed 330 and the filter function 321 to obtain the target function 341. A convolution operation is then performed on the function to be processed 330 and the filter function 322 to obtain the target function 342. Using the target functions 341 and 342, two target values ​​corresponding to each time step are determined. A decision is then made for each target value to obtain the corresponding code symbol. For example, for one time step, code symbol 351 can be obtained, and for another time step, code symbol 352 can be obtained.

[0176] It should be noted that the number of symbols in this embodiment can be any value. The two symbols in the example above are for illustration only and do not constitute an actual limitation.

[0177] like Figure 5 The diagram shown is a schematic diagram of well logging signal demodulation according to another embodiment of this disclosure.

[0178] According to another embodiment of this disclosure, the raw signal acquired by the downhole instrument is shown in the demodulated signal diagram (…). Figure 5 As shown in 501), the Manchester coding model is used for encoding to obtain the encoded function graph ( Figure 5 (502 in the figure), due to interference from the underground environment, the signal of the surface electronic equipment after interference is shown in the first time domain function graph ( Figure 5 As shown in 503). The first time-domain function graph received from the downhole instrument ( Figure 5 After 503 in the middle, for the first time domain function graph ( Figure 5 (503) The method disclosed herein is used to determine the target harmonic, and after determining multiple target functions based on multiple second time-domain functions, a first time-domain function, and the target harmonic, an image such as a harmonic component diagram is obtained for each time point by determining the corresponding target value. Figure 5 (As shown in 504). Then, a decision is made on the target value, resulting in multiple symbol maps ( Figure 5 (505 in the middle).

[0179] This disclosure also provides a well logging signal demodulation device, such as... Figure 6 As shown, including,

[0180] The first determining unit 610 is configured to determine, in response to receiving the signal to be demodulated, a first time-domain function and a power spectrum image corresponding to the signal to be demodulated.

[0181] The second determining unit 620 is used to determine the target harmonic for demodulation based on the power spectrum image;

[0182] Processing unit 630 is configured to process multiple preset second time-domain functions and a first time-domain function according to the target harmonic to obtain multiple filter functions and a function to be processed; and

[0183] The third determining unit 640 is used to demodulate the signal to be demodulated based on multiple filtering functions and the function to be processed, and obtain multiple symbols.

[0184] Since the principle of the above-mentioned device in solving the problem is similar to that of the above-mentioned method, the implementation of the above-mentioned device can refer to the implementation of the above-mentioned method, and the repeated parts will not be described again.

[0185] like Figure 7The diagram illustrates the structure of a computer device according to an embodiment of this disclosure. The apparatus in this disclosure can be the computer device in this embodiment, executing the methods described above. The computer device 702 may include one or more processing devices 704, such as one or more central processing units (CPUs), each processing unit implementing one or more hardware threads. The computer device 702 may also include any storage resource 706 for storing information of any kind, such as code, settings, data, etc. Without limitation, for example, the storage resource 706 may include any one or more combinations of: any type of RAM, any type of ROM, flash memory, hard disk, optical disk, etc. More generally, any storage resource can use any technology to store information. Further, any storage resource can provide volatile or non-volatile retention of information. Further, any storage resource may represent a fixed or removable component of the computer device 702. In one case, when the processing device 704 executes associated instructions stored in any storage resource or combination of storage resources, the computer device 702 can perform any operation of the associated instructions. The computer device 702 also includes one or more drive mechanisms 708 for interacting with any storage resource, such as a hard disk drive mechanism, an optical disk drive mechanism, etc.

[0186] Computer device 702 may also include an input / output module 710 (I / O) for receiving various inputs (via input device 712) and providing various outputs (via output device 714). A specific output mechanism may include a presentation device 716 and an associated graphical user interface (GUI) 718. In other embodiments, the input / output module 710 (I / O), input device 712, and output device 714 may be omitted, and the device may function solely as a computer device within a network. Computer device 702 may also include one or more network interfaces 720 for exchanging data with other devices via one or more communication links 722. One or more communication buses 724 couple the components described above together.

[0187] Communication link 722 can be implemented in any way, such as via a local area network, a wide area network (e.g., the Internet), a point-to-point connection, or any combination thereof. Communication link 722 may include any combination of hardwired links, wireless links, routers, gateway functions, name servers, etc., governed by any protocol or combination of protocols.

[0188] This disclosure also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0189] This disclosure also provides a computer program product, which includes a computer program that, when executed by a processor, implements the above-described method.

[0190] Those skilled in the art will understand that embodiments of this disclosure can be provided as methods, systems, or computer program products. Therefore, this disclosure can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this disclosure can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0191] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0192] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0193] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0194] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of this disclosure. It should be understood that the above are only specific embodiments of this disclosure and are not intended to limit the scope of protection of this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for demodulating logging signals, characterized in that, include: In response to receiving a signal to be demodulated, a first time-domain function and a power spectrum image corresponding to the signal to be demodulated are determined; Based on the power spectrum image, the target harmonic for demodulation is determined; Based on the target harmonic, multiple preset second time-domain functions and the first time-domain function are processed to obtain multiple filter functions and functions to be processed; as well as Based on the plurality of filtering functions and the function to be processed, the signal to be demodulated is demodulated to obtain a plurality of symbols; The step of determining the target harmonic for demodulation based on the power spectrum image includes: Based on the power spectrum image, determine the energy values ​​corresponding to multiple frequency bands to obtain multiple energy values; For each frequency band, at least one energy difference between the frequency band and at least one target frequency band is determined, wherein, for each frequency band, all frequency bands smaller than that frequency band are identified as target frequency bands; and The target harmonic is determined based on the frequency band corresponding to at least one energy difference that meets the preset conditions; The process of determining the target harmonic based on the frequency band corresponding to at least one energy difference that meets the preset conditions includes: determining a corresponding threshold based on the frequency band and the target frequency band; determining that the frequency band meets the preset conditions when the energy difference between the frequency band and each target frequency band is greater than the corresponding threshold; and determining the harmonic corresponding to the frequency band as the target harmonic.

2. The method according to claim 1, characterized in that, The step of processing multiple preset second time-domain functions according to the target harmonic to obtain multiple filter functions includes: Perform a Fourier transform on each second time-domain function to obtain multiple first Fourier series expansions; Based on the target harmonic, determine multiple first zero-setting terms in each first Fourier series expansion; and By determining that the coefficients of the plurality of first zero-set terms in each first Fourier series expansion are zero, a plurality of filter functions are obtained.

3. The method according to claim 1 or 2, wherein when there are two of the plurality of second time-domain functions, it is characterized in that, The plurality of second time-domain functions include: Among them, the and stated These are the second time-domain functions, For time, and It is a periodicity.

4. The method according to claim 1, characterized in that, The step of processing the first time-domain function according to the target harmonic to obtain the function to be processed includes: Perform a Fourier transform on the first time-domain function to obtain the second Fourier series expansion; Based on the target harmonic, determine multiple second zero-setting terms in the second Fourier series expansion; Determine that the coefficients of the plurality of second zero-set terms in the second Fourier series expansion are zero, thus obtaining the function to be processed; and Perform an inverse Fourier transform on the function to be processed to obtain the function to be processed.

5. The method according to claim 1, characterized in that, The step of demodulating the signal to be demodulated according to the plurality of filtering functions and the function to be processed to obtain a plurality of symbols includes: Perform convolution operations on the function to be processed and each filter function to obtain multiple target functions; Based on the objective function, multiple objective values ​​are determined for each time step; and For each time step, multiple target values ​​are considered to obtain the corresponding code symbol for each time step. Based on the symbols corresponding to each time moment, multiple symbols corresponding to the signal to be demodulated are obtained.

6. The method according to claim 5, characterized in that, When there are two target values ​​among the multiple target values, the decision includes: Among them, the The value is a positive integer. For the period, the and stated These are the objective functions, respectively. The codewords at the corresponding time, and the... The symbol for the next moment after the corresponding moment.

7. A well logging signal demodulation device, characterized in that, include, The first determining unit is configured to determine, in response to receiving the signal to be demodulated, a first time-domain function and a power spectrum image corresponding to the signal to be demodulated. The second determining unit is used to determine the target harmonic for demodulation based on the power spectrum image; The processing unit is used to process multiple preset second time-domain functions and the first time-domain function according to the target harmonic to obtain multiple filter functions and functions to be processed; as well as The third determining unit is used to demodulate the signal to be demodulated based on the plurality of filtering functions and the function to be processed, to obtain a plurality of symbols. The step of determining the target harmonic for demodulation based on the power spectrum image includes: Based on the power spectrum image, determine the energy values ​​corresponding to multiple frequency bands to obtain multiple energy values; For each frequency band, at least one energy difference between the frequency band and at least one target frequency band is determined, wherein, for each frequency band, all frequency bands smaller than that frequency band are identified as target frequency bands; and The target harmonic is determined based on the frequency band corresponding to at least one energy difference that meets the preset conditions; The process of determining the target harmonic based on the frequency band corresponding to at least one energy difference that meets the preset conditions includes: determining a corresponding threshold based on the frequency band and the target frequency band; determining that the frequency band meets the preset conditions when the energy difference between the frequency band and each target frequency band is greater than the corresponding threshold; and determining the harmonic corresponding to the frequency band as the target harmonic.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, performs the method of any one of claims 1-6.

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