Mud continuous wave pilot synchronization method

Abstract

The invention discloses a mud continuous wave pilot synchronization method, which relates to the field of drilling technology. The main idea is to form a mud pressure wave signal through coding and modulation in the well according to the formulated frame structure; to perform noise elimination processing on the well for the mud pressure wave signal transmitted through the mud continuous wave channel; to obtain a synchronization curve with the signal after noise elimination and the local synchronization signal or / and the synchronization training codeword, so as to realize that the well receiving end uses the peak detection method to perform time synchronization on the mud pressure wave signal inserted with the synchronization signal or / and the synchronization training codeword, and finally completes the well demodulation and decoding. The present invention can improve the synchronization accuracy of the mud continuous wave system of the measurement while drilling, effectively solve the problem that the synchronization accuracy of the mud continuous wave system of the measurement while drilling decreases when the depth increases, and more reliably resist noise interference, improve the accuracy and stability of synchronization, thereby greatly reducing the bit error rate and improving the anti-noise performance, thereby increasing the transmission depth of the measurement while drilling system.

Description

Technical Field

[0001] The invention relates to the technical field of drilling, and in particular to a mud continuous wave pilot frequency synchronization method. Background Art

[0002] In recent years, in order to further improve drilling efficiency, the real-time logging information such as orientation, formation characteristics and drilling parameters required to be transmitted by the Measurement While Drilling (MWD) system has shown an explosive growth trend.

[0003] The traditional positive / negative pulse MWD data transmission system is limited by the low data transmission rate, which has become a technical bottleneck restricting the further development of the MWD system. In order to meet the increasing demand for information, the industry has proposed a technical solution to achieve mud continuous wave using shear valves. This continuous wave data transmission technology can significantly improve the data transmission rate of the MWD system and become a promising alternative technology. Compared with traditional pulse transmission, continuous wave technology has higher transmission bandwidth and data throughput, and can better adapt to the growing data transmission needs of the MWD system.

[0004] In the MWD mud continuous wave system, accurate time synchronization is one of the key technologies to ensure high-speed data transmission. The MWD mud continuous wave system achieves the interception effect on the mud by the continuous movement of the rotor of the motor-controlled pulser to form a continuous pressure wave. The mud pressure wave signal generated in this way is a non-standard sinusoidal signal and a non-standard linear frequency modulation signal (LFM), that is, the transmitter produces nonlinear distortion; at the same time, in practical applications, the peak of the synchronization curve is affected by noise, especially with the increase of depth, the amplitude of the signal received by the ground receiving end gradually decreases, which leads to the gradual deterioration of the synchronization accuracy of the system, further causing the system bit error rate to increase, and ultimately limiting the effective transmission depth of the MWD system; in addition, there are multiple reflections and refractions in the mud channel, resulting in multipath effects, which will generate multiple synchronization peaks when receiving on the ground, and the influence of superimposed noise is also prone to missynchronization. Summary of the invention

[0005] In view of the above, the present invention aims to provide at least one mud continuous wave pilot synchronization method. In order to solve the problem that the peak value of the synchronization signal correlation result is almost submerged in the noise, in the mud continuous wave measurement while drilling system, the signal can be accurately synchronized reliably and high-speed transmission can be guaranteed. While improving the system synchronization peak value, the influence of noise on the synchronization peak value can be suppressed.

[0006] The technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a mud continuous wave pilot synchronization method, comprising:

[0008] The mud pressure wave signal is formed through encoding and modulation in the well;

[0009] The well performs noise elimination processing on the mud pressure wave signal transmitted through the mud continuous wave channel;

[0010] The de-noised signal is calculated with the local synchronization signal or / and the synchronization training codeword to obtain a synchronization curve; the receiving end on the well uses a peak detection method to time synchronize the mud pressure wave signal inserted with the synchronization signal or / and the synchronization training codeword;

[0011] The synchronized waveform signal is demodulated and decoded on the well.

[0012] In at least one possible implementation manner, the time synchronization specifically includes:

[0013] The downhole transmitting end inserts a preset fixed synchronization signal or / and a synchronization training codeword at the starting position of the transmitted waveform signal data frame;

[0014] The receiving end on the well calculates the received waveform signal and the corresponding local synchronization signal waveform or synchronization training codeword waveform to obtain a synchronization curve;

[0015] The receiving end on the well performs correlation analysis on the synchronization curve to detect the peak value, performs time marking based on the detected peak value, and identifies the starting position of the data frame to complete the time synchronization of the received waveform signal.

[0016] In at least one possible implementation, the noise reduction process includes:

[0017] Learn the pump noise frequency through the pump pulse sensor and generate a simulated pump noise waveform;

[0018] The simulated pump noise waveform is subtracted from the waveform of the received mud pressure wave signal to eliminate the pump noise.

[0019] In at least one possible implementation manner, the synchronization method further includes: eliminating the influence of channel fading by equalization in the well.

[0020] In at least one possible implementation, eliminating the influence of channel fading by equalization in the well includes: selecting a decision feedback equalizer, and adjusting the coefficients of the decision feedback equalizer by RLS algorithm or LMS algorithm to achieve adaptive equalization.

[0021] In a second aspect, the present invention provides a mud continuous wave pilot frequency synchronization device, comprising:

[0022] A signal generation module, used for encoding and modulating mud pressure wave signals in the well;

[0023] A signal denoising module is used to perform denoising on the mud pressure wave signal transmitted through the mud continuous wave channel on the well;

[0024] The signal synchronization module calculates the de-noised signal and the local synchronization signal or / and the synchronization training codeword to obtain the synchronization curve; the uphole receiving end uses the peak detection method to time synchronize the mud pressure wave signal inserted with the synchronization signal or / and the synchronization training codeword;

[0025] The signal analysis module is used to perform on-hole demodulation and decoding on the synchronized waveform signal.

[0026] In at least one possible implementation, the synchronization module includes:

[0027] A data frame pre-adjustment unit is used for inserting a preset fixed synchronization signal or / and a synchronization training codeword at the starting position of the waveform signal data frame transmitted by the downhole transmitting end;

[0028] The signal processing unit is used for the uphole receiving end to calculate the received waveform signal and the corresponding local synchronization signal waveform or synchronization training codeword waveform to obtain a synchronization curve;

[0029] The time synchronization unit is used for the uphole receiving end to perform correlation analysis on the synchronization curve to detect the peak value, perform time marking based on the detected peak value, and identify the starting position of the data frame to complete the time synchronization of the received waveform signal.

[0030] In a third aspect, the present invention provides an electronic device, comprising: one or more processors, a memory and one or more computer programs, wherein the memory may adopt a non-volatile storage medium, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions, and when the instructions are executed by the device, the electronic device performs the method as described in the first aspect or any possible implementation manner of the first aspect.

[0031] In a fourth aspect, the present invention provides a computer-readable storage medium, which stores a computer program, which, when executed on a computer, enables the computer to execute the method as described in the first aspect or any possible implementation of the first aspect.

[0032] In a fifth aspect, the present invention further provides a computer program product, which, when executed by a computer, is used to execute the method in the first aspect or any possible implementation of the first aspect. In a possible design of the fifth aspect, the relevant programs involved in the product may be stored in whole or in part on a memory packaged with the processor, or may be stored in whole or in part on a storage medium not packaged with the processor.

[0033] It should be understood that the second to fifth aspects of the embodiments of the present application are consistent with the technical solutions of the first aspect of the embodiments of the present application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar and will not be repeated here.

[0034] The main design concept of the present invention is to form a mud pressure wave signal through coding and modulation in the well according to the formulated frame structure; to perform noise elimination processing on the well for the mud pressure wave signal transmitted through the mud continuous wave channel; to obtain a synchronization curve through an improved synchronization method for the noise-eliminated signal and the local synchronization signal or / and the synchronization training codeword, and to perform time synchronization on the mud pressure wave signal inserted with the synchronization signal or / and the synchronization training codeword by the peak detection method at the well receiving end, and finally complete the well demodulation and decoding. The present invention can improve the synchronization accuracy of the mud continuous wave system for measuring while drilling, effectively solve the problem that the synchronization accuracy of the mud continuous wave system for measuring while drilling decreases when the depth increases, and more reliably resist noise interference, improve the accuracy and stability of synchronization, thereby greatly reducing the bit error rate and improving the anti-noise performance, thereby increasing the transmission depth of the measurement while drilling system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described below with reference to the accompanying drawings, in which:

[0036] Figure 1 This is a schematic diagram of the rotor of the MWD mud continuous wave system pulser;

[0037] Figure 2 It is a schematic diagram of the pulser's transmitting waveform;

[0038] Figure 3 A schematic diagram of a flow chart of a mud continuous wave pilot synchronization method provided by an embodiment of the present invention;

[0039] Figure 4 A schematic diagram of a mud pressure wave signal data frame structure provided by an embodiment of the present invention;

[0040] Figure 5 A schematic diagram of a Chirp signal improved synchronization curve based on analog data provided in an embodiment of the present invention;

[0041] Figure 6 It is a schematic diagram of the unimproved synchronization curve of the Chirp signal based on the simulation data;

[0042] Figure 7 A schematic diagram of an improved synchronization curve of an m-sequence based on simulated data provided by an embodiment of the present invention;

[0043] Figure 8 It is a schematic diagram of the unimproved synchronization curve of the m-sequence based on the simulated data;

[0044] Fig. 9 A schematic diagram of a Chirp signal improved synchronization curve based on real well data provided by an embodiment of the present invention;

[0045] Fig.10 It is a schematic diagram of the unimproved synchronization curve of the Chirp signal based on the actual well data;

[0046] Fig.11 A schematic diagram of an improved synchronization curve of an m-sequence based on real well data provided by an embodiment of the present invention;

[0047] Fig.12 It is a schematic diagram of the unimproved synchronization curve of the m-sequence based on the actual well data;

[0048] Fig.13 A schematic diagram of a mud continuous wave pilot frequency synchronization device provided by an embodiment of the present invention;

[0049] Fig.14 A schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0051] As mentioned above, the MWD mud continuous wave system achieves the interception effect on the mud by the continuous movement of the rotor of the motor-controlled pulser to form a continuous pressure wave. The mud pressure wave signal generated in this way is a non-standard sinusoidal signal and a non-standard linear frequency modulation signal (LFM) signal, that is, the transmitter generates nonlinear distortion. To expand, the fluid flow through the gap between the rotor and the stator can be expressed as:

[0052] (1)

[0053] in, is the flow coefficient, is the pore area, is the flow rate through the gap, is the density of the liquid, is the pressure difference on both sides of the gap. From the above formula, we can get:

[0054] (2)

[0055] according to Figure 1 The pulser rotor schematic diagram shows that the maximum area through which the fluid can flow is:

[0056] (3)

[0057] in, , and is the stator characteristic radius, in units of ; is the gap width between the rotor outer ring and the inner wall of the drill pipe, in units of .

[0058] When the pulser is running, the flow area is:

[0059] (4)

[0060] in, is the angular velocity of the pulser rotor, in units of , which can be expressed as:

[0061] (5)

[0062] in, is the rotor rotation frequency, in units of ; is the angle of the rotor blades, in degrees; The speed at which the rotor rotates is the given control signal.

[0063] Therefore, the flow area when the pulser is running is:

[0064] (6)

[0065] In summary, the pressure signal of the pulser can be obtained .

[0066] From the above formula, it can be concluded that the pressure signal The relationship with the given signal is as follows.

[0067] (7)

[0068]

[0069] From the above formula, we can see that the pressure signal It has a nonlinear relationship with the given signal. The schematic waveform diagram can be referred to Figure 2As shown in the figure. This nonlinear relationship causes the peak value of the synchronization curve to decrease when the correlation algorithm is used, which affects the accuracy and reliability of the synchronization of the measurement while drilling system. At the same time, in actual application, the traditional correlation synchronization method is greatly affected by noise. When there is too much residual noise, the synchronization peak will not be obvious, causing the system to miss synchronization or missynchronize. In addition, there are multiple reflections and refractions in the mud channel, resulting in multipath effects. Multiple synchronization peaks will be generated when receiving on the ground, and the superimposed noise influence is prone to missynchronization.

[0070] Based on the above analysis of the current situation, the present invention believes that it is necessary to provide a new synchronization algorithm to increase the peak value of the synchronization curve, while suppressing the influence of noise on the synchronization peak value. It should be mentioned here that the mud continuous wave measurement while drilling system is mainly divided into two parts: downhole and uphole. Downhole, the system is mainly composed of modules such as a continuous wave generator, a motor drive circuit, a downhole central control unit and a power supply; uphole, the system is mainly composed of modules such as a ground sensor, a ground data processing unit, a decoding unit and a control unit.

[0071] Different from the past, the downhole part can control the mud (drilling fluid) pressure to generate the expected waveform. The waveform signal is transmitted to the surface through the mud. The surface part processes the waveform transmitted from the downhole via the ground sensor and decodes and restores the data. This process can be broken down into the following: Figure 3 The process scheme shown:

[0072] Step S1, forming a mud pressure wave signal through encoding and modulation in the well;

[0073] The downhole transmitter of the MWD mud continuous wave system will control the motor to rotate the rotor according to the coding method, frame structure, modulation method, data rate and other agreements of the protocol, so that the mud flow between the rotor and the stator will change regularly, and finally reflect the change of the mud pressure wave. In some embodiments of the present invention, the synchronous training codeword in the aforementioned frame structure can adopt OOK modulation, FSK modulation or PSK modulation.

[0074] Step S2, performing noise elimination processing on the mud pressure wave signal transmitted through the mud continuous wave channel on the well;

[0075] What needs to be expanded here is that the influence of the mud continuous wave channel on the useful signal is mainly divided into two parts: interference and attenuation. Specifically, in terms of interference processing, the MWD system while drilling is mainly affected by interference such as pump noise, drill bit reflection, motor noise, etc. Therefore, the present invention proposes that before implementing subsequent synchronization, digital signal processing can be performed on the well to reduce the influence of interference on the decoding of useful signals, so as to correctly obtain downhole data.

[0076] Therefore, it can be considered that the MWD system while drilling uses data signal processing technology to process the mud pressure wave signal collected by the receiving end on the well to eliminate the influence of pump noise and motor noise on the system. In some preferred embodiments, a noise elimination method can be adopted in which the pump noise frequency is learned by a pump stroke sensor and a simulated pump noise waveform is generated, and the simulated pump noise waveform is subtracted from the waveform of the received mud pressure wave signal.

[0077] In addition, as for channel attenuation, in the MWD system, as the well depth increases, the attenuation of the useful signal amplitude increases, and this attenuation belongs to frequency selective attenuation; in addition, channel attenuation is related to the elastic properties of the drill pipe, the friction between particles in the mud, the compression coefficient of the mud, etc. Therefore, due to the influence of channel attenuation, the useful signal received by the well pressure sensor will be distorted, so it can be eliminated by means such as equalization on the well, which will be explained later.

[0078] Next, in step S3, the processed data is calculated with the local synchronization signal or / and the synchronization training codeword to obtain a synchronization curve; the receiving end on the well uses a peak detection method to time synchronize the mud pressure wave signal inserted with the synchronization signal or / and the synchronization training codeword;

[0079] The specific logic reference is as follows:

[0080] Step S31: The downhole transmitter inserts a preset fixed synchronization signal or / and synchronization training codeword at the starting position of the transmitted waveform signal data frame. Since the pre-inserted signal codeword has good autocorrelation, it is convenient for the receiving end to identify and synchronize;

[0081] Step S32, the receiving end on the well obtains a synchronization curve by using an improved synchronization calculation method to compare the received waveform signal with the corresponding local synchronization signal waveform or synchronization training codeword waveform;

[0082] Step S33: The receiving end on the well performs correlation analysis on the synchronization curve to detect the peak value, performs time marking based on the detected peak value, and identifies the starting position of the data frame to complete the time synchronization of the received waveform signal.

[0083] The aforementioned step S32 can be further refined and expanded into the following implementation steps, specifically including:

[0084] Step S321, select each sampling point x(i) in the waveform signal obtained by the uphole receiving end and perform the following calculation: take the log of the received signal x(i: i+L-1) and the local synchronization signal waveform or the synchronization training codeword waveform r(1:L) and perform point multiplication to obtain z 1(i). The number of sampling points of the received signal is selected as I, i+1, i+2, ..., i+L-1, where L is the length of the local synchronization signal waveform or the synchronization training codeword waveform.

[0085] Step S322: z 1 (i) Divide by the standard deviation of the above two signals to normalize and square, and sum to get z 2 (i) Since the DC component is removed in the previous noise reduction step, the mean is 0 (i.e., there is no need to subtract the signal mean).

[0086] Step S323: z 2 (i) Take the square root and take the inverse function of log to obtain the improved synchronization curve amplitude value y(i) corresponding to the i-th sampling point, which is the output result of the improved synchronization algorithm proposed in the present invention for the i-th sampling point.

[0087] Step S324, after performing point-by-point calculation from the first sampling point received from the well to the current sampling point n through the above steps, y(1:n) is obtained, that is, the improved synchronization curve.

[0088] In addition, it should be pointed out that in actual operation, in the MWD mud continuous wave system, it is possible to consider adding special signals to achieve frame synchronization and bit synchronization of the measurement signal. Figure 4 Taking the frame structure shown as an example, under this architecture example, the Chirp signal can be used as the frame synchronization signal, and the m sequence can be used as the bit synchronization signal, and both can be synchronized using related methods. It should be supplemented here that the present invention is not limited to a specific frame structure, for example, it can be Chirp signal + m sequence + data sequence, or Chirp signal + data sequence, or m sequence + data sequence, all of the above. In addition, under the frame structure of Chirp signal + m sequence + data sequence, the Chirp signal synchronization method can also use the improved synchronization algorithm of the present invention, while the m sequence synchronization method still uses the traditional related synchronization algorithm, or vice versa. Therefore, it is represented by or / and in the above embodiments.

[0089] The idea of ​​this step is to process the waveform data after noise elimination in the previous step and the local signal through the improved synchronization mechanism to complete the synchronization of the signal data between the downhole and the surface. The improved synchronization method proposed by the present invention can further suppress the amplitude of noise and other signal components in the synchronization curve, where the other signal components include the remaining frequency component signals caused by nonlinear distortion generated by the downhole transmitting end, and the multipath components and residual noise generated by refraction and reflection in the channel.

[0090] As described above, channel attenuation can be, but is not limited to, performed on-hole equalization processing after synchronization processing. Specifically, by using a fixed codeword to train the equalizer, an equalization coefficient is obtained. In practical applications, the equalizer can also be implemented by a filter. By adjusting the filter parameters, the characteristics generated by the channel are corrected and compensated, thereby reducing inter-code interference. It is preferably, but not limited to, implemented by a linear equalizer or a nonlinear equalizer. In other embodiments, the present invention is implemented by a decision feedback equalizer, and the decision feedback equalizer coefficients are adjusted by an RLS or LMS algorithm to achieve adaptive equalization.

[0091] Step S4: perform uphole demodulation and decoding on the synchronized waveform signal.

[0092] Finally, demodulation can be carried out by coherent demodulation or incoherent demodulation, and then the 01 code word is obtained by judgment, and then the corresponding parameter value is obtained according to the established protocols such as the aforementioned encoding method, frame structure composition, etc. For example, in some embodiments, coherent demodulation and hard decision decoding methods can be adopted, and the present invention does not limit or elaborate on this.

[0093] According to the above detailed overall process plan, further explanation is given here:

[0094] In the MWD mud continuous wave system, the ground decoding system can first eliminate the noise with obvious characteristics such as pump noise and motor noise. In this way, the remaining noise before synchronization is only random noise and it is not related to the signal. Therefore, in actual operation, the peak value and noise suppression ratio of the synchronization signal can be improved by increasing the signal correlation in the synchronization curve. For details, refer to the following formula example:

[0095] (8)

[0096] in, is the local synchronization signal, is the noise-removed signal received on the ground. is the synchronization algorithm output, is the length of the local synchronization signal, is the current sampling point.

[0097] The improved synchronization method based on pilot signal can be used for Chirp signal synchronization and m-sequence synchronization. The synchronization curve is as follows: Figure 5 and Figure 7 To facilitate the comparison of performance differences, the unimproved synchronization curve is shown in Figure 6 and Figure 8 shown.

[0098] from Figure 5-Figure 8It can be seen that the improved algorithm can effectively improve the relative peak value of synchronization, suppress noise, and avoid system missynchronization. In practice, the synchronization peak-to-noise mean ratio based on the Chirp signal increased from 29667 to 159119, an increase of about 4.36 times; the synchronization peak-to-noise mean ratio based on the m sequence increased from 8 to 294, an increase of about 35.75 times. The synchronization peak-to-subpeak ratio based on the Chirp signal increased from 9.85 to 807.10, an increase of about 80.92 times; the synchronization peak-to-noise mean ratio based on the m sequence increased from 1.30 to 2.81, an increase of about 1.17 times.

[0099] Improved synchronization method based on pilot signal In the actual well test, the chirp signal synchronization and m sequence synchronization curves are shown in Figure 2. Fig. 9 and Fig.11 The synchronization curve of the traditional correlation algorithm is shown in Fig.10 and Fig.12 As shown (it can be understood that the traditional synchronization is to perform correlation operation f(a, b) between the transmission waveform a and the local waveform b, and the synchronization curve y1=f(ab), while the present invention changes the synchronization function to g(a, b), and obtains a new synchronization curve y2=g(ab)). Among them, the star point is the synchronization position.

[0100] from Figure 9-12 It can be seen that the improved off-algorithm can effectively improve the synchronization relative peak value, suppress noise, and avoid system missynchronization. The synchronization peak-to-noise mean ratio based on the Chirp signal increased from 6 to 209, an increase of about 31.94 times; the synchronization peak-to-noise mean ratio based on the m sequence increased from 278 to 702, an increase of about 1.52 times. The synchronization peak-to-subpeak ratio based on the Chirp signal increased from 1.24 to 2.38, an increase of about 0.92 times; the synchronization peak-to-noise mean ratio based on the m sequence increased from 1.16 to 1.68, an increase of about 0.46 times.

[0101] Based on the above practical verification and comparison, it can be seen that the synchronization method proposed in the present invention can significantly improve the synchronization peak value of the measurement while drilling system and at the same time suppress the influence of noise on the synchronization peak value.

[0102] In summary, the main design concept of the present invention is to form a mud pressure wave signal through encoding and modulation in the well according to the set frame structure; to perform noise elimination processing on the well for the mud pressure wave signal transmitted through the mud continuous wave channel; to obtain a synchronization curve by an improved synchronization method for the noise-eliminated signal and the local synchronization signal or / and the synchronization training codeword, and to perform time synchronization on the mud pressure wave signal inserted with the synchronization signal or / and the synchronization training codeword by the peak detection method at the well receiving end, and finally complete the well demodulation and decoding. The present invention can improve the synchronization accuracy of the mud continuous wave system for measuring while drilling, effectively solve the problem that the synchronization accuracy of the mud continuous wave system for measuring while drilling decreases when the depth increases, and more reliably resist noise interference, improve the accuracy and stability of synchronization, thereby greatly reducing the bit error rate and improving the anti-noise performance, thereby increasing the transmission depth of the measurement while drilling system.

[0103] Corresponding to the above embodiments and preferred solutions, the present invention also provides an embodiment of a mud continuous wave pilot frequency synchronization device, such as Fig.13 As shown, it may specifically include the following components:

[0104] The signal generation module 131 is used to generate mud pressure wave signals through encoding and modulation in the well;

[0105] The signal denoising module 132 is used for performing denoising on the mud pressure wave signal transmitted through the mud continuous wave channel on the well;

[0106] The signal synchronization module 133 calculates the de-noised signal and the local synchronization signal or / and the synchronization training codeword to obtain a synchronization curve; the uphole receiving end uses a peak detection method to time synchronize the mud pressure wave signal inserted with the synchronization signal or / and the synchronization training codeword;

[0107] The signal analysis module 134 is used to perform uphole demodulation and decoding on the synchronized waveform signal.

[0108] It should be understood that the above Fig.13 The division of the various components in the mud continuous wave pilot synchronization device shown is only a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or they can be physically separated. And these components can all be implemented in the form of software calling through processing elements; some components can also be implemented in the form of software calling through processing elements, and some components can be implemented in the form of hardware. For example, one of the above modules can be a separately established processing element, or it can be integrated in a chip of an electronic device. The implementation of other components is similar. In addition, all or part of these components can be integrated together, or they can be implemented independently. In the implementation process, each step of the above method or the above components can be completed by the hardware integrated logic circuit in the processor element or the instructions in the form of software.

[0109] For example, the above components may be one or more integrated circuits configured to implement the above methods, such as one or more application specific integrated circuits (ASIC), or one or more microprocessors (DSP), or one or more field programmable gate arrays (FPGA). For another example, these components may be integrated together to be implemented in the form of a system-on-a-chip (SOC).

[0110] Based on the above embodiments and their preferred solutions, those skilled in the art can understand that, in actual operation, the technical concept involved in the present invention can be applied to a variety of implementations. The present invention uses the following carrier as a schematic illustration:

[0111] (1) An electronic device. The device may specifically include: one or more processors, a memory, and one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions, and when the instructions are executed by the device, the device performs the steps / functions of the aforementioned embodiment or equivalent implementation.

[0112] The electronic device may specifically be electronic device related to computers, such as but not limited to various computing terminals and electronic products.

[0113] Specifically, the processor, communication interface, and memory can all communicate with each other through a communication bus. Among them, the processor may be a central processing unit CPU, DSP, microcontroller or digital signal processor, and may also include GPU, embedded neural network processor (Neural-network Process Units; hereinafter referred to as: NPU) and image signal processor (Image Signal Processor; hereinafter referred to as: ISP). The processor may also include a specific integrated circuit ASIC, or one or more integrated circuits configured to implement the embodiment of the present invention, etc. In addition, the processor may have the function of operating one or more software programs, and the software programs may be stored in a storage medium such as a memory; and the aforementioned memory / storage medium may include: non-volatile memory (Non-Volatile Memory), such as a non-removable disk, U disk, mobile hard disk, optical disk, etc., as well as read-only memory (Read-Only Memory; hereinafter referred to as: ROM), random access memory (RandomAccess Memory; hereinafter referred to as: RAM), etc.

[0114] Although the present invention does not limit the specific form of the electronic device, for the purpose of illustrative introduction, Fig.14 As shown, the present invention provides a schematic diagram of the structure of an embodiment of an electronic device. Specifically, the electronic device 900 includes a processor 910 and a memory 930. The processor 910 and the memory 930 can communicate with each other through an internal connection path to transmit control and / or data signals. The memory 930 is used to store a computer program, and the processor 910 is used to call and run the computer program from the memory 930. The above-mentioned processor 910 and the memory 930 can be combined into a processing device, and more commonly, they are independent components from each other. The processor 910 is used to execute the program code stored in the memory 930 to implement the above-mentioned functions. In specific implementation, the memory 930 can also be integrated in the processor 910, or, independent of the processor 910.

[0115] In addition, in order to make the functions of the electronic device 900 more complete, the electronic device 900 may further include one or more of an input unit 960, a display unit 970, an audio circuit 980, a camera 990, and a sensor 901, and the audio circuit may further include a speaker 982, a microphone 984, etc. The display unit 970 may include a display screen.

[0116] Furthermore, the electronic device 900 may also include a power supply 950 for providing electrical energy to various devices or circuits in the electronic device 900 .

[0117] It should be understood that Fig.14The electronic device 900 shown can implement each process of the method provided in the aforementioned embodiment. The operation and / or function of each component in the electronic device 900 can be respectively to implement the corresponding process in the aforementioned method embodiment. For details, please refer to the description of the embodiments of the method, device, etc. in the previous text. To avoid repetition, the detailed description is appropriately omitted here.

[0118] It should be understood that Fig.14 The processor 910 in the electronic device 900 shown may be a system on chip SOC, which may include a central processing unit (CPU) and may further include other types of processors, such as a graphics processing unit (GPU), etc., which will be described in detail below.

[0119] In summary, the various processors or processing units within the processor 910 can work together to implement the previous method flow, and the corresponding software programs of the various processors or processing units can be stored in the memory 930.

[0120] (2) A computer data storage medium on which a computer program or the above-mentioned device is stored, which, when the computer program or the above-mentioned device is executed, enables a computer to execute the steps / functions of the aforementioned embodiment or equivalent implementation.

[0121] In several embodiments provided by the present invention, any function, if implemented in the form of a software functional unit and sold or used as an independent product, can be stored in a computer data storage medium. Based on this understanding, some technical solutions of the present invention are essentially or part of the technical solution that contributes to the prior art or part of the technical solution can be embodied in the form of the software product described below.

[0122] It should be particularly pointed out that the storage medium may refer to a server or a similar computer device, specifically, a storage device in a server or a similar computer device storing the aforementioned computer program or the aforementioned apparatus.

[0123] (3) A computer program product (the product may include the above-mentioned apparatus), which, when running on a terminal device, enables the terminal device to execute the mud continuous wave pilot synchronization method of the above-mentioned embodiment or an equivalent implementation.

[0124] It can be seen from the above description of the implementation method that those skilled in the art can clearly understand that all or part of the steps in the above implementation method can be implemented by means of software plus a necessary general hardware platform. Based on this understanding, the above computer program product may include but is not limited to APP.

[0125] In the embodiments of the present invention, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. A and B may be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c may represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, c may be single or multiple.

[0126] Those skilled in the art will appreciate that the various modules, units, and method steps described in the embodiments disclosed in this specification can be implemented by a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0127] In addition, each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. In particular, for embodiments such as devices and equipment, since they are basically similar to method embodiments, the relevant parts can refer to the partial description of the method embodiments. The embodiments of the devices and equipment described above are merely schematic, wherein the modules, units, etc. described as separate components may or may not be physically separated, that is, they may be located in one place, or they may be distributed in multiple places, such as nodes of a system network. Specifically, some or all of the modules and units may be selected according to actual needs to achieve the purpose of the above-mentioned embodiment scheme. Those skilled in the art can understand and implement it without paying creative labor.

[0128] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings, but the above is only a preferred embodiment of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched into a variety of equivalent schemes by those skilled in the art without departing from or changing the design ideas and technical effects of the present invention; therefore, the present invention is not limited to the scope of implementation shown in the drawings, and all changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the specification and drawings, should be within the protection scope of the present invention.

Claims

1. A mud continuous wave pilot synchronization method, characterized in that: include: The mud pressure wave signal is formed through encoding and modulation in the well; The well performs noise elimination processing on the mud pressure wave signal transmitted through the mud continuous wave channel; The de-noised signal is calculated with the local synchronization signal or / and the synchronization training codeword to obtain a synchronization curve; The uphole receiving end uses a peak detection method to time synchronize the mud pressure wave signal into which the synchronization signal or / and the synchronization training codeword are inserted, specifically comprising: the downhole transmitting end inserts a preset fixed synchronization signal or / and a synchronization training codeword at the starting position of the waveform signal data frame transmitted; the uphole receiving end calculates the received waveform signal and the local synchronization signal waveform or / and the synchronization training codeword waveform to obtain a synchronization curve; the uphole receiving end performs a correlation analysis on the synchronization curve to detect a peak value, performs a time mark based on the detected peak value, and identifies the starting position of the data frame to complete the time synchronization of the received waveform signal; The synchronized waveform signal is demodulated and decoded on the well.

2. The method for slurry continuous wave pilot synchronization according to claim 1, characterized in that: The noise reduction process comprises: Learn the pump noise frequency through the pump pulse sensor and generate a simulated pump noise waveform; The simulated pump noise waveform is subtracted from the waveform of the received mud pressure wave signal to eliminate the pump noise.

3. The method for slurry continuous wave pilot synchronization according to any one of claims 1 to 2, characterized in that: The synchronization method further includes: eliminating the influence of channel fading by equalization in the well.

4. The method for slurry continuous wave pilot synchronization according to claim 3, characterized in that: The method of eliminating the influence of channel fading by equalization in the well includes: selecting a decision feedback equalizer, and adjusting the coefficients of the decision feedback equalizer by RLS algorithm or LMS algorithm to complete adaptive equalization.

5. A mud continuous wave pilot frequency synchronization device, characterized in that: include: A signal generation module, used for encoding and modulating mud pressure wave signals in the well; A signal denoising module is used to perform denoising on the mud pressure wave signal transmitted through the mud continuous wave channel on the well; A signal synchronization module, used to calculate the de-noised signal with the local synchronization signal or / and the synchronization training codeword to obtain a synchronization curve; The uphole receiving end uses a peak detection method to time synchronize the mud pressure wave signal into which the synchronization signal or / and the synchronization training codeword are inserted, specifically comprising: the downhole transmitting end inserts a preset fixed synchronization signal or / and a synchronization training codeword at the starting position of the waveform signal data frame transmitted; the uphole receiving end calculates the received waveform signal and the local synchronization signal waveform or / and the synchronization training codeword waveform to obtain a synchronization curve; the uphole receiving end performs a correlation analysis on the synchronization curve to detect a peak value, performs a time mark based on the detected peak value, and identifies the starting position of the data frame to complete the time synchronization of the received waveform signal; The signal analysis module is used to perform on-hole demodulation and decoding on the synchronized waveform signal.

6. The mud continuous wave pilot frequency synchronization device according to claim 5, characterized in that: The synchronization module comprises: A data frame pre-adjustment unit is used for inserting a preset fixed synchronization signal or / and a synchronization training codeword at the starting position of the waveform signal data frame transmitted by the downhole transmitting end; The signal processing unit is used for the uphole receiving end to calculate the received waveform signal with the local synchronization signal waveform or the synchronization training codeword waveform to obtain a synchronization curve; The time synchronization unit is used for the uphole receiving end to perform correlation analysis on the synchronization curve to detect the peak value, perform time marking based on the detected peak value, and identify the starting position of the data frame to complete the time synchronization of the received waveform signal.

7. An electronic device, characterized in that: include: One or more processors, a memory and one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions, and when the instructions are executed by the electronic device, the electronic device executes the mud continuous wave pilot synchronization method according to any one of claims 1 to 4.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the mud continuous wave pilot synchronization method according to any one of claims 1 to 4 is implemented.

9. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the mud continuous wave pilot synchronization method according to any one of claims 1 to 4 is implemented.

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