CN110469326B - Self-adaptive correlation filtering method - Google Patents
Self-adaptive correlation filtering method Download PDFInfo
- Publication number
- CN110469326B CN110469326B CN201910712049.2A CN201910712049A CN110469326B CN 110469326 B CN110469326 B CN 110469326B CN 201910712049 A CN201910712049 A CN 201910712049A CN 110469326 B CN110469326 B CN 110469326B
- Authority
- CN
- China
- Prior art keywords
- mud pulse
- signal
- pulse pressure
- pulse
- adaptive
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/12—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
- E21B47/14—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling using acoustic waves
- E21B47/18—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling using acoustic waves through the well fluid, e.g. mud pressure pulse telemetry
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
- Y02P90/02—Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
Abstract
The invention discloses a self-adaptive correlation filtering method, which comprises the following steps: acquiring original mud pulse pressure data through a ground data acquisition system; preprocessing the collected mud pulse pressure data; adaptively selecting a correlation basis function to perform correlation operation on the pretreated mud pulse pressure signal; detecting and identifying the mud pulse pressure signal after self-adaptive correlation; extracting a related basis function from the synchronization information; and calculating the decoding error rate of the mud pulse pressure signal. According to the method, the correlation basis function is selected in a self-adaptive mode through comparison of the signal decoding error rate and the set threshold value, and detection and identification of the mud pulse signal are achieved based on the correlation operation result, so that the effective mud pulse signal can be identified rapidly, accurately and reliably, and underground data efficient transmission is achieved.
Description
Technical Field
The invention relates to the technical field of petroleum drilling and logging while drilling, in particular to a signal acquisition and processing method in a logging while drilling control system.
Background
The measurement and control while drilling system refers to a system which measures engineering parameters and geological and petrophysical parameters of a stratum to be drilled simultaneously in the drilling process and transmits information to the ground in real time. The measurement and control system while drilling mainly comprises an underground controller, various underground parameter measuring instruments, a data transmission system and a ground information unit. The underground controller is used for configuring each measuring instrument, controlling the working time sequence of each instrument, receiving and processing various measuring parameters and the like; the downhole parameter measuring instrument is responsible for obtaining various geometric, geological, engineering and other data related to the current drilling state and stratum; the data transmission system adopts a wired or wireless channel to transmit the obtained data to the wellhead in a certain coding mode; the ground information unit is responsible for interconnection communication with the downhole controller on one hand, filtering, decoding, receiving, processing, displaying and the like of the transmission signal on the other hand.
In measurement and control while drilling technology, data transmission systems hold a significant position. The data transmission method mainly comprises a cable method, a slurry pulse method, an acoustic wave method, an electromagnetic wave method and an optical fiber method, and each method has the application range and the limitation, and the slurry pulse transmission is the data transmission mode which is most widely used at present and has the greatest development potential due to the overall advantages of good reliability, lower development cost, large-scale application well depth and the like. The mud pulse method adopts a mode of switching or changing the flow area of drilling fluid in a drill string, so as to change the drilling fluid pressure in the drill string, form a mud pressure wave signal with certain frequency and amplitude, transmit the pressure wave to the ground in a pulse mode, and form an electric signal for collection and processing. Common pulse modes include three modes of positive pulse, negative pulse and continuous wave.
For the slurry pulse method, the influence of noise is very large, and the proper signal detection and signal identification method can effectively improve the accuracy and reliability of received data. The noise affecting the mud pulse signal mainly comprises two aspects, wherein a part of noise is caused by a downhole tool, and the transmission direction is consistent with the direction of the uploading pulse signal, such as the mud pulse pressure noise generated by the action of a drill bit and a well bottom, the action of a drill string and a well wall, a downhole turbine generator and the like; another part of noise is derived from ground equipment such as a slurry pump, an air bag and the like, and the transmission direction is opposite to the direction of the pulse signal.
The mud pulse signal is detected rapidly and effectively, so that the drilling track is controlled, the working state of the drilling tool is judged, the stratum characteristics are evaluated, and the method has great significance in reducing drilling risks and improving footage efficiency. However, from the aspect of surface detection of mud pulse, the pressure signal to be detected is a weak signal with low signal-to-noise ratio, which is seriously disturbed by noise of a drilling pump, reflection noise and a series of random noise (caused by mechanical vibration at the bottom of a well, instability of a drill string, friction of mud and the like) and is obviously attenuated along with the transmission distance, and especially in some cases, the pressure signal cannot be effectively detected at all, so that the normal drilling operation is seriously affected.
Because the frequency spectrum of the mud pulse signal is overlapped with pump noise and other various noises, a simple frequency domain filtering mode is difficult to obtain a more obvious pulse waveform. Therefore, how to detect useful signals from complex noise backgrounds with large amplitude and wide bandwidth becomes a key problem in the mud pulse transmission technology.
Disclosure of Invention
The invention aims to solve the problems in the prior art and provides an adaptive correlation filtering method. According to the method, the correlation basis function is selected in a self-adaptive mode through comparison of the bit error rate and the set threshold value, detection and identification of the mud pulse signal are achieved based on the correlation operation result, and therefore rapid, accurate and reliable identification of the effective mud pulse signal is achieved, and efficient underground data transmission is achieved.
The technical scheme of the invention is as follows:
an adaptive correlation filtering method, comprising the steps of:
s1, acquiring original mud pulse pressure data through a ground data acquisition system;
s2, preprocessing the collected mud pulse pressure data;
s3, adaptively selecting a correlation basis function to perform correlation operation on the pretreated mud pulse pressure signal;
s4, detecting and identifying the mud pulse pressure signal after self-adaptive correlation;
s5, extracting a related basis function from the synchronous information;
s6, calculating the decoding error rate of the mud pulse pressure signal.
The above scheme further includes:
the S2 mud pulse pressure data preprocessing comprises spectrum analysis, low-pass filtering processing and direct current component removal of original mud pulse pressure data in an operation window;
the adaptive selection of the relevant basis function of the S3 is realized through the following steps:
1) If the decoding program is operated for the first time, the related basis functions are designated by a user and comprise triangular waves, square waves and bell-shaped functions, and if the related basis functions are not selected, the related basis functions are defaulted to be one related basis function;
2) If the decoding program is not operated for the first time, the related basis function is adaptively determined according to the magnitude relation between the error rate of the last calculated mud pulse pressure signal and the set threshold, specifically, when the error rate is greater than the set threshold, the related basis function extracted from the synchronous information is adopted as the related basis function, and when the error rate is not greater than the set threshold, the original related basis function is kept unchanged;
the step S4 of detecting and identifying the self-adaptive correlated mud pulse pressure signal comprises the following steps:
1) Calculating an average value of the amplitude of the self-adaptive filtered signal in the operation window as a signal base value;
2) Subtracting the basic value from the self-adaptive filtered signal, and if the difference exceeds a preset threshold value, considering that the coded pulse is detected;
3) If the code pulse is detected, further searching a local maximum value of the jump value, and recording the position of the local maximum value for decoding;
4) According to the relative position of the identified pulse, finishing pulse decoding by calculating the pulse interval;
the step S5 of extracting the relevant base function from the synchronous information means that if the synchronous head pulse exists in the operation window, the last pulse of the synchronous pulse is automatically extracted as a prototype of the relevant base function, and then simple filtering and noise elimination processing is carried out on the prototype, so that the relevant base function is extracted, and the relevant base function extracted from the original stored synchronous information is updated; if the synchronization head pulse does not exist in the operation window, the original stored synchronization information extraction related basis function is unchanged.
The operation window refers to data in a data window processed by the mud pulse signal detection and identification program each time.
The ground data acquisition system comprises a mud pulse generator and a mud pulse force sensor, wherein the mud pulse generator is arranged at the bottom of a drill string and above a drill bit, and the mud pulse force sensor is arranged on a vertical pipe.
The self-adaptive correlation filtering method has the advantages that on the basis of fully generating, transmitting and adding noise characteristics according to the mud pulse signal while drilling, the method extracts the correlation basis function of the synchronous information and adaptively selects the correlation basis function according to the decoding error rate, the method is simple and reliable, the mud pulse signal with high signal-to-noise ratio can be effectively obtained, the signal detection and recognition precision is effectively improved, and the method has great practical value.
The invention will be further described with reference to the drawings and embodiments.
Drawings
FIG. 1 is a flow chart of an adaptive correlation filtering method;
FIG. 2 is a schematic diagram of a mud pulse pressure signal acquisition system;
FIG. 3 is a waveform diagram of a raw mud pulse pressure signal;
FIG. 4 is a spectrum profile of a raw mud pulse pressure signal;
FIG. 5 is a waveform of a low pass filtered signal;
FIG. 6 is a waveform diagram of the signal after DC component removal;
FIG. 7 is a waveform diagram of a signal after filtering using adaptive correlation;
FIG. 8 is a graph of the effect of mud pulse pressure signal detection and identification;
fig. 9 extracts a correlation basis function from synchronization information.
Detailed Description
The adaptive correlation filtering method is described in detail below with reference to the accompanying drawings.
Fig. 1 is a flowchart of an adaptive correlation filtering method, which mainly includes an original mud pulse pressure data acquisition S1, a data preprocessing S2, an adaptive selection of a correlation basis function for correlation operation S3, a detection and identification of a mud pulse pressure signal S4, a correlation basis function extraction from synchronization information S5, and a calculation of a decoding error rate of the mud pulse pressure signal S6.
Furthermore, the embodiment of the invention takes the processing procedure of a section of the acquired mud pulse pressure signal while drilling as an example, and the invention is further described.
(1) Raw mud pulse pressure data acquisition
Fig. 2 is a schematic diagram of a mud pulse pressure signal acquisition system. For a mud pulse signal flow channel, a mud pulse generator is arranged at the bottom of a drill string and above a drill bit and is used for transmitting underground measurement while drilling information. The method comprises the steps of coding underground information and modulating the underground information through a mud pulse generator, wherein the mud pulse generator adopts a switch or a mode of changing the flow area of drilling fluid in a drill string according to coding modulation rules to change the drilling fluid pressure in the drill string, so as to form a mud pulse pressure signal with certain frequency and amplitude, and the mud pulse pressure signal carries the underground information, propagates upwards along the drilling fluid in the drill string and is transmitted to the ground. A mud pulse pressure sensor installed on the ground on the vertical pipe detects mud pulse pressure signals, converts the detected analog signals into digital signals and transmits the digital signals to a computer through a ground interface box. The waveform of the original mud pulse pressure signal acquired by the original mud pulse pressure data acquisition system is shown in fig. 3.
(2) Data preprocessing
The data preprocessing comprises spectrum analysis, low-pass filtering processing and direct-current component removal of original mud pulse pressure data in an operation window (data in a data window processed by a mud pulse signal detection and identification program).
In this embodiment, the spectrum distribution of the original mud pulse pressure signal is shown in fig. 4, the abscissa represents the frequency, the ordinate represents the amplitude, and the frequency components of the collected original mud pulse pressure signal, the frequency of the effective signal and the frequency of the main interference source can be obtained through the spectrum distribution.
Further, since the mud pulse effective signal is a low frequency signal, the high frequency parts of the signal are all disturbances. According to the spectrum analysis result of the original mud pulse pressure data, parameters of a low-pass filter can be determined, and the type of the low-pass filter can be selected from Butterworth, chebyshev, window functions and the like, and in the embodiment, an FIR low-pass filter is selected. The waveform of the low-pass filtered signal of this embodiment is shown in fig. 5.
The dc level of the signal fluctuates considerably due to the effect of the actual signal channel, which is a great disturbance for the detection of the effective signal of the mud pulse. The direct current component can be obtained by directly averaging the signal values, and in the process of calculating the direct current component, the average length cannot be too long to reflect the change of the direct current quantity along with time, and the average length cannot be too short to lose the normal signal amplitude modulation. The waveform of the signal after removing the dc component in this embodiment is shown in fig. 6.
(3) Self-adaptive selection of correlation basis function for correlation operation
The adaptive selection of the relevant basis function is achieved by:
1) If the decoding program is operated for the first time, the related base function is specified by a user, such as triangular wave, square wave, bell-shaped function and the like, and if the decoding program is not selected, the related base function is defaulted to be a related base function;
2) If the decoding program is not operated for the first time, the related basis function is adaptively determined according to the magnitude relation between the error rate of the last calculated mud pulse pressure signal and the set threshold, specifically, when the error rate is greater than the set threshold, the related basis function extracted from the synchronous information is adopted as the related basis function, and when the error rate is not greater than the set threshold, the original related basis function is kept unchanged.
In the embodiment, the waveform of the signal after the adaptive correlation filtering is shown in fig. 7, and the adaptive correlation filtering method can be used for suppressing the amplitude of noise, so that the signal-to-noise ratio of the signal is effectively improved, and the detection and the identification of an effective mud pulse signal are facilitated.
(4) Detection and identification of mud pulse pressure signals
The detection and identification of the mud pulse pressure signal comprises the following steps:
1) Calculating an average value of the amplitude of the self-adaptive filtered signal in the operation window as a signal base value;
2) Subtracting the basic value from the self-adaptive filtered signal, and if the difference exceeds a preset threshold value, considering that the coded pulse is detected;
3) If the code pulse is detected, further searching a local maximum value of the jump value, and recording the position of the local maximum value for decoding;
4) Pulse decoding is accomplished by calculating pulse intervals based on the relative positions of the identified pulses.
The effect of detecting and identifying the mud pulse pressure signal in this embodiment is shown in fig. 8, where the black and thick lines represent the signal base values, and the circles mark the identified pulse positions.
(5) Extracting relevant basis functions from synchronization information
Extracting the relevant base function from the synchronization information means that if the synchronization head pulse exists in the operation window, the last pulse of the synchronization pulse is automatically extracted as a prototype of the relevant base function, and then simple filtering and noise elimination processing is performed on the prototype, so that the relevant base function is extracted, and the relevant base function extracted from the original stored synchronization information is updated, and the relevant base function is extracted from the synchronization information in the embodiment as shown in fig. 9; if the synchronization head pulse does not exist in the operation window, the original stored synchronization information extraction related basis function is unchanged.
(6) Calculating decoding error rate of mud pulse pressure signal
According to the coding rules and the check standards (parity check, accumulation and check, CRC check, etc.) of the code element, the number of successful decoding and error codes can be determined in the process of decoding the mud pressure pulse signal according to the formula: bit error rate = bit error in transmission/total number of codes transmitted x 100%, the decoding bit error rate of the mud pulse pressure signal can be calculated.
Claims (3)
1. An adaptive correlation filtering method, characterized in that it comprises the steps of:
s1, acquiring original mud pulse pressure data through a ground data acquisition system;
s2, preprocessing the collected mud pulse pressure data;
s3, adaptively selecting a correlation basis function to perform correlation operation on the pretreated mud pulse pressure signal;
s4, detecting and identifying the mud pulse pressure signal after self-adaptive correlation;
s5, extracting a related basis function from the synchronous information;
s6, calculating a decoding error rate of the mud pulse pressure signal;
the S2 mud pulse pressure data preprocessing comprises spectrum analysis, low-pass filtering processing and direct current component removal of original mud pulse pressure data in an operation window;
the adaptive selection of the relevant basis function of the S3 is realized through the following steps:
1) If the decoding program is operated for the first time, the related basis functions are designated by a user and comprise triangular waves, square waves and bell-shaped functions, and if the related basis functions are not selected, the related basis functions are defaulted to be one related basis function;
2) If the decoding program is not operated for the first time, the related basis function is adaptively determined according to the magnitude relation between the error rate of the last calculated mud pulse pressure signal and the set threshold, specifically, when the error rate is greater than the set threshold, the related basis function extracted from the synchronous information is adopted as the related basis function, and when the error rate is not greater than the set threshold, the original related basis function is kept unchanged;
the step S4 of detecting and identifying the self-adaptive correlated mud pulse pressure signal comprises the following steps:
1) Calculating an average value of the amplitude of the self-adaptive filtered signal in the operation window as a signal base value;
2) Subtracting the basic value from the self-adaptive filtered signal, and if the difference exceeds a preset threshold value, considering that the coded pulse is detected;
3) If the code pulse is detected, further searching a local maximum value of the jump value, and recording the position of the local maximum value for decoding;
4) According to the relative position of the identified pulse, finishing pulse decoding by calculating the pulse interval;
the step S5 of extracting the relevant base function from the synchronous information means that if the synchronous head pulse exists in the operation window, the last pulse of the synchronous pulse is automatically extracted as a prototype of the relevant base function, and then simple filtering and noise elimination processing is carried out on the prototype, so that the relevant base function is extracted, and the relevant base function extracted from the original stored synchronous information is updated; if the synchronization head pulse does not exist in the operation window, the original stored synchronization information extraction related basis function is unchanged.
2. The adaptive correlation filtering method of claim 1, wherein the operation window is data in a data window processed by the mud pulse signal detection and recognition program each time.
3. An adaptive correlation filtering method according to claim 1 or 2, wherein the surface data acquisition system comprises a mud pulse generator mounted on the bottom of the drill string above the drill bit and a mud pulse force sensor mounted on the riser.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910712049.2A CN110469326B (en) | 2019-08-02 | 2019-08-02 | Self-adaptive correlation filtering method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910712049.2A CN110469326B (en) | 2019-08-02 | 2019-08-02 | Self-adaptive correlation filtering method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110469326A CN110469326A (en) | 2019-11-19 |
| CN110469326B true CN110469326B (en) | 2023-05-12 |
Family
ID=68508547
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910712049.2A Active CN110469326B (en) | 2019-08-02 | 2019-08-02 | Self-adaptive correlation filtering method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110469326B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111914806B (en) * | 2020-08-18 | 2023-12-15 | 成都爱科特科技发展有限公司 | Method and device for detecting ultrashort wave weak signals in high noise environment, terminal equipment and storage medium |
| CN116032310B (en) * | 2023-02-20 | 2023-07-04 | 西安瀚博电子科技有限公司 | Signal self-adaptive detection reconstruction method based on channelized filtering |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100410486C (en) * | 2004-02-16 | 2008-08-13 | 中国石油集团钻井工程技术研究院 | Method and device for receiving and detecting mud pressure pulse signal |
| CN104343440B (en) * | 2014-08-29 | 2017-10-17 | 北京市普利门电子科技有限公司 | The detection method and system of mud pressure pulse signal |
| CN106437689B (en) * | 2016-09-13 | 2019-04-09 | 中国石油大学(华东) | A kind of processing method with sludge slurry positive pulse signal |
| CN106321080B (en) * | 2016-09-13 | 2019-04-09 | 中国石油大学(华东) | A kind of processing method with brill mud continuous-wave pulse signal |
| CN108985119A (en) * | 2017-05-31 | 2018-12-11 | 华为技术有限公司 | The method and apparatus of structured light decoding |
| CN107294616B (en) * | 2017-06-12 | 2021-03-23 | 西北工业大学 | Dual-extension underwater acoustic channel Doppler diversity communication method based on basis extension model |
-
2019
- 2019-08-02 CN CN201910712049.2A patent/CN110469326B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110469326A (en) | 2019-11-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2201552C (en) | Noise detection and suppression system for wellbore telemetry | |
| US7313052B2 (en) | System and methods of communicating over noisy communication channels | |
| US8792304B2 (en) | Downlinking communication system and method using signal transition detection | |
| US8111171B2 (en) | Wellbore telemetry and noise cancellation systems and methods for the same | |
| CN106321080B (en) | A kind of processing method with brill mud continuous-wave pulse signal | |
| CN106437689B (en) | A kind of processing method with sludge slurry positive pulse signal | |
| CN110469326B (en) | Self-adaptive correlation filtering method | |
| CN104343440B (en) | The detection method and system of mud pressure pulse signal | |
| US9933538B2 (en) | Adaptive optimization of output power, waveform and mode for improving acoustic tools performance | |
| Chen et al. | MWD drilling mud signal de-noising and signal extraction research based on the pulse-code information | |
| US10955581B2 (en) | Using an adjusted drive pulse in formation evaluation | |
| Jianhui et al. | An effective approach for the noise removal of mud pulse telemetry system | |
| CN114183127B (en) | Method for reducing interference of mud pulse signals on drilling tool movement | |
| US11725505B2 (en) | Machine learning mud pulse recognition networks | |
| US10125603B2 (en) | Frequency sweeps for encoding digital signals in downhole environments | |
| NO20171368A1 (en) | Drill bit positioning system | |
| CN112183268A (en) | MWD mud pressure wave processing method | |
| KR20200134082A (en) | Method and apparatus for transmitting data based on frequency modulation through a load pipe for mining and construction, oil drilling | |
| CN216767376U (en) | Device for reducing interference of mud pulse signals to drilling tool movement | |
| CN111832332A (en) | Mud pulse signal processing method and device | |
| US11655708B2 (en) | Telemetry using pulse shape modulation | |
| GB2472535A (en) | Noise in a first communication channel is estimated and compensated for using noise measurements in adjacent channels |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| TA01 | Transfer of patent application right | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20220208 Address after: 100029 Chaoyang District, Beijing Hui Xin Street six, Twelfth level. Applicant after: SINOPEC OILFIELD SERVICE Corp. Applicant after: SINOPEC SHENGLI PETROLEUM ENGINEERING Co.,Ltd. Applicant after: Sinopec Jingwei Co.,Ltd. Applicant after: Geological measurement and Control Technology Research Institute of Sinopec Jingwei Co.,Ltd. Address before: 100101 Beichen West Road, Chaoyang District, Beijing 8 Beichen world center, block A 703. Applicant before: SINOPEC OILFIELD SERVICE Corp. Applicant before: SINOPEC SHENGLI PETROLEUM ENGINEERING Co.,Ltd. Applicant before: Sinopec Shengli Petroleum Engineering Co.,Ltd. Measurement and Control Technology Center While Drilling |
|
| GR01 | Patent grant | ||
| GR01 | Patent grant |