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CN-116010839-B - Noise suppression method and system based on threshold amplitude, electronic equipment and storage medium

CN116010839BCN 116010839 BCN116010839 BCN 116010839BCN-116010839-B

Abstract

The invention provides a noise suppression method, a noise suppression system, electronic equipment and a storage medium based on threshold amplitude, which comprise the steps of selecting a certain seismic channel from an original seismic record, calculating the median absolute difference of the seismic channel, calculating the threshold amplitude of the seismic channel based on the median absolute difference and an amplitude threshold factor, judging whether the amplitude value of the seismic channel reaches the threshold amplitude, carrying out attenuation processing on the seismic channel according to the threshold amplitude, and outputting the attenuated seismic channel. The technical scheme of the invention has the advantages that the median amplitude and the given amplitude threshold factor are adopted to define the threshold amplitude, the amplitude threshold factor changes along with time and space, the amplitude value of the seismic channel is attenuated according to the threshold amplitude so as to achieve the aim of suppressing abnormal noise, effective signals can be protected, the signal-to-noise ratio of seismic data materials can be improved, and the method has a very good application effect on abnormal noise interference in single cannons collected in the field of the detection area.

Inventors

  • ZHANG LIN

Assignees

  • 中国石油化工股份有限公司
  • 中国石油化工股份有限公司石油物探技术研究院

Dates

Publication Date
20260512
Application Date
20211020

Claims (6)

  1. 1. A method for noise suppression based on threshold amplitude, comprising: step S1, selecting a certain seismic channel from the original seismic record, and calculating the median absolute difference of the seismic channel; step S2, calculating the threshold amplitude of the seismic channel based on the median absolute difference and an amplitude threshold factor; Step S3, judging whether the amplitude value of the seismic channel reaches the threshold amplitude, if so, turning to step S4 for processing, and if not, not processing; S4, carrying out attenuation treatment on the seismic channel according to the threshold amplitude, and outputting the attenuated seismic channel; When the amplitude value of a certain seismic trace is in the threshold amplitude range, the amplitude threshold factor is calculated by the following formula (2): (2); Wherein, the X is a sliding factor for the amplitude threshold factor; in the step S2, when a certain trace is a data trace with large attenuation amplitude, the threshold amplitude of the trace is calculated according to the formula (3): (3); or when a certain trace is a data trace with small attenuation amplitude, calculating the threshold amplitude of the trace according to the formula (4): (4); Wherein, the For a certain trace of the threshold amplitude of the seismic trace at time t band f, For the median absolute difference of a trace in time t band f, For the median amplitude of a trace of seismic trace at time t band f, Is the amplitude threshold factor.
  2. 2. The noise suppression method based on the threshold amplitude according to claim 1, wherein the step S1 comprises the steps of firstly calculating the absolute difference between the median amplitudes of a certain channel based on the time t and the frequency band f of the selected certain channel, and then calculating the amplitude of each channel in the median width according to the absolute difference between the median amplitudes to obtain the median absolute difference of the certain channel in the time t frequency band f; The median absolute difference is calculated by the following formula (1): (1); Wherein, the For the median absolute difference of a trace in time t band f, To median all traces of a trace within the median width of time t band f, Amplitude energy at time t band f for a trace of seismic energy.
  3. 3. A threshold amplitude based noise suppression system implementing the threshold amplitude based noise suppression method of claim 1 or 2, comprising: The first calculation module is used for calculating the median absolute difference of a certain channel of seismic channels according to the seismic channels selected from the original seismic records; The second calculation module is used for calculating the threshold amplitude of the seismic channel based on the median absolute difference and an amplitude threshold factor; the judging module is used for judging whether the amplitude value of the seismic channel reaches the threshold amplitude or not; the attenuation processing module is used for carrying out attenuation processing on the seismic channel according to the threshold amplitude; The seismic channel output module is used for outputting the attenuated seismic channel; The noise suppression system further comprises a third calculation module, and when the amplitude value of a certain seismic trace is in a threshold amplitude range, the third calculation module calculates the amplitude threshold factor according to the following formula: ; Wherein, the X is a sliding factor for the amplitude threshold factor; when a certain seismic trace is a data trace with large attenuation amplitude, the second calculation module calculates the threshold amplitude of the seismic trace according to the following formula: ; or when a certain seismic trace is a data trace with small attenuation amplitude, the second calculation module calculates the threshold amplitude of the seismic trace according to the following formula: ; Wherein, the For a certain trace of the threshold amplitude of the seismic trace at time t band f, For the median absolute difference of a trace in time t band f, For the median amplitude of a trace of seismic trace at time t band f, Is the amplitude threshold factor.
  4. 4. The threshold-amplitude-based noise suppression system of claim 3, based on the time t and the frequency band f of a selected trace of seismic traces, the first calculation module includes: The first calculation unit is used for calculating the absolute difference between the median amplitudes of a certain channel of seismic channels; the second calculation unit is used for calculating the amplitude of each seismic trace in the median width according to the absolute difference between the median amplitudes to obtain the median absolute difference of a certain seismic trace in the time t frequency band f; The median absolute difference is calculated by the following formula (1): ; Wherein, the For the median absolute difference of a trace in time t band f, To median all traces of a trace within the median width of time t band f, Amplitude energy at time t band f for a trace of seismic energy.
  5. 5. An electronic device, the electronic device comprising: at least one processor, and A memory communicatively coupled to the at least one processor, wherein, The memory stores instructions executable by the at least one processor to enable the at least one processor to perform the threshold amplitude based noise suppression method of claim 1 or 2.
  6. 6. A non-transitory computer readable storage medium storing computer instructions for causing a computer to perform the threshold amplitude-based noise suppression method of claim 1 or 2.

Description

Noise suppression method and system based on threshold amplitude, electronic equipment and storage medium Technical Field The invention belongs to the technical field of seismic exploration data processing methods, and particularly relates to a noise suppression method, system, electronic equipment and storage medium based on threshold amplitude. Background In seismic data processing, abnormal noise is a common noise, the form of which appears to have no certain propagation direction and apparent velocity, and is extremely powerful, and if not pre-stack compressed, the subsequent velocity modeling and offset imaging are both very unfavorable, so the compression of abnormal noise is very critical. How to effectively remove abnormal noise is always an important problem in data processing. The method of noise suppression is generally to convert data into the frequency domain and then apply spatial median filtering. Given a specific threshold, the frequency band range extracted from the medium value amplitude is multiplied by a specific calibration operator or the interpolation frequency band of the surrounding channels is used for replacing the original amplitude value. When the median amplitude of the sample points exceeds the median amplitude within the band, then this band is considered an outlier. It is common practice to employ a threshold factor, which may be of the median or median absolute difference type. The absolute difference between the median amplitudes is calculated and the amplitude of each track within the median width is calculated to obtain the median absolute difference. When the data space is greatly changed, the median absolute difference also needs to be automatically adjusted, and when the data is less complex, the median absolute difference also needs to be correspondingly adjusted. Therefore, a noise suppression method based on threshold amplitude is expected, and aims to suppress abnormal noise of seismic data and eliminate abnormal noise interference. Disclosure of Invention The invention provides a noise suppression method, a system, electronic equipment and a storage medium based on threshold amplitude, which adopt median amplitude and a given amplitude threshold factor to define threshold amplitude, the amplitude threshold factor changes with time and space, and the amplitude value of an earthquake channel is attenuated according to the threshold amplitude so as to achieve the aim of suppressing abnormal noise, so that effective signals can be protected, and the signal to noise ratio of earthquake data materials can be improved. In order to achieve the above object, the present invention provides a noise suppressing method based on threshold amplitude, comprising: step S1, selecting a certain seismic channel from the original seismic record, and calculating the median absolute difference of the seismic channel; step S2, calculating the threshold amplitude of the seismic channel based on the median absolute difference and an amplitude threshold factor; Step S3, judging whether the amplitude value of the seismic channel reaches the threshold amplitude, if so, turning to step S4 for processing, and if not, not processing; and S4, carrying out attenuation processing on the seismic channel according to the threshold amplitude, and outputting the attenuated seismic channel. Preferably, the step S1 comprises the steps of firstly calculating the absolute difference between the median amplitudes of a certain channel based on the time t and the frequency band f of the selected certain channel, and then calculating the amplitude of each channel in the median width according to the absolute difference between the median amplitudes to obtain the median absolute difference of the certain channel in the time t frequency band f; The median absolute difference is calculated by the following formula (1): Pftk＝medk[|Rftk-medk(Rftk)|] (1); Wherein P ftk is the median absolute difference of a certain channel in the time t frequency band f, med k is the median of all channels of a certain channel in the median width of the time t frequency band f, and R ftk is the amplitude energy of a certain channel in the time t frequency band f. Preferably, when the amplitude value of a certain trace is within the threshold amplitude range, the amplitude threshold factor is calculated by the following formula (2): Wherein U t is the amplitude threshold factor and x is the slip factor. Preferably, in the step S2, when a certain trace is a data trace with a large attenuation amplitude, the threshold amplitude of the trace is calculated according to the formula (3): Qftk＝Sftk+Ut·Pftk (3); or when a certain seismic trace is a data trace with small attenuation amplitude, calculating according to the formula (4) to obtain the threshold amplitude of the seismic trace: Qftk＝Sftk-Ut·Pftk (4); wherein, Q ftk is the threshold amplitude of a certain trace in the time t frequency band f, P ftk is the median absolute difference