Interference suppression method for seismic frequency resonance exploration based on reference trace in survey area

Abstract

The application discloses a seismic frequency resonance exploration interference suppression method based on a reference channel in a survey area, and belongs to the technical field of geophysical exploration. The method comprises the following steps: arranging a reference detector in a survey area to form a reference channel in the survey area, and taking a long-term average value of the reference channel signal during the whole acquisition period as a reference value 1; calculating a proportion factor by calculating the ratio of the instantaneous amplitude of short-period vibration interference appearing in a short time in exploration to the long-term average value, wherein the short-period vibration interference has a large instantaneous amplitude and a wide frequency range; and applying the proportion factor to the full observation segment data of other receiving channels at the same time, and synchronously reducing and raising the signal amplitude according to the proportion, so that the strong interference is accurately suppressed and the non-stationary signal is corrected. The method can effectively suppress the short-time strong vibration interference which is difficult to remove by a traditional method, significantly reduce the interference amplitude, and does not damage the effective resonance signal, thereby greatly improving the signal-to-noise ratio and reliability of seismic frequency resonance exploration data, and being suitable for high-precision seismic resonance exploration data processing in a complex interference environment.

Description

Technical Field

[0001] This invention relates to the field of geophysical exploration technology, specifically to data processing and interference suppression methods in seismic frequency resonance exploration. Background Technology

[0002] During seismic frequency resonance exploration, the excitation signal from nature needs to be a stable plane seismic wave field during the exploration period. However, during the exploration period, the wave field often has amplitude fluctuations and a large amount of exploration interference information, especially interference from high-energy vibration sources with short periods and short durations.

[0003] These non-stationary fluctuations and disturbances are characterized by large amplitude, wide frequency range, long duration, and inconsistent duration. Throughout the entire exploration and observation period, the amplitude of these sudden interference signals is much higher or lower than that of normal signals, and conventional filtering and denoising methods are difficult to remove them effectively. This seriously affects the imaging accuracy of seismic resonance signals and causes uncertainty in exploration results.

[0004] To solve this problem, there is an urgent need for a physical solution that can specifically suppress short-term interference and stabilize the natural excitation source field signal without damaging the effective resonance information. Summary of the Invention

[0005] This invention proposes a method for suppressing and stabilizing seismic frequency resonance exploration interference based on reference signal traces within the survey area. By deploying reference detectors within the survey area and using the long-term average value of the reference trace signal as a benchmark, sudden short-term interference signals and unstable signals are identified and proportionally suppressed, thereby effectively removing interference signals and maintaining the stability of natural excitation source signals during the exploration period.

[0006] The core idea of ​​this invention is as follows:

[0007] First, it is assumed that the signals received by the reference channel during the entire exploration period consist of two parts: one is a deep seismic wave signal carrying geological information, and the other is a short-duration interference signal. The former signal is assumed to be a plane wave with a basically consistent amplitude; any inconsistency over a certain period is defined as non-stationary information. The latter is merely a random event during the entire exploration period. Therefore, at least one reference geophone is deployed within the exploration area to form a reference channel for the exploration data within the area; the reference channel and the measurement channel simultaneously measure the aforementioned information.

[0008] We set the average value of the recorded signal from the entire reference channel during the measurement period as the baseline value. For short-period interference signals that occur during the measurement, since their instantaneous amplitude is much larger than the baseline value, a scaling factor is obtained by calculating the multiple relationship between the instantaneous amplitude and the long-term average value. In data processing, the amplitude of signals recorded by other geophones at the same time is synchronously reduced across the entire frequency band according to this scaling factor, thereby accurately suppressing the amplitude of short-term strong interference. For non-stationary deep geological information, the above steps also yielded an amplitude at the same level as the baseline value, thus maintaining the consistency of the amplitude level of the excitation source wavefield.

[0009] This invention can cleanly remove short-term, wideband, and high-amplitude interference that is difficult to suppress by traditional methods without damaging the effective signal, and maintain the condition of consistent plane wave field amplitude under the passive source frequency resonance exploration hypothesis, thereby significantly improving the signal-to-noise ratio and reliability of seismic frequency resonance exploration data. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0011] Figure 1 Overall flowchart of the method of this invention;

[0012] Figure 2 A schematic diagram of the layout of reference channels and exploration receiving channels within the survey area in this invention;

[0013] Figure 3 A schematic diagram comparing the instantaneous amplitude of the long-term reference signal with that of short-term strong interference;

[0014] Figure 4 A schematic diagram comparing data before and after interference suppression using the method of this invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0016] Reference Figures 1 to 4 The present invention will now be described in further detail with reference to specific implementation steps.

[0017] (1) Reference road layout

[0018] At least one reference geophone is deployed in the seismic frequency resonance exploration area to form a reference channel within the exploration area.

[0019] The reference channel and the exploration receiving channel use the same acquisition system to ensure time synchronization, consistent sampling rate, and unified observation system.

[0020] (2) Calculate the long-term average value of the reference channel.

[0021] Throughout the entire data acquisition period, all signals recorded by the reference channel were statistically analyzed to obtain their long-term average amplitude, which was then defined as the baseline value 1, representing the normal background vibration level of the survey area.

[0022] (3) Calculate the scaling factor

[0023] At the measurement time, the ratio of the instantaneous amplitude to the long-term average value of the reference channel during each acquisition interval is calculated to obtain the scaling factor, which represents the amplification factor of the current interference relative to the background signal.

[0024] (4) Synchronous suppression of all receiving channels

[0025] Applying this scaling factor to the data from all exploration receivers at the same time will proportionally and synchronously reduce and increase the signal amplitude across the entire observation segment, thereby suppressing short-term strong interference and non-stationary signals to near-normal background levels.

[0026] (5) Implementation results

[0027] Since the effective seismic resonance signal does not deviate from the reference value, it will not be excessively suppressed;

[0028] It targets and attenuates or enhances only sudden strong interference and non-stationary signals, significantly suppressing interference amplitude while protecting effective signals, thereby improving data quality and interpretation accuracy.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for suppressing seismic frequency resonance exploration interference based on reference traces within the survey area, characterized in that, Includes the following steps: Step 1: Deploy reference geophones within the seismic frequency resonance exploration area to form a reference channel within the exploration area; Step 2: During the entire data acquisition period, calculate the long-term average value of the signal recorded by the reference channel and use this average value as the baseline value 1; Step 3: Divide the measurement time into segments according to the interval of the detector observation events. Step 4: Calculate the ratio of the amplitude of the observed value to the long-term average value at each time step to obtain the scaling factor; Step 5: Apply the scaling factor to the signals recorded by other exploration geophones at the same time, and synchronously increase or decrease the amplitude of each signal segment proportionally to achieve amplitude suppression of short-term strong interference and correction of non-stationary signals.

2. The seismic frequency resonance exploration interference suppression method according to claim 1, characterized in that, The short-period vibration interference is a vibration source interference with large amplitude, wide frequency range, and only occurring for a short time, with a large instantaneous amplitude.

3. The seismic frequency resonance exploration interference suppression method according to claim 1, characterized in that, Based on the long-term statistical average of the reference channel, amplitude suppression and correction of non-stationary information are only performed on the moment when the instantaneous anomaly exceeds the reference, without changing the normal amplitude of the effective signal.

4. The seismic frequency resonance exploration interference suppression method according to claim 1, characterized in that, The scaling factor is determined by the ratio of the instantaneous amplitude of the reference channel to its long-term average value, and is applied synchronously to the full-band data of all receiving channels at the same time.

5. A seismic frequency resonance exploration data processing device, characterized in that, include: The system includes a reference channel acquisition unit, an average value statistics unit, a transient interference identification unit, a scaling factor calculation unit, and an interference suppression unit. The seismic frequency resonance exploration data processing device is used to execute the seismic frequency resonance exploration interference suppression method according to any one of claims 1 to 4.

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