A ghost reflection suppression method and device for undulating sea surface

Abstract

The invention provides an undulatory sea surface ghost reflection suppression method and device. The undulatory sea surface ghost reflection suppression method comprises that based on an undulatory sea surface reflection coefficient calculation formula, the angular frequency, the wave number, the ocean wave height and the seawater speed which correspond to the obtained seismic data in a frequency-wavenumber domain are calculated to obtain a reflection coefficient; a white noise coefficient is obtained by calculating the angular frequency corresponding to the seismic data in the frequency-wavenumber domain; a ghost reflection suppression operator, of the frequency-wavenumber domain, corresponding to preset towing cable scanning depth is obtained by calculating the reflection coefficient and the white noise coefficient; frequency-wavenumber domain suppression data is obtained by means of the suppression operator; then the frequency-wavenumber domain suppression data is converted into time-space domain suppression data; the time-space domain suppression data is divided by a preset time window interval; the sum of absolute values of frequency domain data corresponding to the towing cable scanning depth in the same time window is worked out; and the time-space domain suppression data corresponding to the minimum sum of the absolute values serves as seismic data of the corresponding time window after ghost reflection suppression. According to the invention, undulatory sea surface ghost reflection can be effectively suppressed.

Description

technical field [0001] The invention relates to the technical field of seismic data processing, in particular to a ghost reflection suppression method and device for undulating sea surfaces. Background technique [0002] When the streamer seismic exploration is carried out at sea, the source and the geophone are placed at a certain depth below the sea surface. Due to the large difference in wave impedance between sea water and air, the contact surface between the two is a good reflection surface, and the primary wave reaching the interface It will be reflected back to the ground again, so in addition to receiving the usual primary reflection wave, the receiver will also receive the accompanying wave related to the reflection of the sea level. This accompanying wave is called ghost reflection (ghost wave). Since the polarity of the ghost reflection is opposite to that of the primary wave, and the time difference between the two is very small, the ghost reflection is superimpo...

AI Technical Summary

Problems solved by technology

However, in these methods, there is an assumption: the sea surface is horizontal, the sea surface reflection coefficient is constant, and the streamer is horizontal and the depth is fixed.

However, due to the movement of seawater in actual production, the sea surface is fluctuating, and the depth of the towline is also changing, which causes the theory to be inconsistent with the reality, so that the existing methods cannot completely eliminate the ghost reflection in the actual data, and cannot effectively improve the seismic performance. Data Resolution

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