Deghosting of over/under towed-streamer seismic data with wavefield extrapolation

Abstract

In marine seismic acquisition, ghost effect due to the strong reflection of the sea surface causes serious notch trap in the spectrum. Ghost effect can be reduced by over/under towed streamer acquisition. Howerver, most of deghosting technology for over/under streamer acquisition is based on seismic kinematics method, which cannot effectively solve the ghost wave interference and brings incomplete ghost suppression and distortion of the effective signal. In this paper, we propose a new deghosting method for over/under streamer acquisiton based on analytical fk-domain seismic wavefield extrapolation characterized by high computing efficiency. Cases studies of synthetic and real seismic datasets demonstrate that our seismic wavefield extrapolation based on Fourier transform ensures the consistency of the seismic amplitude and phase of over/under streamer seismic data and significantly eliminates the amplitude and phase error of far offset especially for the long streamer condition, which helps to decouple the real wave and the ghost wave and fill notch effect in the spectrum.