PZ Summation of 3D WAZ OBS Receiver Gathers

PZ summation is a typical processing flow for 2-Component Ocean Bottom Seismic (OBS) data, which takes advantage of the simultaneous recording of the pressure and vertical velocity wavefields to separate the up-going and down-going wavefields and to attenuate the water bottom receiver-side peg-legs. However, practical implementations are often either monochannel/1D or designed for 2D receiver gathers, while modern acquisition geometries often lead to 3D, wide-azimuth (WAZ), densely sampled receiver gathers. Such 3D gathers can be processed in the tau-px-py domain with a monochannel algorithm. In this paper we extend the method to directly process 3D gathers, without the need for tau-px-py transforms. Some current implementations also attenuate the source-side multiples, but they rely on a first order approximation for the amplitudes and on the 1D geology (horizontally layered medium) assumption. By introducing a simultaneous 3D predictive deconvolution operator in the peg-leg attenuation formulation, we remove the first order approximation and we improve the attenuation in the case of deviations from the 1D assumption.