Nonstationary adaptive S-wave leakage suppression of ocean-bottom node data

Abstract

Ocean-bottom node (OBN) is widely used because of its wide azimuth, long offset, and low frequency advantages. However, in the vertical component of the OBN geophone, a significant amount of shear waves induced noise may be recorded. This significantly impacts the quality of the vertical component data and may affect the follow-up merging of dual-sensor data. Some commercially available methods apply normal-movement correction, which necessitates velocity data. We avoid this by adaptive matching method, which relies solely on seismic data. Therefore, we developed a novel adaptive subtraction method for S-wave leakage suppression using the horizontal component as the noise model. Our method effectively handles the non-stationarity of the input seismic data in all time and space directions, mitigating instability caused by manual selection of the smoothing radius. A method is introduced for estimating a global non-stationary smoothing radius using the noise model. Compared to the commercial and stationary smoothing methods, our method can better suppress shear wave noise while balancing residual noise and signal leakage more effectively. Both synthetic and field data examples demonstrate significant improvement of the proposed method.