Multiscale Noise Attenuation of Multicomponent (4C) Towed-Streamer Data

Kemal Özdemir, Ahmet (WesternGeco) | Kjellesvig, Bent (WesternGeco) | Özbek, Ali (Schlumberger) | Martin, James (Schlumberger)


The particle velocity vector enables us to calculate the 3D upgoing wavefield at any desired position within the aperture of the seismic spread and this allows improving not only the temporal bandwidth by removing ghost notches, but also the spatial bandwidth. However, particle motion sensors measure streamer-borne noise with amplitudes typically several orders of magnitude stronger than the corresponding noise recorded by hydrophones at frequencies below about 20-Hz. Therefore, stronger noise attenuation for particle velocity data is needed at these frequencies. In this paper, we introduce a multiscale noise attenuation algorithm that provides a high-fidelity particle motion measurement at frequencies down to 3 Hz. We also show that the new technique provides improved noise attenuation on pressure data. In this paper, we present the characteristics of the noise recorded by the particle motion sensors in the multicomponent (4C) towed streamer and introduce the multiscale noise attenuation (MSNA) algorithm that is used to attenuate noise on both pressure and particle motion data. We show that the MSNA algorithm provides increased noise attenuation on hydrophone data compared to conventional methods and a high-fidelity particle motion measurement at frequencies down to 3-Hz. Introduction Robertsson et al. (2008) introduced the concept of a multicomponent (4C) towed streamer that acquires both pressure and the full particle velocity vector with inline, crossline, and vertical components.