Noise attenuation in seismic reflection data combining empirical mode decomposition and SVD filtering

Abstract

Noises are common events in seismic reflection that have very striking features in the seismograms, hindering the data processing and interpretation. The attenuation of seismic noise is a challenge, in general frequency filters are employed, but they often do not show good results. The characteristic of noise depends mainly on the type of data we are working. In land data, the most common is the ground roll, that has low frequencies and high amplitudes whereas in marine data (on a shallow water acquisition), head waves and harmonic modes are linear and dispersive events that mask part of the interest reflections, influencing the delimitation of lithological layers. In this study, we used the methods of Empirical Mode Decomposition (EMD) and Singular Value Decomposition (SVD) in order to mitigate some types of noise in seismic reflection and create alternatives to interpretation based on different frequency content present in seismic section. This new approach consists in relating the operation mode of each method with the main features of the noise, resulting in a technique that can identify and mitigate the unwanted event from the seismograms, trying always to preserve or enhance the interest signal. To test the effectivity of this new approach, were used land seismic data from the Tacutu Basin and marine from the Grane oilfield area, Norway.