Application of minimum variance filters in power-line noise attenuation

Noise is a factor that influences the reliability of the seismic data to provide a better understanding of the hydrocarbon reservoir characteristics. Coherent and random (incoherent) noises are two important types of noise that contaminate the seismic reflection data. Power-line noise falls in the coherent type of noise (Yilmaz, 2001; Sheriff and Geldart, 1995). It is a class of noise often existing in land acquisition in populated areas. It produces a characteristic 50 or 60 Hz sinusoidal noise on seismic reflection traces and covers the seismic data from reflectors. Its amplitude is time invariant, whereas the seismic data amplitude decays with time (Xia and Miller, 2000; Dingus, 2010). Coherent noise attenuation, particularly power-line attenuation, is one of the problems in seismic reflection data processing. Several methods have been introduced for elimination of power-line noise from seismic reflection data. Xia and Miller (1998 and 2000) predicted the amplitude and phase of a harmonic using the Levenberg-Marquart method and subtracted the harmonic constructed by the predicted amplitude and phase from the seismic trace to attenuate the power-line noise.