Study of Quantitative Evaluation of the Effect of Prestack Noise Attenuation on Angle Gather

With the increasing refinement of exploration activity, the information of different angles has to be used in the extraction of prestack attributes and prestack inversion. For large angle gather, denoising methods should be different from conventional prestack noise attenuation methods used in CSP and CMP gathers. We established specific theoretical model and quantitatively study the effect of prestack noise attenuation on angle gather. Through the research, we draw the following conclusions: 1) The antinoise ability of angle gather stacking is much better than that of CMP stacking. 2) The larger the apparent velocity of coherent noise is, the more seriously the effect of it on angle gather. Otherwise it is opposite. 3) Surface wave has strong energy and low frequency and a small amount of residues will affect the angle gather largely. After suppressing surface wave, there will be energy loss in near angle gather, which should be compensated.