Abstract：In thin-layer development zone, either the common stack velocity analysis or residual velocity evaluation in prestack time migration processing should consider the influence of thin-layer interference response on velocity. By analysis of thin-layer interference phenomenon, the paper points out that the offsets appearing the thin-layer interference change with buried depths,average velocity of formation, thickness of thin layer and dominant frequencies of seismic waves. The thinner the thickness of formation, the smaller the offsets appearing the interference; the reflections from top and bottom interfaces of thin layer can not be identified when the thickness of formation is less than 1/4 wavelength; the higher the dominant frequency of seismic waves,the larger the offsets appearing interference;the deeper the buried depth of formation and higher the velocity, the larger the offsets appearing interference when the thickness of formation is certain and without change of frequency of seismic waves. Therefore, during the seismic data processing in practical thin reservoir development zones,we should avoid the influence resulted from interference at larger offsets when choosing mute parameters and offset range, ensuring the correctness of velocity pickup.
