Abstract:Because three dimensional seismic exploration is restricted by operation way and surface condition, three dimensional seismic data stack actually becomes the stack of seismic data which project at a common mid point (or in a bin) in different apparent dips. Thus, the velocity derived from conventional velocity analysis will damage stack accuracy of three dimensional seismic data. Hence, we put forward three parameter velocity analysis and its spectrum interpretation. For usual medium, three parameter velocity analysis evaluates both the bin center stack velocity v without dip influence and the apparent interface dips at two perpendicular directions. This technique makes two perpendicular angular spectra which are then used to obtain stack velocity spectrum without dip influence. We details the principle of three parameter velocity analysis, the making and interpretation of angular and velocity spectra. It is illustrated that the technique selves the direction. problem of bin stack velocity, favors both improving seismic resolution and establishing migration velocity field, and optimizes seismic data processing sequence.