The Application on Q Value Inversion with the Direct Wave of VSP in ShengLi Oilfield

Abstract

The earth filtering is inevitably in seismic wave propagation and the parameters to represent earth filter intensity is the absorption coefficient and the Q value. Using zero-offset vsp's down-going direct wave to estimated Q value is considered the most reliable way to extract stratigraphic quality factor Q value. We used Ken 71 well zero-offset VSP down-going direct wave with the centroid frequency shift method to estimate layer Q value. First, by processing the zero-offset VSP data, we separated down-going-direct wave and up-going wave. Then, we analysis and calculated the layer-velocity and layer Q value using down-going wave. At last, we made the bridge comparison chart by the up-going-wave processed. The bridge comparison chart compared with the layer-velocity and layer-Q value, results show that the corresponding relations are very good.