Average versus interval Vp/Vs
Robert R. Stewart, Henry C. Bland, Qi Zhang, Felix Guthoff
The average Vp/Vs value of a set of layers is a weighted sum of the interval Vp/Vs values. The weighting is the fractional transit time in the interval relative to the total travel time across the set of layers. The average value is also bounded by themaximum and minimum interval values. The thicker a specific layer is or the more anomalous its Vp/Vs value, the greater is its influence on the average value. Two modeling results (for a porous dolomite case and a sand channel) indicate that average Vp/Vs analysis should be able to discern anomalous reservoir values.