VELOCITY -THOUSANDS OF FT/SEC. 



10 15 20 



1 I I I I I I I I I I 



INTERVAL TRAVEL TIME (ms) 



.7 0.6 0.5 0.4 



I 1 1 



1 



POROSITY % 



40 30 20 10 

 I 1 1 1 1 



Figure 21-8. Correlation of velocity log and limestone porosity. 



The Viola has been the objective seismic horizon in central Oklahoma for 

 years. The number of seismic maps labeled "Viola" which have been prepared 

 from Hunton data probably is considerable. The continuous velocity log can end 

 much of the controversy over the correct identification of reflections obtained 

 from this zone. 



Velocity Log Compared With Limestone Porosity 



The results of an experimental investigation by Magnolia Petroleum Com- 

 pany to correlate interval velocity with limestone porosity is demonstrated in 

 Figure 21-8. The envelope of the porosity log shows marked similarity to the 

 interval velocity curve, increased porosity with decrease in velocity. Cores were 

 taken in this experiment and porosity values were obtained in the laboratory, as 



416 



