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effective porosity estimation method
Select the porosity estimation method. For example, you can select Combination Neutron Sonic to determine porosity using Neutron and Sonic Logs.
use porosity log 
use sonic log use density log
Select the log on which to base the porosity calculation.
matrix DT fluid DT
Complete if from sonic using matrix DT selected.
matrix density fluid density
Complete if from density using matrix density selected.
Combination Neutron-Density Combination
Neutron-Sonic
From the logs available in your cross section, select
neutron and either sonic or density logs to use when estimating effective
porosity.