Flow Zone Index for Improving Permeability and Porosity Relation and Facies Description

A well-defined relation between permeabilty and effective porosity is a way for calculating permeability in all cases where direct lab measurements are impossible. In homogeneous rock formations, correlations between discussed reservoir parameters are always high. In the group of lab data from the Rotliegendes formation from the Polish Lowland, correlations between permeablity and porosity showed not very good R coefficients and a great dispersion. The data originated from 78 wells, over a dozen of them was chosen for analysis. The whole research area was divided into smaller ones. We assumed the smaller data groups would be more homogeneous than the whole data set as regards lithology and facies composition. The relations permeability vs. porosity were determined for them and the results were better than those obtained for the whole data set, but still they were not satisfied. The Flow Zone Indexes were calculated for the units of the same hydraulic parameters and relations permeability vs. porosity were separately calculated for each such unit. The correlation coefficients were good and the prediction equations for permeability were constructed. The obtained formulas can be applied to calculating the continuous permeability log in the borehole profile on the basis of the porosity curve.