Fig. 10

Vertical bore logs of lithological and mineralogical properties and the corresponding histograms. a Results from LDS gamma-ray log, implying reduced API values in the middle of the reservoir. b Ratio of \(\nu_{\text{s}}\) and \(\nu_{\text{p}}\) wave velocities, used to determine the purity of the reservoir sandstone. Typical values for sandstone are marked in blue