This paper presents the attempts to calculate the pseudo-anisotropy of elastic parameters for the Silurian and Ordovician shale formations of several wells located in the Baltic basin. For this purpose, well-logging data were used, in particular data recorded with acoustic dipole tools. With the P and S waves velocities available, measured at the dipole setting in two orthogonal directions XX or YY (S$_{Fast}$ and S$_{Slow}$), the elastic $\varepsilon$ and $\gamma$ parameters were calculated. In this paper we evaluate the effect of different factors e.g., porosity, clay and kerogen content on the velocity of anisotropy shale gas formations. A geostatistical analysis of elastic and reservoir properties was carried out in order to determine the character of the variability of Silurian and Ordovician shale formations in all of the studied wells. Semivariograms for each well characterizing the variation of elastic parameters in the vertical direction were calculated.
The principles of 3D modelling of deposit parameters by means of geostatistical procedure of 3D ordinary kriging were outlined. The use of the procedure was illustrated by example of Cu content assessment in exploitation blocks in a one of the deposits Cu-Ag from Fore-Sudetic Monocline. A new classification of accuracy of mean Cu content estimation in exploitation blocks was proposed.
