Rock mass as a porous medium:: Gas filtration ability in triaxial state of stress

The knowledge of filtration ability (gas permeability) of rocks in the conditions of triaxial state of stress simulating the conditions in massif is of great importance for all works relating to rock massif as an environment in which filtration of liquids or gases takes place. Currently, it is necessary to estimate the gas permeability in order to select a suitable collector as a gas reservoir in the rock massif, gas deposit in low porosity sandstone, for exploiting coal bed methane or for solving and evaluating natural or synthetic insulating barriers. It is possible to use the results of laboratory measurements for classification of possibility of grouting of rock mass, too. The frequent type of the Upper Carboniferous sediments of the Upper Silesian basin is the medium-grained sandstone. Influencing of the texture, structure and diagenesis on the porous medium of sedimentary rocks is described on this paper. Above mentioned analysis was completed by measurement of the important physical properties of rocks as volume weight, total porosity, absorptive water capacity, effective porosity and coefficient of gas permeability.