Bulk Viscosity Measurements in Creep Experiments

It is known that creep deformation of rocks significantly affects fluid flow processes in the Earth. The bulk and shear viscosities are important parameters observed during the creep. However, determination of these parameters is a time consuming and laborious process and thus is rarely reported. To calculate viscosities, multistage creep experiments under the triaxial compression conditions were conducted. Before the testing several synthetic samples were subjected to freezing cycles. And, it was observed that permeability of samples increased with each cycle while porosity and mechanical properties did not show significant changes. It was also being noticed considerable volumetric and shear creep deformation in the course of the experiments. Bulk and shear viscosities were calculated from the stress relaxation curves. The values of viscosities are in agreement with previously published results.