ИСТИНА

Effective viscosity is an important parameter for describing hydrodynamic and geomechanical processes in the earth's crust. Due to the fact that the procedure for measuring this parameter is long and time-consuming, it is rarely measured in laboratories. Current measurements were performed in the compaction mode and did not take into account decompression. However, decompression can affect the distribution of fluid flow in a porous medium and create highly porous channels such as chimneys seen in underwater tanks and tires. To calculate the effective viscosity, we performed a series of different multi-stage experiments in both modes. 20 samples were examined, 6 of them artificial, 12 limestone and 2 samples from the Barents sea (shale). The diameter of the samples was 30 mm, and the height of 60 mm, except for one (slate), subjected to multistage tests with acoustic measurement, its diameter and height were 50 and 100 mm, respectively.