Determination of Rheological Properties of Bischofite from Triaxial Tests

Bischofite rock samples from a well at the Vologda underground gas storage are subjected to rheological tests. The time curves of deformation are plotted at different axial and lateral stresses. A viscoelastic phenomenological model is proposed, and the equation to describe these dependences is obtained. Being developed and algorithmically implemented, the experimental data interpretation procedure allows determining rheological characteristics of test rocks at different stress ratios. It is found that rheological properties of bischofite weakly depend on depth.