EXPERIMENTAL INVESTIGATION OF VISCOELASTIC AND STRENGTH PROPERTIES OF LAYERED ROCKS UNDER TRUE TRIAXIAL INDEPENDENT LOADING
The experimental results are presented on the investigation of the influence of the orientation of the principle stress axes with respect to layering orientation on viscoelastic deformation and strength of specimens of layered rocks (sandstones) from oil deposit collectors under true triaxial independent loading. The experiments were carried using the Triaxial Independent Loading Test System (TILTS) IPMech RAS on cubic specimens with the edge 40 mm, cut at various angles to the vertical core axis, which is normal to the plane of layering, namely, 0 <sup>о</sup>, 30 <sup>о</sup>, 45 <sup>о</sup>, 60 <sup>о</sup>. The essential dependence of the parameters in question on the angle between the maximal principle stress and the plane of layering was regained. The learned effects have the crucial value for determining the optimal regimes of oil and gas well drilling and exploitation.