In order to study the mechanism of destruction of rocks of various genesis and the formation of fractured reservoirs at great depths, laboratory studies of rock samples in the loading conditions of comprehensive pressure with registration of acoustic emission (AE) and parameters of the process of changing the strength and deformation properties of samples were carried out. The spatial distributions of the hypocenters of AE events for each sample were investigated. By the nature of the distributions, the fracture geometry is described, then visually compared with the position of the formed macrofractures in the samples as a result of the tests. The time trends of the amplitude distribution b, set by the Guttenberg – Richter law, were calculated, which were compared with the loading curves and trends of the calculated AE activity. Based on the analysis of the AE process for three types of rocks – igneous (urtites), metamorphic (apatite-nepheline ores), and sedimentary (limestones) – parameterization of acoustic emission was carried out to determine the features of the deformation process and related dilatancy. As a result, three types of destruction of samples were identified, their geometry and changes in strength and seismic criteria were established.
The Article contains the results of researches of dynamics in changes of physical and mechanical properties of enclosing sedimentary rocks and hard coals of the Kuzbass and Vorkutsk deposits. The general condition of change in permeability factor on gas was obtained, depending on forms and types of moisture bonds in rocks and intensity of stress state. In the research tasks necessary for solving the problem of methane extraction, the methodological aspects are a matter of interest to study the processes of sorption-desorption in natural gassaturated coals. Study of the sorption characteristics of coal has shown that its sorption capacity depends on the stage of metamorphism within the whole studied range of saturation pressures.
The Article considers the rheological tests of rock samples being carried out with using the direct (classical) and quick-acting (stepwise) techniques. In the stepwise test of one sample a family of creeping curves was obtained. The comparable tests have shown a satisfactory similarity of test results obtained in various testing techniques.
Complex investigations have been conducted of rheological properties of undisturbed and disturbed rocks under laboratory conditions in the modes of creeping, relaxation and lateral pressure. It was stated that the rheological properties of disturbed rocks substantially differ from those properties of undisturbed rocks. Recommendations are given for the use of the obtained results in solution of tasks in mining geomechanics.
