Analysis and modeling of the hydrogeodynamic situation within the Stebnyk deposit of potassium salts

The purpose of the research was to determine the danger degree of saline waters breakthrough in the mine No. 1 due to the self-flooding of mine No. 2 by constructing digital models of the basic geological and hydrogeological elements, matching them with the stressed state of rocks within zones of the “Western” and “West” pit shafts and the seal of mines № 1 and № 2. Geophysical studies were carried out by the method of the natural pulsed electromagnetic field of the Earth (ENPEMF), which makes it possible to promptly assess the stress-strain state of rocks. In addition, the geological and hydrogeological situation of the study area was simulated to solve this problem. According to the results of the analysis of hydrogeological regime observations in the period from 2004 to 2017, long-term trends of changes in the groundwater level of the aquifer were established. Taking into account the filling of mines № 2 and drainage, the movement of groundwater from the research area towards the north – northwest is currently noted. There is a difference in groundwater levels up to 13 meters. Based on the results of interpretation of geophysical research data on the basis of which ENPEMF intensity maps were constructed, as well as taking into account geological and hydrogeological models, it was found that no significant anomalies of the field intensity corresponding to catastrophic stressstrain state were observed at present (including through additional hydraulic pressure to testify about the danger of a breakthrough reservoir water). Obviously, that obtained results do not raise any doubts about the further operation of mine № 1 at present. However, when the mine № 2 be completely flooded, it is advisable to check the regime hydrogeological observations of groundwater levels and the ENPEMF measurements to investigate possible changes in the stress-strain state of the rock mass.