Samjylov V. Industrial hydrogeological conditions of the exploitation and their influence on the containment of the underground gas storage facilities in Dniepr-Donets artesian pool.

The dissertation is devoted and to the definition and the evaluation of the industrial hydrogeological conditions of the underground gas storage in Dniepr-Donets artesian pool of the gas-holders in order to increase the efficiency of their exploitation, to control the containment and to provide the ecological safety. In order to elucidate the influence of the gas-holders exploitation on the upstream waterbearing stratums, the generalization of the background hydrogeological indices was done. The comparison of the modern hydrogeological conditions with the background indices gave ground for the evaluation of the vertical containment of the artificial deposits. On the basis of direction of the pressure gradients between artificial gas deposit and water-saturated part of the layer-reservoir in the neutral periods, they distinguish three industrial hydrogeological types of the underground gas storage facilities. In the first type the pressure gradients are directed from the artificial gas deposits to the water drive system. In the second type the pressure gradients are constantly directed from the water drive system to the artificial gas deposits. The investigations of the layer-reservoirs water system reaction to the gas pumping and selection showed up that there are active and inactive groups of the pressure observation wells on every underground gas storage facility. The directions of the wells active group location is characterized by the lower-range values of the pressure differences between the gas-pool outline and the water drive system, and are the probable way of the lateral gas escape. On the basis of the complex analysis and comparison of the different methods (gas geochemical, hydrogeological and geophysical) of control of the underground gas storage facilities functioning, the staging is grounded and a scheme of investigation volumes optimizations by each method is suggested.