This book is devoted to the most important and urgent problems arising during the operation of underground gas storage facilities (UGS) and associated with the destruction of the reservoir and sand production into the wells. UGS facilities play a special role in ensuring high reliability of stable and guaranteed gas supplies to consumers. However, despite many years of experience in UGS well operation, there is still no sufficiently substantiated geomechanical model of reservoir failure and a mathematical description of the processes occurring in the reservoir-well system, taking into account the peculiarities of the mechanical behavior of reservoir rocks during cyclic injection and extraction of gas. As a result, there are no reliable criteria for establishing a rational regime for the operation of an UGS wells in conditions of a possible destruction of reservoir rocks. Further development of underground gas storage direction requires the introduction of innovative technologies that can be used both in the design of new UGS facilities and to extend the safe and efficient operation of existing underground gas storage facilities. To solve these problems, the most promising technologies, taking into account their efficiency, relatively low cost and environmental safety, are those based on the geomechanical approach. The book is addressed to specialists in the development and operation of underground gas storage facilities, as well as specialists in geomechanics of oil and gas fields. It can be useful for students and graduate students studying in the speciality "Development of oil and gas fields".