Abstract: A method is described for producing gas from fluid-containing formations, including the steps of generating elastic vibrations by a generator and stimulating a fluid-containing formation by the elastic vibrations, extracting gas from a gas trap through a well, the generating step involving the step of increasing frequency of elastic vibrations within a frequency range from 0.1 Hz to 350.0 Hz, followed by the step of reducing the frequency within the same frequency range.

Abstract: A method and apparatus for determining the physical state parameters of a medium under study generates oscillations in a reference medium and establishes the relation between one of the oscillatory process characteristics and a particular one of the parameters. The reference medium is then brought into contact with the medium under study, the oscillations generated again and the value of the particular parameter determined from changes in the oscillatory process characteristics. The oscillations generated are modulated ultrasonic or hypersonic oscillations. The oscillatory process characteristics include resonance frequency or Q-factor, propagation speed or absorption coefficient of the oscillations and relaxation frequency. Liquid, magnetorheological or electrorheological media are used as the reference medium.

Abstract: The invention relates to instruments for precision measurements at different pressures and temperatures of the physical properties of fluids such as isothermal and adiabatic compressibility, density, coefficient of thermal expansion, velocity and absorption of ultrasound; for determining on their base the heat capacities, other thermophysical and thermodynamic properties, functions and potentials. The apparatus comprise a casing (1), made as a pressure vessel with a measuring chamber, a piston (8), a unit (14) for excitation and reception of signals, recording and processing of data, an oscillation transducer (5) installed in the chamber and forming two measuring intercommunicating cells with a constant (6) and a variable (7) path respectively. A piston insert (17) may be installed with a slide fit between the piston and the oscillation transducer. The apparatus ensures a higher accuracy and resolving power of measurements of physical properties of fluids under various pressures, volumes and temperatures.

Abstract: A method for supplying gas to gas consumers, which method resides in forming a storage reservoir above a gas-saturated water-bearing horizon under development, filling the storage reservoir thus-formed with gas by periodically subjecting the horizon under development to extraneous effects, followed by delivering the gas to gas consumers. Extraneous effects can be exerted by generating elastic vibrations, providing a pressure difference, raising the temperature, applying electromagnetic field oscillations, or combining these factors. If the method of the invention is used in seismically active areas or in regions exposed to effects of elastic vibrations, its efficiency is considerably increased.