ИСТИНА

The East Siberian gas-condensate fields in Russia have some specific conditions for gas production. The low gas-bearing horizon temperatures, high mineralization of formation water, the salt deposits in porous space in gas-bearing horizon and low water dew point of natural gas complicate the technology of natural gas recovery. All these factors cause the technological problems as the secondary hydrate formation in bottom-hole area and hydrate and salt plugging in wellbore and gathering pipelines. The investigation of hydrate formation kinetics is necessary in wide range of pressure and temperature to optimize thermodynamic conditions in wellbore and gas gathering pipelines. The study of methane hydrate formation in highly mineralized solutions proves the methods of hydrate plugging prevention. The kinetics of methane hydrate formation in highly mineralized solutions was studied. The experimental hydrate cell was constructed based on gas-liquid reactor with “pressure- temperature” automatic control system. The control system was able to measure the methane quantity to maintain the gas pressure in the process of gas hydrate formation. The procedures to study the kinetics of hydrate formation in mineralized water were developed in pressure range 2.5 – 15.0 MPa. The hydrate formation in aqueous solutions of Na chlorides was studied. The kinetic model for hydrate formation in mineralized water was presented. The dependency of kinetic constants on the process driving force was discussed. It was experimentally shown the formation rate of the methane hydrate in mineralized water was lower at the same driving force in comparison with pure water. This was explained by the diffusion mechanism of hydrate formation.