METHOD FOR PRODUCTION OF NATURAL GAS FROM GAS-HYDRATE POOLS AND DEVICE FOR ITS REALISATION Russian patent published in 2013 - IPC E21B43/24 

FIELD: oil and gas industry.

SUBSTANCE: method includes decomposition of gas hydrates in a massif of their occurrence by heating to temperature exceeding temperature of their natural decomposition by means of water injection along a pipe string via a well into a gas-hydrate pool and discharge of produced gas to the surface along the specified well. According to the invention, the gas-hydrate pool is developed in blocks. In the centre of each block a development well is drilled down to the pool foot and fixed. The section of the casing string in the pool interval is perforated. A heat insulated suspended string is lowered into the casing string down to the pool foot, along which water is injected, which is heated to temperature exceeding at the outlet of the suspended string the natural temperature of gas hydrate decomposition. Discharge of released gas is carried out in the annular space of the casing and suspended strings in the form of a gas and water mixture and in the gas lift mode. The block of the gas-hydrate pool is developed to detect a gas leak to the day surface bypassing the casing string and termination of gas lift effect, which certify formation of a contour of the hydrate decomposition area to the roof of the gas-hydrate pool. Then they start developing another block. At the same time intensity of gas hydrate decomposition and volume of produced gas are controlled by changing temperature and flow of water injected along the string, and also by depression and reduction of its initial value in the mined pool, achieved by establishment of casing and suspended strings in the annular space for the gas-water mixture of the gas lift mode supplied to the surface.

EFFECT: increased efficiency of production with the possibility to use conventional facilities.

7 cl, 1 dwg