GAS WELL COMPLETION METHOD Russian patent published in 2013 - IPC E21B43/10 E21B33/14 

FIELD: oil and gas industry.

SUBSTANCE: gas well completion method involves drilling of a well shaft with formation of an annular chamber in a non-permeable roof of productive formation. Casing string is equipped with a device with through preliminarily closed holes, which are interconnected with the space inside the string. Installation of the casing string is performed in the well so that through holes are located opposite the annular chamber. Before cement setting, such excess pressure is created in the casing string, under the action of which process liquid contained in the space inside the string opens the holes of the device and enters the annular chamber. A packer is installed above perforation interval below the annular chamber, and process liquid is replaced with the liquid having the density providing excess hydrostatic pressure of its column above formation pressure, thus forming a hydraulic seal preventing gas migration via casing string annulus.

EFFECT: increasing the gas well efficient and safe operation.

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