PROCEDURE FOR MAINTAINING PRESSURE IN BOREHOLE OF WELL (VERSIONS) AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2011 - IPC E21B33/126 

FIELD: gas-and-oil producing industry.

SUBSTANCE: flexible pump-compressor pipe and movable device on it for maintaining pressure in borehole of well are used for this procedure. The procedure consists in lowering the flexible pump-compressor pipe into the borehole of the well to the first depth while the movable device is held back for maintaining pressure on surface, in advancing the pump-compressor pipe through the device for pressure maintaining, in securing the movable device for pressure maintaining in a position on the pump-compressor pipe, and in lowering the flexible pump-compressor pipe into the borehole of the well to the second depth. The device consists of a bushing for installation on the flexible pump-compressor pipe and of a released arresting unit to lock the said device on the flexible pump-compressor pipe. Also, the flexible pump-compressor pipe can be passed through the device when the arresting unit is not in a locking position.

EFFECT: improved extraction of oil or gas.

40 cl, 16 dwg