OIL, OIL-AND-GAS WELL Russian patent published in 2009 - IPC E21B43/00 

FIELD: oil-and-gas production.

SUBSTANCE: invention relates to oil and gas industry, particularly to devices which provide for uninterrupted operation of wells, for example oil or oil-and-gas or oil-and-gas condensate wells, etc., characterised by annular gas show. The well has a production casing with a flow column, a wellhead with wellhead equipment joining them, underground production equipment, including at least a production packer, circulating and shear valves and at least one inhibitor valve. As part of the wellhead equipment, an X-mas tree is mounted on the casing head, the X-mas tree of which includes shut-off, measuring fittings, a regulating throttle valve, well control system elements and a device for safe operation of the well. The latter is a check valve, which comprises a hollow body, hydraulically connected through the formation fluid to the flow column and through gas to annular space of the well, fitted with formation fluid and annular gas supply pipes and outlet pipes for the mixture of formation fluid and annular gas, as well as an internal unit with a cup-shaped body with at least one opening or channel in its side wall for releasing annular gas, situated in the body of the check valve at an angle to the flow vector of the formation fluid and intersects with it, forming an annular cavity with the internal surface of the wall of the body of the check valve, where the annular cavity is linked to the supply and outlet pipes through the formation fluid. The check valve also contains at least one shutting-off device in the cup, with a movable and an immovable part, and dividing its cavity into an inlet part in front of the shutting-off device and a working part behind the shutting-off device in the direction of flow of gas, linked with the formation fluid stream through the said opening or channel in the side wall of the cup, situated in the volume radian sector of the viewing angle of the said wall from the axial point of the cross-section of the outlet opening of the outlet pipe for the mixture of formation fluid and annular gas.

EFFECT: more reliable operation of wellhead equipment due to optimum thermal conditions in a given zone under any unfavourable external conditions in the zone of the wellhead.

19 cl, 2 dwg