SEALING DEVICE OF TUBING-CASING ANNULUS ON WELL HEAD Russian patent published in 2013 - IPC E21B33/03 

FIELD: mining.

SUBSTANCE: device includes a housing with a flange, an internal annular bore in upper part, and axial and radial central channels for side branch pipes. In lower part of the housing there is a loaded connection thread for interaction with a casing coupling. A supporting ring is arranged in the casing coupling so that it is supported from a casing string. A centraliser made in the form of a sleeve with stepped outer surface and cylindrical inner surface, as well as with through axial channels is arranged on the supporting ring coaxially with it. A sealing assembly is arranged in the internal annular bore of the housing so that a cover with a flange mating the housing flange can be pressed with an annular projection. Cleat wedges are installed on shear elements in longitudinal wedge-shaped slots. Slots are made on cylindrical inner surface of the centraliser. Wedges are uniformly located in a circumferential direction with possibility of axial and radial movement relative to the centraliser at interaction with a lower end face of the coupling of the production string.

EFFECT: improving sealing reliability of tubing-casing annulus on a well head owing to improving centring quality of a production string in the device housing.

6 cl, 4 dwg