COLUMN HEAD Russian patent published in 2009 - IPC E21B33/03 

FIELD: mining.

SUBSTANCE: present invention pertains to mining industry, particularly to wellhead equipment of oil and gas wells. The column head has a cylindrical flanged body frame with an inner conical surface and side holes fitted with connecting pipes, a cover with a central axial channel, double-end bolts with nuts, put into openings uniformly distributed around the flange of the body frame and the cover, and sealing elements. Inside the body frame there is an adapter, with an outer ring-shaped ledge and a step in the middle part, a thread in the top part, for fitting a landing flange and a thread in the in the bottom part for fitting a housing pipe, and a moveable centraliser, part of the outer surface of which is conical for mating with the conical surface of the body frame. The sealing elements are in form of elastic top and bottom cuffs, support and packing rings, and a ring-shaped metal seal. The cover has, in the central axial channel, a ring-shaped ledge in the top part and a conical surface. The bottom part of the elastic cuff is put into the space between the body frame and the adapter. Above the outer ring-shaped ledge of the adapter in the space between the cover and the switcher are serially fitted support ring, top elastic cuff, mated to the conical surface of the cover by its conical surface, and a packing ring. The ring-shaped metal seal is fitted in circular grooves in mated surfaces of the flange of the body frame and the cover.

EFFECT: more reliable sealing of inter-pipe space during drilling, increased safety of operation and repairability.

1 dwg