CONTROLLED WELLHEAD ASSEMBLY Russian patent published in 2009 - IPC E21B33/04 

FIELD: oil and gas industry.

SUBSTANCE: used for pulling force control of housing pipe within wellhead casing pipe necking. Controlled wellhead assembly contains cylindrical flange body with pipe junctions mounted in radial holes. The body accommodates assembled adapter-sub and centraliser adjoining internal taper surface of the body, bearing, threaded joint sleeve, flexible upper cup and nut. Besides the body contains cover with flat upper surface and circular groove thereupon. The cover is tied locking pin with screw box inserted to pitch centre holes of the body flange and cover. In circular grooves in adjoining surfaces of the body and cover, ring metal seal is provided. Chamber between joint sleeve and internal taper surface of the cover contains lower cup. Chamber between adapter-sub and internal taper surface of the joint sleeve contains upper cup.

EFFECT: design simplification, higher accuracy of pipe pulling force control, simplification of control process, lower work content and universality.

1 dwg