WELLHEAD SPLIT SEALER Russian patent published in 2014 - IPC E21B33/03 

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to wellhead equipment. Said sealer comprises split cylindrical case composed of two half-cases jointed together and sealed by deformed copper-bearing shims. The plane of butts of half-cases is perpendicular to direction of eccentricity of conductor string and mid string. Half-face-plate with circular groove is welded to bottom end of every half-case to receive split seal ring made of soft metal. Circular groove is turned with allowance for maximum wall thickness of conductor string and maximum eccentricity of said string and mid string. Semi-flange is welded to outer side surface of every half-case. Tie plates with angle pieces are welded between semi-flanges and half-face-plates while tie plates with strips are welded under half-face-plates. All tie plates have bores for studs with nuts while pipe is welded in one of half-cases. Semi-ring with tapered top end surface is welded to inner side surface of every half-case. Self-sealing taper rings made of resilient material and split over their height are arranged above semi-rings. Split bottom box with its halves clamped by latches is arranged above said self-sealing taper rings. Bottom box lower end surface is tapered with angle in its end surface inclination φ to sealer vertical axis defined from inequality. End top surfaces of semi-rings and self-sealing taper rings feature taper corresponding to that of split bottom box lower end surface. Top part of bottom box and semi-flanges have through bores to receive studs with nuts. Split thrust bush with threaded bores at bottom end surface is arranged above bottom box. Split thrust bush is coupled with locking inserts to make an integral part. Slips rest in inner side surface of split thrust bush.

EFFECT: reliable isolation of space between conductor string and mid string, accelerated re-equipment of acting wells.

3 dwg