DEVICE FOR WELLHEAD FRAMING Russian patent published in 2004 - IPC

FIELD: equipment for sealing or packing oil-producing exploitable boreholes or wells.

SUBSTANCE: device has body with inner longitudinal through channel of different diameters and with through radial channel. Packing members and gripping members are arranged in the body. Body includes upper and lower bushings connected one with another by coupling nut. Upper end of lower bushing has outer thread and upper bushing includes upper bead for coupling nut connection. Upper end of upper bushing has outer thread for cap installation. Annular groove with upper ledge is formed inside upper bushing. Upper packing member with spacing rings is arranged in the groove. Cylindrical channel with diameter mating to outer diameter of well surface casing and with ledge for upper surface casing end supporting is formed from lower end of upper bushing inside thereof. Lower end of upper bushing may be inserted in annular groove in which lower packing member is located. Inner longitudinal through channel of lower busing mate to outer diameter of well surface casing. Through radial channel is formed in upper bushing under inner upper ledge of annular groove. Gripping members are made in lower part of lower bushing in the form of at least three cylindrical channels extending obliquely towards longitudinal bushing axis and arranged along perimeter thereof. Lower opened ends of three cylindrical channels communicate with inner longitudinal channel of lower bushing. Balls spring-loaded from its tops are inserted in the cylindrical channels. Lower opened ends of channels with balls are closed by ring fixed to lower end of lower bushing. Device is pre-assembled without compressing upper and lower packing members. Device is introduced into flow tubing through upper end thereof and is put on surface casing. After that device is fit by inner ledge thereof on upper surface casing end. Gripping members provide device fixed connect ion to surface casing by coupling nut tightening and cap threading against stop which results in sealing drill string-casing gap of wellhead.

EFFECT: increased safety of performing works at wellheads and sealing thereof due to welding operations elimination, reduced labor intensity.

3 cl, 1 dwg