UNIVERSAL CASING HEAD FOR CONNECTIONS OF CASING STRINGS ON WELLHEAD Russian patent published in 2001 - IPC

FIELD: mining, particularly, oil producing industry; applicable in major repairs and drilling of new oil-gas wells. SUBSTANCE: universal casing head has external and internal casing heads for connection with casing strings, sealing members in annular space, channels for fluid circulation made in wall of external casing head. Internal casing head has fine-pitch teeth crossed by transverse grooves for engagement with mating fine-pitch teeth on end face of string locking insert. End face member is installed for reciprocation in circular groove made in wall external casing head and crossing channels of fluid circulation. Insert for casing string locking has spherical surface on adjusting screw which is tightly connected through threaded members and cylindrical hole with a plug. The plug is installed in radial threaded hole made in wall of external casing head and combined with circular groove. EFFECT: excluded unscrewing of casing pipes and provided control over sealing in gap between internal and external casing heads. 3 cl, 4 dwg