BLOWOUT PREVENTER Russian patent published in 1998 - IPC

FIELD: oil and gas producing industry; applicable in sealing wellheads. SUBSTANCE: preventer has body accommodating slips with seals and drive. Slips are cylindrical in cross-section confined by upper and lower semicircumferences eccentrically located relative to each other. Supporting part of each slip has key with slope engageable with slip key. Distance between centers of upper and lower semicircumferences is determined by relation S = (D + 2L) ctn $$$/2, where d is diameter of sealed pipes; mm; L is wall thickness of preventer body, mm; $$$ is angle formed by lines running through center of one of slip semicircumference up to point of conjugation of these semicircumferences, deg. EFFECT: higher reliability of tightness of sealed pipes. 6 dwg