PREVENTER Russian patent published in 2001 - IPC

FIELD: oil and gas production. SUBSTANCE: invention is related to fixtures used to seal well-heads to prevent blowouts and to be part of complex blowout prevention equipment. In hydraulic drive of preventer there is provided additional cylinder with piston not fixed on rod that augments pressure on rod when preventer is open. This piston is capable of action on piston of working cylinder. Heating chamber is formed by outer wall of working cylinder of hydraulic drive and housing. Cylindrical pin with limiting nut is located in hinge of lid. Collector is made fast to lid that is mounted for limited movement together with it and jointly with hydraulic drive along pin of ear. Combined rubber and polymer seals are provided between ear and pin. Usage of invention provides for rise of operational reliability of preventer thanks to re-distribution of load on radial seals, for tightening of well-head under operational pressure with closure of pipe dies on cylindrical part of pipe and of blind dies when there are no strings, for closure and opening of dies under operational pressure of well, for manual closure of dies of hydraulic preventers in absence of controlling pressure, for replacement of dies without removal of preventer from well- head and without dismantling of hydraulic lines, for centering of embraced pipe with closure of preventer, for heating of seals and dies by heat transfer agent ( steam ) when ambient temperature is below 0 C. EFFECT: raised operational reliability of preventer. 1 cl, 3 dwg