WELL PRESSURE COMPENSATION FOR BLOWOUT PREVENTERS

摘要

WELL PRESSURE COMPENSATION FORBLOWOUT PREVENTERSAbstractA method and apparatus of compensating for the closing forceon a blowout preventer caused by well pressure for reducing the wearon the blowout preventer sealing element when moving a drill stringthrough a closed blowout preventer. A hydraulic opening force isapplied to the blowout preventer which is actuated by and is propor-tional to the well pressure. A compensating line is connected betweenthe blowout preventer fluid supply line and the blowout preventeropening line. A control valve is provided in the compensating linesfor applying an opening force on the blowout preventer and a pilotcontrol pressure regulator is provided in the compensating line forlimiting the compensating pressure. The pilot control line is con-nected between the regulator and the well pressure in the blowoutpreventer whereby the output pressure is proportional to the wellpressure for compensating for the closing force on the blowout pre-venter caused by the well pressure.