BLOWOUT PREVENTER Russian patent published in 2002 - IPC

FIELD: oil and gas producing industry; applicable in removal of hydrate-paraffin accumulations, geophysical investigations and other operations on cable for preventing emergency outburst of instruments by oil or gas streams. SUBSTANCE: blowout preventer has apparatus, cable, cable head and member of braking engagement with casing or tubing. Said member is made in the form of rod which has cutoff in its lower part for entering gap between cable head and internal surface of casing or tubing and wedging of preventer. Preventer upper part is secured to cable above apparatus. Length of rod is selected on basis of cable sagging on rod section during outburst of instrument. Rod central part has projection contacting cable for producing initial sagging of cable. Cable head has chamber opposite to rod for ensuring surface contact with angle exceeding friction angle. EFFECT: increase of braking during increase of speed of emergency motion up to preventer stop. 1 dwg