دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a device, similar to a ball, used to manipulate hydraulically operated down- hole tools. See ball.

a pump-down fluid separation device. May also be used to operate tools downhole by hydraulic forces.

n: See dart-valve bailer.

n: A part of dart-type blowout preventer, consisted by projecting board and ball valve.

n: A kind of inside blowout preventer installed at the top of drilling string when blowouting.

n: a drill pipe inside blowout preventer that is installed on top of the drill stem when the well is kicking through the drill stem. It is stabbed in the open position and then closed against the pressure. The valve that closes is dartshaped, thus the name.

n: A kind of bailer in cable drilling. The ball valve connected with projecting board is installed in the bailer. Open the ball valve and bail when projecting board touchs the bottom or object on the surface.