duse

CONT: Cette boue est [...] un paramètre de forage [...] surtout par la puissance hydraulique qu'elle permet de fournir aux duses (orifices calibrés montés sur l'orifice du trépan pour augmenter la vitesse de la boue dans l'attaque de certains terrains) [...]

CONT: Surface chokes are part of the Christmas tree and contain a choke nipple, or bean, with a small-diameter bore that serves to restrict the flow. Chokes are also used to control the rate of flow of the drilling mud out of the hole when the well is closed in with the blowout preventer and a kick is being circulated out of the hole.
CONT: A choke is a type of valve with a conical gate and matching seat concentric with the bore of the valve. The choke can be adjusted to give whatever orifice is required to provide a back pressure on the well in order to control it ...