دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: A kind of double core barrel drill. The top of inner barrel is hung by ball bearing. It is good for improvement of core recovery if inner barrel does not roll with outer barrel.

n: Using double core barrel drill to break the annular stone at bottom and keep the central cylindrical core. Cut it down and hoist it to the surface when the length satisfies requirement.

the core barrel composed by outer barrel and inner barrel and the drill fluid flow through the theannular space to the well bottom

n: refer to double core barrel