Patent ID: 6009960
Filing Date: 2000-01-04
Classification: E21B

Abstract:
A full closure valve and core retention assembly for connection with a coring tool having an inner barrel, comprising:a mandrel connectable to the inner barrel of the coring tool at its upper end and connectable at its lower end to a core catcher housing, said mandrel defining a body about its intermediate portion for housing a ball closure valve, said mandrel being provided with a longitudinal bore disposed therethrough;said ball closure valve comprising a substantially spherical ball through which is disposed a bore, said ball defining opposed flattened portions which include pivot means about which said ball pivots in said housing between an open and a closed position, said open position aligning the bore through said ball with the bore of said mandrel, said closed position moving said bore to a position normal to the axis defined by the mandrel bore;a sleeve slidably secured on said mandrel and moveable between a first and a second position, said sleeve being operably coupled to said ball such that said sleeve and ball are cooperatively moveable between said open and closed positions, said sleeve being normally biased in said closed position;means for locking said sleeve and said ball in said open position;piston means responsive to fluid pressure to unlock said sleeve from said open position so as to enable said ball to move to said closed position thereby severing the core and closing said inner barrel.