Abstract: A subsea well safing method and apparatus to secure a subsea well in the event of a perceived blowout in a manner to mitigate the environmental damage and the physical damage to the subsea wellhead equipment to promote the ability to reconnect and recover control of the well. The safing assembly is connectable to a subsea well and a marine riser. Pursuant to a safing sequence, the well tubular is secured in the upper and lower safing assemblies and the tubular is then sheared between the locations at which it has been secured. Subsequently, an ejection device may be actuated to physically separate the upper safing assembly and the connected marine riser from the lower safing assembly the subsea well.

Abstract: A high energy tubular shear is connectable within a drilling system and includes a body forming a bore through which a tubular is disposed, a cross-bore intersecting the bore, opposing cutters moveably positioned in the cross-bore on opposite sides of the bore, and the each cutter in hydraulic communication with a respective hydraulic intensifier.

Abstract: A pyrotechnic pressure accumulator includes an elongated body extending from a first end of a pyrotechnic section to a discharge end of a hydraulic section. A propellant charge located in a gas chamber of the pyrotechnic section, a piston movably disposed the hydraulic section, and a fluid disposed in a hydraulic chamber between the piston and the discharge end, wherein the fluid is exhausted under pressure through a discharge port in response to ignition of the propellant charge.