A perforation trigger bypass conduit assembly (10) for a well perforation gun (17) positioned in a well casing (12) at a down-hole location below a tubular completion assembly (16). A pressure sensing device (20) senses a detonation pressure of fluid communicated from a pump (21) through bypass conduit assembly (10) to the sensor (20). The sensing device (20) triggers the gun upon sensing a pressure surpassing a predetermined value, which perforates the casing (12). The bypass conduit assembly (10) is formed to enable blocking of the bypass conduit assembly (10) after triggering of the perforation gun (17) to prevent pumping of production and power fluid back into the formation upon severing of a portion (34) of the conduit assembly (10). Blocking can be effected by removing a member (25) which contains a passageway (51) forming part of the bypass conduit assembly (10) and replacing the removable member (25) with a passageway-free insert member (35).

A valve lockout device having two pieces. A first piece of the device is a hollow object, substantially tubular or block-shaped, open at a bottom end and having slots open on two sides, that fits over a valve whose handle is to be fixed (or locked). A pocket in the first piece receives the handle and limits the motion of the handle relative to the valve body, thereby preventing operation of the valve. A second piece of the device is a substantially U-shaped object which is pivotally attached to the first piece. When the second piece is rotated to a closed position, it captures the valve handle in the pocket of the first piece, thereby preventing the valve lockout device from being removed. When the second piece is in the closed position, a padlock loop on the first piece extends through a padlock receiving opening in the second piece. Putting a padlock through the padlock loop will prevent the second piece from being rotated out of its closed position, thereby locking the device to the valve.

The present invention provides an apparatus for use in completing a subterranean zone penetrated by a wellbore. One aspect of the invention comprises a housing member with a longitudinal bore and a valve member located within the housing member that is movable between open and closed positions. A sliding sleeve having a longitudinal bore is disposed within the housing member and can move between an upper position and a lower position. Attached to the sliding sleeve is a seating element where the valve member can seat. When the sliding sleeve is in the lower position, the valve member is held in the open position and communication is established between the longitudinal bore of the housing above and below the valve member. When the sliding sleeve is in the upper position, the valve member is held in the closed position and communication between the longitudinal bore of the housing above and below the valve member is restricted.

A tool for making a cut inside a downhole tool, including a housing adapted to move in the downhole tool, a plurality of openings in a wall of the housing that provides a passage from inside the housing to an exterior of the housing, a plurality of cutters disposed in the housing that are adapted to protrude from the plurality of openings to the exterior of the housing, wherein the plurality of cutters provides 360 degree cutting regardless of the orientation of the tool, and an actuation mechanism adapted to force the plurality of cutters to protrude through the plurality of openings.

Apparatus and associated methods provide convenient and reliable deposition of a radially deflectable blocking member relative to a downhole tool. In a described embodiment of the apparatus, a lock-out tool has mechanisms which effect latching of the tool to an internal profile of a safety valve, displacement of an opening prong of the safety valve to open the safety valve, and deposition of an expandable ring to prevent closure of the safety valve. The ring is accurately positioned by the tool and is constructed in a manner which enables it to resist relatively large axial loads, but which also enable it to be significantly radially compressed.