Patent ID: 6220370
Filing Date: 2001-04-24
Classification: E21B

Abstract:
A tubing conveyed perforating apparatus used in perforating a surrounding well bore, the apparatus comprising:a tubular assembly made up of a plurality of tubular sections, the tubular sections presenting a generally cylindrical exterior and a concentric interior bore, the tubular assembly having an upper connecting end for connection in a tubing string extending to the well surface and a lower end;at least one selected tubular section comprising a tubular firing section having a plurality of explosive charges carried therein, each of the explosive charges being initially aligned with a region of reduced wall area provided within the tubular firing section surrounding the explosive charges;a piston sleeve mounted on the exterior of the tubular firing section, the piston sleeve having a plurality of apertures therein which are initially aligned with the respective regions of reduced wall area provided in the tubular firing section and thus with the explosive charges;a firing means located within the tubular assembly for detonating the explosive charges to puncture the regions of reduced wall area, thereby creating openings in the tubular firing section, while perforating the surrounding well bore;pressure responsive means for applying a shifting force to the piston sleeve, whereby the piston sleeve apertures are moved out of alignment with the respective openings created in the tubular firing section to thereby trap any resulting debris within the interior bore of the tubular firing section.