Patent ID: 9022116
Filing Date: 2015-05-05
Classification: E21B,F42B,F42D

Abstract:
1. An explosive well tool assembly comprising: a shaped charge housing secured to a top sub, an explosive shaped charge within said housing, said shaped charge having first and second substantially matched explosive units, each unit being a singular element developed substantially symmetrically about an axis of revolution, each unit comprising an explosive material intimately formed between a conical metallic liner and a metallic backing plate, a truncated apex of said liners joined coaxially along a substantially common juncture plane, each of said backing plates having an external surface opposite from said explosive material and substantially normal to said axis of revolution, an external surface of at least one backing plate having a plurality of blind pockets therein distributed in a prescribed pattern about said axis, said top sub having a substantially planar distal end-face aligned substantially normal to said axis, assembly means for securing said housing to said top sub with a plane of said one backing plate external surface adjacent to and substantially parallel with said top sub end-face plane, and a moisture barrier secured to said top sub between a detonator and said explosive shaped charge to prevent the transfer of moisture from a cavity of said top into said shaped charge housing, said moisture barrier comprising a cup member having a rim wall and a vessel volume wherein said rim wall is secured to said top sub around an aperture and said vessel volume encloses a distal end of said detonator.