rest of the equipment in the perforation apparatus 122 in one embodiment the perforation apparatus 122 includes a plurality of select fire subs u201c sfs u201d 130 132 134 135 and a plurality of perforation charge elements or perforating gun or u201c pg u201d 136 138 140 and 142 in one embodiment the number of select fire subs is one less than the number of perforation charge elements the perforation charge elements 136 138 140 and 142 are described in more detail in the discussion of fig4 it will be understood by persons of ordinary skill in the art that the number of select fire subs and perforation charge elements shown in fig1 and 2 is merely illustrative and is not a limitation any number of select fire subs and sets of perforation charge elements can be included in the perforation apparatus 122 in one embodiment the perforation apparatus 122 includes a bull plug u201c bp u201d 144 that facilitates the downward motion of the perforation apparatus 122 in the well bore 114 and provides a pressure barrier for protection of internal components of the perforation apparatus 122 in one embodiment the perforation apparatus 122 includes magnetic decentralizers not shown that are magnetically drawn to the casing causing the perforation apparatus 122 to draw close to the casing as shown in fig1 in one embodiment a setting tool not shown is included to deploy and set a bridge or frac plug in the borehole fig3 shows the result of the explosion of the lowest perforation charge element.