Shaped charges that generate fan-like jets can produce slotted holes in
rock formations. A shaped charge includes a case having on open front
end, an external surface and a longitudinal axis, all transverse
cross-sections of the case being bi-symmetric; an explosive material
disposed in the case, the case including at least one opening extending
from the external surface to the explosive material for initiation of the
explosive material; and a liner disposed over the explosive material;
wherein a pair of substantially identical longitudinal slots are formed
on the external surface, the longitudinal slots being about 180 degrees
apart.