psi, actually, it is more likely a result of your tombstone...

psi,

actually, it is more likely a result of your tombstone tight reservoir that is causing the packers to fail,

ie, during inflation, if the fluid in the interval can't go anywhere (in formation due to tombstone), then the small reduction in interval volume due to the increase in packer size results in a large spike in bottomhole pressure that is either relieved through the fluid forced into the formation (fraccing it) or packer failure. either way, you've got your answer on the permeability of your formation.