logging perforation & testing, page-2

Apart from all the info regarding the impact of the perforation zone, the target structure/sands can also be too tight, ie not permeable or porous enough to support flow.

you will flow for a short time and the emptying gas bearing sands won't refill fast enough to maintain that flow. Also supported by slow build up pressure. Fast build up pressures equal communicating sands.

Fraccing with acid might clean up the area around where the perforation has taken place, but if the nature of the sands is low porosity / permeability then the flow rates will not be enough to lift any cushion or maintain flow rate.

This is the risk of these bipassed sands. they can pump the mud out with nitrogen which will have less pressure, common practice. but all these things cost time and money.