A technique facilitates formation of perforations into a formation surrounding a borehole in a manner which enhances fluid flow along the perforations. The technique comprises providing a plurality of perforating charges which may be detonated in the borehole to create perforations. The detonation is used to initiate a time delay device for controlling a subsequent detonation of a corresponding charge. The corresponding charge is used to create a pressure underbalance in the borehole. This relatively lower pressure in the borehole is selectively established to create a reverse flow through the perforations which cleans the perforations.