A one trip system for perforating and fracking multiple intervals uses a releasable barrier. The barrier can be an inflatable. A pressure booster system is associated with the BHA so that the existing hydrostatic pressure is boosted when the gun or portions thereof are fired. After firing in one interval, the BHA is raised and the barrier is redeployed and the pattern repeats. Instruments allow sensing the conditions in the interval for optimal placement of the gun therein and for monitoring flow, pressure and formation conditions during the fracturing. Circulation between gun firings cleans up the hole. If run in on wireline a water saving tool can be associated with the BHA to rapidly position it where desired. A multitude of perforation charges mounted in the BHA can be selectively fired by selected corresponding detonator based on a predetermined sequence or surface telemetry command.