A completion assembly designed to perforate a section of casing along a wellbore, comprises a perforating gun, a canister, and a locator device. The canister contains ball sealers that are dimensioned to seal perforations, while the locator device is a casing collar locator that senses the location of the assembly within the wellbore based on the spacing of casing collars. The completion assembly also includes an on-board controller configured to send an actuation signal to the perforating gun to cause one or more detonators to fire when the locator has recognized a selected location of the completion assembly, thereby perforating the casing, and to release the ball sealers from the canister. Methods for seamlessly perforating and fracturing multiple zones along a wellbore are also provided, using a select-fire perforating gun.