Abstract: The present application relates to systems and methods for use in wellbore completion. Embodiments of the invention relate to a method and system for operating a downhole tool, such as a downhole tool associated with well fracturing.

Abstract: A downhole tool comprises a housing defining a main bore and an actuatable member moveable from a first configuration to a second configuration to permit actuation of the tool. The tool includes an indexer mounted within the housing and arranged to progress linearly in a first direction along the main bore of the housing in a predetermined number of discrete sequential and progressive steps of linear movement in said first direction by passage of a corresponding number of objects through the indexer to cause said actuatable member to move towards its second configuration.

Abstract: A mechanical counting device for actuating a plurality of output devices, the device comprising: linear indexing means adapted to count a plurality of actuating signals and to cause actuation of the output devices when a predetermined number of actuating signals for each output device has been received, wherein the mechanical counting device is adapted to cause actuation of a particular output device when a different predetermined number of actuating signals has been received such that the output devices are sequentially actuable.