Abstract: A wellbore completion system utilizes casing conveyed devices to establish a fluid communication path between a downhole formation and the casing string. Extendible pistons are mounted in the wall of the casing pipe string and are extended toward contact with the downhole formation after the casing is set. An explosive device is mounted in the pistons and includes a detonator and a shaped charge. The detonator is housed in a plug threaded into one end of the piston. The shaped charge is housed in a canister conveniently inserted into the other end of the piston. The explosives included in the system may thus be conveniently assembled at the well site. Explosive in the pistons are activated by a separately conveyed activation system which produces a pressure wave to detonate the explosives and establish fluid communication between the casing and formation.

Abstract: A system for centralizing casing pipe in a wellbore includes lateral pistons in the side wall of the casing string which are movable by force applied to their inner end, from a retracted position within the maximum exterior profile of the casing pipe string to a predetermined extended position which will move the casing pipe string toward a central position in the borehole. Various well operations can be performed using the pistons in addition to the centralizing function. When a predetermined deploying force is applied to the pistons, they are released from their retracted position for movement to a fixed extended position. The deploying force is accurately determined by a simple retaining mechanism involving a snap ring and groove on the pistons.

Abstract: A system for centralizing casing pipe in a wellbore includes lateral pistons in the side wall of the casing string which are movable by forces applied to their inner end, from a retracted position within the maximum exterior profile of the casing pipe string to a predetermined extended position which will move the casing pipe string toward a central position in the borehole. Various well operations can be performed using the pistons in addition to the centralizing function.