Abstract: A vent subassembly includes a vent body having an opening which is covered or uncovered dependent upon the location of a vent sleeve relative to the vent body. The vent subassembly can be connected below a packer, and the vent sleeve can be connected to a perforator so that movement of the vent sleeve is concurrently communicated to the perforator, such as for initiating the firing of the perforator. The vent sleeve is moved by an actuator subassembly, which is to be connected above the packer if the vent and actuator subassemblies are used with a packer. The actuator subassembly has a piston housing, a piston slidably disposed in the piston housing, and a connector string extending from the piston to the vent sleeve. The piston is responsive to a differential pressure existing between the annulus outside the actuator subassembly and an interior pressure within the actuator subassembly.

Abstract: A detonator bar has an outer housing, an inner housing connected to the outer housing by at least one first frangible member, an explosive charge disposed in the inner housing, and a firing piston with firing pin held in the inner housing by at least one retaining dog and at least one second frangible member. Operation occurs in response to a relatively small impact force between the detonator bar and a perforator or other explosive object located in a subterranean well. This relatively small impact breaks the at least one first frangible member.

Abstract: A vent subassembly includes a vent body having an opening which is covered or uncovered dependent upon the location of a vent sleeve relative to the vent body. The vent subassembly can be connected below a packer, and the vent sleeve can be connected to a perforator so that movement of the vent sleeve is concurrently communicated to the perforator, such as for initiating the firing of the perforator. The vent sleeve is moved by an actuator subassembly, which is to be connected above the packer if the vent and actuator subassemblies are used with a packer. The actuator subassembly has a piston housing, a piston slidably disposed in the piston housing, and a connector string extending from the piston to the vent sleeve. The piston is responsive to a differential pressure existing between the annulus outside the actuator subassembly and an interior pressure within the actuator subassembly.

Abstract: In a tubing conveyed perforating gun assembly, a detonator is discharged by a weight bar dropped into the tubing string, subject to unintended sticking. The disclosed safety anchor includes a rope socket enabling the safety anchor to be lowered into the tubing string. The safety anchor has an elongate body connected below the rope socket by a shear pin. The body has a mandrel and sleeve construction cooperatively connected with a bottom located grapple cage around collet fingers enabling a fishing neck on the weight bar to be grasped and firmly held. A slip radially expands to lock the safety anchor in the tubing string, enabling the weight bar to be held against falling for safe retrieval.

Abstract: In a tubing conveyed perforating gun assembly having shaped charges to perforate a well, an improved pressure sequence shaped charge detonator is included. The preferred form of device is appended to the bottom of the assembly to function as a backup detonator. First and second piston and cylinder assemblies in an elongate body provide pressure initiated arming and subsequent pressure initiated firing pin movement to achieve primer cord detonation for perforation of the well. The pressure sequence is controllable, selectively to a specified pressure to arm and thereafter to fire.

Abstract: In a tubing conveyed perforating gun assembly having shaped charges to perforate a well, an improved pressure sequence shaped charge detonator is included. The preferred form of device is appended to the bottom of the assembly to function as a backup detonator. First and second piston and cylinder assemblies in an elongate body provide pressure initiated arming and subsequent pressure initiated firing pin movement to achieve primer cord detonation for perforation of the well. The pressure sequence is controllable, selectively to a specified pressure to arm and thereafter to fire.

Abstract: There is disclosed a flex joint for connecting the upper end of wellhead equipment including a blowout preventer stack with the lower end of a riser pipe which includes means for use in sensing and producing a signal representing the angle between and relative direction of the longitudinal axes of the stack and pipe.

Abstract: A pipe connector having tubular members whose telescopically interfitting end portions are latched against separation, wherein one of the tubular members is stretchable to preload the latch means and move a shoulder thereon in an axial direction away from the latch means, and a nut is threadedly mounted on the other tubular member to permit a shoulder thereon to be moved against the shoulder on the one member to hold the preload on the latch means.