Abstract: An annularly shaped modular debris barrier can be mounted to an internal or an external member that are spaced apart to define an annular gap that could collect debris. The modules rotationally lock. Modules have circumferential segments that can be initially spaced apart to promote flexing that can occur when there is relative axial movement between the structures that define the annular gap. The gaps between segments are circumferentially offset as between adjacent segments to create a labyrinth through which the fluid can move in opposed direction while at the same time causing the debris to be retained. The segments stay in a flexed condition to exert a contract stress on the free ends thereof that touch the adjacent structure.

Abstract: An annularly shaped modular debris barrier can be mounted to an internal or an external member that are spaced apart to define an annular gap that could collect debris. The modules rotationally lock. Modules have circumferential segments that can be initially spaced apart to promote flexing that can occur when there is relative axial movement between the structures that define the annular gap. The gaps between segments are circumferentially offset as between adjacent segments to create a labyrinth through which the fluid can move in opposed direction while at the same time causing the debris to be retained. The segments stay in a flexed condition to exert a contract stress on the free ends thereof that touch the adjacent structure.

Abstract: An apparatus and method for delivering a liner wiper plug into a well bore on a workstring with a liner pipe, releasing the wiper plug from the workstring, and giving a positive indication of release of the wiper plug. A sleeve captures a collet to a latch ring until a plug is pumped down the workstring to cause a pressure buildup, which shears a shear screw, allowing the sleeve to shift, releasing the latch ring and the wiper plug from the workstring. A rupture disk is provided in the event of jamming of the apparatus, to allow pressurization above the wiper plug, shearing a weak link in the latch ring to release the wiper plug.

Abstract: An apparatus and method for delivering a liner wiper plug into a well bore on a workstring with a liner pipe, releasing the wiper plug from the workstring, and giving a positive indication of release of the wiper plug. A sleeve captures a collet to a latch ring until a plug is pumped down the workstring to cause a pressure buildup, which shears a shear screw, allowing the sleeve to shift, releasing the latch ring and the wiper plug from the workstring. A rupture disk is provided in the event of jamming of the apparatus, to allow pressurization above the wiper plug, shearing a weak link in the latch ring to release the wiper plug.