Abstract: A method and apparatus for milling a window in a downhole structure, such as a casing or a liner, includes a mandrel that supports milling elements arranged in a predetermined pattern. In one example, the milling elements are arranged in one or more continuous channels each having a generally helical pattern. The milling elements are able to cut the window in the downhole structure substantially continuously to the desired size.

Abstract: A method and apparatus to protect explosive components used in various tools, such as tools for use in wellbores, includes a component with an adsorptive material. Example tools include perforating gun strings that include shaped charges, detonating cords, and booster explosives. Other tools may include surface tools containing explosive components. In these tools, a build up of corrosive gases or liquids may occur, which may cause damage to the explosive components. As a result, the structural integrity or reliability and thermal stability may be weakened or reduced. To reduce the amount of build up of corrosive gases or liquids, an adsorptive material is placed inside tools in the proximity of explosive components.