Abstract: A release mechanism for a downhole tool is actuated by radial movement of a locking member. The locking member provided as much as full circumferential support in the locked position and once released can be prevented from re-gripping the previously connected elements. Illustrative examples of the mechanism for radial movement for release comprise sleeves that expand and radially oriented pistons. Shear pins or collets are not used to hold the components together in the preferred embodiment. Internal pressure fluctuations before initiating the release sequence will not cause unwanted release. The mechanism is applicable to a variety of downhole tools and is illustrated in the context of a hydraulic release.

Abstract: A valve, such as a liquid level sight glass gage valve, has a valve unit and a passageway that extends through the valve unit. The passageway has a stem receiving area, a seal receiving area, and a bonnet receiving area that has a non-circular inner perimeter. A packing assembly is provided to isolate the bonnet receiving area from the fluid path. A bonnet is located within the bonnet receiving areas and has a non-circular outside surface for mating relationship with the non-circular inner perimeter of the valve unit. A valve stem is in sealing relationship with the packing assembly and selectively engages a valve seat. The stem threadably engages the bonnet. A bonnet nut is threadably received on the valve unit for securing the bonnet within the valve unit and allowing axial movement of the bonnet against the packing assembly, thereby effecting compression of the packing.

Abstract: A pilot casing mill for removing unwanted pipe from a well bore, which includes a cylindrical pilot having helical vanes and adapted for mounting on one end of a cylindrical mill body. The mill body is provided with longitudinal slots which receive outwardly-extending blades fitted with multiple cutting elements for engaging and cutting the pipe when the pilot casing mill is mounted on the end of a rotatable drill string and inserted in the well. In a preferred embodiment of the invention the blades are removably secured in the slots by removable wedge blocks and may be longitudinally adjusted in place to align adjacent rows of cutting elements, by operation of multiple adjusting screws seated against an adjusting screw ring mounted in a circumferential slot provided in the mill body.