Abstract: A releasable connection between the lower end of a running string and a well tool that is subject to being stuck in a well includes inner and outer members movable telescopically between contracted and extended positions, a tension sleeve connecting the members in the contracted position and being disrupted by a predetermined pull to allow telescoping movement, a stop nut to limit such movement in the extended position of the members, and a mechanism responsive to a certain number of cycles of telescoping movement for disabling the stop nut to allow complete release and separation of the members.

Abstract: A hydraulic jar device for use in connection to coil tubing which consists of an elongate tube having an upper hammer sub, a kelly cylinder and a hydraulic cylinder with central restrictor. A lower sub connects to the bottom end of the hydraulic cylinder. The sliding interior components are an upper mandrel secured to an anvil sub which, in turn, is fastened to an axial plunger, all of which are slidable down within the elongate tube. A guide means prevents relative rotation between the mandrel and the elongate tube consisting of hammer sub, kelly cylinder, hydraulic cylinder and lower sub. A metering ring retained on the plunger interacts with the central restrictor of the hydraulic cylinder to control force effected up and down jars that occur when the mandrel strikes the hammer sub on the down stroke, and when the anvil sub strikes the hammer sub bottom on the up stroke.

Abstract: A device is disclosed which is to be incorporated into a drill string used for drilling in subterranean formations. The device includes a first member concentrically mounted with drill pipes disposed above the device and a second member concentrically mounted with drill collars or drill pipes disposed below the device. An intermediate member connects the first and second members and a retainer member maintains the device in its first operative position wherein the entire device is concentric with the longitudinal axis of the drill string. In the first operative position of the device rotation can be transmitted from the first member to the second member and the device acts as an ordinary member of the drill string. The first, second and intermediate members are configured to be capable of occupying a second operative position relative to one another wherein the first member is off-center relative to the second member and wherein the first member does not rotate the second member.

Abstract: Hydraulic jar apparatus to be disposed in a drilling string used in drilling a well bore or other bore hole, embodying inner and outer telescopically arranged bodies, with a hammer on the inner body adapted to strike an anvil on the outer body, the bodies being initially releasably locked or interconnected in fully telescoped or contracted relation by a locking device which can be released while the apparatus is in the bore hole before the apparatus can function as a jarring device or a bumper sub.

Abstract: A new and improved apparatus and method for lowering the apparatus downwardly in a drill string on a wireline to releasably engage a recess in a threaded joint or collar of the drill string to prevent further downward movement of the apparatus and to thereafter detonate an explosive by manipulating a wireline actuated jar with repeated downward blows for exerting a jarring force to the joint as a result of the explosion to release the threads at the joint upon simultaneous application of a back-off torque to the drill string. The apparatus can be released and removed from the well without breaking or damaging the collar locating and supporting portion of the apparatus.