Abstract: A drilling jar is disclosed. The jar has particular application in directional drilling operations and includes a swivel which allows the drilling jar to operate substantially independently of any right hand torque that becomes trapped in the drill string. The swivel includes a bearing cage that engages the polished stem of the drilling jar to the jay stem of the drilling jar. This bearing cage holds a number of bearings against the jay stem and the polished stem. The swivel allows the jay stem to rotate substantially independently of the polished stem. The drilling jar may further include splines formed onto the outer surface of the polished stem for transmitting torque from the polished stem to the barrel of the drilling jar without simultaneously transmitting torque from the polished stem to the jay stem.

Abstract: A jarring device for use in drilling comprises first and second members longitudinally relatively movable between a locked position and a released position said device comprising control means including a pair of locking devices each arranged to prevent relative movement between said members until a predetermined force is applied to one of said movable members in either of two longitudinal directions. The control means includes two locking devices each of which locks in one of the two directions.The locking devices may comprise pivotable bolts pivoted on a sliding member so that the free ends of the bolts contact an abutment on one of the movable members to effect locking, the bolts being retracted from engagement with the abutment by movement of the sliding member.

Abstract: A mechanical jar used primarily on drill strings, in earth boreholes, to aid in freeing drill strings stuck in a well bore. A telescoping drill string component is constrained in a selected telescoped condition by a biased lock until enough axial stress is applied to the telescoped jar to release the lock. Energy stored in the stressed length of drill string then moves rapidly to strike a solid limit to the telescoping travel. The inertia of the moving part of the drill string applies a shock to the stationary, downwardly continuing part of the drill string. The shock is to aid in releasing the stuck string situation. The tension required to release the lock is adjustable, as a design alternative, by applying torque to the drill string. The jar can, by design alternative, be used to strike in either or both axial directions.

Abstract: A mechanical well jar is disclosed having inner and outer tubular members movable longitudinally relative to each other a limited distance for connecting in a pipe string. Annular shoulders on the members engage to limit the relative longitudinal movement of the members. A plurality of laterally spaced, arcuate cam plates are attached to the inner surface of the outer member. Each plate has a laterally extending U-shaped notch opening into the space between the plates and formed with curved outwardly flaring sidewalls. Rollers are mounted on the outer surface of the inner member to extend into the spaces between the cam plates for movement into the U-shaped notches to hold the members from longitudinal movement relative to each other.

Abstract: A jar tool having a mandrel and a housing substantially surrounding said housing. The mandrel and housing are splined such that they may move longitudinally relative to each other. First and second pairs of abutment faces for the jar and bump strokes respectively, are provided between the mandrel and the housing. Both sets of abutment faces are enclosed within the jar tool.

Abstract: A mechanical jar having a variable diameter tension ring which can be reciprocated from a large into a small diameter chamber and vice versa. When a fishing tool is connected to the jar, the jar is run downhole and set down, and a mandrel retracts into a barrel, causing a collet to move the ring into the large diameter chamber whereupon the ring expands to a large diameter and telescopingly receives the collet fingers therewithin. As the jar is picked up, the mandrel moves the ring from the large to the small diameter chamber, thereby reducing the diameter of the ring. This action releasably latches the ring and the collet fingers together. Accordingly, a very large axial force must be applied to the mandrel in order to cause the collet to be released from the ring; and, a very small reverse axial force is required for the collet to latch onto the ring.

Abstract: Method and apparatus for firing perforating apparatus in a borehole. A mechanically operated firing assembly is run into the borehole on the end of a cable and latched onto a perforating apparatus. Tension is pulled on the cable. At a predetermined tension force a firing rod is automatically released and as a result of force exerted by a compression spring driven into impactment with a percussion firing head to thereby detonate the perforating apparatus. Additionally, the firing assembly can be reset by application of downward force thereto.

Abstract: An upstroke wireline jar having a hammer 12 at the bottom end of an operating rod 3 which is axially slidable in a casing 2 having an anvil 13 at its upper end. This casing also includes a releasable coupling means which is biased downwards by a spring 5 to a rest position, said coupling means comprising a sleeve 4 which receives the rod 3 into its upper end and a plurality of arcuate segments 9 which are contained in apertures in the sleeve and engage in a circumferential groove 10 in the rod. Circumferential recesses 11 and 17 in the interior wall of the casing 2 are adapted to partially receive the segments when the sleeve is in appropriate registration therewith thereby facilitating disconnection and subsequent re-engagement of the operating rod with the sleeve. The spring 5 is mounted below the hammer so as to allow free travel of the latter along a substantial portion of the casing.

Abstract: The present invention comprises a pressure balanced tubular spring slip-joint and jar including a generally tubular outer housing having longitudinal slot means in the wall thereof, and a hammer area of increased wall thickness at one end thereof, within which housing slidably extends a jar mandrel means having first and second longitudinally spaced enlarged diameter anvil areas, at least one fastener tapped into one of those anvil areas, the heads of said fastener protruding into said slot means. Both said housing and said mandrel means possesses axial bores therethrough, which are placed in communication via the bore of a tubular spring within the housing, whereby during extension and contraction of the slip-joint and jar means of the present invention the area within said axial bores and said spring bore is of a constant volume.

Abstract: For use in a well jar, a mounting apparatus for resilient elongate snubbers is described. In the preferred and illustrated embodiment, parallel elongate resilient snubbers are formed on metallic backing strips. They are profiled to define sloping elongate sides which slidably fit within undercut grooves. The undercut grooves extend from an encircling shoulder to enable easy insertion into the grooves. The shoulder is adjacent to an encircling narrow neck, thereby enabling an expandable lock ring to be positioned in the neck, securing the resilient snubbers in position.

Abstract: An oil field jar includes a barrel and mandrel selectively interconnected by a ball transfer mechanism so that pulling upwardly on the jar causes a ring spring assembly to be stressed. As the spring assembly reaches its limit of stroke, the ball transfer mechanism trips so that the mandrel moves relatively freely with respect to the barrel. A hammer and an anvil carried by the mandrel and barrel then impact to create an upwardly directed jar on the fish to which the tool of this invention is connected. The ball transfer mechanism includes a plurality of balls which move both axially and radially of the tool during operation.

Abstract: Disclosed is a bidirectional fluid operated jarring apparatus. The apparatus includes a tubular body having a lower end defining a downwardly facing body hammer. A tubular knocker sub is axially slidingly mounted to the body adjacent the body hammer and includes an upwardly facing anvil engageable with the body hammer and spaced apart oppositely facing internal hammers, the upper one of which defines an internal anvil. A tubular mandrel having a low passage therethrough is axially movably mounted in the body and knocker sub. The mandrel includes a hammer positioned within the knocker sub between the internal shoulders. A valve is provided for closing the mandrel flow passage so that fluid pressure urges the mandrel axially downwardly with respect to the body and opening the mandrel flow passage upon predetermined downward movement of the mandrel. When the knocker sub is in a retractive position, the apparatus produces a downward jarring force.

Abstract: A multiple drill stem for cable tool drilling operations, in which the drill stem is repeatedly hoisted and dropped to impact, has an internal hammer that moves a short distance to strike an anvil in a lower end of a drill stem casing. The improvement relates to a cocking spring that is positioned along an uppermost portion of the hammer and away from harmful debris that collects where the hammer strikes the casing anvil. The casing bears against an upper hammer anvil to cock the spring between a spring-compressing flange at one end and a restriction in the casing interior that blocks an opposite end of the spring, but allows the hammer to slide through it. The spring is further compressed when the drill stem is dropped to a point of initial impact, so that the hammer strikes a follow-up blow on the lower casing anvil. A method of assembling the drill stem is also disclosed.

Abstract: A double acting hydraulic drilling mechanism, i.e. drilling jar, is disclosed for use in a tubular drilling string for applying upward or downward jarring forces for dislodging a "fish" from a well. The jar is adapted to be run into a well on a drill string and connected to a fishing tool in the well bore. This jar comprises outer and inner housing members positioned in telescoping relation for longitudinal movement of one relative to the other and having a hammer member on one and an anvil member on the other. The housing members enclose a chamber adapted to contain a fluid for controlling application of jarring forces. A pair of pistons are positioned in spaced relation for movement of each relative to the other in the hydraulic fluid chamber. The pistons are arranged so that movement of one housing relative to the other in one direction will move the first piston toward the second and movement in the opposite direction will move the second piston toward the first.

Abstract: A downhole fishing jar mechanism for freeing stuck objects within a well bore which incorporates a housing structure defining an internal anvil element through which an upwardly-directly impact force is adapted to be transmitted to the body structure. A striker element, incorporated with an elongated operator element is adapted to strike the anvil with an impact force that is controlled by means of an adjustable compression spring. A spherical detente-type latching mechanism is adapted to establish a releasable interconnection with the operator element and further is operative to transmit the compression of the spring to the operator element. The latch mechanism releases automatically upon predetermined upward movement of the operator element and latch mechanism within the body structure, thereby allowing the operator element to move upwardly and cause the striker to impart a predetermined impact force to the anvil.

Abstract: Well bore drilling shock absorber device for absorbing drill bit vibratory displacement shock, especially in elevated temperature formation drilling, in which the pair of slidably associated elements, e.g. telescoping inner mandrel and outer housing, interconnected for common rotation for drilling purposes and relative reciprocal displacement longitudinally for shock absorbing purposes, and adapted to be interposed operatively between a drill string thereabove and a drill bit therebelow, is provided with longitudinally resilient mechanical tension shock absorbing means, e.g. linear means or cable means such as wire rope, rods, tubes, chains, etc.

Abstract: A telescopic shock absorber for incorporation in a drill string connected to a rotary bit for drilling a bore hole in earth formations, the shock absorber including a single spring assembly which is compressed downwardly when sufficient downwardly directed drilling weight is transmitted from the drill string through the shock absorber to the drill bit, and which is compressed upwardly when the internal drilling fluid pressure in the shock absorber fully overcomes the downwardly directed drilling weight, assuring that the spring assembly is in its compressed condition when the shock absorber is telescoped or extended, enabling it to absorb shocks and vibrations incident to the drilling operation and under both conditions.

Abstract: A jar for use in facilitating the removal of stuck objects from wells. The jar has a telescoping assembly held in a collapsed position by a latching means urged into latching position by a resilient means so that the hammer of the jar is spaced from the anvil thereof. The release of the latching means is actuated by a predetermined longitudinal force applied to the upper end of the jar which overcomes the resilient means to cause the hammer to strike the anvil with a sudden impact translated by a connecting means from the jar to the stuck object.

Abstract: A remotely operated connector for electrically and mechanically coupling a wireline to a connector located at the bottom of a drill string. The connector includes a spring-actuated jar that facilitates the release of the connector.

Abstract: A deep well elastic-tensile energy storage tool provided for incorporation in a drill string just above a fishing tool assembly, the latter embracing a fishing tool for directly engaging the fish, a conventional jar and one or more drill collars in the order named; said energy storage tool incorporating a cylindrical tubular column of molded polyurethane which is compressible axially one-twelfth its length to develop therein an internal reaction force of up to 125,000 pounds which is released by the jar for sudden application to the fish in a jarring operation.