Abstract: An accelerator for a fishing jar is disclosed. The accelerator includes front, compression, rear, and air chambers. These chambers insure that the pressure of the fluid in the compression chamber is substantially independent of the temperature of the fluid and the hydrostatic pressure of the well. These chambers also insure that the high pressure seals of the compression chamber are lubricated on each side of each seal. The accelerator also insures that a threshold upward force which is proportional to the hydrostatic pressure must be applied to the drill string before the fluid in the compression chamber begins to be compressed, thereby providing an accelerator that has a higher maximum load in deep wells.

Abstract: A well packer is shown of the type having a packer head and a pair of tubular extending downwardly therefrom. An upper seal, a gripping assembly, a lower seal and a lock body are all located about the mandrels extending successively downwardly from the packer head. An actuator within the lock body is provided for effecting outward radial movement of the seals and gripping assembly to seal and grip a surrounding well conduit. A push rod extending from the lock body through the lower seal to the gripping assembly moves the gripping assembly, as a unit, in the direction of the upper seal to compress the upper seal before the lower seal is compresed. A tie rod extends from the packer head through the upper seal to the gripping assembly and carries a locking mechanism which allows unidirectional movement of the gripping assembly with respect to the upper seal whereby sealing force applied to the upper seal from the gripping assembly is locked into the upper seal.

Abstract: A slide joint is shown which is used to provide a floating seal between an inner floating member and a surrounding conduit in a well bore. The floating member has a clutch element which is engaged at one end thereof. A circumferential, compressible packing is carried on the exterior of the floating member and is sandwiched between a fixed nut, at one end, and the clutch element at the other end. The clutch element includes downwardly extending clutch portions which are engageable with mating recesses provided within the inner bore of the surrounding well conduit when the floating member is run into position. The floating member can then be rotated by rotating the associated tubing string which extends to the well surface. As the floating member is rotated, the clutch element crawls up the externally threaded surface on the floating member in the direction of the compressible packing and the fixed nut.

Abstract: A single acting hydraulic fishing jar, for use in a tubular drilling string for applying upward jarring forces for dislodging a "fish" from a well, may be run into a well on a drill string to operate a fishing tool in the well bore. The jar has housing members in telescoping relation for longitudinal movement of one relative to the other with a hammer member on one and an anvil member on the other. The housing members enclose a chamber containing an incompressible hydraulic fluid for controlling application of jarring forces. A sliding seal closes one end of the chamber and supports the inner housing member, i.e. mandrel, for sliding movement in the outer housing member. A piston is spaced from the sliding seal so that movement of one relative to the other. Movement of one housing relative to the other in one direction moves the piston toward the sliding seal. The chamber between the piston and the sliding seal has an outlet controlled by a valve member slidably supported for movement on the mandrel.

Abstract: An improved seal assembly is shown for use in an oil well packer of the type having a packer body having a longitudinal bore, a packer carried on the body for sealing off the annular space between the body and a surrounding well conduit, a mandrel slidably disposed within the body longitudinal bore, the mandrel being spaced-apart from the body to define a fluid flow path between the mandrel exterior and the interior of the body, and wherein the mandrel is slidable between an open, running-in position in which the fluid flow path communicates the annular space above the packer with the mandrel longitudinal passageway and a closed, set-position in which the fluid flow path is sealed off. The improvement comprises a face seal housing as a part of the mandrel which has a weight loading shoulder and a deformable seal portion. The weight loading shoulder is engageable with the packer body when the mandrel is in the closed, set position to thereby support the weight of the mandrel from the body.

Abstract: An expendable plug assembly of the type adapted to be received within the bore of a well packer is shown having a shear sleeve and a plug body initially received within the shear sleeve interior. The plug body has a closed end for preventing flow of well fluid through the well packer when the plug body is in place within the shear sleeve. A lock ring is provided for releasably supporting the plug body within the shear sleeve interior. A collet body mounted about the plug body has a collet extension at one end thereof and a plurality of collet fingers at the opposite end thereof. The collet fingers are selectively engagable within the well packer bore to fix the plug assembly within the bore. Shear screws are provided for releasably connecting the collet extension to the shear sleeve. The shear screws are severable by downward movement of the shear sleeve relative to the collet extension.

Abstract: A retrievable well packer is shown of the type adapted for releasable setting within a well conduit. The packer has a central mandrel extending within an outer assembly, seal members carried on the outer assembly for sealingly engaging the conduit, anchoring slips carried on the outer assembly for grippingly engaging the conduit, and a hold down piston-collet assembly for releasably connecting the mandrel to the outer assembly to maintain sealing and gripping engagement between the seal members an anchoring slips and the conduit. The collet is movable between a locking position in contact with the piston whereby the mandrel is connected to the outer assembly, and a release configuration out of contact with the piston whereby the mandrel is released for longitudinal movement relative to the outer assembly. A shear wire fixes the piston in the locking configuration in contact with the collet.

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: An improved mounting and sealing assembly is provided for a rotating ball valve required to open under increased differential pressures and close against high flow rates. The valve assembly includes a trunnion-mounted ball and two pressure biased sealing assemblies. The primary seal constitutes an elastomeric seal element which is axially shiftable into engagement with the ball, and the secondary seal comprises a metallic element which is also axially shiftable relative to the ball. To open the valve, the seals are moved in sequence axially away from the ball and the hydraulic seal is fully broken before the ball is rotated. In closing, the ball is rotated to its closed position and the seals then moved axially in sequence into contact with the ball.

Abstract: An improved mounting and sealing assembly is provided for a rotating ball valve required to open under increased differential pressures and close against high flow rates. The valve assembly includes a trunnion-mounted ball and two pressure biased sealing assemblies. The primary seal constitutes an elastomeric seal element which is axially shiftable into engagement with the ball, and the secondary seal comprises a metallic element which is also axially shiftable relative to the ball. To open the valve, the seals are moved in sequence axially away from the ball and the hydraulic seal is fully broken before the ball is rotated. In closing, the ball is rotated to its closed position and the seals then moved axially in sequence into contact with the ball.

Abstract: A well tool is provided which is adaptable to be moved longitudinally within a well conduit. The tool contains normally retracted slip elements which are manipulated into engagement with the conduit by expander elements. An elastomeric packing element, of known construction, is expandable exteriorly around the well tool and is adapted to selectively seal with the well conduit. Booster means are provided for transmitting the compressive force defined by differential pressure acting across the packing element when the slips are in expanded position against the conduit and the packing element is sealed with the well conduit, such that the packing element is maintained in sealing relationship with the well conduit.

Abstract: A fishing jar is provided for removing stuck objects from a well bore wherein an upward strain on the running string compresses hydraulic fluid in a compression chamber to the amount of the upward jar or impact load desired to be applied to the fish stuck in the well. A pressure relief mechanism is provided to transfer compressed hydraulic fluid within the compression chamber to automatically activate the jarring mechanism when the load on the jar exceeds the recommended operating load. In a preferred form, the relief mechanism is provided in a piston means which has a normally activated flow regulator bypass means therein together with the pressure relief mechanism.

Abstract: Primary explosives, e.g. lead azide, dispersed in a liquid medium, e.g. enol, are filtered, washed and dried in a novel centrifuge, wherein the rotatable extractor basket has an open bottom, which is closed by peripheral attachment to the large open end of an invertible funnel. The small open end of the funnel is attached to an axial shaft, which can be raised and lowered, whereby said small open end can be held upright to retain the contents in said basket and lowered to invert the funnel to discharge the dried free-flowing explosive particles by gravity through said small open end.

Abstract: Primary explosives, e.g. lead azide, dispersed in a liquid medium, e.g. enol, are filtered, washed and dried in a novel centrifuge, wherein the rotatable extractor basket has an open bottom, which is closed by peripheral attachment to the large open end of an invertible funnel. The small open end of the funnel is attached to an axial shaft, which can be raised and lowered, whereby said small open end can be held upright to retain the contents in said basket and lowered to invert the funnel to discharge the dried free-flowing explosive particles by gravity through said small open end.