Abstract: A new and improved mechanical jar apparatus for delivering downhole blows in a wellbore in either of opposite directions in response to the controlled application of a longitudinal force. A plurality of mechanically released collets are employed to releasably secure the concentric telescoping members of the jar apparatus in the ready condition until the longitudinal actuation force is applied to move the telescoping members to the longitudinally extended or compressed jarring positions. The plurality of collets may be arranged for controlling the magnitude and direction of the jarring force without inadvertently triggering a jarring force in the undesired direction.

Abstract: A fluid flow control apparatus, shifting tool and method for oil and gas wells in which a sliding sleeve valve is connected in a string of well tubing in a wellbore casing. The sliding sleeve valve functions to selectively control fluid communication between the well tubing and the wellbore casing. A shifting tool is provided for opening and closing the sliding sleeve valve and is connected to reeled tubing for receiving a fluid. The shifting tool includes a nozzle for discharging the fluid into the well tubing during or after the valve shifting operation.

Abstract: A double acting hydraulic drilling jar 1 includes a mandrel 2 arranged in a housing 3 for sliding longitudinal movement. A hammer 69 is positioned on the mandrel 2 and interacts with anvil surfaces 64, 66 in the housing 3 to deliver both upward and downward jarring forces to a drill string. A hydraulic valve arrangement permits the storage of large amounts of static force before releasing the hammer 69 to strike the anvil surfaces with great force. The hydraulic valve arrangement includes a tripping valve 95 positioned to be actuated by a first pair of engaging surfaces in response to downward movement of the mandrel 2 in the housing 3 and a second pair of engaging surfaces in response to upward movement of the mandrel 2 in the housing 3. Thus, independent control over the upward and downward jarring action is achieved.

Abstract: A mechanical down jar and method for its use in connection with coil tubing and with jointed tubing for releasing stuck objects within a well bore for installing coil tubing within deviated and horizontal well bores and for conducting other downhole servicing operations. The mechanical down jar mechanism incorporates a tubular body of significant mass having fixed anvils and telescoping mandrels at each end. The lower mandrel is adapted for connection to the stuck object. An internal load spring is released upon application of predetermined downward force to the housing by a firing lug and firing ring release mechanism having an adjustable release force. When released the housing with its lower anvil is rapidly moved downwardly by the force of the load spring and an accelerator spring impacts with signficant force against the force transmitting sub of the lower mandrel thus transmitting downwardly directed shock force to the stuck object or to tubing to be moved downwardly.

Abstract: A running tool useful for installing lock mandrels and other subsurface wireline tools in a well bore, the running tool comprising top sub (12), retainer sleeve (14), bottom setting sleeve (16), core (18), insertion sleeve (44) and lockout sleeve (66). Running tool (10) is adapted to set lock mandrel (22) in landing nipple (60) and thereafter be released by jarring up to disengage lock retainer lug (28) from recess (30) in lock mandrel (22) and to disengage locking sleeve lug (32) from recess (34) in locking sleeve (36). Outwardly biased leaf spring (108) and latching lug (112) are provided to lock running tool (10A) in a fully released position. Emergency shear screws (68) and lockout lugs (90) are provided to permit withdrawal of running tool (10) and lock mandreal (22) from the well bore in case of a misrun.

Abstract: A jar mechanism is described, which comprises a piston (5) movably mounted in a fluid chamber (9). A jar member (2) is releasably coupled to the piston (5) by a release device (3, 4; 3, 38, 39, 40, 54, 64) so that when the piston (5) is in a first position in the fluid chamber (9), the jar member (2) is coupled to the piston (5) by the release device (3, 4; 3, 38, 39, 40, 54, 64). A first force exerted on the jar member (2) moves the piston (5) to a second position within the fluid chamber (9) against the resistance of the fluid (11). When the piston (5) is in the second position, the action of the first force applied to the jar member (2) actuates the release device (3, 4; 3, 38, 39, 40, 54, 64) to enable the jar member (2) to be uncoupled from the piston (5).

Abstract: In accordance with an illustrative embodiment of the present invention, a hydraulic drilling jar includes a mandrel and a housing movable between extended and retracted relative positions to deliver jarring blows to a struck object, a piston on the mandrel that slides in a cylinder in the housing, and a restriction assembly on the housing having an internal seal that engages an enlarged section of the mandrel to enclose a high pressure, oil-filled chamber between the piston and the restriction assembly, the restriction assembly including a pin check valve that provides a very slow leakage of oil from the high pressure chamber while the enlarged section of the mandrel is engaged with the seal. An oil-filled compensating chamber on the opposite side of the restriction means from the high pressure chamber has its pressure equalized with the pressure inside the mandrel by ports through the wall of the mandrel.

Abstract: An invention relating to method and apparatus for the running of various tools and devices used to service oil and gas wells in combination with coiled tubing units that permits the application of a sudden downward force of predetermined magnitude.

Abstract: A jar tool for inclusion into a well fishing operating string which provides resilient tensional stretch to operate the tool. The tool is adapted to compress an upper release spring to store energy corresponding to tensional force in the operating string force. A release latching lug array connects the spring to a central mandrel having an impact hammer. The tool housing forms an impact anvil. The spring is compressed to a designated compressional force by the distance that the latch lug array is moved in an adjustable latch release sleeve before suddenly releasing the spring from the mandrel. The tension in the operating string then pulls the mandrel hammer into jarring impact with the housing anvil. Provision is made for designating this pre-release movement of the latching lug array and also provides apparatus for adjusting the distance of the pre-release movement and thereby the compressional force imparted into the spring.

Abstract: A multiple blow percussion drill assembly is specially configured to provide significantly increased maintainability and adjustability in the field, thereby greatly extending its service life and usefulness over a wide variety of drilling conditions. Both spring replacement and impact hammer delay time variations are rapidly accomplished by virtue of unique positioning and interactions of the internal components, without the need for dissassembly of the sealed high impact energy portion of the drill assembly. Advantageously, a first chamber housing the high impact energy transferring components is isolated from a second chamber housing the control components, such that the control components may be rapidly cleaned, adjusted, or replaced via a simple access port.

Abstract: A hydraulic jar for use in a well and a method of operating same in which an outer housing assembly extends around an inner mandrel assembly in a coaxial relation thereto to define two fluid chambers separated by a piston. The housing assembly is movable relative to the mandrel assembly to force the fluid from one of the chambers to the other. The fluid flow rate is varied between a relative low flow rate and a relative high flow rate in response to the relative position of the housing assembly causing corresponding movement at the latter assembly. A high impact load is transferred to a member connected to the jar in response to a movement at the relatively high flow rate. The jar can be used to create a high impact load in both an upward direction and a downward direction.

Abstract: A mechanism for accurately positioning a well tool in axially concentric relationship to a well conduit comprises a housing having a plurality of stabilizer linkages mounted thereon with one end of each linkage being pivotally secured to the housing and the other end free to move in an axial direction. A compression spring engages a force transmitting connection to the other ends of the stabilizer linkages to bias same to a radially expanded position engaging the conduit wall. The connection between the compression spring and the stabilizer linkage includes two telescopically related sleeve elements which are secured together by a shear screw. In the event that the stabilizer linkage becomes stuck in the well, upward jarring movements of the housing will shear the shear screw and permit the stabilizer linkages to collapse radially inwardly and thus permit removal from the well.

Abstract: A method and apparatus are provided for introduction into a subterranean well on a continuous length of remedial tubing which is concentrically insertable through production tubing previously positioned within the well, the production tubing carrying at least one longitudinally manipulatable member. The apparatus comprises a cylindrical tubular housing having a fluid passageway therethrough communicable with the interior of the remedial tubing for transmission of fluid from within the remedial tubing, through the apparatus, and within an auxiliary apparatus carryable within the well by the remedial tubing, and positionable in the well in proximity to one of the longitudinally manipulatable members. The apparatus also comprises means selectively co-engagable with the longitudinally manipulatable member for moving the manipulatable member to manipulated position.

Abstract: A jar tool for inclusion into a well fishing operating string which provides resilient tensional stretch to operate the tool. The tool is adapted to compress an upper release spring to store energy corresponding to tensional force in the operating string forces. A release latching lug array connects the spring to a central mandrel having an impact hammer. The tool housing forms an impact anvil. The spring is compressed to a designated compressional force by the distance that the latch lug array is moved before suddenly releasing the spring from the mandrel. The tension in the operating string then pulls the mandrel hammer into jarring impact with the housing anvil. The provision is made for designating this pre-release movement of the latching lug array and also provides remotely actuated apparatus for adjusting the distance of the pre-release movement and thereby the compressional force imparted into the spring.

Abstract: A hydraulic well jar mechanism capable of developing jarring force in an upwardly or downwardly direction or in both upward and downward directions for imparting jarring forces to stuck well pipe. Inner and outer tubular members cooperate to define an annulus therebetween, which annulus contains a volume of metering liquid such as oil. One or more metering valves are disposed within the annulus and establish metering of the metering liquid during a portion of the stroke of the well jar to thus retard movement thereof. After a certain metering movement has occurred, the operative metering valve will be clear of the metering surface and the jar mechanism will then have relatively free movment from the retarded position to the jarring position. Closing movement of the jar mechanism may be induced by a compression spring closure.

Abstract: An energy accumulator for use with a well pipe string to enhance the jarring impact delivered to an object stuck in a well bore by an up and/or down jar mechanism includes inner and outer telescopically connected members relatively movable longitudinally to accumulate energy in a mechanical spring arrangement, gas or compressible liquid in the accumulator. Cooperating surfaces on the inner and outer members of the energy accumulator assure that the jarring impact of the jar mechanism members is delivered to the stuck independently of the tensile or compressive load applied to the object jar mechanism and independently of the load rate of accumulating energy in the energy accumulator.

Abstract: A jar accelerator including an elongated tubular tool body and an elongated mandrel axially slidingly mounted within the tool body and having an outwardly facing shoulder. A composite plurality of frusto-conical disc springs are disposed inside the tool body about the mandrel and between the shoulders to provide a preselected accelerating function.

Abstract: A hydraulic drill string jar is powered and actuated by drilling fluid pressure controlled from the earth surface. By selective manipulation of drilling fluid flow, the jar can be conditioned to operate in drilling mode to avoid activation of the jars while normal drilling and fluid flow activities take place. By different fluid flow manipulations, the jar is conditioned to operate in the jarring mode. In the jarring mode, the jars will axially shock the drill string each time the flow rate is reduced below a preselected amount and then increased to a higher preselected amount.

Abstract: Apparatus is disclosed for connecting the firing head of a downhole tool to a set of jars to allow the jars to jar up and jar down. The apparatus includes a firing head housing, a hammer located in the housing, and a spring urging the hammer toward a firing pin. A mandrel extends into the housing. It has one end connected to a jar and the other end connected to the hammer by a shear pin. The mandrel also has longitudinally spaced oppositely facing shoulders and one or more lock segments around the mandrel between the shoulders. The movement of the lock segments along the axis of the housing is limited and the lock segments engage the oppositely facing shoulders to limit axial movement of the mandrel relative to the housing in either direction when the pin is sheared and the hammer released to strike the firing pin.

Abstract: Apparatus including a side pocket mandrel for inclusion in a well tubing string for removably receiving an instrument in its offset receptacle bore for monitoring at least one parameter such as pressure, temperature or the like, at a downhole location, there being an electrical conductor wire extending from equipment at the surface downward to the side pocket mandrel and a plug in the lower end of the receptacle for electrically connecting the instrument in the receptacle with the conductor wire extending from the surface so that electrical energy may be transmitted downhole to power the instrument, that the instrument may generate electrical signals representing data sensed in the well and transmit them to the surface for processing and immediate display, printout, or storage. Suitable kickover tools and running tools are also disclosed.

Abstract: A jarring apparatus for use with an electric line for upward jarring of a tool element stuck in an oil well including a tubular member having a tool element attached to its lower end. A hammer disposed in the tubular member is attached to a cylindrical rod for motion therewith by an electric line disposed through a longitudinal bore in the rod and is moved from a first configuration upwards to a second configuration by a quick, generally upward motion of the electric line toward an opposed anvil included with the tubular member, the quick generally upward motion of the cylindrical rod from its first configuration to its second configuration rapidly moving the hammer to strike against the anvil to provide a generally upward jarring action which is transmitted to jar the element in a generally upward direction. If the jarring does not loosen the stuck tool, disconnect means are provided for leaving the tubular member and tool element in the well but retrieving the electric line.

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 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: The rotary drilling jar includes inner and outer mandrels releaseably locked against relative longitudinal movement. The inner mandrel is connected to the drilling string and the outer mandrel is connected to the drill bit or other well tools suspended below the jar in the well bore. A detent mechanism releaseably connects the inner and outer mandrels and includes a stack of Belleville springs that is configured to determined the amount of force required to move the detent mechanism to unlock the mandrels to permit relative longitudinal movement. In one aspect, the jar also includes an upwardly facing shoulder on the inner mandrel and outwardly facing shoulder on the outer mandrel that are in engagement when the jar is being lowered into, suspended in, and pulled from the well bore to prevent the imposition of string weight on the detent mechanism.

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: Stuck well pipe is removed from a well bore by applying an upward pull to the stuck pipe while applying an upward jarring action to the pipe by an air hammer which applies rapid blows to a linkage mechanism connected to the pipe.

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: 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: A method and apparatus for flushing a well involves the use of a tool which enables a certain jarring displacement to cause a flush valve to be opened. Rotary oscillation of a stem in a given direction may be converted by a ratchet mechanism into rotation of a sleeve in the same direction. The stem may oscillate in either of two rotary directions but rotation in only one direction is transferred to the sleeve. In addition, the ratchet mechanism may be arranged so that rotation of the stem by a given amount results in rotation of the sleeve by a lesser amount. The rotation of the sleeve may be converted into a reciprocating motion of a valve portion through a cam-like engagement between the sleeve and the valve portion. The valve portion includes a port which is capable of communicating with a port in the barrel in response to a predetermined extent of displacement along the longitudinal axis of a drill string.

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: A hydraulic jarring tool for imparting up-jarring impacts to release a stuck earth boring drill string component is shown. The tool defines upper and lower closed fluid chambers between telescopically moveable concentric cylinders. A fluid metering valve in one fluid passage between the chambers provides limited flow from one chamber to the other and permits telescopic movement at a rate which establishes tension on the drill string and causes the tool to jar. A normally open valve is provided in a by-pass passage between the chambers and is responsive to the fluid velocity therethrough to move to a closed position, restricting fluid flow to pass through the metering valve. However, the tool can be telescopically extended at a somewhat lesser rate insufficient to cause the velocity responsive valve to close thereby permitting the tool to be extended smoothly without a jarring impact.

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: A downhole tool includes a pipe string portion which is disposed in a pipe string of a well and a probe portion which can be lowered by wireline or other suitable means into the well for engagement with the pipe string portion. The pipe string portion includes a sliding sleeve valve which is biased in a closed, or unactuated position, by a spring contained within the pipe string portion. The probe portion includes a connector mechanism which engages lugs of the pipe string portion for imparting an opposing force to the sliding sleeve valve which overcomes the biasing force of the spring so that the valve can be opened to permit reservoir pressure to enter a cavity of the probe portion containing a sensor mechanism. The coupling and decoupling of the connector mechanism with the lugs is effected through two downward and two upward movements of the probe portion.

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: This invention concerns an impact wrench for breaking a threaded connection between a first section of pipe and a second section of pipe. It includes an arcuate gripping member having an exterior gripping means for gripping the inside of the first section of pipe and an impact tool for directing multiple sudden distinct forces of torque through said gripping means to the first section. It also includes a second arcuate gripping member for gripping the interior of the second section of pipe which is connected to the first and means for the second arcuate gripping member to receive the reaction torque from the impact tool.

Abstract: A gravel packing method and apparatus for oil and gas wells having high angled portions, i.e. angled a substantial degree from the vertical, wherein slow rotation of the drill pipe is maintained throughout the pumping of the gravel ladened fluid to inhibit the accummulation of the gravel along the drill pipe in the high-angled portions. Each of several different embodiments of a selective rotation and releasing tool comprises tubular members that are relatively movable by vertical movement of the drill pipe to engage or disengage keys in keyways to selectively rotate or not rotate, respectively, a threaded releasing screw for releasing the liner at the completion of the gravel pack. The tool includes members for impacting one another upon rapid lowering of the drill pipe to jar the liner.

Abstract: Adjustable torsional type latching means (5) for triggering a mechanical well jar tool comprises torsionally actuated gear racks (20,22) including acme threads or teeth which extend axially on opposite adjacent side portions of telescopic parts (1,2). The gear rack teeth which mesh in the latched position have incline tooth faces that can be disengaged by applying a strong axial force which torsionally stresses and rotates a torsion sleeve (16) portion of one telescoping part (1) and gear rack (20) thereon away from the other part (2) and gear rack (22). Upon release of the latching device (5) the telescopic parts (1,2) of the well jar and the kinetic energy stored therein are freed for a limited longitudinal jarring movement. The torsion sleeve portion (16) has an end portion connected to the other telescopic parts by a second slot-spline-gear (15) of relative short axial length, which serves as a torque support in the latched position and becomes deengaged during a jarring stroke.

Abstract: A device or drift for gauging the inside diameter of pipe comprising an elongated body having a cylindrical outer surface adapted to receive a set of bushings having an outside diameter consistent with the inside diameter of the pipe to be gauged. A plurality of bushing sets are available for use on the body to gauge various weights and sizes of pipe. The body is formed of a hard, heavy material to force the drift through the pipe, while the bushings are formed from a softer material so as to avoid injury to the pipe when the drift passes through it. The bushings are formed with channels and holes axially therethrough to allow the passage of fluid contained in the pipe in order that such fluid will not hinder the movement of the drift.A retriever is also disclosed which may be dropped through the pipe to dislodge a stuck drift. The retriever has a shock transfering end which imparts momentum to the drift in order to free it.

Abstract: No-blow tool for braking rapid upward movement of a pulling tool and the device being retrieved caused by sudden upward fluid flow. The no-blow tool is assembled as part of a wire line tool assembly below jars and above the pulling tool. The no-blow tool includes three telescoping members, the lowest of which is secured to the pulling tool. Rapid upward movement of the pulling tool and the lowest telescoping member relative to the intermediate telescoping member cams serated slips radially outwardly to grip a well conduit, thereby braking the upward movement. A shearable connection between the upper and intermediate telescoping members permits jarring forces to be transmitted downwardly through the tool, without interference from the slip system.

Abstract: This invention relates to drilling rigs, and more particularly to novel apparatus for supporting a plurality of pairs of block and tackle systems with the tackle systems of each pair operable sequentially and alternately, the one being used to support a main drilling or tubing string while the other is being used to rack stands of tubing therefrom.

Abstract: An oil well tool retrieving device in the form of a jar is provided having a hollow casing including a downwardly facing impact surface, a hammer of cylindrical construction slidably engaging an inner surface of the casing and impacting with the impact surface in one direction and an upwardly facing casing impact surface in the other, a mandrel of cylindrical construction from which the hammer is supported slidably engaging an inner surface of the casing, a double track raceway formed in and extending along a length of the mandrel, resiliently mounted bearing elements supported from the casing and for engaging the double track raceway and a hump element mounted in one of the tracks of the double track raceway while the other track is a free raceway.

Abstract: A shock wave, e.g., from a short time electric arc, is used instead of any explosives to loosen a screw connection between two pipes.

Abstract: A downhole casing anvil device is described that provides a surface against which the casing can be driven down a drilled hole from near the bottom of the casing. The anvil device includes a solid body having a mounting plate that is complementary to the cross-sectional configuration of the casing, and an anvil shoulder that projects outwardly therefrom. The shoulder is adapted to fit through an aperture in the casing and to project into the casing interior. The plate includes a mounting surface that fits flush against the casing when the anvil shoulder is fitted through the casing aperture. Axial edges of the plate may be welded to the casing, clear of the aperture, to secure the anvil device to the casing.

Abstract: A drilling jar to be installed in a set of drill collars in a drill string is disclosed. In the illustrated embodiment, first and second tubular members telescope relative to one another. At the upper end of the lower tubular member, a set of protruding lugs match shoulders having undercuts which permit relative rotation of the two tubular members through part of a turn, thereby permitting the two members to axially telescope whereby locking or unlocking the telescoping movement is controlled. The lower tubular member has an upwardly facing shoulder which is abutted against the lower end of the upper tubular member. This permits the two to be reciprocated and banged together to create a jar for the drill string. A dual jarring activity is developed by a cam actuated radially yieldable collet-type release mechanism that allows relative linear movement of the tubular members and permits selected jarring activity independently of or in conjunction with the lugged locking and releasing portions thereof.

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 jet carrier assembly for cleaning well liners has a jet tool stabilized by a centralizer proximate to each of the tool's upper and lower ends. The jet tool is an elongate member having about 4 to 8 pairs of jet nozzles axially spaced therebetween, the axial spacing between alternate pairs being equal. The jet nozzles are spaced to provide a jet fluid track that covers any given point on the liner at least once but not more than twice when the member is lifted at a constant selected vertical speed and a constant selected rotational speed. The nozzles are mounted within adapters which are in turn detachably mounted to the elongate member. The adapters, which are provided in various sizes depending upon the diameter of the well liner, are interchangeable. The centralizers are capable of axial and rotational movement along mandrels attached to the upper and lower ends of the tool.

Abstract: A hydraulic well jar of the type having a longitudinally slidable inner mandrel within an outer case, the inner mandrel having a hammer element threon which impacts on an anvil element in the case. Hydraulic fluid is disposed between the case and mandrel. Initial movement of the mandrel with respect to the case is impeded by a hydraulic fluid metering jet mechanism, which is bypassed as the mandrel reaches a predetermined point in its travel, allowing a sudden, more rapid movement of the mandrel, thereby generating a greater impact force. The present invention comprises an improved fluid bypass design, as well as an improved mounting system for the hydraulic fluid screen and jet of the metering mechanism. An improved seal arrangement between the metering mechanism, which is attached to the mandrel and the interior of the outer case provides greater seal life and better performance for the jar.

Abstract: A hydraulic drilling jar apparatus having axially elongated outer housing and inner mandrel members that telescope relative to each other when tripped by a predetermined axial force applied to the mandrel to deliver an impact blow to an object stuck in a well bore. A negative pressure is developed within the apparatus during initial retarded telescoping movement to effect acceleration of the mandrel member upon release at a rate exceeding the acceleration rate otherwise imposed by the axial force.

Abstract: A hydraulic jarring tool includes a temperature compensated hydraulic detent actuation means. The jarring tool includes an outer member and an inner member telescopically arranged. Spline means between said outer member and said inner member transmit torque. A hammer and anvil system provide a jarring effect upon actuation of the tool. An upper seal and lower seal provide a fluid seal between said outer member and said inner member. A working fluid is maintained in a working fluid chamber between the upper and lower seals. The hydraulic detent actuation means provides a tripping action to produce the jarring effect. The hydraulic detent actuation includes a sliding sleeve member with an orifice passage that produces a detent action by the slow metering of the hydraulic working fluid. A valve means is positioned in the orifice passage for providing a consistent flow through the sleeve valve to produce the hydraulic detent irrespective of the temperature of the working fluid.

Abstract: A jet carrier assembly for cleaning well liners has a jet tool stabilized by a centralizer proximate to each of the tool's upper and lower ends. The jet tool is an elongate member having about 4 to 8 pairs of jet nozzles axially spaced therebetween, the axial spacing between alternate pairs being equal. The jet nozzles are spaced to provide a jet fluid track that covers any given point on the liner at least once but not more than twice when the member is lifted at a constant selected vertical speed and a constant selected rotational speed. The nozzles are mounted within adapters which are in turn detachably mounted to the elongate member. The adapters, which are provided in various sizes depending upon the diameter of the well liner, are interchangeable. The centralizers are capable of axial and rotational movement along mandrels attached to the upper and lower ends of the tool.