US3307636A - Jarring tool - Google Patents

Description

` March; .7.;1-1196711 J. v, LE BLANC JARRING TOOL s sheets-sheet 1 Filed. June 29 1964 l March 7, 1967 J. v. LE BLANC JARRING TOOL 3 Sheets-Sheet 2 Filed June 29, 1964 y 3 w C m. M r f m T H m m Z wm f A ,n f w m d 2 w d M b,\ A ,n M w MV/MVVV/ /v 1 Y ,I r I M v 9 fmch 7, 1967 J. v. LE BLANC JARRNG TOOL 3 Sheetivheet 5 Filed June 29, 1964 INVENTOR.

United States Patent Gilice 3,307,636 Patented Mar. 7, 1967 3,307,636 EARRING 'I'OL Joseph V. Le Blanc, 102 N. Delmont E., Conroe, Tex. 77301 Filed .lune 29, 1964, Ser. No. 378,598 9 Claims. (Cl. 173-13) This invention relates to a tool commonly known as a hydraulic jar, and more particularly it relates to a hydraulic jarring tool adapted to be permanently positioned in an oil well drill string for the purpose of providing at desired times automatically repeating impacts on the drill string.

In the drilling and maintenance of oil wells it is frequently desirable or necessary to apply a series of impacts or vibrations to equipment in the Well bore. For example the drill bit or `the drill collars above the drill bit may become stuck in the drill hole due to caving in of the formation being drilled or to some other cause. As a result the drill bit or other piece of equipment cannot be turned or withdrawn by ordinary pulling or rotation of the drill string to which it is attached. For the purpose of freeing such stuck or jammed equipment, various types of jars have been developed. Most of the jarring tools heretofore devised are used to transmit a relatively powerful blow at very low frequency to the stuck equipment. In addition most such prior art jarring tools require releasing of the tool between blows so that any gain made by the blow in pulling the tool may be lost` when the tool is released between blows. Such tools must be reset after each 'blow in order to effect another blow.

In addition-jarring tools heretofore used have been of such design that they could not remain permanently in the drill string but must be added to the drill string when jarring is required.

An object of this invention is the provision of a well jar for producing a series of sharp impacts in rapid succession.

Another object of this invention is the provision of a vibratory well jar which is hydraulically operated by the ordinary drilling mud used in the drilling operations.

Another object of the invention is the provision of a hydraulic vibratory well jar which permits a continuous upward strain o r pull to be maintained on the stuck equipment throughout the period of time during which jarring is taking place.

Still another object of this invention is to provide a jarring tool which may be permanently placed in the drill string and which has a full opening therethrough for normal passage of drilling mud or tools through the jar.

Another object of the invention is to provide a jarring tool which is actuated solely by the application of a strain to the drill string and the normal pumping of drilling mud into the drilling string, and which automatically repeats without any manipulation to reset it Ibetween impact blows.

According to this invention these and other objects are accomplished by means of a hydraulic jarring tool which is automatic in operation, in that the drill pipe need not be raised and lowered at the surface between blows of the jar. Jai-ring is accomplished by hydraulically elongating the drill string with increased fluid pressure within the tool, and quickly releasing the pressure and allowing the elasticity of the drill string to contract the string and pull the impact surfaces together at high velocity so as to cause a jar to the stuck portion of the drill string. In a preferred embodiment, this tool comprises a pair of telescopically engaged tubular elements which are connected in the drill string. One of the tubular elements, which for example may comprise a housing, is attached to the drill string below the jarring tool and the other tubular element, which may comprise a mandrel, is attached to the drill string above the jarring tool. The mandrel has a fluid passageway therethrough which is preferably of substantially the same size as the passageway through a drill collar so that there is no restriction of ow through the jarring tool. In normal drilling operations the housing and mandrel are in engagement with each other so that they can rotate together, whereby drilling torque may be transmitted through the jarring tool. The mandrel and housing are each provided with impact faces which strike each other to cause the jarring action. In the preferred embodiment, the housing and mandrel are sealingly engaged with each other, and an annular space is provided between them to receive drilling mud under pressure. A valve mechanism carried by the mandrel may be actuated when tension is applied to the drill string to cause drilling mud to ilow into the annular space and thereby force t-he mandrel and housing to move longitudinally with respect to each other so as to increase the tension on the drill string. Then at a predetermined point the valve is operated to release the drilling mud from the annular space so that the tension built up in the drill string causes the mandrel and housing to move longitudinally in the opposite directions whereby the impact surfaces strike each other to cause a jar. Upon striking each other the valve is again actuated to divert the flow of drilling mud. Thus it is seen that the tool is able to automatically repeat the blows of the impact faces without any manipulation from the surface between blows.

For a better understanding of the invention reference is now made to the accompanying drawing wherein VFIGURES 1A, 1B, 1C, and'lD are longitudinal sections of successive portions of a preferred embodiment of the jar of this invention; i FIGURE 2 is a horizontal section of the embodiment ofthe jar shown in FIGURES 1A to 1D, taken at line 2--2 of FIGURE 1B;

FIGURES 3A and 3B are longitudinal sections of successive portions of the embodiment of FIGURES lA to 1D but shown at a different stage of the operation of the jar; and

FIGURE 4 is a horizontal sectional view of the tool in the stage of operation shown in FIGURES 3A and 3B, taken at line 4-4 of FIGURE 3A.

FIGURES 1A to 1D and 2 show a preferred embodinient of the invention as it appears when no jarring is taking place. As shown in FIGURE 1A the tool of the embodiment shown is attached to a drill string by means of a tool joint pin 10 at the upper end of the tool and a tool joint box 12 at the lower end of the'tool. The pin and box 10 and 12 are respectively attached to the drill string above the jarring tool and the drill string below the jarring tool. Usually the box 12 will be at the upper end of a string of drill collars.`

In the embodiment shown in the drawing, a mandrel 14, having a maximum diameter substantially no greater than the diameter of the tool joint 10, is threadedly secured to the tool joint pin, and is also attached, as by means of readily releasable threads such as square threads 16, to a housing 18. Housing 18 also has a maximum diameter substantially no greater than the diameter of a tool joint or drill collar in the drill string. In the embodiment shown, the threads 16 are shown as being female threads on the mandrel 14 and male threads on the housing 1S, although they may of course be reversed if desired. As shown in the drawing, the portion of the housing 18 about which threads 16 extend is ofreduced diameter, forming Ian inwardly extending annular shoulder 19, and is provided with internallyv facing packing members 20 which sealingly engage a cylindrical portion 22 of the mandrel which is telescopically received inside the housing. An annular space 24 is formed between the main ybody of the housing 18 and the major portion of the mandrel 14 which is received within the housing.

At itsv lower end the cylindrical portion 22 of the' man-v drel is threadedly engaged in a valve lbody 26 Which is carried on and forms a part -of the mandrel 14.4 At its lower end the valve body 26 is connected to another tubular portion 28 of the mandrel, which extends below the valve body longitudinally within the -housing 18.V The valve body 26 is preferably not completely cylindrical in shape, but is provided with flat sides 27 to provide increased fluid flow area, as will hereinafter appear. The lower end of the tubular portion 28 has a piston 30 formed thereon which sealingly engages the inner wall lof the housing 18. The lower end of the housing 18 is threadedly engaged with a cross-over sub 32, which is provided with a tool joint pin 34 adapted to be connected to tool joint box 12.

The valve body 26 has a ilongitudinal passageway 36 therethrough which is substantially the same diameter as the lbore through the drill collars of the drill string, so that flow of drilling fiuid and movement of tools therethrough is not restricted. This passageway is provided at each yend with threads 38 and 39 for engagement by the tubular portions -22 and 28, respectively, of the mandrel 14. Approximately midway of the length of the valve body 26, a transverse bore 40 is provided to rotatably receive a generally cylindrically shaped valve core 42, the axis of which extends at right angles to the axis of the passageway 36 through the valve body. The valve core 42 'has la transverse passageway 44 extending therethrough which is of substantially the same size as the passageway 36 and, in the position shown in the FIGURES 1A to 1D and FIGURE 2, is substantially in alignment with the passageway 36, so as not to restrict fiow therethrough. The valve lcore also has a passageway 48 which extends axially through the core and is therefore at `right angle-s t0 the passageway 36. The passageway 48 connects the passageway 44 with the annular space 24 between the valve body and the housing 18. This -axially extending passageway 48 may be somewhat smaller than the passageway 44 andmay, for example, be approximately half the'area of the passageway 44. The valve corel 4is also provided with a port 46 which extends -at right langles to each of the 'passageways 44-and 48 and provides communication of the exterior' of the valve core with the intersection of the passageways 4'4 and 48.v The port 46 does not extend all the way through the valve core as does passageway 44, but only from the outside surface to the center.

Each end of the valve core has formed thereon a pair of pins S positioned approximately 180 apart and extending longitudinally of the valve core a short distance from the end of the core. A similar pair of pins 52 are fixed on each side of the valve body 26` with one of each pair being positioned upwardly from the valve core, and the other of each pair being positioned downwardly therefrom substantially centrally disposed transversely of the valve body. Each of said vpins 52 hasmounted thereon a rocker arm 54 adapted to pivot about the axis of the pin. Each rocker arm has pivotally attached at one end a connecting rod 56, each connecting rod extending between the upper and lower of one pair of lrocker arms 54 and being pivotally mounted at substantially its central point on a pin 50 on the valve core. The opposite end of each rocker arm is provided with a pin 58 which is slidably received in a transverse slot 60 in a push rod 62'. The other pin 50 on the valve core is slidably received in a similar slot 64 in the push rod, which slot is positioned approximately midway between the slots 60 ofthe push rod.

' A push rod 62 -is carried on ea-ch side of the valve body 26 and extends longitudinally thereof. Each end of each push rodvis preferably positioned substantially centrally laterally of the valve body, but the intermediate portions of the push rods are laterally displaced in order to suit-Y ably engage the pins 58 on the rocker arms 54. At each end of the valve body, a strap 66 attached thereto provides means for guiding the ends of the push rod.

A valve operating mechanism is positioned just below the valve body and surrounding the tubular portion 28 of the mandrel 14. The operating mechanism comprises a cylindrical spring 'housing 68, which is attached at one end to the push rod's 62 and extends downwardly therefrom in surroundilng relationship with the tubular portion 28 of theimandrel. At its upper end, the housing 68 has -aninturned flange 70 which fits around the tubular portion 28, and at theother end of the housing there is an inturned flange 72, which sealingly engages the tubular portion 28, as by means of packing 74.V i Intermediate the inturned flanges 70 and 72, an annular spring collar 76 is formed on the tubular portion 28 and sealingly engages the interior of the spring housing 68. A fluid passageway 98 provides communi-cation between the bore of the tubular portion 28 of the mandrel and the annular space between the inturned flange 72 and the spring collar 76. A heavy coil compression spring bears lagainst the inturned flange 70` and the spring collar 76. The upper end of the spring housing 68 is therefore biased upwardly toward the valve body 26 and the push rods 62 are resiliently biased toward the position shown in FIGURES 1A and 1B.

A plurality of resilient fingers 80 are formed on the lowerend of the spring housing 68 and extend downwardly therefrom, being circumferentially spaced around the tubular portion 28 of the mandrel 14. Each finger 80 has an outwardly upset portion 82 thereon, forming a shoulder 84 with the mainV body of the finger. At their lower ends, the outwardly upset portions 82 taper inwardly, and are preferably arcuately tapered inwardly to a reduced thickne-ss at the extreme end of the finger. In the position of the tool shown in FIGURES 1A to 1C, and particularly as shown in FIGURE 1C, the upset portions 82 of the fingers are received within longitudinal openings 86 formed in a' collar 88' on the tubular'portion 28 of the mandrel. In this same position the lower end of the upset portions of these fingers is received within a ring 90, which is held in the position shown by means of a plurality of dog point set screws '92 which engage an annular external groove 94 on the ring. The ring has an annular internal bevel 96 at its upper end for a purpose which will hereinafter be described. The internal diameter -of the ring 98 is no larger than the ex. ternal diameter of the openings 86 in the collar 88 and preferably is slightly smaller. The resilient fingers 88 tend to spring radially outwardly, and therefore bea-r on the bore of the ring 98.

In the use of the jarring tool of this invention, it is normally permanently positioned in the drill string, usually just above the drill collars. In ordinary drilling, torque will be transmitted through the loose fitting right hand threads 16 connecting the housing 18 and the mandrel 14, and thus through the housing 18 into the peru tion of the string therebelow. Drilling fluid is co cted through the mandrel, including the passageway 44 the valve core, to the drill bit. When the drill string below the jar becomes stuck so that it cannot be loosened by either rotationor pulling on the drill string, the string is rotated c'ounterclo'ckwise at the-surface so as todisengage the threads 16, and allow the mandrel 14 to be-moved longitudinally with respect to the housing 18. The portion of the drill string above the connection 16 is then lifted upwardly, suicient force being applied to lift all that portion of the drill string above the jar.

As the drill string is lifted up, the mandrel 14 will be lifted, along with the valve body26 thereon and the tubular portions 22 and 28, as well as the piston 30 on the lowerend of the mandrel 14. As the valve body 26 moves upwardly, the push rv-ods 62 will engage the shoulder 19 on the housing 18. Further upward movement of the mandrel will cause relative movement between the push rods 62 and the valve body 26, the valve body moving upwardly relative to the push rods until the upper end 100 of the valve body hits the `shoulder 19. It will be apparent that such upward movement of the valve body relative to the push rods will, due to the linkage formed by the rocker arms 54 and connecting rods 56, cause the valve core 42 to be rotated. The proportioning of the linkage and locations of the various pins are such as to cause a rotation of the valve core of approximately 90 upon movement of the push rods 62 from the position shown in FIGURE-1A to a position wherein the upper ends of the push rods are substantially flush with the upper end 100 of the valve body 26. l

Such a 90 rotation of the valve core will cau-se the passageway 44 through the valve core to be rotated until its axis is at approximately 90 to the axis of the passageway 36 through the valve body. The port 46 will, however, then be in communication with the passageway 36. FIGURE 4 shows this position of the valve core. Thus, drilling fluid being pumped down through the drill string is passed through the port 46, and then at right angle-s thereto through th'e passageways 48 into the annular space 24 intermediate the mandrel and the housing 18.

It will be appreciated that the upward movement of the drill string, pulling the valve body 26 up so that the push rods 61 engage shoulder 19, also has the effect of moving the lower tubular portion 28 of the mandrel upwardly so that the upset portions 82 of the resilient finge-rs 80 are pulled out of the ring 90. Then, when the upward movement of the valve body 26 continues, since the push rods 62 are prevented from moving upward, the collar 88 is being moved upwardly relative to the resilient fingers 80. The lingers 80 are resiliently biased outwardly, so

that when the collar 88 moves past the shoulders 84 on the fingers, the lingers snap outwardly to lock the shoulder 84 beneath the collar 88.

At the same time, the upward movement of the mandrel with respect to the spring housing 68; causes the spring 78 to be compressed between the spring collar 76 and the inwardly turned flange 70. The relative movement of the valve operating mechanism and the mandrel also draws fluid from inside the drill string below the valve to the annular space intermediate the housing 68 and the mandrel. It will be appreciated that the locking of the upset portions 82 of the resilient fingers behind the collar 88 holds the spring in compression until the resilient fingers are released.

The flow of drilling fluid through the port 46 and the axial passageway 48 through the` valve core and into the annual space 24 causes pressure to be exe-rted against the inturned shoulder 19 and the piston 30 at the lower end of the mandrel 14. Such pressure causes the piston to be forced downwardly. If the drill string is held at the surface against longitudinal movement, the force of this pressure will cause elongation of the drill string due to its elasticity. Application of pressure is continued until the resilient fingers 80 are moved "down far enough that the beveled ends on the upset portions ,engage the bevel 96 on the upper end of the ring 90.

Such engagement with this bevel causes the resilient fingers to be forced radially inwardly. FIGURES 3A and 3B show the tool at the point where the fingers are being pushed inwardly toward the point at which they are released from their locked position below the collar 88. The force of the compressed spring 78 together with fluid pressure on the lower end of the spring housing 68, thereby causes the push rods 62 to be moved rapidly upwardly to rotate the valve core back to its original position. Fluid under pressure in the annular space 24 may therefore flow rapidly back through the axial passageway 48 in the valve core and into the main uid passageway through the valve and valve body. Thissudden release of the pressure in the annular space 24 releases the tension 6 on the drill string thereby allowing the upper end 100 of the valve body 26 to move upwardly with great force and velocity to strike the shoulder 19. The striking of these impact surfaces causes a jar to the stuck portion of the drill string below the jarring tool.

Of course, as soon as the valve body moves upwardly to strike the shoulder 19, the push rods 62 are again engaged by the shoulder 19 to turn the valve core to a position to allow fluid to begin to ow into the annular space 24 so that the operation of the jarring tool is automatically repeated. Thus, it will be seen that automatically repeating blows of the jar will be achieved by merely applying suflicient tension to the drill string to insure that the upper end of the valve body 26 engages the shoulder 19 and by continuing the pumping of drilling mud through the drill string at sufficient pressure to insure adequate elongation of thedrill string to cause the tapered ends of the resilient ngers to engage the bevel of the ring 90. The weight indicator at the surface will indicate the jarring action by showing a greatly increased weight during the downward movement of the mandrel relative to the housing and a relaxation of this weight during the Vupward movement of the mandrel. The substantial cessation of this fluctuation in indicate-d load at the 'surface will indicate that the stuck pipe has been loosened. i

Following the loosening of the stuck pipe, the drill bit can be merely lowered to the bottom of the hole, and the telescoping mandrel moved downwardly into the housing and and then rotated in clockwise direction to fully engage the threads 16. It is not necessary to pull the drill string from the hole to remove the jarring tool after jarring operations are completed.

It will be noted that the jarring tool of this invention need not be any larger in diameter than the drill collars or the tool joints in the drill string, and yet can provide a full hole opening. The opening may be designed to be the same diameter as the passageway through the drill collars, whereby there is no impediment to ow of drilling mud through the tool or to the passage of tools therethrough.

The jarring tool of this invention will undoubtedly be found to be most useful where drilling mud is being used, but it will also provide satisfactory operation where a gaseous d-rilling fluid is used as opposedy to a liquid.

Many modifications within the scope of the present invention will be apparent to those skilled in the art. For example although the embodiment shown has been described in terms of use for upward jarring only it will be apparent that this invention can be utilized to obtain downward jarring o-r both upward and downward jarring. The invention is therefore not limited to the described embodiment but only as defined by the claims.

What is claimed is:

1. A hydraulic jar comprising a mandrel having a l'irst impact surface,

a housing telescopically receiving said mandrel and having a second impact surface adapted to be engaged by said first` impact surface, and

valve means actuable by longitudinal movement of said mandrel with respect to said housing in one direction to direct uid under pressure to cause said impact surfaces to be moved apart, and actuable by longitudinal movement of said mandrel in the other direction to release said fluid to allow said impact surfaces to move into engagement with each other.

2. A hydraulic jar comprising a tubular housing,

means on the lower end of said housing adapted to be attached to a pipe string therebelow,

a downwardly facing inwardly extending `annual anvil y adjacent the upper end of said housing,

a tubular rnandrel telescopically received within said housing and forming an annular space therebetween,

an upwardly facing' annular hammer on'said mandrel,

means sealingly engaging the upper end of said housing labout said mandrel, y

a piston on the lower end of said mandrel sealingly engaging the interior of said housing,

a valve in said mandrel adapted to be operated between a first position allowing ow through said mandrel and a second position cutting off ow through the mandrel and providing communication between the interior of the mandrel above the valve and said annular space,

andv valve operator means carried by said mandrel adapted to operate said valve to said second position upon relative longitudinal movement of said mandrel and said housing to engage said hammer with said anvil, and to operate said valve to said iirst position upon opposite relative longitudinal movement of said mandrel and said housing to a preselected point.

3. A hydraulic jar as dened by claim 2 wherein said valve toperato-r means comprise-s an element mounted on said mandrel adapted to engage said housing upon movement of said hammer toward engagement with said anvil whereby the mandrel moves upwardly relative to said element,

means eccentrically connecting said element to said valve, whereby said valve is rotated from said irst position to said second position in response to said relative movement of said element and said mandrel,

means responsive to said lrelative movement of said element and said mandrel adapted to lock said eiement to said mandrel for movement therewith in a direction to move said hammer and said anvil apart,

means on said housing positioned to `release said lock upon movement of the element and mandrel to a predetermined position, and v means resiliently biasing said element toward upward movement relative to said mandrel to rotate said valve to said first :position upon release of said lock.

4. A hydraulic jar comprising a tubular housing, 4

a tubular mandrel telescopically received in said houslng cooperating impact surfaces on said housing and said mandrel,

means for applying tension to said mandrel to move the impact surfaces together,

means responsive to the movement of the impact surfaces together for directing a pressure fluid between said mandrel and said housing to move the impact surfaces apart and increase the tension on said mandrel,

and means responsive to the movement apart of said impact surfaces a predetermined distance for releasing said pressure fluid and allowing the impact surfaces to strike each other.

5. A hydraulic jar comprising a pair of telescoping members adapted to be connected in a drill string with one of said members connected to the drill string above the jar and the other of said members connected to the drill string below the jar,

, opposed impact surfaces on said members,

means in said jar for applying the pressure of the drilling mud flowing through the drill string in a manner to cause relative longitudinal movement of said members in a direction to cause said impact surfaces to be moved apart and said drill string to be stretched, and

means in said jar adapted to release said pressure upon completion of a predetermined amount of movement, whereby the drill string retracts `and the impact surfaces strike each other.

6. A hydraulic jar comprising a tubular housing,

means on said housing for attachment to a pipe string,

an annular inwardly extending anvil in said housing,

a tubular mandrel telescopically received within said housingl and forming an annular space therebetween,

means on said mandrel for attachment 'to a pipe string,

an annular hammer on said mandrel,

means sealingly engaging said mandrel with said housing at both ends of said annular space, and

valve means in said ymandrel actuable upon relative longitudinal movement of said mandrel and housing in one direction to direct uid under pressure to said annular space to cause said hammer and anvil to be moved apart, and actuable upon relative longitudinal movement of said mandrel and housing in the other direction to release the fluid from said annular space to allow the hammer and anvil to move into engagement with each other.

7. A hydraulicnjar as defined by claim and including an element on said mandrel positioned to engage said housing as said hammer approaches said anvil, said element being connected to said valve means and adapted to operate said valve means, upon such engagement, to direct said uid to said annular space,

means on said mandrel resiliently biasing said element in a direction to operate said valve means to release said fluid from said annular space,

cooperating means on said mandrel and said element adapted to lock said element against movement by said biasing means, and

means on said housing adapted to release said lock upon movement of said hammer and said anvil a predetermined distance apart;

8. A hydraulic jar adapted to be connected in a drill string having a passageway therethrough for conducting drilling uid to a drill bit comprising a tubular housing adapted to be connected at one end to said drill string,

a first impact surface in said housing,

a tubular mandrel telescopically slidably received in said tubular housing and forming an annular space therebetween,

a passageway through said mandrel having substantially y the sa-me diameter as the drill string passageway,

means for connecting one end of said mandrel to said drill string,

a second impact surface on said mandrel positioned to strike said first impact surface upon longitudinal movement of said mandrel in one direction with respect to said housing, v

means responsive to the movement of said impact surfaces together to cut off the flow of drilling uid through said mandrel passageway and to direct it into` said annular space, whereby said mandrel is moved longitudinally in another direction with respect to said housing and said impact surfaces are moved apart, and

means responsive to the movement apart of said impact surfaces a predetermined distance to release said drilling iiuid from said annular space and allow said impact surfaces to move toward each other.

9. A hydraulic jar for connection between lower and upper portions of a drill string comprising a first tubular member having means thereon for connection to the upper portion of the drill string,

a second tubular member telescopically engaging said rst tubular member and having means thereon for connection to the lower portion of the drill string,

opposed upper and lower impact surfaces on said members movable into contact with each other upon upward movement of the upper portion of the drill string relative to the lower portion,

valve means in one of said tubular members having a first position allowing uid flow axially through the upper portion of the drill string, the inner tubular member, and the lower portion of the drill string, and a second position preventing uid fiow into the lower portion, and,

9 10 piston means connected to one of said tubular members 2,245,786 6/ 1941 Johnson 175-296 adapted to move said impact surfaces apart when said 2,344,725 3/ 1944 Phipps 175296 valve means is in said second position. 2,389,711 11/ 1945 Armentrout 175-296 2,622,372 12/ 1952 Moulden 173-19 References Cited by the Examiner 5 2,969,771 1/ 1961 Coudill 173-134 UNITED STATES PATENTS FRED C. MATTERN, IR., Primary Examiner. 1,569,183 1/1926 Herman etal. 175296 2,102,754 12/1937 Shannon 175 296 L. P. KESSLER, Assistant Examinez'.

Claims (1)

1. 2. A HYDRAULIC JAR COMPRISING A TUBULAR HOUSING, MEANS ON THE LOWER END OF SAID HOUSING ADAPTED TO BE ATTACHED TO A PIPE STRING THEREBELOW, A DOWNWARDLY FACING INWARDLY EXTENDING ANNUAL ANVIL ADJACENT THE UPPER END OF SAID HOUSING, A TUBULAR MANDREL TELESCOPICALLY RECEIVED WITHIN SAID HOUSING AND FORMING AN ANNULAR SPACE THEREBETWEEN, AN UPWARDLY FACING ANNULAR HAMMER ON SAID MANDREL, MEANS SEALINGLY ENGAGING THE UPPER END OF SAID HOUSING ABOUT SAID MANDREL, A PISTON ON THE LOWER END OF SAID MANDREL SEALINGLY ENGAGING THE INTERIOR OF SAID HOUSING, A VALVE IN SAID MANDREL ADAPTED TO BE OPERATED BETWEEN A FIRST POSITION ALLOWING FLOW THROUGH SAID MANDREL AND A SECOND POSITION CUTTING OFF FLOW THROUGH THE MANDREL AND PROVIDING COMMUNICATION BETWEEN THE INTERIOR OF THE MANDREL ABOVE THE VALVE AND SAID ANNULAR SPACE,

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