US2344725A

US2344725A - Jar

Info

Publication number: US2344725A
Application number: US348138A
Authority: US
Inventors: John T Phipps
Original assignee: S R BOWEN CO
Current assignee: S R BOWEN CO
Priority date: 1940-07-29
Filing date: 1940-07-29
Publication date: 1944-03-21
Anticipated expiration: 1961-03-21

Description

March 21, 1944. J. T. PHIPPS JAR Filed July 29, 1940 5 Sheets-Sheet l ZZZ 6n 1Z- flzaz FIG. 20"..

Jo /v 7T Pym/ 5 INVENTOR ATTORNEY March 21, 1944. p pps JAR Filed July 29, 1940 5 Sheets-Sheet 2 16. 4. .26. 4a. .FZ'G. 5. lZZ'G. 5a.

Joy/v TPH/PPS,

INVENTOR ATTORNEY J. T. PHIPPS March 21, 1944.

JAR

Filed July 29, 1940 FIG. 6a.

5 Sheets-Sheet 5 INVENTOR .EZZG. 7a.

day/v KPH/PA;

a y a? 521 ATTORNEY March 21., 1944. J. T. PHIPPS JAR 5 Shee'ts-Sheet 5 Filed July 29, 1940 dofln/l'py/flps,

INVENTOR 5y ATTORNEY Patented Mar. 21', 1944 JAB John T. Phipps, Huntington Park, Calif., assignor to S. R. Bowen 00., Huntington Beach, Calif a corporation of California Application July 29, 1940, Serial No. 348,138

16 Claims.

My invention relates to jars and has particular reference to Jars employed in connection with the drilling of deep wells for the purpose of producing a jarring blow upon tools or other devices which have become stuck in the well bore.

In the drilling and manipulation of deep wells, particularly oil wells, it frequently occurs that tools or other apparatus employed in the well bore become stuck in the bore preventing the ready dislodging thereof by the mere upward pull exerted upon the string of pipe or tubing upon which the tools are suspended. In such cases it is necessary to provide a jarring or hammer- !ike blow in the pipe or tubing string in order to dislodge the stuck tool or other device.

It also frequently occurs that in the manipulation of packers, testers, and other devices employed in the well that such devices become so securely fastened in the well as to require the use of jarring hammer-like blows to dislodge them.

Jars for this purpose have consisted essentially of a tool including a hammer element and an anvil element interconnected by some releasable mechanism which, when a predetermined lifting strain is placed upon the drill string or a predetermined rotary movement is given to the drill string, will be released to permit the hammer and anvil elements to move relative to each other in the direction of the axis of the well bore and engage each other with a violent impact.

It has long been felt that the jarring blow most effective in the movement of such devices should be produced while a relatively great lifting strain is imposed upon the stuck tool or fish, but heretofore all of the jarring tools have been so constructed that, while an upward strain is taken upon the fish prior to the production of the jarring blow, the operation of the release mechanism to produce the jarring blow effectively releases the upward strain which has been placed upon the fish.

It is therefore an object of my invention to provide a jar in which an upward strain of any desired value may be placed upon the fish and.

may be effectively and continuously maintained while the jarring blow or blows are produced,

Another object of my invention is to provide a jar in which a rigid connection is maintained at all times between the drill string and the fish, and in which a jarring blow is produced upon the fish while a predetermined strain is maintained upon the fish through such rigid connection.

It is also an object of my invention to provide a device of the character set forth in the preceding paragraph wherein the upward jarring blow is developed by a movable hammer adapted to be rapidly moved into striking engagement with an anvil portion formed as a part of the means for effecting the rigid connection between the drill string and the fish.

It is an additional object of my invention to provide a jar of the character set forth in the preceding paragraphs wherein the hammer is moved toward the anvil by means of a strong compression spring.

It is a still further object of my invention to provide a.jar of the character set forth in the preceding paragraphs wherein a means is provided for storing energy in the compression spring which drives the hammer and a means for releasing such stored energy to permit the spring to move the hammer into striking engagement with the anvil.

It is also an object of my invention to provide a jar of the character set forth hereinbefore wherein the energy which is stored in the compression spring is derived from the well drilling fluid circulation pumps disposed at the ground surface and transmitted to the location of the jar by the wash opening provided in the drill string extended between the ground surface and the jar.

it is a still further object of my invention to provide a jar of the character set forth in the preceding paragraphs with a pressure responsive means which operates to release the compression spring and allow the spring to force the hammer upwardly into striking engagement with the anvil whenever the fluid pressure in the drill string rises to a predetermined value.

Another object of my invention is to provide a jar of the character described in which after the first jarring blow has been produced, the jar can be re-set for a repetition of blows without lowering the drill string and without releasing the upward strain maintained upon the fish as distinguished from prior art constructions in which. it was necessary, not only to release the upward strain in order to re-set the jar for a second blow, but in fact required that considerable downward force be exerted upon the fish during the re-setting operation, thus tending to aggravate the binding of the fish in the bore.

It is an additional object of my invention to provide a jar of the character set forth hereinbefore which includes a means for repeatedly actuating the hammer mechanism to cause a series of upwardly directed jarring blows to be struck without requiring that the steady upward pull on the fish be released or aim: ished.

It is a still further object oi my invention to provide a jar construction of the character set forth hereinbeiore wherein the pressure respon sive means which controls the action of the hammer is automatically reset so that the jar will continue to strike upwardly directed jarring blows at periodic intervals as long as the well fluid circulating pumps are in operation.

Other objects and advantages oi my invention will be apparent from a study of the following specifications. read in connection with the accompanying drawings. wherein:

Fig. l is a fragmentary longitudinal vertical section of the upper half of one form of iar constructed in accordance with my invention illustrating the relative positions of the parts at the time a connection is effected with the fish and prior to the initiating of any jarring operations:

Fig. la represents a continuation of Fig. 1 and illustrates the construction of the lower half of the Jar:

Fig. 2 is a view similar to Fig. 1 but illustrates the relative positions occupied by the parts after the well fluid circulation pumps have been started to transmit energy to the jarring mechanism pre aratory to striking a jarring blow;

Fig. 2a is a view similar to Fig. la and comprises a continuation of Fig. 2 illustrating the lower portion of the jar:

Fig. 3 is a cross sectional view taken substantially along the line l'lIIlI 01' Fig. l to illustrite the relative disposition of the parts employed: Fig. 4 is a view similar to Figs. 1 and 2 but illustrating the positions occupied by the parts at the time the pressure responsive means or control valve is released to permit the compression spring to move the hammer portion oi the Jar upwardly to later effect an upwardly directed jarring blow;

Fig. 4121s a view similar to Figs. 1a and 2a and represents a continuation oi Fig. 4 to illustrate the lower portion of the jar;

Fig. 5 is also a view similar to Figs. 1 and 2 but illustrating the relative positions occupied by the parts at the time the hammer portion of the Jar is moved into striking relationship with the anvil portion. and illustrating the mannor in which the pressure responsive means or control valve is re-set so as to permit a second arring blow to be produced in the same manner as that employed for producing the first jarring blow:

Fig. 5a represents a continuation of Fig. 5 to illustrate the lower portion of the jar;

Fi 61s a view similar to Fig. 1 but illustratin a different embodiment of my invention, Fig. 6 illustrating the various parts in the positions they occupy at the time a connection is efiected with the flsh and before any attempt is made to develop a jarring blow;

Fig. 6a is a continuation of Fig. 6 and illustrates the construction of the lower half of the Jar, the upper half only being illustrated in Fig. 6;

Fig. 7 is a view similar to Fig. 6 but illustrating the positions occupied by the parts after energy has been stored in the compression spring and prior to the release of the energy to deliver a jarring blow:

Fig. 7a is a continuation of Fig. 7 illustrating ne ates the positions occupied by the parts disposed in the lower portion of the jar;

Fig. 8 is also a view similar to Figs. 6 and '1 but representing the manner in which the pressure responsive device or control device is released to permit the release of the hammer so as to later effect an upwardly directed jarring blow;

Fig. 8a is a continuation of Fig. 8 illustrating the lower portion of the jar;

Fig. 9 is also a view similar to Figs. 6 and 7 but illustrating the positions occupied by the parts immediately prior to the striking of the jarring blow, the hammer being illustrated as having been moved part way toward a position engaging the anvil portion of the Jar:

Fig. 9a is a continuation of Fig. 9 illustrating the positions occupied by the mechanisms disposed in the lower portion of the .1 ar;

Fig. 10 is a fragmentary longitudinal sectional view illustrating a modified construction which may be employed on a jar of the character illustrated in Figs. 6 through 9a; and

Fig. 11 is a View similar to Fig. 10 illustrating still another modification of my invention.

Referring to the drawings, I have illustrated in Figs. 1 and la one form of jar of my invention as including an elongated tubular housing i connected as by means of threads 2 at its upper end to an adaptor member 3 which carries a pin e permitting attachment thereof to the lower end of a drill string as by threaded engagement with a box portion 5 of a tool joint half secured to such drill string. The lower nd of the housing i may also be connected as by means of threads 6 to an adaptor or tool joint member 7 which defines a box 8 permitting the adaptor i to be threadedly engaged with the pin portion 9 of a tool joint half 50, which latter tool joint half may be connected to an additional length or lengths of drill pipe and extended downwardly to the bit, fishing tool, or other device which is securely attached to the fish which is to be removed from the well.

The lower adaptor i is preferably provided with a relatively small diameter wash opening H which, at its junction with the upper end of the adaptor l, defines a shoulder I2 upon which may be rested a large and stifi compression spring i3 which is enclosed by the housin i. The compression spring may have a length and spring constant as desired, depending upon th type of blow which the jar is intended to strike, the spring it being adapted to exert an upwardly .dlrected accelerating force on a hammer M which is slidably mounted within the housing I and rested upon the upper end of the spring l3.

The upper end of the hammer I4 is preferably provided with a striking end which may be formed .as desired but which is preferably rounded as indicated at i5 in Fig. l to permit a reasonable amount of deformation thereof as a result of the blows struck without impairing the operation of the device. The striking and I5 is adapted to engage a similarly formed striking portion or 'anvil i6 formed as an integral part of the upper adaptor 3.. The adaptor 3 is likewise provided with a fluid passage or wash opening I! communicating with the conventional circulation pas sage provided in the drill string to which the device is secured so as to permit drilling fluid to be pumped from the ground surface into the housing I.

In order that the pressure of the circulating fluid which may bepumped into the housing I through the wash opening II may be employed to compress the spring I3, I prefer to form the hammer, I4 with a longitudinally extending bore II which carries in its upper end a valve construction I9 adapted to be moved between a position closing oi! the passage I8, as is illustrated in Fig. 1, and a position opening such passage,

as is illustrated in Fig. 4. The valve construcindicated at 2I to receive the sleeve 20 and to provide a shoulder 22 against which the sleeve 20 may be seated. The sleeve 20 may be secured within the enlarged bore 2| as by means of a threaded engagement such as that indicated at 23 in Fig. 1.

The sleeve 20 is likewise provided with a longitudinally extending bore 24 within which is slidably mounted a valve member 25, the slidable movement of the valve member being limited to an upper position such as that illustrated in Fig. 1 and a lower position such as that illustrated in Fig. 4 by suitable stop means which may comprise a pin 26 carried in the sleeve 20 and extended transversely across the bore 24, the lower portion of the valve member 25 being provided with slots 21 through which the pin 25 is passed, the length of the slots 21 being so adjusted that engagement of the ends of the slots with the pin ,26 will serve to limit the movement of the valve member 25 in the above defined positions. It will be observed that with the valve I! and the hammer I4 in the positions illustrated in Fig. 1, the circulation passage through the jar is closed off by the valve 25 at the upper end of the hammer I4.

In order that operation of the mud pumps at the ground surface to force fluid downwardly through the interior of the drill string will compress the spring I3, I employ a construction wherein the wash opening II terminates in an annular recess 28 having a diameter considerably in excess of the diameter of the wash opening 21, fluid connection between the recess 28 and the housing I being established by means of a plurality of smaller longitudinally extending

bores

29 and 30, the outer ones 29 of which are disposed a greater distance from the center of the housin I than the radius of the valve member 25 so that the valve 25 will not interfere with the wash opening. This construction permits the fluid which is pumped downwardly through the drill string by the mud pumps to be conveyed to the interior of the housing I at a point above the upper end of the hammer I4 with the result that the fluid pressure developed thereby and exerted on the upper end of the hammer I4 will force the hammer downwardly within the housing I and compress the compression spring l3, the position of the hammer after such downward movement has taken place being illustrated in Fig. 2.

As soon as the hammer has been displaced a distance corresponding to the maximum force which it is desired to exert upon the spring I3, the pressure which has forced the hammer into that position should be substantially instantly released to allow the spring I3 to impart an accelerating force to the hammer I4 30 that it will be moved upwardly with a high velocity so as to strike the anvil portion IS a severe blow.

The valve construction I9 above described includes a means which is responsive to the pressure which is exerted by operation of the mud pumps upon the upper end of the hammer I 4 and causing the valve member 25 to move to an open p sition to elect whal s ofthe hammer u. The valve member 25 is accordingly preferably provided with an internal bore II which extends upwardly from the lower end of the valve member to a point closelyadjacentthe upper end thereof so as to define a fluid. passage extending substantially the full length of the valve member 25 but not entirely therethrough. This fluid passage may be extended into communication with the exterior of the valve member 25 as by providing a plurality of ports 22 therein, these ports .being disposed in such position as to communicate with an annular recess or enlarged diameter portion 33 of the bore 24 which is' provided in the sleeve 20. Thus when the valve member 25 is moved to its lowermost position such as that illustrated in Fig. 4, the fluid pressure which is exerted on the top of the hammer I4 may be released by flow of fluid downwardly through the upper end of the bore 24 past the head portion of the valve member 25 and into the enlargement or recess 33. The path of the fluid fiow is from the recess 23, through the ports 32. into the bore II provided in the valve member 25 and from thence downwardly and into the fluid passage l8 which is provided in the interior of the hammer I4.

In order that the movement of the valve member 25 from the position illustrated in Fig. 1 to the position illustrated in Fig. 4 may be made responsive to the fluid pressure existing in that portion of the housing disposed above the upper end of the hammer I4, I prefer to provide a plurality of longitudinally extending slots 34 through the wall of the tubular portion of the valve member 25 so as to define a plurality of longitudinally extending spring members, each of these members having formed thereon an outwardly extending projection 35 adapted to be received in a corresponding recess 35 formed in the interior surface of the bore 24. The lower surface which defines the recess 36 is preferably inclined inwardly and downwardly at a slight angle and the corresponding surface of the projection 35 is preferably similarly inclined so that when the downward force which is exerted upon the upper end of the valve member 25 reaches a certain predetermined value, the inwardly directed component thereof which is developed at the engagement between the two aforementioned inclined surfaces will be suilicient to cause the spring members which are defined by the slots 34 to be defiected inwardly a distance sufficient to cause the circle which is defined by the exterior surface of the projections 35 to be reduced to a diameter corresponding to the diameter of the bore 24.

When this condition obtains, the valve member 25 will be released from its upper position and will be permitted to move downwardly under the urging of the fluid pressure exerted on the upper end thereof. As aforementioned, this downward movement will be limited in the position illustrated in Fig. 4 by the action of the pin 26 and slots 21.

The immediate release of fluid pressure from above the hammer I4 will permit the spring I3 to drive the hammer I4 upwardly into violent impact with the anvil I6. This impact will be transmitted through the housing I and the lower adaptor I to the fish with which the jar is engaged so as to effect a loosening of such fish.

The preferred mode of operation of my device contemplates the exertion of a considerable upward force on the fish prior to the time the jar,

loosen the fish from whatever condition is causing the fish to be stuck within the well bore.

As soon as the blow is struck by the hammer,

it is necessary that the valve member 25 be moved from the position illustrated in Fig. 4 back to a closed position, as is illustrated in Fig. 1, in order to permit a second blow to be struck by the hammer.

The device of my invention-provides for an automatic re-setting of the valve member 251 by means of the force developed by the inertia of the valve member 25 at the time the hammer It comes into engagement with the anvil it. The valve member is therefore made of such weight as to cause the inertia force to be sufficient to overcome the sliding friction of the projections 35 on the walls of the bore 24 and move the valve member upwardly to the initial position as is illustrated in Fig. 1. g

It will therefore be seen that the valve member is self-resetting so that immediately upon the delivering of the jarring blow, all of the mechanism is rastored to the positions occupied before any attempt to strike was initiated, as is illustrated in Fig. 1. It therefore follows that as long as the mud pumps at the ground surface are maintained in operation, the above described be repeated so that it is possible to exert a steady upward pull on the fish while repeatedly striking upwardly directed jarring blows, thus permitting the fish to be gradually inched away from the cave-in or condition that is causing the fish to stick within the well bore.

The same cycle of operation and the same advantages may be obtained by a construction such as that illustrated in Figs. 6 through 9a. This device operates on the same principle as the modification previously described and accordingly includes a barrel 5|} connected as by means of threads 5| to an upper adaptor 52, the adaptor 52 carrying a pin portion 53 permitting attachment to the aforementioned tool joint half 5 comprising the lowermost end of the drill string. The lower end of the housing 50 is similarly engaged as by means of threads 54 to a lower adaptor 55, this adaptor being provided with a box 56 permitting attachment to the pin portion 8 of the aforementioned tool joint half I form- ,ing a part of the connection between the jar =,and the fish.

As in the previously described modification, the lower adaptor 55 is provided with a wash open- :ing 51 which, at its junction with the upper end of the adaptor 55, defines a shoulder 58 upon 'whicha strong compression spring 59 may be adaptor I2 is provided with a wash opening 63 assayed which may be enlarged as indicated at M to define a housing for enclosing a valve spring 85. The valve spring 65 is adapted to exert an a stem portion d1 of which is mounted for alidable movement in a spider 88 secured as by means of threads 69 in an enlarged lower portion of the bore $4. The upper end of the valve stem 81 may carry a spider ill adapted to serve the dual purpose of effecting connection between the valve spring 65 and the valve stem 81 and limiting the upward movement of the valve member 68 through engagement of the spider 15 with a shoulder H formed at the junction between the wash opening 63 and the enlargement 64 thereof. The spider Ill is preferably constructed in the form of a star or similar shape so as a establish a fluid connection between the wash opening 83 and the valve spring housing 86 at the time the spider 10 is engaged with the shoulder 1| and a fluid connection between the valve spring housing 64 and the upper portion of the housing 50 is preferably established as by providing a plurality of fiuid passages 12 in the aforementioned lower spider 68.

The valve member 66 is adapted'to engage an annular seat 13 which is formed at the upper end of the hammer 60 by the intersection therewith of a longitudinally extending bore I4 which is formed in the hammer. It will be observed that the valve member 65 thus serves to close oh the fluid passage through the housing d at the top of the hammer 60 so that when the mud pumps are started the pressure which is transmitted to the interior of the housing 5d will be applied to the upper end of the hammer $0, and serve to move the hammer downwardly within the housing 60 and compress the spring 59. It will also be noted that the pressure which is exerted on the upper end of the hammer do is also exerted on the valve member 66 so as to tend to hold the valve member 66 in a closed position and to tend to cause the valve member 56 6 to be moved downwardly along with the hammer The valve spring 65 is preferably made sumciently light to permit this following movement of the valve member 65 to take place so that the parts may be moved by operation of the mud pumps into positions such as that illustrated in Fig. 7. When this position is reached by the parts, the valve spring 65 is compressed substantially to its upper limit and it is necessary, in order that the desired upwardly directed blow be 55 struck by the jar, to at this point open the valve 66 substantially instantly. I therefore provide a push rod or valve opening member 15 which is disposed within the bore 14 formed through the hammer 60, the push rod 15 carrying at its lower to end an annular flange portion 16 adapted to rest upon a small compression spring I1.

The compression spring I1 may be housed within an enlargement. 18 of the aforementioned wash opening 51 which is provided in the lower adaptor 65 55, the lower end of the compression spring 11 being rested upon a shoulder 19 which is formed at the Junction of the wash opening 51 and the enlargement 18 thereof. The flange portion 18 is preferably apertured as indicated at 80 in Fig. 70 7a to provide a fluid interconnection between the interior of the housing 50 and the wash opening The spring constants of the valve spring 5 and the push rod spring 11 are preferably so adjusted that when they are exerting their maxiupwardly directed force upon a valve member $8.

mum combined force, such force is insufliclent to eflect an opening of the valve 88. when the; springs are thus adjusted, the simultaneous downward movement of the hammer 80 and the valve member 88 will continue until the valve member 88 engages the upper end of the push rod 18 at which time the push rod 15 will also be moved downwardly with the valve member 88. This downward movement of the push rod will continue until the adjacent turns of the helical spring 11 are brought into engagement with each other, at which time further downward movement of the push rod 18 is positively prevented.

The relative positions of the parts at the time the downward movement of the push rod 18 is arrested is illustrated in Figs. 7 and 7a. When the parts occupy these positions, continued operation of the mud pumps serves to force the hammer 80 downwardly an additional small distance. Because such movement of the hammer 80 is permitted while further movement of the valve member 68 is positively prevented by the push rod 15, the valve member 88 will be slightly raised from its seat 13 so as to dispose the parts in positions such as that illustrated in Figs, 8 and 841. Such partial opening of the valve causes fluid to flow from that portion of the interior of the housing 80 which is disposed above the valve 88 into the bore 1,; provided in the hammer 88 with the result that the downward force on the valve member 88 is reduced. As soon as such a reduction in force occurs, the push rod spring 11 and the valve spring 85 serve to impart an upwardly directed accelerating force to the valve member 88, the spring 11 serving to provide a high acceleration during the first part of the upward movement of the valve and the valve spring 88 serving to cause a continuation of the upward movement of the valve to its final upward position such as that illustrated in Fig. 9. Simultaneously with the retraction of the valve member 88, the pressure exerted on the top of the hammer 80 is also released with the result that the compression spring 59 immediately starts the hammer 88 in a continuously accelerating upward movement. The movement of the hammer 88 is arrested by engagement of the striking portion 8| thereof with the anvil 82 at which time a severe upwardly directed impact is transmitted to the fish.

In order that this operation may take place, it is necessary that the mass of push rod 18 and the valve 88 be so adjusted with respect to the force which is exerted by the spring 85 and 1.1 as to cause the valve member 88 to accelerate at a higher rate than does the hammer 80 in order to permit the valve member 86 to be completely retracted before the hammer 88 is moved to impacted position. It will be observed by having reference to Fig. 6 that as soon as the blow is struck, the valve member 88 again occupies a closed position relative to its seat 18 so that continued operation of the mud pumps will cause a repetition of the above described cycle.

It will be appreciated that with the above described embodiments of m invention, the valve member 88 will be abruptly closed as soon as the jarring blow has been struck by the hammer, with the result that a considerable water hammer" will be produced. Such a water hammer causes extremely high pressure to be momentarily produced with the attendant possibility of injuring the joints in the drill string between the jar and the ground surface.

Such water hammer may be prevented by employing an additional refinement constructed which is extended downwardly from the upper along the lines illustrated in Fig. 10. The pressure developed the instant the valve member 88 closes may be relieved by providing a fluid bypass around the valve member 88. As is illustrated in Fig. 10 this by-pass may conveniently comprise a longitudinally extending bore 8| surface of the hammer 88, the bore 8| being extended into communication with the internal bore 14 or the hammer 88 by means of one or more laterally extending bores 82 which are extended between the bore 14 and the bore 8|. 'ihe bore 8| is preferably enlarged as indicated at 88 to define a shoulder 84 against which a compression spring '88 may rest. The compress sion-spring 85 serves to urge a ball valve member 88 upwardly into engagement with a seat member 81 which may be secured as by means of threads 88 within the upper end of the bore 83.

The cross sectional area or the seat member 81 and the spring constant of the valve spring 85 are so adjusted as to maintain the ball valve member 88 closed when the fluid pressure exerted on the upper end of the hammer 88 rise; to a value suilicient to force th hammer to its lowermost position. but are so adjusted as to cause an opening of the valve should the fluid pressure exceed this operating value by any substantial amount. By so adjusting the pressure at which the valve 88 opens, water hammer will be prevented at'the time the main valve member 88 closes for the reason that the abrupt rise in pressure produced by the closing of the valve member 88 will cause the valve member 88 to open the by-pass around the valve member 88 and thus relieve the pressure which is developed on the upper side of the valve member 88. This relief will prevent the momentary increase of pressure on the upper side of the valve member 88 from reaching a sufliciently high value to produce the undesired effects of a water hammer.

I have also illustrated in Fig. .10 an alternative arrangement for effecting the opening of the valve member 88 at the time the hammer 88 is moved to its lowermost position. It will be noted that in the construction illustrated in Fig. 10, the push rod 15 and its spring 11 are omitted. The functions of these two elements may be retained, however, by so adjusting the proportions of the valve spring as to cause adiacent turns thereof to come into abutting relation with each other at the time the hammer 88 is moved to a point closely adjacent its lowermost position. When this condition obtains further downward movement of the valv member 88 will be prevented, with the result that additional downward movement of the hammer 88 will break the fluid seal at the valve member 88 and permit upward movement of the valve member and the resulting operation of the device in the manner previously described.

When this form of construction is employed, the valve spring 88 should be made with suillcient stiifness as to p uce a higher acceleration of the valve member 88 than is imparted to the hammer 80 so as to prevent the hammer from overtaking the valve member during upward movement of the hammer.

The ball valve and by-pass construction just described may be incorporated in the valve member 88 if desired by employing a construction such as that illustrated in F18. 11. As is illustrated in that figure, the head of the valve membar 66 is elongated in an axial direction to provide a cylindrical head 90. The-increased length of the head 90 may be accommodated by providing a skirt portion 9| on the upper adaptor 52 so as to dispose the anvil 82 thereof at a somewhat lower location than in the form of the invention illustrated in Figs. 6 through 9a. The valve head 90 is: preferably provided "with an upwardly extending ,longitudinal bore 92 which is providedwith a reduced diameter ex- 10 tension 93 thereof; extended into communication with'the space above the hammer 60 as by means of a fluid passage 94. The extension 93 serves as a valve seat foraball valve member 95 which may be urged thereagainst by means of a compression spring 98 supported upon a bushing19'| threadedly secured within the lower end of the". bore 92.

It will be observed that this structure functions in the same manner as the modification 20 illustrated in Fig. 10, the valve member 95 being moved to an open position as soon as the pressure which i exerted upon the upper end of the hammer B0 rises to a predetermined maximum value so as to prevent a water hammer '25 from being produced by the closing of the valve 66.

I have also illustrated in Fig. 11 an additional refinement which may be incorporated in this and in the other modifications of my inventiori'flao" previously described and consisting in the provi- A sion of an orifice for limiting th rate at which fluid may be supplied to the interior of the housing within which the hammer is mounted. jIfhis orifice may be provided by employing afheanf. which may comprise a cylindrical plug member 98 externally threaded as indicated at 99 to permit its being secured within a correspondingly threaded bore formed in the upper portion of the tool joint half 52. The "bean" or plug B8 is 40' provided with a small diameter longitudinally ex--- tending bore I00 adapted to permit the passage of drilling fluid downwardly into the chamberldefined by the housing. It has been found that the provision of such a device as the bean 98 or other fiow limiting means serves to permit the pressure above the hammer to be lowered to a substantially lower value when the jar mechanism is tripped than is the case when such a flow limiting device is not employed, and also serves to reduce the rate of flow of fluid past the hammer during upward movement thereof to a-sufficiently low value as to materially reduce the fluid drag on the hammer and thus permit thedevelopment of the maximum impact on the anvil.

Another useful function which may be ascribed to the flow limiting device is that of slowing down the operation of the jar so that the blows which are struck by the hammer will be spaced apart. whereas, if the bean is not employed, it may be found that the blows delivered by the jar will occur in very rapid succession particularly where the slush pumps employed are high speed and large capacity pumps.

It is intended that the bean 98 or other similar 5 flow limiting means be employed with the previously described modifications of my invention as 5a, inclusive.

From the foregoing it will be observed that I have provided a jar construction by means of which a constant and undi-minished upwardly directed force may be exerted on a fish with which the jar is engaged and that this force may be maintained while repeated upwardly directed jarring blows are also exerted on the fish.

It will be noted furthermore'that the jarring action of the device of my invention is controllable from the ground surface by the control of.

the mud pumps; that is, that th jarring action may be started by the starting of the mud pumps and may be continued for as long a time as is, desired and may be stopped by merely stopping the mud pumps.

It will also be observed that .I have provided; in the jar of my invention two types of control equipment for controlling the jarring action of the jar, the first form of the invention described herelnabove being provided with a pressure responsive means for releasing the compression spring to al-:

low that spring to force the hammer upwardly to develop the jarring blow,.whil the second form of the invention described hereinbefore is provided with a displacement responsive device which is responsive to compression of the spring a pre- While I have shown and described the preferred embodiment of my invention, 1. do not desire to be.

limited to any of the details of construction shown or described herein, except as defined in the appended claims. I claim: 1 I 1. In a jar for delivering upwardly directed impacts to a fish stuck me. well bore, the combination of: a strain member adapted to be inserted in said well bore and attached to said fish;

and having an anvil thereom hammer means mounted for retracting movement away from said anvil and for striking movemenj j nto impacting relation therewith for imparting upwardly directed impacts to said anvil; means normally urging said hammer toward impacting position; means for applying a force to said hammer to move said hammer. away from said anvil; and tripping means responsive to a predetermined resistance to said letracting movement for removing said force from saidhammer, whereby said hammer is moved into impacting relation with said anvil.

2. In a jar for delivering upwardly directed impacts to a fish stuck in a well bore, the combination of: a strain member adapted to be-in-' serted in said well bore and attached to said fish and having an anvil thereon; hammer means mounted for retracting movement away from said anvil and for striking movement into impacting relation therewith for imparting upwardly directed impacts to said anvil; means normally urging said hammer toward impacting position; means for applying a force to said hammer to move said hammer away from said anvil; tripping means responsive to a predetermined resistance to said retracting movement,

for removing said force from said hammer, whereby said hammer is moved into impacting relation with said anvil; and means responsive to arrival of said hammer at impacting position for re-setting'said tripping means to re-apply said force to said hammer.

8. In a Jar ior delivering upwardly directed impacts to a fish stuck in a well bore, the combination of: a strain member adapted to be inserted in said well bore and attached to said fish and having an anvil thereon; hammer means mounted for retracting movement away from said anvil and for striking movement into impacting relation therewith for imparting upwardly directed impacts to said anvil; means normally urging said hammer toward impacting position;- means for applying a force to said hammer to move said hammer away from said anvil; and tripping means responsive to retracting movement of said hammer a predetermined distance for removing said force from said hammer, whereby said hammer is moved into impacting relation with said anvil.

' 4. In a Jar for delivering upwardly directed impacts to a fish stuck in a well bore, the combination of: a strain member adapted to be inserted in said well bore and attached to said fish and having an anvil thereon; hammer means mounted for retracting movement away from said anvil and for striking movement into impacting relation therewith for imparting upwardly directed impacts to said anvil; means normally urging said hammer toward impacting position; means for applying a force to said hammer to move said hammer away from said anvil; tripping means responsive to retracting movement of said hammer a predetermined distance for removing said force from said hammer, whereby said hammer i moved into impacting relation with said anvil; and means responsive to arrival of said hammer at impacting position for re-setting said tripping means to re-apply said force to said hammer.

5. In a jar for delivering upwardly directed impacts to a fish stuck in a well bore. the combination of: a housing adapted to be inserted in a well bore and attached to said fish and including means for attachment to a conduit extending from the ground surface and into communication with the interior of said housing; an anvil carriedby the upper end of said housing; a. piston-like hammer mounted in said housing for slidable movement toward and away from said anvil; spring means for normally urging said hammer into engagement with said anvil whereby the supplying of fluid under pressure to said housing through said conduit moves said hammer away from said anvil against the urging of said spring means; and tripping means actuable in response to rise of fluid pressure in said housing to a predetermined value to establish a fluid connection through said hammer to release the fluid pressure whereby actuation of said tripping means permits said spring means to move said hammer back into engagement with said anvil to impart an upwardly directed impact to said fish.

6. In a jar for delivering upwardly directed impacts to a fish stuck in a well bore, the com bination of: a housing adapted to be inserted in a well bore and attached to said fish and including means for attachment to a conduit extending from the ground surface and into communication with the interior of said housing; an anvil carried by the upper end of said housing; a piston-like hammer mounted in said housing for slidable movement toward and away from said anvil; spring means for normally urging fiuid connection through said hammer to release I the fluid pressure whereby actuation of said tripping means permits said spring means to move said hammer back into engagement with said anvil to impart an upwardly directed impact to said fish.

'7. In a jar for delivering upwardly directed impacts to a fish stuck in a well bore, the combinationof: a housing adapted to be inserted in a well bore and attached to said fish and including means for attachment to a conduit extending from theground surface and into co munication with the interior of said housing; an anvil carried by the upper end of said housing; a piston-like hammer mounted in said housing for slidable movement toward and away from said anvil; spring means for normally urging said hammer into engagement with said anvil whereby the supplying of fluid under pressure to said housing through said conduit moves said hammer away from said anvil against the urging of said spring means; and tripping means actuable in response to rise of fiuid pressure in said housing to a predetermined value to establish a fluid connection through said hammer to release the fluid pressure whereby actuation of said tripping means permits said spring means to move said hammer back into engagement with said anvil to impart an upwardly directed impact to said fish; and means coacting with said tripping means and responsive to movement of said hammer into engagement with said anvil to actuate said tripping means to close said fluid connection and permit said hammer to be again moved away from said anvil.

8. In a jar for delivering upwardly directed impacts to a fish stuck in a well bore, the combination of: a housing adapted to be inserted in a well bore and attached to said fish and including means for attachment to a conduit extending from the ground surface and into communication with the interior of said housing; an anvil carried by the upper end of said housing; a pistonlike hammer mounted in said housing for slidable movement toward and away from said anvil; spring means for normally urging said hammer into engagement with said anvil whereby the supplying of fluid under pressure to said housing through said conduit moves said hammer away from said anvil against the urging of said spring means; and tripping means actuable in response to rise of fluid pressure in said housing to a predetermined value to establish a fluid connection through saidhammer to release the fluid pressure whereby actuation of said tripping means permits said spring means to move said hammer back into engagement with said anvil to impart an upwardly directed impact to said fish; and means coacting with said tripping means and responsive to movement of said hammer into engagement with said anvil to actuate said tripping means to close said fluid connection and permit said hammer to be again moved away from said anvil.

9. In a jar for delivering upwardly directed impacts to a fish stuck in a well bore, the combination of a housing adapted to be inserted in a well bore and attached to said fish and includassav'as v i e through said conduit moves said hammer away tion with the interior of said housins; an anvil carried by said housing; a piston-like hammer mounted in said housing for slidable movement toward and away from said anvil: spring means for normally urging said hammer into engagement with said anvil; means deflning a fluid passage extending from the exterior of said housing to the interior thereof between said hiimmer and said anvil; valve means normally closing said fluid passage and movable by fluid pressure exerted thereon to a position opening said passage; and means for holding said valve in closed position releasable in response to rise in said fluid pressure to a predetermined value to permit movement of said valve to open position, whereby the supplying of fluid under pressure to said housing through said conduit moves said hammer away from said anvil against the urging of said sprin'g means and opening said valve releases said fluid pressure and permits said spring means to move said hammer into engagement with said anvil to impart an upwardly directed impact to said flsh.

10. In a jar {or delivering upwardly directed impacts to a flsh stuck in a well bore, the combination of: a housing adapted' to be inserted in a well bore and attached to said iish and including means for attachment to a conduit extending from the ground surface and into communication with the interior of said housing; an anvil carried by said housing; a piston-like hammer mounted in said housing for slidable movement toward and away from said anvil and having a fluid passage extending longitudinally therethrough; spring means for normally urging said hammer into engagement with said anvil; valve means normally closing said fluid passage and movable by fluid pressure exerted thereon to a position opening said passage; and means iior holding said valve in closed position releasable in response to rise in said fluid pressure to a predetermined value to permit movement of said valve to open position, whereby the supplying of fluid under pressure to saidhousing through said conduit moves said hammer away from said anvil against the urging of said spring means and opening said valve releases said fluid pressure from said anvil against the urging of said spring means and opening said valve releases said fluid pressure and permits said spring means to move said hammer into engagement with said anvil to impart an upwardly directed impact to said flsh; and means coacting with said holding means and responsive to momentum of said valve means at the time oi! engagement of said hammer with said anvil for permitting movement of said valve to closed position and thereafter holding said valve in said closed position.

12. In aim for delivering upwardly directed impacts to' a fish stuck in a well bore, the combination of: a housing adapted to be inserted in a well bore and attached to said flsh and including means for attachment to a conduit extending from the ground surface and into communication with the interior of said housing; an anvil carried by said housing; a piston-like hammer mounted in said; housing for slidable movement toward and away from said anvil and having a fluid passage extending longitudinally therethrough; spring means for normally urging said hammer into engagement with said anvil; valve means for closing said fluid passage mounted for movement relative to said hammer between open and closed positions; and means responsive to movement of said hammer to a position a predetermined distance from said anvil for moving said valve to said open position, whereby the supplying of fluid under pressure to said housing through said conduit moves said hammer away from said anvil against'the urging of said sprin and permits said spring means to move said hammer into engagement with said anvil to impart an upwardly directed impact to said flsh.

11. In a jar for delivering upwardly directed impacts to a flsh stuck in a well bore, the combination of: a housing adapted to be inserted in a well bore and attached to said flsh and including means for attachment to a, conduit extending from the ground surtace and into communication with the interior of said housing; an anvil carried by said housing; a piston-like hammer mounted in said housing for slidable movement toward and away from said anvil and having a fluid passage extending longitudinally therethrough; spring means for normally urging said hammer into engagement with said anvil; valve means normally closing said fluid passage and means'and opening said valve releases said fluid pressure and permits said spring means to move said hammer into engagement with said anvil to impart an upwardly directed impact to said 13. In a jar for delivering upwardly directed impacts to a flsh stuck in a well bore, the combination of: a housing adapted to be inserted in a well bore and attached to said flsh and including means for attachment to a conduit extending {mm the ground surface and into communication with the interior of said housing; an anvil carried by said housing; a piston-like hammer mounted in said housing for slidable movement toward and away from said anvil and having a fluid passage extending longitudinally therethrough; spring means or normally urging said.

housing in a position extending through said pas-- sage and disposing one end thereof a predetermined distance from said anvil, whereby movement 0! said hammer and valve to a position engaging said head member and said push rod arrests movement of said valve'and subsequent additional movement of said hammer opens said valve to relieve said fluid pressure and permit said spring to move said hammer into engagement with said anvil.

14. In a jar for delivering upwardly directed impacts to a flsh stuck in a well bore, the combination of: a housing adapted to be inserted in a well bore and attached to-said fish and including means for attachment to a conduit extending from the ground surface and into communication with the interior of said housing; an anvil carried by said housing; a piston-like hammer mounted in said housing for slidable movement toward and away from said anvil and having a fluid passage extending longitudinally therethrough'; spring means for normally urging said hammer into engagement with said anvil; valve means mounted on said housing for movement with said hammer and independently thereof, said valve means including a head portion extended across said fluid passage, whereby fluid pressure transmitted to said housing through said conduit will hold said valve against said hammer and move said hammer and valve simultaneously away from said anvil against the urging of said spring means; a push rod supported on said housing in a position extending through said passage and disposing one end thereof a predetermined distance from said anvil to engage said head member when said hammer and valve are moved away from said anvil; means mounting said push rod for limited axial movement in the direction of movement of said hammer to arrest movement of said valve member when said push rod is moved to the end of its limited movement and thereby open said valve upon subsequent additional movement of said hammer; and accelerating spring means for normally urging said push rod toward said anvil to accelerate movement of said valve member away from said hammer when said valve is open.

15. In a jar for delivering'upwardly directed impacts to a fish stuck in a well bore, the combination of: a housing adapted to be inserted in a well bore and attached to said flsh and including means for attachment to a conduit extending from the ground surface and into communication with the interior of said housing; an anvil carried by said housing; a piston-like hammer mounted in said housing for slidable movement toward and away from said anvil; spring means for normally urging said hammer into engagement with said anvil tripping means actuatable in response to movement of said hammer a predetermined distance away from said anvil to establish a fluid connection from the exterior of said housing to the interior thereof between said hammer and said anvil, whereby the supplying of fluid under pressure to said housing through said conduit moves said hammer away from said anvil against the urging of said spring means and actuation of said tripping means permits said spring means to move said hammer into wardly directed impact to said fish; means coacting with said tripping means and responsive to movement of said hammer into engagement with said anvil to actuate said tripping means to close said fluid connection and permit said hammer to be again moved away from said anvil; and a pressure relief valve actuatable in response to rise in fluid pressure in said housing to a predetermined value toestablish a fluid connection from the exterior of said housing to the interior thereof to prevent water hammer upon re-closing of said tripping means.

16. In a jar for delivering upwardly directed I impacts to a flsh stuck in a well bore, the combination of: a housing adapted to be inserted in a well bore and attached to said fish and including means for attachment to a conduit extending from the ground surface and into communication with the interior of said housing; an anvil carried by said housing; a piston-like hammer mounted in said housing for slidable movement toward and away from said anvil and having a fluid passage extending longitudinally therethrough; spring means for normally urging said hammer into engagement with said anvil; valve means mounted on said housing for movement with said hammer and independently thereof, said valve means including a head portion extended across said fluid passage, whereby fluid pressure transmitted to said housing through said conduit will hold said valve against said hammer and move said hammer and valve simultaneously away from said anvil against the urging of said spring means; accelerating spring means for normally urging said valve means toward open position; means for arresting movement of said valve means a predetermined distance from said anvil, whereby additional movement of said hammer away from said anvil permits said accelerating spring means to move said valve to open position and permits movement of said hammer into engagement with said anvil: a fluid by-pass channel extended from said fluid passage and into communication with the interior of said housing at a point disposed between said hammer and said anvil; and a pressure responsive valve normally closing said fluid by-pass channel and actuatable in response to rise in said fluid pressure above a predetermined value to open said by-pass channel, whereby water hammer resulting from the re-closing of said valve means is prevented by the opening of said pressure responsive valve.

JOHN '1'. Pumps.