US3406770A

US3406770A - Jarring tool

Info

Publication number: US3406770A
Application number: US560617A
Authority: US
Inventors: Bryant P Arterbury; Thomas C Burroughs
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-06-27
Filing date: 1966-06-27
Publication date: 1968-10-22
Anticipated expiration: 1985-10-22

Description

Oct. 22, 968 B. if. ARTEREURY Erm, 3,406,770

JARRING TOOL 5 Sheets-Sheet l Filed June 27, 1966 Oct. 22, 1968 E, R ARTERBURY ET AL 3,406,770

JARRING TOOL Oct. 22, 1968 Q P, ARTERBURY ET AL 3,406,770

JARRING TOOL 5 Sheets-Sheet 3 Filed June 27, 1966 United States Patent O 3,406,770 .JARRING TOOL Bryant P. Arterbury and Thomas C. Burroughs, Houston, Tex., assignors of thirty-three and one-third percent to Roy L. Arterbury, Houston, Tex.

Filed June 27, 1966, Ser. No. 560,617 8 Claims. (Cl. 175-299) ABSTRACT OF THE DISCLOSURE A well tool adapted to impart jarring impacts to a device within a well bore, said tool having a tubular body with an internal projection, a latch body having arms extending through the projection, a means for preselecting the force at which the latch arms pull through the projection, a hammer on the latch body adapted to impact against one end of the tubular body, means for connecting to the device to be jarred and to the surface so that a lifting force may be exerted on the tool to cause it to vbe actuated and to impart its jarring impact to the device.

The present invention relates to an improved well tool adapted to impart jarring impacts to a device within a well bore.

Jarring tools have been used to jar a well tool or string which is stuck in a well bore to loosen the stuck tool or string and allow its recovery. Additionally, jarring tools have been used to set or release other well tools within a well bore by the impact which the jarring tool delivers.

In the uses of such jarring tools, it is often desirable to be able to deliver repeated jarring impacts and particularly to be able to deliver jarring impacts in both an up- Ward and a downward direction.

It is, therefore, an object of the present invention to provide an improved jarring tool to deliver multiple jarring impacts in both directions within a well bore.

Another object is to provide an improved well jarring tool which will jar upwardly or downwardly in any sequence desired.

A further object is to provide a well jarring tool for jarring in both directions and having a preselected jarring force.

Still another object is to provide a double-acting jarring tool for use in a well bore which may be actuated to jar upwardly or downwardly by manipulation of the means suspending the tool in the well bore.

A still further object is to provide an improved doubleacting jarring tool for use in a well bore which is lowered and operated in the well bore on a wire line,

Another object is to provide an improved well jarring tool in which the means supporting the well jarring tool in a well bore is at least partially insulated from the shock of the jars created by the tool.

Another object is to provide an improved Well jarring tool of limited length which may be inserted into a well bore and retrieved therefrom through the usual lubricator.

A further object is to provide an improved well jarring tool which is releasably held in inactive position until it is positively released to deliver a jar.

These and other objects of the present invention are hereinafter set forth.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and where- FIGURE l is a sectional view ofthe preferred form of CII 3,406,770 Patented Oct. 22, 1968 jarring tool of the present invention with its component parts in position for lowering into the well bore;

FIGURE 2 is another similar sectional view of the jarring tool of FIGURE 1 in position immediately before an upward jar;

FIGURE 3 is a sectional view of a portion of the jarring tool of FIGURE l at the moment of upward impact;

FIGURE 4 is a sectional view of a portion of the jarring tool of FIGURE 1 at the moment of downward impact;

FIGURE 5 is a detail sectional view of the adjustable jar assembly;

FIGURE 6 is a cross-sectional view of the jar assembly taken on line 6-6 in FIGURE 5;

FIGURE 7 is a side view of the hammer to illustrate the various positions of the releasable means for holding the jar of the present invention in inactive position; and

FIGURE 8 is a sectional view of a modied form of well jarring device of the present invention which is suitable for insertion into a Well bore through the usual lubricator.

The jarring tool of the present invention is a mechanical jar which, in its preferred form, includes a spring-loaded accelerator to provide the desired impact force for jarring and to at least partially insulate the means supporting the jar from the impact forces. The mechanical jar assembly I is provided with a fishing connection F of any suitable type for engaging a device in a well bore. The jar assembly I is below and connected to the accelerator assembly A. The weight assembly W is provided with the usual wire line connection at its upper end and connects to the accelerator assembly A at its lower end. The jarring tool is lowered into a well bore wit-h the assemblies connected, as shown in FIGURE l, on the wire line 10. The fishing connection F engages to the device to be jarred before the jarring tool is actuated.

The weight assembly W is sufficiently long to provide the weight necessary for resetting the jar assembly after it has jarred in an upward direction. The body 12 of weight assembly W is connected to the wire line connection 14 at its upper end and has a sub 16 at its lower end to engage the stem 18 extending upwardly from the accelerator assembly A.

The accelerator assembly A provides the storingv of energy for the jarring tool so that when the jar assembly releases, the accelerator assembly A exerts a force to accelerate the moving components of t-he jar assembly I to impact. The body 20 of accelerator A is tubular in shape with a central bore 22 extending therethrough. Upperv sub 24 is secured into the upper end of body 20 and is provided with a central bore 26 through which the stem 18 extends. The bore 26 is larger than stem 18 to allow the stem 18 freedom of sliding movement therein. The stem 18 is secured to the sub 16 as by threading and extends through the bore 26 into the bore 22, terminating in head 28. The head 28 is smaller in diameter than the bore 22 in body 20 to allow reciprocating movement of head 28 therein. The head 28 is biased downward with respect to the body 20 by the spring 30 which surrounds stem 18 within body 20. The upper end of spring 30 abuts the lower surface 32 on upper sub 24 and the lower end of spring 30 abuts the upper surface 34 on head 28. In this way the spring 30, whenever compressed, exerts a downward force on head 2.8 and an upward force on up` per sub 24. Thus, the spring 30 provides a resilient connection between the weight assembly W and the jar assembly I The lower end of body 20 includes the sub 36. The jar assembly I is connected to the accelerator assembly A by the threaded engagement of the sub 38 within the sub 36 and the connecting rod 40 engaging in the sub 38.

The function of the jar assembly I is to resist an upward pull by the wire line 10 when it has engaged the device to be jarred and to suddenly release with a rapid movement to cause an impact which is transmitted to such device. The body 42 of jar assembly I is tubular and includes a central bore 44. Rod 40 extends through the upper closure 46 and terminates in the hammer 48 as best seen in FIGURE 5. In running position means is provided, such as shear pin 49, to releasably secure the hammer 48 to the body 42 as hereinafter explained with reference to FIGURE 7. Latch body 50 is threaded into the lower end of hammer 48. The intermediate portion of latch body 50 is cylindrical in shape and is provided with internal threaded bore 52 to receive adjusting screw 54. The lower end of latch body 50 is divided into a plurality of downwardly extending arms 56, each of which terminates in outward projections or dogs 58.

Cooperating with the dogs is the inward projection 60 on tubular member 62 which is threaded into the lower end of body 42. The upper outer portion of each of the dogs 58 is provided with a steep or sharply tapered surface 64 which engages the sharply tapered surface 66 on projection 60 when the latch body 50 is raised with respect to jar body 42. The lower outer portion of dogs 58 is provided with the gradually tapered surface 68 which cooperates with the upper gradually tapered surface 70 on projection 60 for resetting the jar assembly J after an upward impact.

The position of the head 72 on adjusting screw 54, the flexibility of the arms 56 and the steepness of the tapered surfaces 64 and `66 determine the tension needed in wire line 10 to actuate the jar assembly I to provide an upward jar. This tension in wire line 10 to release the dogs, because of the compression of spring 30 in the accelerator assembly, is therefore also directly related to the severity of the impact force produced. The marks 57 on the arms 56 yare used to Preselect the jar force to be developed. Such marks 57 can be seen through the window 63 defined by the member 62 and the body 42. By positioning the head 72 of adjusting screw 54 with reference to the marks 57, the jar force may be preselected. For example, t-he upper mark may be selected to provide a 10U-pound jar, the intermediate mark a 200-pound jar land the lower mark a 300Jpound jar.

The force necessary to shear the pin 49 is always less than the force to actuate the jar. In this manner, the pin 49 holds the jar assembly in inactive position luntil it is ready to exert jarring impacts. The wire line 10 is raised with sufficient tension to create the force necessary to shear the pin 49.

As seen in FIGURE in dashed lines, the adjusting screw 54 has been lowered with respect to its solid line position. Since release of the jar assembly J requires that the dogs S8 pass through the restricted area defined by the projection 60, the position of head 72 on screw 54 varies the amount degree of bending of arms 56 for release. With the head 72 in its solid line position, the bending necessary for release of arms 56 takes place over a longer distance than with the head 72 in its lower position. Thus, the lower the head 72 is positioned, the greater the force is which is required to pull the dogs 58 through the projection 60. For this reason, by aligning the head 72 of the adjusting screw 54 with the marks 57 in the arms 56, the jar force may be preselected as previously described. The fishing connection F is connected to the lower end of tubular member 62 so that any jar of the jar assembly J is transmitted to the device which is to receive the jarring impact.

As previously explained, the means releasably holding the jar inactive includes the shear pin 49 which extends through one of the holes in the body 42 `and the hammer 48. As best seen in FIGURE 7, a pluarlity of holes of different sizes extend through body 42 and hammer 48 to receive the pin 49 which has been preselected to determine the force needed to activate the jar assembly. The smaller the pin the smaller the force needed to shear it and activate the jar.

In operation, the jarring tool is run into a well bore in the position as shown in FIGURE l. When the fishing tool F has engaged the device to be jarred, the wire line is lifted. Lifting of the wire line raises the weight assembly W, the rod 18 and the head 28 on rod 18 to initially shear the pin 49 Iand thereafter to compress the spring 30. The jar assembly J and the body of the accelerator assembly A are not moved initially.

FIGURE 2 illustrates the position of the jarring tool as the dogs 58 start their upward movement. In this position, the spring is compressed to exert an upward force on accelerator body 20 and on rod 40. When the dogs 58 are above the projection 60, the rod and hammer 48v are acceleratedin an upward direction bythe force of spring 30. The jarring impact occurs when hammer 48 hits upper closure 46. This moment of impact is illustrated in FIGURE 3. This impact is transmitted from closure 46 through jar body 42, tubular member 62 and fishing connection F to the device to be jarred.

Resetting of the jarring tool is accomplished by lowering wire line 10 until the dogs 58 are forced downwardly through the interior of projection 60. The tapers on

surfaces

68 and 70 on the projection 60 and dogs 58 are sufciently gradual to allow the weight of the tool above to accomplish the resetting. With the dogs 58 below the projection 60, the tool is then ready to deliver another im# pact.

A downward impact may be delivered by lifting the wire line 10 with a force less than the force required to release the jar assembly I and, thereafter, releasing all tension on the wire line 10. Before the wire line 10 is released, the spring 30 is under almost as much compression as during release for upward jar. When the wire line 10 is released, the spring force is exerted to accelerate the downward movement of head 28 and weight assembly W. This downward movement is transferred by impact of the weight assembly W on accelerator body 20 which hits upper closure 46 of the jar assembly J with a downward impact. This downward impact is transmitted through the tubular member 62 and the fishing connection F to the member being jarred. The downward impact between accelerator assembly A and jar assembly J is shown in FIGURE 4. When a downward jar is applied by the jarring tool, no resetting of the jar assembly J is required since the dogs 58 remain below the projection at all times during a downward jar.

The accelerator assembly A, in addition to preserving the energy for the jars, insulates the wire line 10 from the shocks of the impacts since the spring 30 forms a part of the connection between the jar assembly J and the wire line 10.

In certain applications on well bores, it is desirable that the length of the well jarring tool be short to allow the whole assembly to be inserted into the well bore through the usual lubricator. In such applications, the modified form of the present invention illustrated in FIG- URE 8 is used. This well jarring tool is the same as the preferred form of well jarring tool previously described except that it does not include the accelerator assembly A. This modified tool includes a weight assembly W-l supported on a wire line by the wire line connection 82, the jar assembly I-l and the fishing connection F-l.

The weight assembly W-l is sufficiently long to provide the weight necessary for resetting the jar assembly after it has been jarred in an upward direction. The body 84 of the weight assembly W-1 is connected to the wire line connection 82 at its upper end and has a sub 86 at its lower end to engage the rod 88 extending upwardly from the jar assembly J-l.

The function of the jar assembly J-l is to resist an upward pull by the wire line 80 when the fishing connection F-l has engaged the device to be jarred and to suddenly release with a rapid movement to cause an impact which is transmitted to such device. The body 90'of the jar assembly J-l is tubular and includes a central bore 92. Rod 88 extends through the upper closure 94 and terminates in the hammer 96 as shown in FIGURE 8. In running position, means li`s provided, such as shear pin 98, to releasably secure hammer96 to the body 90 as hereinafter explained.v Latch body 100 is threaded into the lower end of' hammer'96. The intermediate portion of latch body 100 is cylindrical in shape and is provided with internal threaded bore'to receive an 'adjusting `screw (not shown) as hereinbefore described with respect to the jar assembly J of FIGURE 1. The lower end of latch body 100 is divided into a plurality of downwardly extending arms 102, each of which terminates in outward projections or dogs4. The inner projection 106 of body 90 functions to hold the dogs 104 until a preselected upward force has been applied;` The construction of theremainder of the ja'r assembly 1*1 is identical'to the'construction of the jar assembly I as previouslydes'cribed with respect to FIGURE 1. The releasable holding means, the shear pin 98 and the provision for insertion of different-size shear pins through the body 90 and the hammer 96 is also identical in structure andoperation to that previously described with respect to the jar assembly J.

"From 'FIGURE 8 and the foregoing description, it can beseen that the welljarringj tool of rthemodifiedform shown and described omits the accelerator assembly and, therefore, is sufficiently short in length to allow it to be installedinto a well bore through the usual lubricator.

In operation, the modified form of the well jarring assembly provides both an upward and a downward jar. Since the accelerator assembly has been omitted, the length of the wire line 80 should have suicient elongation to maintain the upward velocity of the hammer 96 once the dogs 1,04 have passed through the inner projection 106. When it is placed under the tension sutlicient to actuate the well jarring assembly, the wire line 80 has a certain amount of elongation without any permanent deformation; and when the dogs release the jar assembly before jarring, the tension in the wire line exerts an upward force to move the weight assembly W-l and the hammer 96 upwardly until the hammer reaches and impacts against the upper colsure 94 of the jar assembly J-L Following an upward jar, the jar assembly J-1 is readily reset by releasing the tension on the wire line 80 allowing the whole weight of the weight assembly W-1 to force the rod 88, the hammer 96 and the latch ybody 100, including the arms 102 and the dogs 104,- downwardly until the dogs 104 pass through the inward projection 106. Impact between the sub 86 of the weight assembly W-l and the upper closure 94 of the jar assembly J-1 on resetting creates a downward jar which is transmitted through the body 90 and the fishing connection F-1 to the device which is stuck in the well.

The modified form of well jarring tool of fthe present invention can be run into a well bore through the usual lubricator and, in most cases, has a sufficiently short length to allow the jar to be run connected to well swabs. The shear pin 98 holds the jar in an inactive position unxtil such time as it is connected to the device which is to receive an impact jar. At that time, lifting of the wire line creates sufficient force to shear the lshear pins activating the jar and thereafter providing a jar whenever sufficient Iadditional upward force is exerted on the wire line 80 to cause the dogs 104 to pass through the inward projection 106 in the body of the jar assembly.

From the foregoing it can be seen Athat the jarring tool of the present invention may readily be operated by wire line from the surface of a well bore to provide jarring impacts to a member in the well bore. These impacts may be imparted either upward or downward in any desired sequence and the jarring tool further has provision for preselecting the impact force before the jarring tool is run. Also, the modied form of the well jarring tool of the present invention can be used in applications where the tool is to be inserted into a well bore through the usual lubricator.

In both forms of the invention illustrated, the means holding the well jar assembly in an inactive position-that is, the shear pi-ns restraining movement'of the hammer with respect to the bodyassures that the jar is not actuated until suiiicient force has been exerted on the wire line to shear the pins.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, Iand various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1. A rwell tool adapted to impart jarring impacts to a device within a well bore, comprising:

a mechanical jar including a tubular body, an inward projection |within said body, a latch body having arms extending through said projection and each arm ter- I minating in an outwardly extending dog, said projection and said dogs having sharply tapered mating surfaces for the actuation of said jar in one direction and gradually tapered matingsurf-aces for the resetf ting of said jar after' actuation in said one direction,

means connecting to said mechanical jar and adapted -to engage a device within the well bore to be jarred,

means adjusting said mechanical jar including an adjusting screw in threaded engagement fwitlh said latch body and having a head surrounded by said arms, the position of said head determining the force necessary to actuate said jar in said one direct-ion,

releasable means holding said jar in inactive position,

a weight assembly connected to said jar, and

means connecting said weight assembly to the surface whereby the lifting of said connecting means imposes a load on said jar which is preselected to release said releasable engaging means and thereafter to exceed the preselected force necessary to actu-ate said jar.

2. A well tool according to claim 1, including:

means indicating the jar force in relation to the position of said adjusting screw.

3. A well tool according to claim 2, wherein said indicating means includes:

a window defined by and extending lengthwise of said body from the upper to the lower position of one end of said adjusting screw, and

indicia on one of said arms marking at least two position's to locate said end of said adjusting screw with reference to said indicia and to thereby preselect lthe force of impact of said mechanical jar.

4. A well tool adapted to impart jarring impacts to ya device within a well bore, comprising:

a mechanical jar including a tubular body, an inward projection within said body, a latch body having arms extending through said projection 'and each arm terminating in an outwardly extending dog,

said projection and said dogs having sharply tapered mating surfaces for the actuation of the jar in one direction and gradually tapered mating surfaces for the resetting of the jar after actuation in said one direction,

means on said jar for engaging a device within the well bore to be jarred,

a spring-loaded accelerator connected to said jar to impose a load on said jar when said accelerator is lifted,

means connecting from said spring-loaded accelerator to the surface,

the lifting of said connecting means lifting said accelerator to impose a load on said jar which is predetermined to exceed the force to actuate the jar in one `direction and to impose a load on said jar which is predetermined to be less than the force .to actuate said jar in the opposite direction upon release of said connecting means,

an adjusting screw in threaded engagement with said latch body and [having a head surrounded by said arms, the position of `said head determining the force necessary to actuate said jar in said direction, and

said accelerator being adapted to accumulate the lifting force of the accelerator connecting means and to transmit said force to said latch body whereby when the preset actuating force is exceeded, said arms pass through said projection and said latch body impacts against said tubular body.

S. A well tool adapted to impart jarring impacts to a device within a well bore, comprising:

a mechanical jar including a tubular body having an rupper closure and an inward projection wiltxhin said body and a latch body having arms extending through said projection,

means coacting with said arms to preselect the force necessary to pull said arms through said projection,

'a rod extending through said closure `and a hammer within said tubular body and adapted .to engage said upper closure to impart upward impacts thereto,

a spring-loaded accelerator connected to said rod,

first means for connecting from said spring-loaded accelerator to the surface of the well bore in which said jar and accelerator are positioned,

second means for connecting from said tubular body to a device stuck in the well bore whereby impacts on said closure are transmitted to said device,

said accelerator having a sub adapted to engage said upper closure to impart downward impacts thereto,

said accelerator being adapted to accumulate the lifting force of said first connecting means and to transmit said force to said rod whereby when said preselected force is exceeded, said arms of said latch body pass connecting means comprises a lwire line connecting to said well tool.

8. A well tool according toclaim S, wherein:

the spring of said accelerator is compressed during loading of said mechanical jar and upon release exerts a force to increase the -impact force.

References Cited UNITED STATES PATENTS 1,848,535 3/1932 McCullough 175--302 1,989,907 2/1935 Beck 175-304 X 2,143,349 1/1939 Hobbs v175---302 2,144,869 1/1939 Boulter 175--299 2,241,477 5/ 1941 Rasmussen 175-302 2,671,640 3/ 1954 Baker 175-299 2,733,046 1/ 1956 Thompson 175-304 X 2,876,993 3/1959 Hooks 175-301 3,203,482 8/1965 Lyles 175--299 DAVID H. BROWN, Primary Examiner.