US2557238A - Adjustable jar trip spring - Google Patents

Description

June19, 1951 ER 2,557,238

ADJUSTABLE JAR TRIFSPRING I Filed March 22, 1948 I 2 Sheets-Sheet 1 INVENTOR, 270M224 Zflcyjer;

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' ADJUSTABLE JAR TRIP SPRING Filed March 22, 1948 2 Sheets-Sheet 2 fly 8.

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Patented June 19, 1951 ,UNITED STATES PATENT OFFICE 2 Claims.

This invention concerns apparatus used in the deep well industry and is an adjustable tension, tripping jar assembly attachable at a suitable location in the length of a tool or other well string.

Jar assemblies are used to strike sudden sharp jolts to lower sections of a tool string while in use in a well hole, and a purpose of the instant invention is to provide a jar assembly in which the degree of string tension required before the hammer element can trip oif can be readil regulated from the top of the tool string while the jar assembly is in operational position deep in the hole.

It has long been the practice to regulate the tripping tension in jar tools and an intent of this invention is to provide an improvement and simplification of the tripping control means.

Further, the invention provides a tripping control in which the individual parts are simple of manufacture and installation, and, particularly, are of sturd structure whereby to stand up for a long service life notwithstanding the severe strains and attritional nature of the employment of the tool.

Especially, it is an object to provide a tool jar which is free of delicate elements and tricky modes of adjustment and release.

The invention resides in certain advancements in this art as set forth in the ensuing disclosure and having, with the above, additional objects and advantages as hereinafter, developed, and whose constructions, combinations and sub-combinations and details of means and the manner of operation will be made manifest in the following description of the herewith illustrative embodiment; it being understood that modifications, variations, adaptations and equivalents may be resorted to within the scope, spirit and principles of the invention as it is claimed hereinafter.

Figure 1 is an axial, sectional elevation, with the barrel locked in open or stroke prepared position as to the inside mandrel.

Figure 2 is a cross-section on line 2-2 of Fig. 1.

Figure 3 is a cross-section on line 33, Fig. 1.

Figure 4 is a cross-section on line d4, Fig. 1.

Figure 5 is a cross-section on line 5-5, Fig. 1.

Figure. 6 is a side elevation of the mandrel with its affixed wash pipe stem and the expander.

Figure '1 is a side elevation of the locking sleeve,

Figure 8 is an elevational section of the internally grooved shoe.

The jar assembly embodies a top sub 2 attachable to the near section of a drilling or other tool string (not shown) and has a packing 3 on a wash pipe or stem 4. A feature of this stem 2 is that it has external threads 4t later referred to again and constitutes a part of the means whereby the intensity of the hammer impact on a jar anvil is regulated.

The lower end of the stem 4 is securely threaded at 5t into and becomes a rigid part of a mandrel 5 having a bottom pin 6 to attach to a drill collar or other work tool (not shown).

When the collar and its tool become frozen in a hole the attached mandrel stands as an anchor therewith. The purpose of this invention is to loosen and pull as much of the attached lower tool as may be possible.

Slidable along the lower end of the mandrel 5 is a bushing H fixed in and forming the hammer part of an elongate barrel 1 whose upper end screws onto the sub 2. The barrel can be lowered or raised on the mandrel by operation of the drill string when the jar is in assembly and use therewith.

The main body of the mandrel slidably and turnably fits the barrel bore above the bushing H and a torque drive rib 8 of the barrel is designed to shift down into one or another of lower keyways 50 formed in the mandrel 5 for rotational drive of the mandrel (in either direction), and is adapted to move up, as the barrel is pulled, into slots 5s between longitudinal lugs 5:1: rigid with the upper portion of the mandrel.

The lugs 5a: are spaced up from the channels 50 a distance slightly more than the length of the drive rib 8 of the barrel to form a circumferential clearanceway on the mandrel 9 which permits the rib to be rotated with the barrel about the upper end of the mandrel. This capacity for rotation is availed of as later shown herein.

For the purpose of putting tension in the tool string and inv the frozen mandrel, as may be needed, and to use the stretched tool string as a contractile spring there is rigidly fixed in the barrel l a removable, tubular locking sleeve l0 whose bore is annularly grooved at llig to solidly receive peripheral beads l lb provided on the central portion of an elongate sleeve II. The sleeve II is longitudinally kerfed or split at Illc to its top end to form spring fingers H) which constantly contract toward, and slide on, a central, conic expander described later herein. The unsplit, lower end of the sleeve H slidably fits on the stem 4 below a stem shoulder 5b whose function is to engage a sleeve seat H s stop-upward shift of the sleeve at that limit as the barrel is being pulled upward and lifts the sleeve from the top end face of the mandrel body (to which position it can drop). A barrel liner Illa: holds the 3 locking sleeve ID in position on a shoulder 15 of the barrel; said liner fitting the barrel bore wall in the barrel.

Fig. 1 shows the hammer bushing H spaced below the anvil face a of the mandrel 5, and shows the sleeve ll interlocked at Hb with and as pulled by the locking sleeve [0, in the barrel, up against and stopped by the shoulder 51). As tension in the drilling string (in use of the jar assembly) is increased to pull the mandrel, eventually the locking sleeve will compress the mandrel arrested spring sleeve fingers II and the barrel organization will be free to snap up and bang the hammer bushing 1-1 against the anvil 5a of the mandrel 5.

The shock on the mandrel may loosen the attached stuck collar and its tool but if not then the barrel is lowered to effect re-engagement of the barrel locking sleeve on the sleeve beads ill) and a string tension and jar function is repeated.

Means are provided in this assembly whereby the degree of tripping resistance of the spring sleeve can be increased or decreased at will by operation of the drilling string while the jar assembly is still in working position in the given fish hole. This means includes an elongate expander tube l3 slidably fitting the mandrel stem 4 below and engaging the mentioned threads it. A spline l4 fixed in the sub 2 slides in a splineway 13s in the expander tube, and when the barrel sub is rotated the spline rotates the expander tube and this is screwed at it up or down on the stem i and inward or outward as to the contracted ends of the trip fingers of the sleeve. The finger engaged end of the stationary expander tube is conical and therefore the fingers are thereby positively expanded or are permitted to contract and thereby regulate the resistance offered to the locking sleeve I l; according to direc tion of expander tube shift. Thus the blow by the hammer is controlled.

The expander tube can only be rotated 0n the pipe 4 when the rib 8 of the barrel is brought to the level plane of the clearanceway 9. At such a register of the parts a rotation of the barrel will turn the spline I and this will rotate the expander tube to expand or to contractively release the fingers of the spring sleeve H and therefore change their reaction on the locking sleeve l0. Following such an adjustment of trip control the barrel is again put under tension to efiect a new jar stroke. Repeated strokes and resetting of spring reaction can be made until the fish comes loose, or the job has to be given up for lost.

The operation is as follows: Fig. 1 shows the hammer H spaced down from the anvil for a jar stroke, and the fingers I I f are in looking with the grooves of the locking sleeve H]. Tension is now put on the barrel to a degree that will overcome the inbending resistance of the tube supported fingers and at that moment the barrel becomes unlocked and inherently springs the hammer up against the stuck mandrel anvil. Greater tension may be built in the barrel if the fingers are additionally expanded as desired by axial adjustment of the expander tube as above set out.

What is claimed is:

1. A well tool jar assembly comprising, in combination; a hammer barrel having a tubular hammer bushing mounted in its lower end and a tube slidably mounted in its upper end, said tube having a conical lower end, an elongate stem mounted within said barrel and upon which said tube is mounted, an elongate spring sleeve slidable in the barrel and having an upwardly projecting set of resilient, contractile fingers whose tips slidably engage said conical tube end and said spring sleeve being slidable on said stem and the latter having an abutment shoulder located below said tube and serving to engage an internal flange in said spring finger sleeve to hold the spring finger sleeve in a given position on the stem, a mandrel element slidably mounted in the lower end of said barrel and having a pin connection at its lower end and connected to said stem at its upper end, an anvil shoulder positioned on the lower end of said mandrel element in opposed relationship to said hammer bushing, the upper end of said mandrel element having a set of splines and a set of keyways therein spaced below the set of splines to form an annular clearanceway, a drive key fixedly mounted within the lower end of said barrel and engageable in lowered position within said keyways on said mandrel element and turnable on the mandrel element in the clearanceway, and trip release means for releasably connecting the mandrel element to the barrel including a looking sleeve fixedly mounted within said barrel having a series of internal grooves therein, said spring sleeve having annular bead members externally thereof and adapted to be engaged in the grooves of said locking sleeve, whereby said abutment shoulder and internal flange serve to prevent upward movement of said spring sleeve when upward pull is applied to said barrel and upon reaching a predetermined tensile force the beads on the spring sleeves are released from the grooves of said locking sleeve to allow sudden relative movement of the barrel and the mandrel element to impact said hammer bushing upon said anvil shoulder.

2. The assembly of claim 1; the said tube bein threaded on said stem and splined to the barrel so that rotation of the barrel and said key, in the clearanceway, on the mandrel element will axially shift the tube and thereby vary the tensile force required to overcome the spring force of the contractile fingers according to the relative position of the conical tube end.

DGNALD U. SHAFFER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,885,043 Beck Oct. 25, 1932 1,954,513 Beck Apr. 10, 1934 1,989,907 Beck Feb. 5, 1935 2,013,127 Bowen Sept. 3, 1935 2,158,406 Collett et a1 May 16, 1939 2,309,866 Reed Feb. 2, 1943

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