US2272529A - Fishing tool - Google Patents

Description

Feb. 10, 1942.

A. D. LARSON I FISHING TOOL Filed March 7, 1941 241.5507 0. MASON INVENTOR ATTORNEY Patented Feb. 16, 1942 4 Claims.

This invention relates to fishing tools and more particularly to sucker rod sockets.

Sucker rod joints ordinarily include a box carried by one section of rod for receiving a pin carried by another section of rod. As the entire sucker rod string is reciprocated during the pumping of a well the sucker rod joints suffer severe strain and wear. They oftentimes become so worn as to be almost egg-shaped in cross section. When the sucker rod string has operated continuously over a considerable period of time the metal of which the various sections are made often becomes fatigued, usually at the joint, causing breakage of the string and leaving a considerable portion of the string in the well.

Many tools of generally known construction are capable of entering the well and grasping a normally sized sucker rod box or pin which is not unduly worn. Few of them, however, can accommodate various sizes of both boxes and pins worn in varying degrees.

It is the chief object of my invention to provide a tool which can be let down into the well and which will receive a sucker rod box or pin, and which then can be operated from above to grip the box or pin regardless of its diameter or degree of wear, and which may then be withdrawn to remove that portion of the sucker rod string which was broken off in the well.

As stated, my invention will accommodate various sizes of sucker rod joints in various degrees of wear and in varying cross sectional shapes without the necessity of removing the tool from the well and changing or adjusting any of its parts.

The details in the construction of a preferred form of the invention, together with other objects attending its production, will be better understood from the following description when read in connection with the accompanying drawing which is chosen for illustrative purposes only, and in which Figure 1 is a vertical, central, longitudinal View thru a tool embodying the invention, with a portion of a sucker rod joint locked within the body of the tool;

Figure 2 is a similar view of the tool in unlocked or open position;

Figure 3 is a bottom plan view of a portion of the tool illustrated in Figures 1 and 2;

Figures 4, 5 and 7 are horizontal sectional views taken along extensions of the lines 4, 5 and l, of Figure 2; and

Figure 6 is a horizontal sectional view taken along the extension of the line 6 of Figure 1.

Like characters of reference designate like parts in all the figures.

The embodiment of the tool illustrated includes a tubular body Ill, the bore of which is reduced eccentrically at its lower end, forming an eccentric shoulder ll. Its extreme end is beveled as indicated by the numeral ['2 to facilitate entry of a broken sucker rod joint into the lower end of the tool. A replaceable eccentric collar I3 is held against rotation on the eccentric shoulder H by means of a set screw [4 passing thru a slot l5 in the wall of the body Hi. This collar I 3 is beveled slightly outward on its upper surface as indicated by the numeral 46 to form a relatively sharp inner edge for contact with any part of the sucker rod joint. It is also made of extremely hard metal to resist Wear. The upper end of the tubular body It is threaded to receive a head I! which is threaded at its upper end for attachment to a fishing string. The head is hollow at its lower end to receive a spring I8. Intermediate its ends the head H is provided with a plurality of perforations H) which afford communication with the interior bore in the lower end of the head. These perforations I9 permit paraffin and other detritus which may have accumulated on the inner walls of the production tubing to pass thru the tool without obstructing the downward passage of the tool.

Inside the body or barrel l 0 I provide an eccentric sleeve 29 which is preferably split longitudinally along its thinnest wall. This sleeve 20 rests on the upper edge of the collar I3, and it is rotatable and slidable within the barrel It. When this sleeve is rotated to one position its bore is concentric with the bores of the collar l3 and with the bore in the extreme lowerend of the barrel It), as inFigure 2L When it is rotated in either direction its bore has the relation to the bores in the collar l3 and in the lower end of the barrel H) as shown in Figure 6. In other words the open space thru which an object may pass axially is considerably reduced in diameter by the rotation of this sleeve.

As a means of locking the sleeve in either of the positions shown in Figures 1 and 2 I provide a plug ii for its upper end. This plug has an upper portion of relatively largediame-ter which is of such size as to be rotatable and slidable within the barrel It. The lower portion 22 of this plug is also cylindrical but is eccentric with respect to the axis of the upper portion. The diameter of this lower portion is such that it will enter the upper end of the sleeve 20. An eccentric shoulder 23 is thus formed between the upper and lower portions of this plug. Extending downwardly from the shoulder are a plurality of pins 24 and 25 which are adapted to be received in complemental holes in the upper edge of the thickest portion of the wall of the sleeve 20. When the plug is seated in the upper end of this sleeve 29, the pins 24 and 25 thus lock the plug and the sleeve for rotation together, while the shoulder 23 limits the penetration of the plug into the sleeve. In the exterior surface of the largest portion of this plug 2| a circumferential groove 26 is formed. This groove extends approximately half way around the plug and at each of its ends it communicates with short axially extending grooves 21 and 28. These grooves are adapted to receive an inwardly projecting pin 29 made integral with or set rigidly in the wall of the barrel ID, as shown in Figure 4. A spring I8 bears against the upper end of this plug 2| and thus normally keeps the sleeve ID seated on the upper edge of the collar l3. Another axially extending groove 30 (Figure 3) is provided in the lower portion 22 of the plug to permit the entrance of the pin 29 into the groove 26. As indicated by the dotted lines in both Figures 1 and 2, the plug 2| is provided with a central bore 3|, which facilitates the passage of paraffin and other detritus thru the tool. The extreme lower surface of the plug 2| is provided with a plurality of ridges 32, or is roughened in any other manner to afford a substantially non-skid surface.

The pin 29 is placed at such a distanc from the collar I3 that the pin 29 must at least have partially entered either the grOOVe 21 or the groove 28 before the plug can assume its position of maximum penetration into said sleeve, in either of which positions both the plug and the sleeve are locked against rotation with relation to the barrel. The tension of spring l8 naturally keeps the plug seated in the upper end of the sleeve 20.

In operation, with the sleeve in the relative position shown in Figure 2, the tool is let down into the well thru the production tubing until the broken upper end of the sucker rod string passes into the bore of the tool. The upper end of the broken rod or joint contacts the roughened lower surfac of the plug 2| forcing the plug to move upward slightly within the barrel H] until it contacts the lower end of the head N. This longitudinal movement of the plug brings the groove 26 into alignment with the pin 29 on the inside of the barrel. The barrel is now rotated 180 by rotation of the fishing string to which the tool is attached, the pin 29 traveling through the groove 26 until it reaches the groove 21 which prevents further rotation. Weight is then removed from the tool and the spring I8 again forces the plug 2| downward in the barrel, the pin 29 entering the axial groove 21. During its rotation the plug has also forced the sleeve 29 to rotate with it, and the interior bore of the tool has been reduced, as shown in Figure 6. This reduction in diameter forces the sucker rod joint toward the thickest part of the collar I3, and when a lifting forc is applied to the tool this collar l3 contacts some portion of the sucker rod joint and positively prevents its movement out of the lower end of the tool. The tool is then simply withdrawn from the well and the broken sucker rod string is withdrawn with it. A reversal of these steps will naturally result in releasing the work being handled, if desired. This ability to release the work is an important feature of my invention, and to my knowledge there is no such tool in general commercial use which can be 0D- erated to release the work until after it is withdrawn from the well.

While I have described and illustrated a specific embodiment of my invention, I am aware that numerous alterations and changes may be made therein without departing from the inventive principle, and I do not wish to be limited, except by the prior art and by the scope of the appended claims.

.I claim:

1. A fishing tool comprising: a barrel having at its lower end a work receiving bore of abruptly reduced diameter which bore is eccentric with relation to the remainder of the larger bore in said barrel; an eccentric sleeve of such exterior diameter as to fit snugly but rotatably within said larger bore, the diameter of the sleeve bore and the eccentricity thereof being substantially the same respectively as the diameter and eccentricity of the reduced bore in said barrel; an eccentric plug slidable but non-rotatable in the upper end of said sleeve, and slidable and rotatable in the large bore of said barrel; co-operating means on plug and barrel for limiting the rotational movement of said plug and said sleeve, said means also being adapted to lock said plug, and consequently said sleeve, in at least two positions of orientation with relation to said barrel; and a tool head for said barrel.

2. A fishing tool comprising: a barrel having the major portion of its bore of relatively large diameter and substantially concentric with its exterior wall surface, and having at its lower end a communicating eccentric bore of abruptly reduced diameter; an eccentric sleeve of such exterior diameter as to fit snugly but rotatably within the larger bore of said barrel, the diameter of the sleeve bore and the eccentricity thereof being substantially the same respectively as the diameter and eccentricity of the reduced bore in said barrel; an eccentric plug the eccentric Y portion of which is slidable but non-rotatable in the upper end of said eccentric sleeve, and the remaining portion of which fits snugly but is rotatable and slidable within the large bore of said barrel adjacent the upper end of said sleeve; a circumferentially extending groove cut in the exterior of the last mentioned portion of said plug, the opposite ends of said groove each communicating with a short axially extending groove of similar depth also cut into the exterior of said plug; an inwardly projecting pin carried on the inner surface of the barrel and adapted to travel in the circumferential groove when said barrel is rotated with relation to said plug and sleeve, and to enter either of the axial grooves for locking the barrel against rotation with relation to said plug and sleeve; spring means exerting force on said plug and on said barrel to urge the two units into locked, relatively non-rotatable relation; and a tool head for said barrel.

3. A fishing tool comprising: a barrel having a concentric upper bore and an eccentric lower bore; a similarly eccentric sleeve in said upper bore rotatable with relation to said lower bore to vary the cross sectional size of the axial free passage area thru said barrel; a plug non-rotatably secured in the upper end of said eccentric sleeve, said plug, however, being rotatable within said barrel; and co-operating means on plug and barrel for locking the two in different positions of relative orientation.

4. A fishing tool comprising: a barrel having a concentric bore; a removable eccentrically bored insert adapted to be rigidly but removably secured in the lower end of the bore of said barrel; a similarly eccentric sleeve in the concentric bore of said barrel rotatable with relation to said insert to vary the cross sectional size of the axial free passage area through said barrel; a plug non-rotatably secured in the upper end of said eccentric sleeve, said plug being rotatable within said barrel; and co-operating means on plug and barrel for locking the two in different positions of relative orientation.

ALBERT D. LAB/SON.

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