US2502567A - Overshot grab fishing tool for oil wells - Google Patents

Description

April 4, 1950 c. M. HOWARD ovERsHoT GRAB FISHING ToorJ FOR on. WELLS Filed 001'.. 5, 1948 I INVENTOR. 2f/0MM. HUM/m, BY 4777/017- Patented Apr. 4, 1950y UNITED STATES PATENT ol-ElcE y 2,502,561 ovEnsno'r om nsnmc 'root Fon on.

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Cliiord M. Howard, Fontana, Calif. Y Application october 5, 1948, Serial No. 52,801 4 claim. (cl. :s4-ss) This invention relates to a iishing tool used in the drilling of oil wells, and the primary purpose is to recover a lost piece or section of pipe commonly termed a fish, and by fishing tool is the overshot type, that is, the tool passes over the lost pipe section, and means is provided within the tool to securely grip this pipe so that it can be recovered.

An object of my invention is to provide a novel fishing tool of the character stated in which the circulating fluid is jetted outwardly from the tool,4 thus forcing the tool against one side of the bored hole to enable the bottom iinger to engage the lost pipe.

Another object of my invention is to provide a novel means to pack oi! around the lost pipe after the pipe has entered the tool, thus forcing the circulating iiuid downwardly through the lost pipe, tending to loosen this pipe so that it can be more readily recovered.

Another object of my invention is to provide a novel tool of the character stated which includes slips, a pack ofi ring, a mill, al1 of whichoperate automatically when the tool engages the lost section of pipe.

A feature of my invention is to provide a frangible disc in the lower end of the tool, said disc being broken by the lost pipe section as it enters the tool.

Other objects, advantages and features 0f invention may appear from the accompanying drawing, the subjoined detailed description and the appended claims.

In the drawing:

Figure 1 is a side elevation of my iishing tool with parts broken away to show the inner construction thereof.

Figure 2 is a sectional view taken on line 2--2 of Figure 1.

Figure 3 is a sectional view taken on line l-3 of Figure 1.

Referring more particularly to the drawing, niv fishing tool I, includes a top sub 2, which is provided with a threaded socket 3, to receive the drill pipe (not shown) upon which my tool is lowered into the well. A middle pipe section I, is threaded onto the lower end of the sub 2, and a finger I, is threaded onto the lower end of the pipe section 3. 'Ihe nger 4. is formed in the shape of a helix or screw, substantially as shown, for the purpose of moving the lost'pipe towards the center of the tool so that the pipe can enter the bore of the tool and be recovered in a manner to be subsequently described.

A plurality of slips 5, rest on a tapered seat It 2 I, in the pipe section 3. A heavy coil spring L bearsagainstthetopoftheslips 5, thus urging the slips downwardly against the seat 6. The slips 5,are held in raised and extended position by the lugs 8, which enter the J-slots 9, in the slips. Rotation of the top sub 2 will move the lugs ltoapositiontopermitthespring 1,to press the slips downwardly into the seat 6, thus pressing the slips inwardly to grip the lost pipe section. The slips 5 are normally so positioned that they will engage and loosely grip the iish when the iish is pushed upwardly into these slips. This gripping of the slips on the sh is suiilcient to enable the slips to be adjusted by rotation of the body of the tool. A rubber or plastic packing collar III, rests on a tapered seat II. Also in the pipe section 3, the packing ring is positioned below the slips 5. substantially as shown. When the pipe section passes upwardly through the packing ring III, this ring will loosely grip the pipe section and a slight relative movement vertically between the tool and the pipe section will cause the packingring I0, to slide downwardly on the seat I I thus pressing the rubber packing ring inwardly tightly against the pipe. This seals the outside of the pipe, and thus the circulating iiuid is directed downwardly within the sh. A milling ring I2, is mounted below the packing ring III, and this mill is provided with hardened teeth I 3, which will cut any outwardly projecting fragments on the top of the lost pipe. A frangible disc I4. is iixedly. mounted in the bottom linger I, and within the bore I 5, of the linger. A hole I6. in the disc .permits a certain amount of circulating fluid to pass downwardly through the nger 4, while the tool is being run into the well. A horizontal port I'I,Y extends through the wall of the iinger 4, above the disc il, and the purpose of this port is to jet circulating fluid against the wall of the bored hole thus pressing the tool to one side of the bored hole and enabling the ilnger I, to engage and -pack oi! the lost pipe section. as the tool is rotated on the drill pipe.

Once the iinger I, engages the ilsh, it is drawn to the center of the tool ,and can pass upwardly through the bore I5, breaking the disc Il, as it passes upwardly. Any rough edges on the top of the iish will be reamed oli by the mill I2, after which the pipe passes up through the packing Il. and is engaged by the slips 5, and an upward pull on the tool will then move the lost pipe out of the well.

Having described my invention, I claim:

l. An overshot grab iishing tool for oil wells comprising a tubular body, a scat in said body, slips on said seat, spring means pressing the slips downwardly in the seat, a yieldable tubular packing, and a seat in said body on which said packing rests. a frangible disc mounted in said body, and extending transversely thereof,said disc having a' hole extending therethrough and said body hav- Y ing a jet port extending through the wall thereof, said jet port being positioned above said disc.

2. An overshot grab ilshing tool for oil wells comprising a tubular body, a. seat in said body, slips on said seat, spring means pressing the slips downwardly in the seat, a yieldable tubular :packing, and a tapered seat in said body on which said packing rests, a frangible disc mounted in said body, and extending transversely thereof, said disc having a hole extending therethrough, and said body having a jet port extending through the wall thereof, said jet port being positioned above said disc.

3. An overshot grab iishing tool for oil wells comprising a tubular body, a seat in said body, slips on said seat, spring means pressing the slips downwardly in the seat, a yieldable tubular packing, and a seat in said body on which said packing rests, a milling ring mounted in said body below said packing, a frangible disc mounted in said body and extending transversely thereof, said disc having a hole extending therethrough and said body having a jet port extending through the wall thereof, said jet port being positioned above said disc.

4. An overshot grab fishing tool for oil wells comprising a tubular body, a tapered seat in said body, slips mounted on said seat, a coil spring engaging the slips and pressing the samedown-` wardly in the seat, a yieldable tubular packing, a tapered seat in said body on which said packing rests, said packing being movable vertically on its seat, a milling ring xedly mounted in the body below said packing, and a spiral finger on the lower end of said body a frangible disc mounted in said body, and extending transversely thereof said disc having a hole extending therethrough and said body having a jet port extending through the wall thereof, said jet port being positioned above said disc.

CLIFFORD M. HOWARD.

REFERENCES CITED AThe following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Namev Date 1,696,378 Brauer Dec. 25, 1928 1,757,363l Fischbach May 6, 1930 2,122,602 Beck July 5, 1938 2,394,832 Young Feb. 12, 1946

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