US1906895A - Well fishing device - Google Patents

Description

May 2, 1933. (a. J. ARMSTRONG WELL FISHING DEVICE Filed June 14, 1932 Invenlor Patented May 2, 1933 Fries Aren't GEORGE J. ARMSTRONG, OF OKLAHOMA CITY, OKLAHOMA WELL FISHING DEVICE Application filed June 14,

deeper additional sections are installed, being connected with tool joints or couplings. Then water or fluid is forced under pressure down the pipe through a swivel device at the top and passes out the bottom through one or more holes in the bit.

The object of forcing fluid through the pipe and out through the bit is to mix the cuttings from the bit into a slush form and convey it to the surface of the ground where th fluid is passed through a settling process and forced back through the pipe. This circulation continues throughout the drilling of the Well.

The strain is very great on the drill pipe while drilling and it is a common occurrence for the pipe to part and become lost in the hole. When this happens means must be had for taking hold of the lost pipe to withdraw it from the well.

There are several methods and devices for taking hold of the pipe that has become lost in the hole; that is, namely: die nipple, spear, and overshot. The over-shot is the most practical and is used most frequently. When a string of pipe parts in the well it is very important that it be removed as soon as possible because the longer it is allowed to remain stationary and without circulation, the harder it is to take hold of or pull out of the hole due to the fact that cuttings and formation inside the well settle around the pipe and tend to freeze it in place.

There are several makes of overshots on the market that have proven fairly successful but all have certain inherent defects which I believe I have overcome, namely: a positive release, that is, when the overshot is lowered into the well and has gripped the lost pip-e, my novel device for releasing the overshot at the will of the driller by a simple operation 1932. Serial No. 617,223.

allows disengagement of the overshot when the lost pipe is stuck so fast in the hole that it cannot be readily extracted. Also,- when the pipe can be extracted and is with drawn from the well the oversh'ot may be released from the pipe by a simple operation without taking the oversh'ot apart. My overshot contains also a substantial device for packing oil when the overshot is set down over the lost pipe.

Furthermore, owing to the novel construction of my overshot the driller can readily tell whether the overshot has enveloped the lost pipe when lowered into the hole for that purpose, by observing the way the fluid pump is running. F or example, the driller knows about where the top of the lost pipe should be, then should the overshot as it is lowered into the hole pass by the lost pipe without engaging it there is not any disturbance of the fluid pump pressure.

The pump is kept running at all times while the overshot is being lowered, of course. On the other hand, if the overshot does engage the top end of the lost pipe, the packoil' rubber ring in the lower end of the overshot will seal off the fluid and force it down into the lost pipe thereby increasing the pressure necessary for the pump to produce in order to force the fluid into the lost pipe and out through the bottom of it, and of course the strain will show up in the pump immediately. A beveled seat inside the overshot also cooperates with this rubber ring, as do two separate friction rings, and thus make the sealing off more efiicient.

In carrying the present invention into practice, I have discovered and mechanically assembled the requisite details for accomplishing the desired results (noted above) in a highly practical and gratifying manner.

in the accompanying illustrative drawing, wherein like numbers or numerals are employed to designate like parts throughout the same:

Figure 1 is a view in section and elevation showing the manner in which the improved overshot device is constructed and used.

Figure 2 and 8 are horizontal cross-sectional views taken approximately on the planes of the lines 22 and 3-3 respectively of Figure 1.

In Figure 1, the numeral 4 designates a drill tube and 5 denotes the improved fishing device as a unit. This comprises a coupling 6 attached to the tube and in turn detachably threaded to the upper screw-threaded end of the tubular body 7 of the improved device. The end 6a forms a shoulder whose purpose is to be described later.

The lower end of the body 7 is thickened to provide a tapered conical seat 8 and then reduced and screw-threaded to provide a nipple 9 to tap into the screw-threaded end of the pilot collar 10. This collar 10 has a flared entrance 11 serving to facilitate the overshot in engaging lost pipe A. Moreover, the collar 10 is formed intermediate its ends with a shoulder 12 against which the heavy rubber closure ring 13 is clamped. The numerals 1 f designate the interfitting toothed slips of expansible and contractible form which are made to provide a cone for cooperation with the conical slip contracting surface 8 of the body 7 as shown in Figure 1.

The numeral 15 designates a friction-packing ring and is located in the upper portions of the slips 14. It serves as a friction and packing ring to assist friction-packing ring 19 in overcoming the downward pull of gravity, to such an extent that the pipe-gripping device designated as slips 1 1- are held up in a position above tapered portion 8, and thus kept expanded so as to permit continued disengagement of overshot from lost pipe if so desired.

The numeral 19 also designates a frictionpacking ring, and it is located in the ring 16. This ring 19 serves the same purpose as the ring 15 with which it co-operates. The functions of the two friction- packing rings 15 and 19 are as follows: They expand outward against inner wall of the body 7 and tend to seal off fluid from passing downward between drag ring 16 and the inner wall of the body 7', and between the outer sides of slips let and the inner wall of the body 7.

By expanding outward against inner wall of the body 7 these rings 15 and 19 cause considerable friction, and co-operating with each other they hold slips 1 1 in an expanded position above tapered portion 8. The functions of these two rings 15 and 19 are very important inventions, constituting the feature of the improved overshot which permits disengagement of overshot after it has once gripped the lost pipe.

When the driller wants to take a grip on the lost pipe he increases the speed of the fluid pump thereby causing heavily increased pressure to accumulate above ring 16 and as he does so he gradually elevates the overshot. The increased fluid pressure over comes the friction caused by rings 15 and 19 and permits tapered portion 8 of the overshot to ascend onto slips 14- Which are being held against tool-joint or coupling of lost pipe by said pressure from above thus contracting slips 1 1 and gripping pipe. Bevelled seat 18 (mentioned in the following paragraph) plays an important part in this oper ation.

VVhenthe overshot has been lowered a sufflcient distance into the hole so that it has enveloped the lost pipe the bevelled seat 18 fits itself against the tool joint or coupling (which is of greater circumference than the body of the lost pipe) thereby checking flow of fluid from above from passing out through lower end of overshot (thus also co-opcrating with rubber ring 13 and friction- packing rings 15 and 19 by diverting flow of fluid from the lower end of overshot into and down through lost pipe) and causing pressure to accumulate above ring 16.

The ring 16 is made up of a plurality of bolts 17 having their lower ends threaded into sockets in the upper part of the slips 14 and having their upper screw-threaded ends passing through apertures in the arcuate ring 16. This ring 16 is a one-piece ring, and it also accommodates friction-packing ring 19.

The use and operation of the invention is as follows: to wit; the overshot is attached to the drill pipe 4 and is lowered into the hole or well and when it is lowered to within a few feet of the top of the lostpipe the fluid pump is started and fluid is forced down through the lowered drill pipe. The fluid naturally returns to the surface by the route of least resistance, which is out through the overshot and up to the surface. vVhen the fluid begins returning to the surface the driller lowers the overshot until the lost pipe (not shown) enters the overshot, or, strictly speaking, until the overshot its itself around the top of the lost pipe.

As the overshot envelopes the top of the lost pipe the rubber pack-off ring shuts off the fluid from passing out of the overshot and forces the fluid down into the lost pipe. This rubber pack-01f ring 13 is the vanguard, so to speak, in sealing off the fluid. In other Words, it is the first sealing-off feature of the overshot to contact the lost pipe. But as the overshot continues its descent (enveloping the lost pipe the while) a coupling or tool joint of the lost pipe is next encountered, which coupling or tool joint is of larger circumference than the lost pipe proper, but not too large that rubber ring 13 cannot pass around it.

However, when the beveled seat 18 encounters the tool joint or coupling the lowering of the overshot must stop because the tool joint or coupling will not pass through the ring 16. This ring 16 has its lower inside edge beveled (beveled seat 18) and this beveled edge fits snugly against the tool joint or coupling (as shown in dotted lines) thus constituting an additional sealing-off feature ofv the overshot.

Then this beveled edge 18 has seated itself against the tool joint or coupling it provides a fluid seal-off feature to co-operate with the rubber ring 13. Now the sealing 01f process is almost accomplished to perfection, except for such small amount of fluid as might leak through between ring 16 and inner wall of 7 and between outside of slips 14 and inner wall of 7. It is at this point that we observe the pack-off features of friction- packing rings 15 and 19.

These rings 15 and 19 which are interposed in slips 14 and ring 16 as above noted, eX- pand outward and press against inner wall of the body 7, thus diminishing to almost nothing the leakage of fluid. Such small amount of fluid as might leak off will of course be stopped by heavy rubber ring 13.

The sealing-off of the fluid having been accomplished the fluid is forced down into and through the lost pipe and there is, of course, an immediate increase of pressure on the fluid pump which indicates to the driller at once that his overshot has fitted itself around the lost pipe. (In case the overshot does not catch the lost pipe and lit itself around the top end of it, there is, of course, no difference in the fluid pressure and the driller consequently knows that he has not made proper contact and can immediately raise the overshot and make another trial. The driller, of course; knows within a very few feet just where the top of the lost pipe should be.) I therefore make the claim that my overshot will give intelligence to the driller at all times as to what it is doing.

When the beveled edge 18 has seated itself against the tool joint or coupling of the lost pipe the descent of the overshot must of course, stop and the sealing-off of the fluid having been accomplished, the driller increases the speed of the fluid pump thereby causing increased fluid pressure to accumulate against ring 16 and hold it downward pressed against said tool joint or coupling of the lost pipe, and now while the fluid pump is running at high speed the driller slowly raises the overshot with the result that the friction caused by rings 15 and 19 is overcome and allows tapered portion 8 to ascend onto conical sides of slips 14 thereby contracting said slips 14 and forcing them to grip the lost pipe.

The slips 14 are of course attached by bolts 17 to the solid ring 16, which ring 16 is held in place against tool joint or coupling of lost pipe by increased pressure which is suilicient to overcome friction of rings 15 and 19 and thus allow the overshot bowl 7 to be raised without also raising pipe gripping device slips 1'4 and parts 15, 16, 17, 18 and 19 until after the pipe has been tightly gripped. When the pipe has been gripped it can be withdrawn from the well.

In the event the lost pipe is stuck or fast in the hole and cannot be Withdrawn the overshot may be disengaged and withdrawn. That is accomplished by the driller in the following manner, to wit: the fluid pump is shut down and pressure against ring 16 is relieved entirely; then the overshot is lowered until tool joint or coupling of lost pipe pressing against beveled edge 18 of ring 16 has pushed slips 14 and parts 15, 16, 17 and 18 and 19 up into upper part of overshot bowl and out of tapered portion 8, thus eX- paneling the slips l4 and loosening entirely their grip on the lost pipe. (Strictly speaking, the slips 14 and parts 15, 16, 17, 18 and 19 are held in place by tool joint or coupling on lost pipe pressing against beveled edge 18 or vice versa while overshot bowl is being lowered and thus tapered portion 8 is lowered off of conical sides of slips 14. hen this is done the pressure caused by tapered portion 8 pressing against the conical sides of slips 14 will have been relieved.) V

The lr-olts 17 are fastened solidly to the se mental slips 14, but are fastened to the ring 16 more loosely, so that the segmental slips 14 are suspended pendulum-like from the ring 16, and when said se mental slips 14 are loosened of grip on the tool oint or coupling they will swing entirely clear. hen the slips 14 are clear the friction rings 15 and 19 hold them and the parts 16, 17 and 18 in a position in the upper part of the overshot bowl and above and off of tapered portion 8 so that said slips remain expanded. Thus the overshot may be withdrawn from the lost pipe.

Novelty is predicated upon the parts 7, 16 and 13, parts 7 and 10 of which are fashioned so as to provide a clamp for heavy rubber ring 13. Incidentally the rubber ring 13 is sometimes referred to herein as the pack-off element, but is also mentioned as a fluid check element in order to accomplish the aforesaid regulation and flow of fluid back down through the lost pipe after the overshot device has enveloped the top end thereof.

Novelty is predicated on the conical contracting surface 8 operating in conjunction with the conical sided slips 14 that are joined toring 16 by bolts 17. Novelty is further predicated on the ring 16 in that it accommodates the friction-packing ring 19, which also is novel, and in that the lower inside edge of said ring 16 is beveled to provide the beveled seat 18.

Further novelty is predicated on the slips 14 in that they accommodate the frictionpacking ring 15 and in that they are so connected by bolts 17 to ring 16 as to allow them to be suspended therefrom pendulum-like. These parts are novel in that they work together and provide an effective means of sealing-off the fluid flow. and diverting it downward through the lost pipe and by so doing provide features of the overshot which makes it a veritable robot for keeping the driller advised of what it is doing and what is happening in the well; they are novel in that they provide features which insure engagement and disengagement with and from the top of the lost pipe at the deliberate will of the driller, as well as providing a simple means of disengaging the overshot after the lost pipe has been withdrawn from the well.

I wish to emphasize the following points of advantageous construction.

An overshot is so designed and built that it can be engaged or disengaged with and from the lost pipe at the will of the driller while the same is in the hole. This engagement and disengagement as the case may be is absolutely subject to the will of the driller and is co-ordinated with raising and lowering the overshot assembly, thus the overshot itself is a perfect fishing tool.

An overshot equipped with such parts, to wit, 15, 19, 18 and 13 provides for sealing oii' fluid from passing out at the overshot, thus forcing the fluid into and down through the lost drill pipe, thus signalling the driller by the token increased pressure on his fluid pump that the overshot has fitted itself around the lost drill pipe. These parts which seal off the fluid and force it down into and through the lost drill pipe also furnish a means for loosening the lost drill pipe in case it is frozen in the hole by settlings, to wit: The fluid which is pumped down through the lost pipe must come out at the bottom and will ascend to the top of the hole by passing around the outside of the lost drill pipe, thus loosening the hold of the settlings and freeing the pipe and permit its elevation.

The overshot can be removed from the lost pipe after it has been withdrawn from the hole and is on top the ground. This can be done by the simple expedient of forcing the overshot down on the pipe until the slips are disengaged. It is unnecesary to take the. overshot apart.

Attention is also called to the presence of the shoulder 6a forming a part of the cou pling 6 which constitutes an abutment a gaiust which the ring 16 may bear to limit the 111'- ward sliding movement of said ring. Otherwise considered the surface 6a may be described as a stop which will come down into contact with the ring 16 to limit the downward movement of the casing 7 and its parts after the bevelled surface 18 has come into engagement with the existing shoulder on the lost tool A as shown in dotted lines in Figure 1.

It is thought that the description taken in connection with the drawing will enable a clear understanding of the invention to be had. Therefore, a more lengthy description is thought unnecessary.

While the preferred embodiment of the invention has been shown and described, it is to be understood that minor changes coming within the field of invention claimed may be resorted to if desired.

I claim:

1. In a well fishing device of the class described, a casing comprising a tubular body member provided at its upper end with means for detachable connection with a drill pipe section, the lower end of the inner wall of said casing being of outwardly flared formation to facilitate placement of the casing over the lost tool, a packing ring carried by the last-named end of the casing and projecting into the bore thereof and adapted to snugly embrace the tool to effect the aforesaid fluid closure, an expansible and contractible tool clamp mounted slidably in said casin and comprising a plurality of companion toothed slips, and a packing equipped friction drag device attached to said slips and in frictional sliding contact with the inner wall of said casing.

2. A well fishing device of the class described comprising a casing including a tubular body internally screw-threaded at its I pper end, having its lower end portion thickened and tapered to provide a conical contracting :at and finally reduced in thickness and en crnally screw-threaded to provide a nipple, a ring-like pilot forming col- :ar internally screw-threzuled, said nipple being tapped into said collar, the lower end of the inner surface of said collar being tapered to facilitate placement of the collar over the lost tool, a fluid check ring clamped between the collar and nipple and protruding into the bore of the casing for the purpose described, a slidable tool clamping device comprising a plurality of segmental tapered toothed slips co-operable with said conical contracting seat, an annulus forming a friction drag device and being provided with a. packing ring in frictional contact with the inner wall or said casing, and bolts connecting said annulus to the slips.

3. In a well fishing tool of the class de scribed, in combination, a drill tube, a tubular casing, a coupling securing the upper end of the to the adjacent end of said drill tube, said coupling forming an internal stop shoulder in the upper portion of said casing, the lower internal portion of said casing being provided with a bevelled base to provide a contracting conical seat, a flexible fluid check ring mounted in the lower end portion of said casing, an expansible and contractible tool clamp slidably mounted in said casing and comprising a plurality of toothed slips co-operable with said expanding and contracting seat, a drag ring, bolts connecting said ring with said slips, packing rings carried by the drag ring and slips respectively, said drag ring being engageable with the aforesaid stop shoulder in the manner described.

4. In a well fishing device of the class described, a casing comprising a tubular body member provided at its upper end with means for detachable connection with a drill pipe section, the lower end of the inner wall of said casing being of outwardly flared formation to facilitate placement of the casing over the lost tool, a packing ring carried by the last-named end of the casing and projecting into the bore thereof and adapted to snugly embrace the tool to effect the aforesaid fluid closure, an expansible and contractible tool clamp mounted slidably in said casing and comprising a plurality of companion toothed slips, and a packing equipped friction drag device attached to said slips and in frictional sliding contact with the inner wall of said casing, said drag device being in the form of a ring and having a beveled seat adapted to fit itself against a portion on a lost pipe.

5. In a well fishing device and in combination, a casing, a packing ring carried in the casing and projecting into the bore thereof and adapted to snugly embrace an element received within it to effect a fluid closure, a clamp slidable and expansible and contractible in said casing above said packing ring, and a drag device frictionally engaging the casing, above the clamp, and at tached to said clamp, said device being in the form of a ring and having a beveled seat adapted to fit itself against a portion of an element which it encounters.

6. In a well fishing device and in combination, a casing, a clamp slidable and expansible and contractible in said casing, and a drag device frictionally engaging the casing and attached to said clamp, said device being annular and having a beveled seat.

In testimony whereof I afiix my signature.

GEORGE J ARMSTRONG.

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