US1944169A - Suction fishing tool - Google Patents

Description

0. A. CAVINS SUCTION FISHING.TOOL

Jan. 23, 1934.

Filed July 11 1932 4 3 Sheets-Sheet l Jan, 23, 1934-. O A c v s 1,944,169

SUCTION FI SHING TOOL Filed July 11, 1932 Inventor Jan. 23, 1934,

o. A. cAvlNs 1,944,169

SUCTION FISHING TOOL Filed July 11, 1932 a Sheets-Sheet 5 W/f/A W1 rh Q? In vemor Patented Jan. 23, 1934 UNITED STATES PATENT OFFICE- SUCTION FISHING TOOL Omar A. Cavins, San Francisco, Calif. Application July 11, 1932. Serial No. 621,761

20'Claims. (Cl. 294-46) This invention relates to fishing tools, such as are used in deep wells for recovering lost tools or parts of the same'at the bottom of the well. This fishing tool is intended to be attached to the lower end of a tool string and is constructed so that it includes a suction chamber separated by a valve from the bowl of the tool. In using the tool, the valve is maintained in closed position until the bowl is brought into position in proximity to the fish. Then the parts of the tool are manipulated so as to effect the openingof the valve, whereupon the well pressure which exists within the bowl is suddenly relieved through thevalve passage to the suction chamber, thereby causing an inrush of material at the bottom of the well which carries the fish into the bowl.

The general object of this invention is to provide simple means for enabling the valve to be opened when desired, and also to. provide a construction which will enable circulation of circulating liquid or mud to be maintained in the tube string and past the valve without interfering with its function in controlling the communication'between the interior of the bowl and the suction chamber.

' A further object of the invention is to provide means for shutting 'ofl the circulationbefore the opening of the valve is effected and to provide means whereby the circulation may be resumed if desired thereafter.

A still further object of the invention is to provide a construction for the tool of this type in which relative rotary movements and relative longitudinal movements of parts of the device may be utilized to effect the opening of the valve to complete the fishing operation. In its construction, the tool includes a circulation pipe that passes down through the tubing .and through the suction chamber, and one of the objects of the invention is to provide for the effective packing of this suction tube in thevicinity of the means which is employed for shutting off the passage of the circulating fluid through the tool.

Further objects of the invention will appear hereinafter.

The invention consists of novel parts and combinations of parts to be described hereinafter, all of which contribute to produce an eificient suction fishing tool.

A preferred embodiment of the invention is described in the following specification, while the broad scope of the invention is pointed out in the appended claims In the drawings Figure 1 is a side elevation of the fishing tool embodying this invention, and representing the same as attached to the lower end of a tool string indicated as broken away; this view also shows the middle portion of the tool broken away and indicates the wall of the well in cross section; 4

Figure 2 is a vertical section taken through the upper portion of the toolupon an enlarged scale and particularly illustrating the packing sub assembly at which the shut-ofi device is located, for shutting off the circulation down through the tool when desired;

Figure 3 is a vertical section upon the same scale as Figure 2, and illustrating the part of the tool immediately below that illustrated in Figure 2;

Figure 4 is a vertical section upon the same scale as Figure 3, and illustrating the main valve assembly of the tool together with the means for effecting the opening of the valve;

Figure 4a is a vertical section of the lower end of the tool, and illustrating the bowl of the device and the part above the same that connects with the lower end of the main valve assembly;

Figure 5 is a horizontal cross section taken on the line 5-5 of Figure 4, and illustrating the relation of the circulation duct and the passages which open up communication from the valve to the suction chamlmr when the valve is open; Figure 6 is a horizontal section taken on the .line 6-46 of Figure 3, and illustrating'the construction of the tool just below the lower end of the suction chamber; this view particularly illustrates the means for effecting communication between the duct or passage referred to in con nection with Figure 5, and the circulation tube that passes down through the suction chamber, and also illustrates the means for effecting the communication between the suction passages up to the suction chamber;

Figure '7 is a'horizontal, section taken on the line 7-,? of Figure 4a, and'particularly illustrating the construction of the bowl at the gate which afiords means for retaining the flsh" within the bowl; this view corresponds to Figln'e 4a, and illustrates the gate in its open position;

Figure 8 is a section-corresponding to Figure 4a, but showing only the lower end of the bowl, and illustrating the gate in its closed position;

Figure 9 is a vertical section taken on the, line 9-9 of Figure 4, and further illustrating details of the main valve illustrated in Figure 4; this view shows the valve in its closed position to correspond with Figure 4; I I

Figure 10 is a vertical section similar to Figure 4, but illustrating the parts of the tool in the'relation which they have when the valve is, be pulled to its open position;

Figure 11 is a horizontal cross sctiontaken on the line 1111 of Figure 8, and further illustrating details of the means for mounting the gate in the bowl.

Before proceeding to a more detailed descripdown through the suction chamber and past the tion of the parts of the apparatus, it should be stated that the tool is constructed with a suction chamber which is separated by a valve from the interior of the bowl. The parts of the tool in the vicinity of the valve are constructed so that a relative rotation of these parts may be efifected, after which the parts of the tool'may be manipulated to efiect the sudden opening of the valve. By reason of the fact that liquid, such as oil or mud, is present in the bore of the well under hydrostatic pressure, it follows that the sudden opening of the valve relieves the pressure existing within the bowl of the tool by permitting an equalization of pressure within the bowl of the tool and the suction chamber. This causes a sudden inrush of sand or other material at the bottom of the well which carries the fish into the bowl and past the gate which immediately closes and retains the fish in the bowl.

In order to enable the tool to be freed from the well hole or for other purposes, the tool is constructed so that circulation may be maintained valve. Means is provided preferably in the form of an auxiliary valve in the circulation line that may be controlled at will, for example by introducing a ball, to shut oif the circulation when desired, and this auxiliary valve is constructed so "that when the circulation pumps are stopped so as to relieve pressure on the auxiliary valve, this valve will open automatically and permit circulation to be resumed.

Circulation is continued until ready to fish. Then the ball is put in the drill pipe to shut ofi circulation. The pumps will stall when the ball seats and closes the auxiliary valve. When the pump pressure is bled off, a spring opens the auxiliary valve.

Referring more particularly to the parts and especially to Figure 1, 1 indicates the packing sub assembly of the tool, the upper end of which is connected by a thread connection 2 to the lower end 3 of a tube string. Below the packing sub assembly, a tube section 4 is connected, formed of regular drill pipe and is sufficiently long to provide a closed suction chamber 5 within it of sufficient volume to insure efficient filling of the bowl when the valve is open.

Below the suction chamber 5, a valve assembly 6 is located, connected by a tube section 7 of special construction with the lower end of the suction chamber 5. This connection or tube section 7 and the casing section 8a of the valve assembly are connected together so that relative rotation may occur between these parts as will be described hereinafter. The casing of the valve assembly includes a lower section 8b connected by a threaded joint 9 (see Figure 4) and the lower end of the casing section 8b connects to the upper end of the bowl 10 of the fishing tool. Bowl 10 is preferably of enlarged diameter, and its lower end or shoe 11 is preferably formed with inclined cutter teeth 12 which enable the bowl to penetrate the sand or formation at the well bottom 13.

Referring particularly to Figure 4, the tube section 7 is connected by a coarse thread connection 14 to the upper end of the casing section 8a of the valve assembly, and below the thread 14 the neck 7 is formed with a beveled extension 15 that is welded onto it as indicated in Figure 4. The beveled extension 15 is formed with a valve seat 16, which is preferably inclined somewhat as indicated in Figure 4, and in this seat a valve port 160. is formed, provided with a threaded bushing 17, which forms the true valve seat for a valve closure 18 preferably in the form of a circular cap that can slide from the valve seat 16. The valve closure 18 is provided with an arm or tongue 20'that extends down from it, and which serves to enable the valve to be pulled downwardly to open the port 16. The tongue 20 is in the form of a hook, that is, its lower end is formed with a hook or bill 21, and this hook or tongue 20 is formed of steel material. The upper end of the tongue is formed with an opening 22 that seats around the edge of the dome or rounded head 23 formed on the outer face of the valve.

Hook 20 is guided freely through a slot-24 in a guide bracket 25 secured to the tubular extension or sleeve 7a that extends downwardly from the lower end of the neck '7, and the interior of this extension forms a valve chamber 19.

In a fishing operation, the shoe 11 of the bowl is permitted to rest on the bottom of the well and rotation is given to the tool so as to insure that the teeth 12 will bite into the well bottom. The weight on the bowl is then eased somewhat and the tube string rotated in a reverse direction so as to unscrew the thread connection 14, and in this way partially disconnect the neck 7 from the casing section 811. By effecting this disconnection, it is then possible to move the neck 7 downwardly within the casing section 8a, and this movement is utilized to effect the connection to the hook 20 to pull the valve open. In order to accomplish this, a valve puller 26 is provided (see Figure 4), which is preferably of tubular form with an enlarged tubular hook head 2'7, said head having-a central opening 28 with an inwardly projecting and downwardly inclined flange 29 around'the opening. The lower end of the valve puller is secured in a cross head 30 fixed in the lower section 8b of the casing. The hook head 2'7 is formed with an annular shoulder 31 against which seats a slip ring 32 that is loosely mounted in the bore of the casing section 8b and which is held up against the shoulder by a powerful coil spring 33.

In operating the tool when the section '7 is moved down relatively to the section 8a, the bill 21 of the hook strikes the inclined flange 29 and snaps into engagement with the flange as indicated in Figure 10. At the same time the lower end of the sleeve 26 has struck slip ring 32 and forced it downwardly, compressing the spring 33. The tube string is then quickly elevated and the weight of the parts below the thread connection 14' assisted by the force of the spring 33, pulls down the valve 18 from its seat. This opens up communication from the interior of the bowl 10 to the suction chamber 5 through two or more passages 34 that extend longitudinally through the neck '7 and communicate at their lower ends with the valve port 16. The upper ends of these passages will be described more in detail later.

In order to hold the valve closure 23 firmly on its seat when the tool string is being run down the well, I prefer to provide a pad or block 35 of rubber or similar material which is jammed under the lower end of the tongue or hook 20. This utilizes the resiliency of the material out of which the hook is formed, to press the valve closure firmly upon its seat, but this cushion or block 35 does not interfere with the action of thebill 21 of the hook in making its connection to the hook head 2'? of the valve puller.

The thread connection 14 may be lubricated ber 19 (see Figure 4).

by removing small screw plugs 36 mounted in the wall of the casing 8a.

In order to enable, circulation to be maintained down past the valve 18, the neck 7 is provided with a circulation duct 37, the lower end of which communicates with the valve cham- The upper end of this duct 37 also communicates with a chamber 38 (see Figure 3), formed in the coupling head 39 of the neck 7 and this chamber 38 has an inlet 40 to which a circulation tube 41 is connected by a thread connection. This tube extends up through the suction chamber 5 and carries the circulation through the suction chamber. The upper end of the circulation tube (see Figure 2), has a thread connection 42 that connects it to an auxiliary valve casing 43 of tubular form which passes down through a stufling box 44 provided with a packing 45, and on this packing a gland 46 rests. enlarged counter-bore 47 which forms a valve chamber for an auxiliary valve 48, said valve being in the form of an inner sleeve having a limited up and down movement in the upper end of the tubular casing 43 by reason of a pin 49 received in the slot 50 in the valve body. The valve 48 is provided with ports 51 through its side wall, and its upper end is formed into a head providing a seat 52 capable of supporting a device such as a ball 53, or a spear.

A spring 54 below the valve 48 in the valve casing or guide, normally holds the valve 48 in an elevated position so that the ports 51 and the open upper end of the valve will permit free circulation of circulating fluid down through the valve past the spring 54 and down through the circulating pipe or tube 41.

In the operation of the fishing tool, the ball 53 is introduced into the circulating fluid that passes down the tube string 3 eventually striking the seat 52 and compressing the spring 54 as it shoves the valve 48 down into its guide or casing 43. This will shut ofi circulation down' through the tube 41. The circulation pumps are then stalled by the rise of pressure and this maintains the pressure above the ball 53 sufliciently to hold the valve48 closed. After this is done, the tube string is rotated as has been described above, so as to disconnect the thread connection 14 to enable the neck 7 to be moved down and then up, to pull the valve 18 off its seat.

The auxiliary" valve 48 and its associated parts are all mounted in the casing 55 of the packing sub assembly. The upper end of the gland 46 is expanded at its upper end to form a bell 4641 against which the lower endv of the tube string 3 is screwed when this joint is made and this holds the packing tight.

As indicated in'Figure 3, the'upper end of the neck 7 is connected to the coupling head 39 by a welded joint 56 and at this joint the lower end of the coupling head 39 is preferably provided with an eccentric threaded tapered pin 57 that screws into a tapered box formed in the upper end of the neck. This tapered pin is formed as a nipple concentric with the circulation duct 37.

The lower end of the bowl (see Figure 4a) is provided with a gate 58 consisting of two semiconical sections 58a and 582) which have hinge connections 59 in the side wall of the bowl. These joints 59 are diametrically opposite each other so as to enable the gates 58a and 58b to swing open as indicated in Figure 4a. They do this when the material is loading into the interior of the bowl,

. sleeve connected by a welded joint 60 to the lower The upper end of the gland has an but they swing back immediately by gravity and by action of the tool when-the tool string is pulledup after the suction has taken place.

The bowl is preferably inthe form of a tubular end of the casing section 811, and at this joint a grid 61 is provided which is dished downwardly. This grid is formed of a stout metal plate and the openings through it permit the sand, oil, or water to pass upwardly when the bowl is being charged.

The gates 58a and 58b are provided with drain openings62. In the closed position of the gates 58a and 581), they present the form of an arch so that they can support considerable weight above them. In this way, they will retain the fish after it has passed into the bowl. In Figure 1, two lost tools or fishes 63 are indicated. lying on the bottom of the well.

The tubular sleeve 26 is preferably provided with two access holes 64 and 65, the former of 95 which is in an elevated positionand about opposite to the valve 18, the latter opening 65 being located near the lower end of the hook 20.

The upper ends of the suction passages 34 extend up into'the head 39 (see Figure 3) and communicate with drilled passages 67 extending down from the upper portion of the coupling head 39, and communicating with the suction chamher 5. At the lower end of the neck 7, these passages 34 communicate with the passages 66 in dicated in dotted lines in Figure 4 that communicate with the valve port 16a.

Just above the hook head 27, removable plug 68 maybe provided in the wall of the casing 8b j to give access to the interior for disconnecting the hook.

The general mode of operation of the fishing tool will now be described:

The tube string is made up and lowered down the well in the usual-way and when this takes place the parts in the valve assembly (Figure 4) will be in the relation shown in this figure. When the bowl 10 arrives at the well bottom, it is permitted to rest with nearly the whole weight of the string on the well bottom, and the tool string is rotated in the proper direction to cause the teeth 12 to penetrate the well bottom and this may bring the fish into the lower end of the bowl, buteven if this does notoccur the fish will be sucked in when the suction is put on. After the bowl is seated in this way, the thread connection 14 is backed oif, which disconnects the neck 7 from the casing 8a (see Figures 4 and 10). If the tool string freezes in the well, circulation is resorted to to free it, but before the actual fishing operation commences the circulation should of coursebe shut oif. This is accomplished by introducing a spear or ball such as the ball 53 (see Figure 3) This ball is of metal and descends with the circulating fluid and when it strikes the valve 48 it closes this valve. The circulation pumps should be stalled so as to hold this valve closed. Whenever it is necessary to resume circulation, this can be accomplished by. stopping the pumps which will enable the valve spring 54 to open the valve 48, when the pressure is relieved.

And after the bowl 10 has been set on the well bottom, the tool string is rotated to back ofi the thread connection 14, after which the tool string is lowered sufliciently to enable the hook 20 to engage the hook head 27 .of the valve puller. Then the tool string is pulled up and the valve 'puller will pull the valve relatively down the seat 16 and uncover the valve port 16a. This suddenly 1 0 opens communication between the interior of the bowl 10 and the suction chamber, the pressure in which is at or about atmospheric pressure. Opening this communication causes an equalization'of pressures with a very considerable drop in pressure in the interior of the bowl, thereby causing the violent inrush of material into the bowl which operates to carry the fish far enough into the bowl to pass the gate 58. The back wash of the material in the bowl will close the gate and retain the fish in the bowl.

The gates 58a and 58b may be held in their open position if desired by means of a small stick jammed diametrically across between them. This stick of course is displaced by the inrush of material in a fishing operation.

It is understood that the embodiment of the invention described herein is only one of the many embodiments this invention may take, and I do not wish to be limited in the practice of my invention, nor in my claims, to the particular embodiment set forth.

What I claim is:

1. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end, and having a closed chamber above the bowl, a valve normally cutting ofi communication between the interior of the bowl and the interior of said chamber, means for attaching the upper end of the casing to a tool string, said casing comprising relatively movable upper and lower sections, a valve puller for engaging the valve, cooperating with the relatively movable sections and brought into action by the relative movement of the said upper and lower sections to effect engagement with the valve and open the same, and thereby cause an inrush of material at the well bottom into the bowl due to the hydrostatic pressure in the well, to carry in the fish, and means for retaining the fish in the bowl.

2. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end, and having a closed chamber above the bowl, a valve normally cutting off communication between the interior of the bowl and the interior of said chamber, means for attaching the upper end of the casing to a tool string, said casing comprising relatively movable sections, means cooperating with the relatively movable sections to effect the opening of the valve, and thereby cause an inrush of material at the well bottom into the bowl due to the hydrostatic pressure in the well, to carry in the fish, means for retaining the fish in the bowl, and means for conducting circulating fiuid down past the said closed chamber and past the valve to the bowl.

3. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end, and having a closed chamber above the bowl, a valve normally cutting ofif communication between the interior of the bowl and the interior of said chamber, means for attaclnrlg the upper end of the casing to a tool string, said casing comprising relatively movable sections, having a connection enabling'the same to be partly disengaged from each other by a relative rotation of the two sections and thereby enabling the sections thereafter to have a relative longitudinal movement, and means cooperating with the sections of the casing in their relative longitudinal movement to effect the opening of the valve, thereby causing an inrush of material at the well bottom to carry the fish into the bowl by action of the hydrostatic pressure in the well.

4. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end, and having a closed chamber above the bowl, a valve normally cutting off communication between the interior of the bowl and the interior of said chamber, means for attaching the upper end of the casing to a tool string, said casing comprising relatively movable sections, said sections of said casing having a thread connection therebetween disconnectible by rotation of the tool string when the bowl is held on the bottom of the well, and enabling the said sections to have relative longitudinal movement after said thread connection has been disconnected, means for cooperating with the valve when the tool string is moved downwardly thereafter to engage the valve and open the same, thereby causing an inrush of material at the well bottom to carry the fish into the bowl, by the action of the hydrostatic pressure in the .well.

5. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end, and having a closed chamber above the bowl, a valve normally cutting off communication between the interior of the bowl and the interior of said chamber, means for attaching the upper end of the casing to a tool string, said casing comprising relatively movable sections with a thread connection connecting the same, disconnectible by a rotation of the tool string when the bowl is held against the well bottom, enabling the said sections of the casing to have relative longitudinal movement thereafter, and means brought into action by a relative downward movement and upward movement of the tool string thereafter to effect the opening of the valve and thereby cause an inrush of material at the well bottom to carry the fish into the bowl due by action of the hydrostatic pressure in the well.

6. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end, and having a closed chamber above the bowl, a valve normally cutting ofi communication between the interior of the bowl and the interior of said chamber, means for attaching the upper end of the casing to a tool string, said casing comprising relatively movable sections with a thread connection connecting the same, disconnectible by a rotation of the tool string when the bowl is held against the well bottom, enabling the said sections of the casing to have relative longitudinal movement thereafter, a valve puller carried by the lower section of the said casing for engaging the valve when the tool string is lowered thereafter, and operating when the tool string is pulled upwardly, to open the valve.

7, In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end, and having a closed chamber above the bowl, a valve normally cutting 01? communication between the interior of the bowl and the inferior of said chamber, means for attaching the upper end of the casing to a tool string, said casing comprising relatively movable sections with a thread connection connecting the same, disconnectible by a rotation of the tool string when the bowl is held against the well bottom, enabling the said sections of the casing to have relative longitudinal movement thereafter, a valve puller carried by the lower section of the said casing for engaging the valve when the tool string is lowered thereafter, and operating when the tool string is pulled upwardly, to open the MED valve, and resilient means cooperating with the valve puller to acceleratethe opening movement of the valve.

8. In a suction fishing tool for use in deep wells, the combination 01a casing having a bowl at its lower end, and having a closed chamber above the bowl, a valve normally cutting 01f communication between the interior of the bowl and the .moved downwardly, and operating to pull the valve ofi its seat when the tool string is pulled upwardly thereafter.

9. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end, and having a closed chamber above the bowl, a valve normally cutting off communication between the interior of the bowl and the interior of said chamber, means for attaching the upper end of the casing to a tool string, said casing comprising relatively movable sections with a thread connection connecting the same, disconnectible by a rotation of the tool spring when the bowl is held against the well bottom, enabling the said sections of the casing to have relative longitudinal movement thereafter, said valve having a hook extending downwardly therefrom, a valve puller carried by the lower section of said casing, having a head'with an opening to receive the hook, with a flange projecting inwardly around the edge of'said opening to engage the hook when the upper section of the casing is moved downwardly, and operating thereafter when the tool string is pulled upwardly, to open the valve. I, p

to. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end and having a closed chamber above the bowl,'said casing including an upper section having means for attaching the same to a tool string and including a lower sectionin the form of a sleeve, said casing sections having a thread connection connecting the same and disconnectible by rotation of'the tool string when the bowl is held against the well bottom thereby enabling the said sections of the casing to have relative longitudinal movement thereafter, a valve carried on the upper casing section normally cutting oil communication between the interior of the bowl and the interior of said chamher, and means operating by the downward and upward movement of the tool string to engage the valve and pull the same oh its seat.

'11. In a suction fishing tool for use in deep wells, the combination of a casinghaving a bowl at its lower end, and having a closed chamber above the bowl, a valve-normally cutting off communication between the interior of the bowl and the interior of said chamber, means for attaching the upper end of the casing to a tool tion for passing circulating fluid down through the tool string and past the valve, to the bowl, means controlled at will from the mouth of the well for closing oiI passage of circulating fluid down the said duct, and means cooperating with the sections of the casing in their relative longitudinal movement to efiect the opening of the valve.

12. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end, and having a closed chamber above the bowl, a valve normally cutting ofl? communication between the interior of the bowl and the interior of said chamber, means for attaching the upper end of the casing to a tool string, said casing comprising relatively movable sections, having a connection enabling the same to be partially disconnected from each other by a relative rotation of the two sections andthereby enabling the sections thereafter to have a relative longitudinal movement, said casing having a duct passing down through its upper section for passing circulating fluid down through the tool string and past the valve, to the bowl, a normally open circulation valve above the first named valve a member to be introduced in the circulating fluid at the mouth of the well to engage the said circulation valve for closing the same to stop the circulation of the fluid down past the first named valve, and means cooperating with the sections of the casing in their relative longitudinal movement, to effect the opening of the first named valve.

13. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end and having a closed chamber abovethe bowl, a fishing valve normally cutting off communication between the interior of the bowl and the interior of said chamber, means for attaching the upper end of the casing to a tool string, said casing comprising relatively movable sections, and having a circulation duct for passing fluid down to the tool string and past the valve, a circulation valve carried above the first named valve constructed to cooperate with a member introduced into the circulating fluid atthe mouth of the well to close the circulation valve and stop the downward passage of the circulating fluid, and means cooperating with the sections of the casing when moved relatively to each other to efiect the opening of the fishing valve.

14. In a suction fishing tool for use in deep wells, the combination of a circulation valve casing having means at its upper end for connecting the same to a tool string, a tubing section attaching to the lower end of the circulation valve casing, a fishing valve casing having means connected with the lower end of the tube section and cooperating with the same to form a closed chamber, a bowl connected with the lower end of the fishing valve casing, a circulation valve mounted in the circulation valve casing, a circulation tube extending downwardly from the circulation valve and passing through the said closed chamber to conduct circulating fluid through the fishing valve casing to the bowl, a fishing valve mounted in' the fishing valve casing, normally closed and cutting off communication between the interiorof the bowl and the interior of said closed chamber, said fishing valve casing having two sections relatively movable to each other, a member to be introduced at the mouth of the well in the circulating fluid for engaging thecirculation valve to close the same and stop passage of circulating fluid through the fishing valve casing, and means cooperating with the relatively movable sections of the fishing valve casing thereafter for opening the fishing valve and thereby causing an inrush of material at the well bottom into the bowl due to the hydrostatic pressure in the well.

15. In a suction fishing tool for use in deep wells, the combination of a circulation valve casing having means at its upper end for connecting the same to a tool string, a tubing section attached to the lower end of the circulation valve casing, a fishing valve casing having means connected with the lower end of the tube section and cooperating with the same to form a closed chamber, a bowl connected with the lower end of the fishing valve casing, a circulation valve mounted in the circulation valve casing, a circulation tube extending downwardly from the circulation valve and passing througn the said closed chamber to conduct circulating fluid through the fishing valve casing to the bowl, a fishing valve mounted in the fishing valve casing, normally closed and cutting ofl communication between the interior of the bowl and the interior of said closed chamber, said fishing valve casing having two sections relatively movable to each other, a member to be introduced at the mouth of the well in the circulating fluid for engaging the circulation valve to close the same and stop passage of circulating fiuid through the fishing valve casing, and means cooperating with the relatively movable sections of the fishing valve casing thereafter for opening the fishing valve and thereby causing an inrush of material at the well bottom into the bowl due to the hydrostatic pressure in the well, and means associated with the circulation valve for opening the same after pressure on the circulating fluid is relieved.

16. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end, and having a closed chamber above the bowl, a valve normally cutting off communication between the interior of the bowl and the interior of said chamber, means for attaching the upper end of the casing to a tool string, said casing comprising relatively movable sections with a thread connection connecting the same,

disconnectible by a rotation of the tool string when the bowl is held against the well bottom, enabling the said sections of the casing to have relative longitudinal movement thereafter, said valve having a resilient tongue extending downwardly therefrom and having a hook on its lower end, means for guiding said tongue when one of the sections of the casing is moved downwardly relative to the other section of the casing, and a valve puller having a hook head for engaging the valve hook when the tool string is moved downwardly, and operating to pull the valve off its seat when the tool string'is pulled upwardly thereafter.

17. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end, and having a closed chamber above the bowl, a valve normally cutting oif communication between the interior of the bowl and the interior of said chamber, said casing comprising an upper section and a lower section with a thread connection connecting the same, means for connecting the upper section of the casing to a tool string, said thread connection being disconnectible by a rotation of the tool string when the bowl is held against the well bottom and enabling the said sections of the casing to have relative longitudinal movement thereafter, said upper casing having a valve seat forthe said valve and having a tubular extension below the valve seat extending downwardly in the lower casing, a hook extending downwardly from the valve, a cross-head in the lower section below the valve, a tubular valve puller mounted in the cross-head and having a hook head at its upper end to cooperate with the hook on the valve, a coil spring disposed around the tubular valve puller and supported on the said crosshead, said upper section operating when moved downward relatively to the lower section to engage and compress the said spring, the hook head of said valve puller operating to engage the valve hook so that when the upper section is pulled upwardly the valve will be pulled off its seat by the valve puller.

18. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end and having a closed chamber above the bowl, said casing comprising an upper section and a lower section with a thread connection connecting the same and disconnectible by a rotation of the tool string when the bowl is held against the well bottom, said upper section having means for attaching the same to the tool string and having a valve seat, a valve on the said valve seat and having a hook in the form of a resilient'tongue extending downwardly herefrom, means on the upper section for guiding said resilient tongue, means received between the lower end of the tongue and the wall of the upper casing for developing a flexing force in the said tongue to hold the valve on its seat, and a valve puller mounted in the lower section, and operating after the thread connection has been disconnected and moved downwardly, to engage the said hook and open the valve when the upper section is pulled upwardly.

19. In apparatus of the kind described, means for shutting oif circulation to a pipe string comprising a casing, a circulation pipe packed in the same and extending downwardly therefrom, a valve guide connected to the circulation pipe, a tubular valve mounted in the valve guide, and having ports above the upper end of the valve guide, a springnormally holding the valve in an elevated position and open position, said valve having a seat at its upper end capable of being engaged by a ball introduced in the circulating fluid, said valve operating when engaged by the ball to move downwardly and close the said ports.

20. In a suction fishing tool for use in deep wells, the combination of a casing having a bowl at its lower end and having a closed chamber above the bowl, a valve normally cutting off communication between the interior of the bowl and the interior of said chamber, means for attaching the upper end of the casing to a tool string, said casing comprising relatively rotatable upper and lower sections, means cooperating with the relatively movable sections and brought into action after a relative rotary movement of the said upper and lower sections has occurred, for opening the valve and thereby causing an inrush of material of the well bottom into the bowl due to the hydrostatic pressure in the well to carry in the fish, and means for retaining the fish in the bowl.

OMAR A. CAVINS.

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