US2623473A - Swab for tapered casing or tubing - Google Patents

Description

Patented Dec. 30, 1952 SWAB FOR TAPERED CASING OR TUBING Howard John Pankratz, Bartlesville, kla., assignor to Phillips Petroleum Company, a corporation of Delaware Application March 11, 1947, Serial No. 733,881

'This invention relates to swabs. In one specific aspect it relates to swabs which are self adjustable to fit and operate properly in a plurali-ty of dimensions of pipe such as the casing or tubing of a well.

In modern practice in deep wells, it is advantageous and economical to use tapered strings of casing and tapered strings of tubing, with thinner tubing or casing for the center portion of the well and increasing the thickness of the walls of the casing or tubing toward the top and bottom of the well. In inserting tubing and casing in a well it is suspended from the derrick in a long string thousands of feet in length and the center portion of the string need not be as strong as the upper portion, which is supporting the lower portion, or as strong as the bottom portion which must withstand the hydrostatic collapse pressure. By making the lower portion lighter, the upper portion has less to support. The only disadvantage of this system is that the inside diameter of the tubing or casing varies from small to large and back to small again as a swab travels up the well and the swab must adjust itself to the change in diameter. The tapering of the tubing is generally not uniform, but usually consists of running severa1 hundred feet of a certain thickness, and then running a similar number of the next thickness, and then the next thickness, etc., until suflicient tubing or casing has been assembled.

During the life of a well it is often necessary to swab the same either as a simple pumping operation, or for other purposes such as causing pressure changes on the formation to stimulate natural flow, or simply to remove liquids or mud from the well.

While satisfactory swabs have been produced which will Work with high efiiciency for long periods of time in a single internal diameter size of tubing or casing, these swabs have proved inefiicient, or inoperative, or have rapidly broken down when used with tapered casing or with tubing having a plurality of internal diameters.

One object of the present invention is to provide an improved swab.

Another object is to provide a simple and easily operated swab having a minimum number of parts which are inexpensive to build and rugged in operation.

Another object is to provide a swab which will operate in a casing or tubing having a plurality of inside diameters.

Another object is to provide aswab which will automatically adjustitself to a wide variation in 2. internal diameters of a pipe through which it is being pulled.

Another object is to provide a swab which uses the hydrostatic head of the liquid being lifted to seal the swab to the pipe.

Another objectis to provide a swab which can be collapsed for easy removal upon dropping a weight.

Another object is to provide aswab which can be collapsed for easy removal by operation of a time clock.

Another object is to provide a swab which is inflatable by a self contained source of gas under high pressure.

Numerous other objects and advantages will be apparent to those skilled in the art upon reading the accompanying specification, claims and drawings.

In the drawings:

Figure 1 is a cross sectional view with parts broken away of a swab embodying the present invention.

Figure 2 is a similar view of a second modified swab embodying the invention.

Figure 3 is a similar view of a third modified swab embodying the invention.

Figures 1, 2 and 3 show only a portion of the swab, the longitudinal axis of the swab running longitudinally of the figures right through the center of the .largeb-alls shown therein. As most of the elements of the swab are volumes of revolution generated around that axis, it is believed that illustration of the broken away portion of the swab is unnecessary.

In Figure 1, a swab generally designated as 4 is designed for operation in pipe of varying diameter in a well for swabbing liquid from said well. Swab l comprisesa first supporting member 6 which is preferably made in two parts 6 and 7 in order to allow access to the interior thereof. At 0 threads are provided for connection with a cable or tubing by which the swab is raised or lowered in the well.

A second supporting member 9 is provided at telescopic relationship with said first member 6, and said member 9 is preferably made in several pieces, namely, body parts 9 and I ll, plug II and cap i2. Cap I2 is provided with holes I3 and acts to push washer I l. Plug II is provided with a passage [6 communicating with passage I! in the interior of 9 and through passages I3 with passage [8 in the interior of 6 and then through passage !9 to the exterior of the swab. Passages 19,18, 13,11 and I6 forms-a by-pass passage aroundthe swab 4 and flow therethrough is controlled by an upwardly opening check valve 2|.

When the swab is first inserted in the well, washer I4 is held above frangible pin 22, but in the position shown in Figure 1, frangible pin 22 has been broken and the broken off portion 23 has fallen to rest on shoulder 24 of member B.

Member 9 is provided with outstanding ears 26 to which arms 21 and 28 are pivoted y pivot pins 29 and M respectively.

Arms 21 and 28 have curved surfaces 32 and 33 respectively to engage rubber cup 34 and extend the same out to the tubing which is of varying diameter.

Cup 34 rests on flange 36 of member I9 and has a sealing flange 31 provided to prevent leakage. Cup 34 is held down by shoulder 39 which is spring pressed by spring 39. The upper edge of cup 34 is turned inward at M and is preferably secured to some form of retaining means such as ring 42 by means of such securing means as bolt 43 and nut 44. Ring 42 is provided with holes 46 and fits loosely around member 8 at 41.

Arm 21 may be provided with a cut away portion 48, if desired, as such cut away portion gives better action to the arm. Arm 21 is pivoted on member 9 at 29 and in effect is pivoted on memher 6 at 49. While only one set of arms 21 may be used if desired it is preferred to have at least another set of arms such as 29. As many sets of arms as desired may be provided, each set being separated by a spacing sleeve and urged apart by a spacing spring 52. The lower set of arms 28 is supported by a spring 39 and support member 53.

Inside of sleeve 5i is provided a space 54 and inside of cup 34 is a space 55 for the collection of liquid in the swabbing of the well as such liquid tends to expand cup 34 into sealin engagement with the well pipe.

In Figure 2, a modified form of swab, generally designated as 6I, is shown having a supporting member 62 which is provided with means 93 at its upper end for'connection to a cable or string of pipe by which said swab is operated upwardly and downwardly in the well.

Member 62 is provided with a central by-pass passage 64 communicating with the wel1 through holes 66 above packer 61 and through hole 68 in plug 69 below packer 61. Flow through this by-pass passage is controlled by the upwardly openin check valve H. Member 62 is provided with upper flange 12 and a lower flange or washer '13, Between flanges 12 and 13 are located the operating portions of the packer.

Packer 61 consists of an annular rubber tube or casing very much like an automobile tire in which is disposed an inflatable inner tube 14 which will expand into space 16 when gas under sufficient pressure is placed in space 11.

A chamber 18 is provided having a gas space 19 containing sufficient gas under sufficient pressure to inflate tube 14 and press casing 31 firmly against the wall of the well ipe, regardless of the diameter of the pipe. As the pipe decreases in diameter, part 91 will be correspondingly deformed and the air in 11 correspondingly compressed.

In order to connect space 19 with 11 a conduit 8| is provided connecting the two. Conduit 8! is controlled by an upwardly opening spring check valv 82 and a downwardly opening spring valve 83. Valve 83 is adapted to be compressed by arm 84 when body 86 is moved downwardly, conduit 8| being flexible at point 81 to allow for 4 such movement. When the device is inserted in the well a flexible pin 88' holds conduit 8| in extended position. When flexible pin 88 is broken, however, due to the weight of liquid above 61, flexible pin 88 becomes broken and valve 83 is forced open.

Conduit 8I may be made up in a large number of ways and may comprise various nipples 89, 9| and 92 and thimbles 93 and 94. Nipple 92 contains valve 96 which maybe opened by contact of plate 91 with head 98. Plate 91 ordinarily can not contact head 99 because spring 99 guided on pin I 9| holds 91 spaced from top plate I02.

The flexible tube assembly 61 includes top plate I92 and lower plate 86 along with intermediate plates I93 and I94 held together by bolt 193. These plates allow the assembly of the device which otherwise would be hard to assemble, as conduit III has a branch I91 connecting to tube 14 by the usual connecting means I99 and I99.

A go-devil tube III is provided with a tapered surface I I2 to avoid contact with flange I92. Godevil III is dropped into the well to open the valve by plate 91 contacting valve 98 by compressing spring 99 when desired.

In Figure 3, a third type of swab, generally designated as H3 is shown. This swab is built into a single body composed of upper member II4 having threads or other means of connection IIB for connecting the same to a cable or operating tubing (not shown); Member H4 is screw threaded to sleeve II1 which in turn is closed by plug H8 having a passage II9 therethrough controlled by upwardly opening check valve I2I. A by-pass conduit is provided at I22 in sleeve II1 with passages I23 below the packer casing I24 and passages I26 above the packer casing for passage of liquid around the casing.

Casing I24 is similar to an automobile tire casing and tube I21 is similar to an automobile inner tube. A guid plate I28 is provided for guiding the upper part of casing I24 and a lower flange I29 on body I I1 guides the lower portion of the casing. A removable annular member or rim I 3| is provided to enabl the tires I24 and I21 to be disassembled.

When gas under pressure blows into chamber I32 inside tube I21, it forces tube I21 to expand through space I33 into contact with tub I24. The lower part of H1 is threaded to receive the lower body portions I34 and I 35. Body portion I35 contains enough gas in I35 and enough pressure to actuate the inflation of tub I21. A time clock I31 in I34 may be wound up by winder I38 and shaft I39. The clock is supported by arms I49 and drives shaft I4I carrying cam I42. Cam I42 has two projections I43 and I44 respectively thereon. Projection I43 engages a valve I46 to allow gas to escape from space I41 and projection I44 engages valve I48 to allow gas to expand from spac I36 into space I41. Gas in I41 passes through passages I49, I5I and I52 into space I32. The usual connecting means I53, I54 and I59 may be provided.

Operation of Figure 1 e In the apparatus of Figure 1, part 1 is removed from part 6 and part 9 is raised up until a new frangible pin 22 can be inserted below washer I4. 1 is then replaced in 6 and pin 22 will hold 9 in the position where arms 21 and 28 are drawn back out of positive contact with cup 34 (although cup. can bepushed back against the arms even in this position),

The swab .4 .is "then ,inserted in the well and lowered down through the liquid. While air or gas is in the well this gas will lift ball 2,I from time to time and force up through openings I6 and outtbrough openings I9. When liquid is encountered, liquid willflow in opening it, lift ball M and pass through openings I3 and I9.

When swab 4 has reached the desired predeterminedlower position itsmotion is reversed and it is raised. Upon raising liquid flows through I9 and .13, and places ball 2I on seat II. Some liquid will scape around the out side between cup 34 and the wall of the well pipe but this will not occur very long because most of the liquid transmits pressure through opening $6 to space 55 throwing considerable weight on flange 36 which breaks-frangible pin 22. Member fi-moves upwardly relative to member a into a position somewhat the same as shown in Figure '1. Arms 2:! and 2,8 rotate and. push the walls of cup 34 out-into sealing relationship with the well pipe '(not shown). As the well pipe increases and decreases in diameter arms 21 and 28 will move upwardly and downwardly about pivots 29 and 31 accommodating for the change in the size of pipe. Upon reaching the top of the well a new pin 22 needs to be inserted below washer It as described above'andthis cycle is thenrepeated.

Operation of Figure 2 Threads 63 are engaged with the cable or pipe in the same manner as threads 3 were in Figure 1. Pin '85 being in place and tire it being deflated. Part III has not been employed as yet and should be disregarded for the moment, The swab {Si is inserted-into the well and on the downwardtrip gasor liquid comes'in opening 68 pushing back ball H and passes through 54 and out hole 56 above packer 61. Liquid flowing past 5? tends to support the same. Upon reaching'the predetermined lowpoint in the well the motion is reversed and the swab EI is hoisted by the means attached at 63. diately and whil some escapes around the outside of packer El the plate I52 is soon loaded with enough weight to break frangible pin 83. Upon this happening, plate 8'5 and ,all related parts move downwardly so that pin 84 o ens valve 83. Gas in i9 then rushes up conduit SI into space H expanding packer it into engagement with the wall of the pipe. If the pipe varies in diameter ii? will .move inward or outward to actuate itself.

If through some trouble, the swab should become stuck in the wellanditis desired to-remove the same with as little effort as possible a godevil pipe I I I is-dropped down into thewell where it strikes plate 9'! and forces this plate to compress spring 99 and contact valv 93 allowing gas in T! to bleed oif through nipple 92 allowing packer 67 to collapse. The swab is then very easily removed.

Operation of Figure 3 Figure 3 operates much the same as Figure 2 except that the inflation of packer I24 is controlled by time clock I 31. The time clock is wound up with the parts in the position shown and :with packer I241collapsed. Part H6 is secured to th -usual operating means consisting of acable or tubing-(not shown). The swab H3 is put into the well and run 'down to the desired position, any fluid in the "well passing through Liquid closes valve II imme- 6. I23, I22 and I19 opening valve :I2I and. passing out opening I126.

When :a sufficient time has passed to allow the swab .to be positionedproperly, clock I31 rotates cam Hi2 until projection I44 opens valve I48. Gas :from I36 passes through I48 and spaces 14;! into passage I49 leading through passages I5I and I52 into space I32 in inner tube I21. Packer 42.4 is thus inflated.

'The swab is drawn upwardly and packer I24 adjusts itself to the different diameter of the pipe.

If the swab IE3 becomes stuck for any reason the operator need only wait until cam I42'rotates until projection M3 contacts I45 and opens the same, whereupon the pressure in tube I32 bleeds out through passage 15.2, I'5l, ltfl'and space I41, whereupon packer I26 collapses and swab H3 is easily removedirom the well.

Numerous conventional changes in size,rshape or arrangement of parts'may obviously be made without departing from the spirit and substance of the present invention as defined in the claims.

Having described my invention, I claim:

1. A swab for swabbing liquid from a well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said member and containing gas under pressure sufiicient to inflate said packer, means forming a conduit connecting said chamber and said packer, a valve controlling said conduit, means for opening said valve when the swab is down in said well to inflate said packer comprising a time clock and a cam driven thereby to contact and open said valve at a predetermined time, and means for venting gas from said packer to deflate the same for easy removal from th well comprising a second valve leading from said conduit into said well and a rise on said Call). to contact and opensaid second valve at a predetermined time.

2. A swab for swabbing liquid from a well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said member and containing gas under pressure suffi cient to inflate said packer, means forming a conduit connecting said chamber and said packer, a valve controlling said conduit, and means for opening said valve when the swab is down in said well to inflate said packer comprising a time clock and a cam driven thereby to contact and open said valve at a predetermined time.

A swab for swabbing liquid. from a well, comp-rising'in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on 'said member and containing gas under pressure suflicient to inflate said packer, means forming a conduit connecting said chamber and said packer, a valve controlling said conduit, meansfor opening said valve when the swab is down in said by pressure, and a weight movable relative tothe swab to contact said second valve andopen the same by saidpressure.

4. A swab for swabbing liquid from a well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said member and containing gas under pressure sufficient to inflate said packer, means forming a conduit connecting said chamber and said packer, a valve controlling said conduit, means for opening said valve when the swab is down in said well to inflate said packer comprising said packer, said packer being constructed to move down and contact and open said valve, and frangible means retaining said packer out of contact with said valve until broken by the weight of liquid in said well upon upward movement of said swab.

5. A swab for swabbing liquid from a well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said member and containing gas under pressure suflicient to inflate said packer, means forming a conduit connecting said chamber and said packer, a valve controlling said conduit, said member being formed with a by-pass passage communicating with said well above and below said packer, an upwardly opening check valve controlling flow of said liquid through said passage, means for opening said valve when the swab is down in said well to inflate said. packer com' prising a time clock and a cam driven thereby to contact and open said valve at a predetermined time, and means for venting gas from said packer to deflate the same for easy removal from th well comprising a second valve leading from said conduit into said well and a rise on said cam to contact and open said second valve at a predetermined time.

6. A swab for swabbing liquid from a well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said member and containing gas under pressure suflicient to inflate said packer, means forming a conduit connecting said chamber and said packer, a valve controlling said conduit, said member being formed with a by-pass passage communicating with well above and below said packer, an upwardly opening checl: valve controlling flow of said liquid through said passage, and means for opening valve when the swab is down in said well to inflat said packer comprising a time clock and a cam driven thereby to contact and open said valve at a predetermined time.

7. A swab for swabbing liquid from a well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said 'member and containing gas under pressure Sllfilcient to inflate said packer, means forming a conduit connecting said chamber and said packer, a valve controlling said conduit, said member being formed with a by-pass passage communL cating with said well above and below said packer, an upwardly opening check valve controlling flow of said liquid through said passage, means for opening said valve when the swab is down in said well to inflate said packer comprising packer, said packer being constructed to move down and contact open said valve, frangible means retaining said packer out of contact with said valve until broken by the weight of liquid in said well upon upward movement of said swab, means for venting gas from said packer to deflate the same for easy removal from the well 8 comprising a second valve leading from said conduit into said well constructed to be opened by pressure, and a weight movable relative to the swab to contact said second valve and open the same by said pressure.

8. A swab for swabbing liquid from a well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said member and containing gas under pressure suflicient to inflate said packer, means forming a conduit connecting said chamber and said packer, a valve controlling said conduit, said member being formed with a by-pass passage communicating with said well above and below said packer, an upwardly opening check valve controlling flow of said liquid through said passage, means for opening said valve when the swab is down in said well to inflate said packer comprising said packer, said packer being constructed to move down and contact and open said valve, and frangible means retaining said packer out of contact with said valve until broken by the weight of liquid in said well upon upward movement of said swab.

9. A swab for swabbing liquid from a well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said member and containing gas under pressure suflicient to inflate said packer, means forming a conduit connecting said chamber and said packer, an inlet valve controlling said conduit, means biasing said inlet valve closed, self-contained means in said swab for opening said inlet valve to inflate said packer when down in said well, an exhaust valve controlline communication between the well bore and said conduit at a point between said inlet valve and said inflatable packer, means biasing said exhaust valve closed, and means to open said exhaust valve.

10. A swab for swabbing liquid from a well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said member and containing gas under pressure suflicient to inflate said packer, means forming a conduit connecting said chamber and said packer, an inlet valve controlling said conduit, said member being formed with a by-pass passage communicating with said well above and below said packer, and an upwardly opening check valve controlling flow of said liquid through said passage, means biasing said inlet valve closed, self-contained means in said swab for opening said inlet valve to inflate said packer when down in said well, an exhaust valve controlling communication between the well bore and said conduit at a point between said inlet valve and said inflatable packer, means biasing said exhaust valve closed, and means to open said exhaust valve.

11. A swab for swabbing liquid from a well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said member and containing gas under pressure suflicient to moval from the well comprising a second valve' leading from said conduit into said well constructed to be opened by pressure, and a weight movable relative to the swab to contact said second valve and open the same by said pressure.

12. A swab for swabbing liquid from a well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said member and containing gas under pressure suflicient to inflate said packer, means forming a conduit connecting said chamber and said packer, a valve controlling said conduit, and means for opening said valve when the swab is down in said well to inflate said packer comprising said packer, said packer being constructed to move down and contact and open said valve.

13. A swab for swabbing liquid from a well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said member and containing gas under pressure suflicient to inflate said packer, means forming a conduit connecting said chamber and said packer, a valve controlling said conduit, said member being formed with a by-pass passage communicating with said well above and below said packer, an upwardly opening check valve controlling flow of said liquid through said passage, means for opening said valve when the swab is down in said well to inflate said packer comprising said packer, said packer being constructed to move down and contact and open said valve, means for venting gas from said packer to deflate the same for easy removal from the well comprising a second valve leading from said conduit into said well constructed to be opened by pressure, and a weight movable relative to the swab contact said second valve and open the same by said pressure.

14. A swab for sw-abbing liquid from a Well comprising in combination a supporting member, an inflatable packer mounted on said member, means forming a chamber mounted on said member and containing gas under pressure sufficient to inflate said packer, means forming a conduit connecting said chamber and said packer, a valve controlling said conduit, said member being formed with a by-pass passage communicating with said well above and below said packer, an upwardly opening check valve controlling flow of said liquid through said passage, and means for opening said valve when the swab is down in said well to inflate said packer comprising said packer, said packer being constructed to move down and contact and open said valve.

HOWARD JOHN PANKRATZ.

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

UNITED STATES PATENTS Number Name Date 2,057,966 Parrish Oct. 20, 1936 2,119,252 Thaheld May 31, 1938 2,207,001 Dillon July 9, 1940 2,233,013 Humason et al. Feb. 25, 1941 FOREIGN PATENTS Number Country Date 617,905 France Feb. 28, 1927

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