US2581981A - Well swab - Google Patents

Description

Jan. 8, 1952 R. G. TAYLOR, JR

WELL SWAB 3 Sheets-Sheet 1 Filed July 18, 1947 Raymond 6. Taylor; .Jgr

attorney Jan. 8, 1952 R. G. TAYLOR, JR

WELL SWAB 3 Sheets-Sheet 2 Filed July 18, 1947 0 M 3 v r /fl/ //////A n ul- 22 f v w mflM/// V/////// Raymond G. Taylor; JK

3nnentor Clitorneg Jan. 8, 1952 R. G. TAYLOR, JR

WELL. SWAB 3 Sheets-Sheet 5 Filed July 18, 194'? w w w w w w q ////7 7 /////////A m 0 M m m w m E G d H m W p R w w 7 3 3 I m 2 Gttomeu Patented Jan. 8, 1952 WELL SWAB Raymond G. Taylor, J r., Dallas, Ten, assignor to The Gulberson Corporation, Dallas, Tex a corporation oi Delaware Application July is, 1947, Serial No. 761,751 7 Claims. (01. 103-225) This invention has to do with a long-lived well swab assembly of few parts and great strength, including an elongated resilient cup in which load and wear are distributed over relatively large surfaces.

The tool employing my invention will run into the well tubing or casing with much greater speed than has been possible with old type swabs. This comes about because of the greater clearance between the inside of such pipe and the outside of the swab assembly, and also because of the greater cross-sectional area in the bore of the mandrel which provides a conduit through the assembly. This is so, notwithstanding that this new swab is very rugged and will carry an unusually large load of fluid.

The invention provides an unusually long swab cup. Its length is usually two to three times its diameter; and the cup itself is divided into three separate areas. each difiering in flexibility and strength, the better to seize, collect, accommodate and carry increasingly large loads of fluid.

The cup is provided with an adJustable device which will allow its lip to be laterally expanded to operate with continued eificiency after the outer face of such lip has been worn away by friction.

Fewer and stronger parts make up a better tool having a lower initial cost and less operating expense, as contrasted with earlier devices in this art.

This invention represents an improvement over presently pending patent application filed on February 6, 1947, under Serial No. 726,900.

Heretofore, swab cups have had a relatively short life. This was largely due to the fact that the friction between the cup and pipe through which it passed wore out the side wall of the cup in a relatively narrow band therearound. Such abrasion soon weakened a belt around the cup wall, so that thereafter it became abnormally extended in such thinned region of the wall, and was rendered useless. One of the primary improvements offered by this invention is the elimination of such trouble.

In the past there was entertained the mistaken idea that a well swab should fit the pipe in which it moved, even to the point of affording a friction flt. Such is unnecessary.

Moreover, it is highly undesirable, as my invention has proved.

My swab will rarely touch the side wall of the pipe into which it is being run while going down for a load of fluid. This fact not only increases the life of the cup, by reasonof less friction 2 thereon, but it speeds the introduction of the tool into the lower part of the well, and it saves a tremendous amount of labor and overhead costs in so doing.

It may well be said that this invention, in fact, presents three diflerent cups, all integrated into one swab cup. and each so shifting the load to another as to make all bear a proportionate share of the load, especially as the load progressively increases. There is therefore no definitely iocaliaed area which is subjected to great friction. The friction band slowly shifts and "slides down" the outside of the cup. as the load increases within the cup.

To accommodate and care for suchvariations in load (all within one cup) the upper region of the cup has been made rather quickly responsive to internal pressure. This is largely due to the fact that the uppermost side walls are not reinforced, and an oi'l'set lip is provided.

The next lower region of the cup is specially reinforced, with flexible materials; but such reinforcing is designed to carry only moderate loads of fluid (to which this section of the cup readily responds).

The third and still lower region of the cup is doubly reinforced, as with wire or yielding steel fingers; and this latter area is designed to carry extremely heavy loads, though expanding somewhat thereunder.

The iourth area of the cup is an extremely strong, non-yielding, and inflexible base, supporting all of the three responsive regions of the cup, and ultimately receiving and carrying weights and pressures originating from the loads of all three.

This base is the foundation for a plural number of series of varyingly extended flexing arms or fingers of cantilever design, all extending upwardly from the base and within the materials of the plastic cup. This construction and de sign permits the recovery of such cantilever fingers by allowing them to spring back into normal position (carrying the cup wall with them), after the load is removed from the cup. The cantileverlike spring fingers are important: and so is the long length of the cup assembly, divided as it is into bands which function separately and/or successively.

In this specification and in the drawings it is desired to make clear that among the objects of this invention are the following:

(1) A greater than usual clearance between the outside of the cup and the inner wall of the pipe in which it may be moved.

(2) An elongated and offset cup lip, which will immediately engage the side walls of the pipe when the swab is being withdrawn, so as to fill the cup. and initially hold the contents therein, and also seal the side wall of the cup against the pipe.

(3) The provision of three separate areas of cup wail. beginning at the top thereof. each increasingly strong ih resistance to pressure. and all so integrated as to make one continuous and elongated cup, in which each lower section will carry a greater load than the one above it; and all this without particularly localizing the area of friction on the outside of the cup. but on the other hand widely spreading such area up and down the side walls of the cup. thus greatly increasing its life by reducing its friction.

(4) Base construction in the cup whereby the reinforcing material and the base itself are so made together as to constitute one stout integrated skeleton. simplifying the assembly of such reinforcing and load-carrying parts and reducing costs and increasing strength. 7

(5) The integration of the reinforcing with the base and with the plastic material of the cup in such way that all three such elements become one responsive assembly, providing cantileverlilre fingers anchored in the base and extending u within the side walls of the cup.

(6-) Maximum fluid passageway outside of the cup and maximum fluid passageway through the cup and through the entire swab assembly.

(7) Fewer and stronger parts in the entire assembly than those ordinarily encountered in swab devices.

(8) Means provided within the cup assembly for lifting up the side wall of the cup and spreading the upper lip thereof. after its outer edge has been worn away by friction. such adjustment being of material aid in continuing the efiiciency of the cup and lengthening its life.

(9) Special provision of a series of notches or passageways on the inner face of the lip of the cup. so that it will always pick up fluid, notwithstanding that it may be adjusted upwardly against a spreading shoulder to enlarge the periphery of a worn cup. These openings on the lip will provide never-closed apertures for the introduction of fluid into the cup.

(10) Overlapping and/or interlocking fingers or wires in the lower region of the side wall of the cup. so arranged that each short member thereof will carry and transmit to each long member a part of its load and stress: and vice versa. This arrangement presents a cooperative and integrated responsiveness in all of the fingers in the cup. so that no one stands alone to carry a partlcular part of the stress; and on the other hand, all of them unite in their resistance to pressure. They. therefore, yield uniformly; and there remains no fixed distortion of the body of the cup. after the load is removed.

(11) An elongated swab wherein the long length of the cup itself adds materially to the swabbing value in that there is practically never any loss of the load being lifted. My cup lifts all of the fluid gathered above it.

(12) A swab which will get the last cupfull of fluid out of the pipe. notwithstanding that various weights of tubing or pipe may be in the string. my cup accommodating itself against the inner walls of pipes of different diameters. and sealing off all the fluid below which it is placed.

(13) The disclosed construction which will prevent the cold flow of rubber or other elastic maouter face theei'of. such as is found in old de vices. There is no construction in my device which will allow the cold flow of rubber or of plastic material through and about the reinforcmg or over and around it, as found in old devices in this art.

The drawings are set out with the oblect of illustrating a typical form of the invention, but it must be understood that this invention may be practiced without resort to the details of such iii) drawings, and that changes may be made without departing from the spirit of this invention. which I desire to claim broadly.

In the attached drawings;

Fig. I is a partially sectionalized elevation of a swab assembly employing my invention.

Fig. II is a partially sectlonalized elevation of the valving mechanism of such assembly.

Fig. III is a plan view taken along the line IIIIII of Fig. I.

Fig. IV is a plan view taken along the line IV- IV of Fig-Ia Fig. V is a plan view taken along the line V--V of Fig. I.

Fig. V1 is a plan view taken along the line VI- VI of Fig. I.

Fig. VII is a seetlonallaed elevation of one form of reinforcing material supporting the swab cup.

Fig. VIII is a partially sectlonalized elevation of a swab cup being run into the well.

Fig. 13 is a partially sectionalized elevation of a swab cup in a static position or in its initial movement of return and while under very light load.

Fig. X is a partially sectionalized elevation of a swab cup under a medium load.

Fig. XI is a partially sectionalized elevation of a swab cup under a heavy load.

Fig. XII is a partially sectionalized elevation of a swab cup which has been so adjusted as to expand its upper lip.

Fig. XIII is a sectionallzed elevation of a modifled form of reinforcing elements which carry and support the cup.

Fig. XIV is a plan view looking down on the top of the reinforcing elements shown in Fig. XIII.

In the drawings. the various parts of my device have been indicated by numerals, and like parts are indicated by the same numeral; and the numeral i indicates well pipe, such as casin or tubing.

The swab cup assembly 2 is made to pass up and down within this pipe. This assembly may be attached to or suspended on any lifting means. such as well tubing. pump rods or cable; and its primary purpose is to lift from the well a volume of fluid. such as oil. gas or water. or any other well fluid.

The swab cup assembly 2 is so arranged that it may be incorporated within the lifting string of pipe. or rod, or cable. as a single unit; or, as is more often the case. a. number of these cup assemblies may be incorporated in the iif ting line. The operator may include as many or as few such cup assemblies as he desires, the requirements of the job being done considered.

In Fig. I there are disclosed two separate swab cup assemblies. They are placed at or near the lower end of the lifting line; and they are run into the pipe within the well by gravity.

The lowermost cup assembly will be threaded and carried on a plain mandrel 3, so that such cup assembly may be easily affixed thereto, and as easily removed and replaced with a new cup.

Further and additional cup assemblies 2 may be carried on the lifting line by having them carried on the outside of another mandrel 3; and the lower end of such mandrel (below the cup assembly) will be threaded into the upper end of a like mandrel 3. In this manner there may be incorporated in the line as many cups asmay be desired.

Below the last cup assembly there is removably attached to the mandrel 3 (which passes through the cup assembly) the retaining nut 4. which is a body having a hollow chamber i8 therein and provided with passages I! through the chamber walls. Usually. the lower end of the retaining nut 4 is slightly rounded off, as shown. This is for safety and for guiding.

While the cup assembly 2 is being dropped into the well. part of the fluid in the well will pass through the openings or passages i9 and into the chamber l8, and thence upwardly through conduit 36. which is a wide open bore through the mandrel 3.

In order that fluid may be lifted with this device. it is arranged with a valve placed above the topmost swab cup assembly 2. Genericalll! this valve assembly is indicated by the numeral 5.

The uppermost cup assembly requires a mandrel for mounting; and this mandrel is indicated as at 6. Such mandrel is very much like the plain mandrel 3, except that the upper part of mandrel E is modified to provide a valve housing or chamber. through the walls of which are arranged a plurality of valve ports I, and in which is provided a valve seat l2. Any suitable type of valve head may be used, such as a poppet type, or other type. However. the ball type, as shown at i3, is very satisfactory.

The arrows. shown in Fig. 11. indicate the direction of the fluid passing upwardly through the mandrel E and out of the valve ports l4. after lifting up the valve ball l3 from its seat. l2. The ball remains in elevated position while the swab assembly is being lowered into the hole.

There is a clear and open conduit 36 running through all of the mandrels used in any given assembly of swab cups on the same line; and the well fiuid enters lower port i9 and. passes upwardly through such conduit 35 until it is even tually discharged from upper ports l4.

It is of importance that the conduit 36 be as large a reasonably possible, the strength required in these mandrels and in the entire assembly being considered. By reason of simplicity in the construction of this swab. and the unusually small number of parts therein, there has been achieved a somewhat enlarged bore 36. This arrangement will facilitate and hasten the lowering of the swab into the well: and it will permit the quick pick-up of a large volume of fluid. to be later lifted out of the hole by the cups 25.

The line of tubing, rod or cable which supports my swab is connected to the uppermost mandrel 6, of the assembled tool, by the use of mandrel sub 1. This sub should be made of hi grade steel; and it should be solid, as no object is served by having it hollow. On the other hand, the solid sub 1 i much stronger. It is usually provided with shoulders at top and bottom, as indicated at 8 and ill; and it is usual to bevel the shoulder 8. so as to minimize the chances of this member being hung under any obstruction encountered within the well. Likewise, it is usual to bevel the outer face of the top edge of mandrel E, and for the same reason.

The member I may be attached to the member 6 in any convenient manner; but one of the simplest and safest forms of attachment is provided by the use of threads, of which the threads 9 and H. on the upper and lower ends respectively of sub I, are typical.

The lower end of a string of tubing (not shown) which it may be desired to have connected to sub 1 should be provided with threads of a; character complementary to threads 5. Such arrangement can be effected by the use of a conventional pipe collar or coupling. A somewhat similar threaded collar may be provided on the lower end of a rod, or of a cable, for connection to sub 1. The male threads ii on the member 1 will find complementary female threads within the upper end of member 6.

Thus united, the entire assemblage, including all of the parts from retaining nut iii to sub 1. inclusive, may be raised and lowered within the well by raising and lowering the lifting line (not shown) which is connected to sub 1.

The extreme simplicity. strength and ruggedness of a typical assemblage incorporating my invention is made plain in Fig. I. It is to be noted that (aside from the swab cup assemblies 2) there are only four members necessary to firmly connect the assemblage together; and these are the sub 1 at the top, the retaining nut l9 at the bottom, and the two mandreis 3 and 6. which are themselves connected together.

These are far fewer parts than are ordinarily found in any knd of swab assembly wherein there is placed a plurality of swab cups: and this is important because of economy, as well as strength.

The incorporation of valving mechanism into one of the mandrels is in itself a simplification of great value, and results in saving labor and material.

Other features of advantage presented by my invention will be found in the design, arrangement, construction and operation of the swab cup assembly 2.

This swab cup assembly is a very strong and long-lived creation. It is made of very few parts; and these are assembled together quickly and inexpensively. My construction and arrangement keeps these parts cverlastingly attached and unified in cooperative response and reaction to the work being done and the load being lifted until they are worn out.

One of the most essential elements of this swab is the elongated plastic cup 25. It is purposely designed and so fabricated that its length is approximately from two to three times its diameter;

.- and its body is made of tough and resilient material, such as rubber or rubber composition, or other plastic compound, and preferably of oil resisting material.

Because of the fact that my swab cup is made relatively small in contemplation of the bore of the pipeinto which it is to be lowered, there is a minimum of friction and resistance offered by the pipe. As a matter of fact, this swab hardly ever touches the pipe while it is being run downwardly therein to pick up a load of fluid Old style swabs could not be thus loosely in-- troduced into a pipe for the simple reason that if they were much smaller than the pipe containing them, they could not reach out or expend to the walls of the pipe and hold the fluid above them. If, perchance, any of them were soft enough to be swelled out against the pipe the could not hold the load. Also, they soon wore in two along a narrow line, after assuming the approximate shape of a ball.

My swab cup 25 is substantially straightwalled; and when in inert position, and not loaded, these walls are vertical. Approximately the same clearance is found all around the cup 25 and between it and the inner walls of pipe I. This is illustrated as at 30, in Fig. VIII. Here my swab is shown while being run into the hole. Note that the fluid rapidly escapes upwardly around the outside of the cup walls, as indicated by the arrow in this figure.

The upper end of cup 25 is preferably finished with a slightly protruding lip 26. The outer edge of this lip should slightly overhang the outer wall of the main body of the cup.

The inner wall of lip 26 is provided with a series of notches 21; and the inner face of this lip 26 (which carries the notches) is preferably of greater diameter than the internal wall of the lower part of the cup.

It is also desirable and recommended that the upper part of the outside of lip 26 be made with a slight bevel. as at i 5.

The lip region and that part of the wall immediately below it, for a short distance, is not reinforced, as is the lower part of the cup wall.

With regard to function, the entire length of the cup wall (including the lip) has been divided into three parts. The upper part is the limber region of the cup; and this unreinforced section is indicated as at A.

The side wall of the cup, along toward its middle part, and below the flexible region A, constitutes the moderately flexible region B, which region is reinforced through the use of strong resilient steel fingers or wire loops, as at 22. This is the region of single reinforcing.

Below the last described region, there is another which is substantially stiff, and it is doubly reinforced. It carries, firmly embedded within the plastic material of the cup wall, both the lower ends of reinforcing members 22 and the upper ends of reinforcing members 23. The latter reinforcement is substantially like the former in appearance, except that it is shorter.

A typical arrangement of reinforcing material is disclosed in Fig. VII. wherein it is to be noted that the reinforcing member 23 presents the appearance of a loop of wire roughly in the shape of a hairpin, with its two free ends firmly em bedded between the members 20 and 2| (the function of which will be later described).

The elongated reinforcing member 22. which furnishes the reinforcing within the region B. is substantially like member 23 in appearance. However, reinforcement 22 is arranged so that its lower ends or legs stand on opposite sides of a typical member 23 (all as shown in Fig. VII). The purpose of such arrangement is to allow the member 22 to act somewhat independently of the member 23, when resisting distortion to the upper part of the cup. Each of these members is fixedly anchored within the thlmble 28, at the base of the cup; and each is so constructed as afford cantilever action, of spring-like and resilient character.

The relatively long reinforcing members 22 and 23, employed as indicated in the construction just described, allow the thimble (in which they are secured) to be made of such small diameter as to provide unusually great clearance around this thimble while the swab is within the well pipe and used for lifting fluid. This important advantage greatly aclds to the life of the swab assembly. because it eliminates a considerable amount of abrasion.

Considerable pressure is required to force the inner ring 2i into place, after the outer ring 29 has been positioned (within a special ha) and loaded with reinforcing fingers, set close together. However, such construction, under pressure, is quick, cheap, strong and safe. It results in a well made and thoroughly integrated cup skeleton, comprising base and fingers, about which the plastic cup is formed and molded.

Where the pipe being swabbed is of large diameter, it is not desirable to cause the cup to move against too great a head of fluid, as there connot be commonly found suflicient power equipment to pull such a load. The construction and ar rangement described immediately above, and as shown in Fig. VII, presents sufficient reinforcing for the larger cups.

Where it is desired to more heavily reinforce the cup, then the structure shown in Figures XIII and XIV may be employed. The construction indicated in Fig. XIII varies from that shown in Fig. VII in certain substantial ways, includin the following:

The lower ends or legs of the reinforcing members 34 and 35 are crowded together as closely as possible within the mandrel 2B, the latter being composed of concentric rings 20 and ti. and the space between the outer wall of inner ring 2| and the inner wall of outer ring 21) bein slightly less than the diameter of the reinforcin members 36 or 35, the latter are held securely \as members 22 and 23 are held).

The most important modification in the reinforcing disclosed in Fig. XIII, as opposed to that as shown in Fig. VII, is to be found in the overlapping nature of the two separate reinforcing members 34 and 35. The near legs of two members 34 are caught within and imprisoned by the outer legs of the single member 35. This is made more clear in Fig. XIV. This results in a singleness of response on the part of both members 36 and 35 (which is not found in the members 22 and 23).

Obviously, the reinforcing shown in Fig. XIII presents a much stouter resistance to distortion from pressure within the cup than that reinforcing shown in Fig. VII.

As pressure increases within the cup carrying the reinforcing shown in Fig. XIII the walls of the cup bend outward slightly in one continuous movement, or in one wave," so to speak. This single wave travels slowly down the cup wall, and does not permit any appreciable quantity of fluid to pass by on the outside of the cup, Indeed, after the cup is loaded, it may be truly said as a practical matter, there is no leak at all around the cup. The seal is as near perfect as can be.

The movement in the sealing of a cup reinforced with the structure shown in Fig. VII is somewhat different. There ls a quick response to the load in the upper part of the cup. and that part of the cup quickly impinges the wall of the tubing in which the cup is moving upwardly. Later, when the load increases sufficiently to spring the members 23 outwardly, the further impingement of the cup with the tubing is created by a second wave, which is occasioned by the outward movement of the entire series of members 23. Thus two separate waves cause pressure by the outer cup wall against the confining tubing wall.

However, if the load is greatly increased, the distortion increases laterally in the lower part of the cup. involving both the members 23 and the lower part of the members 22 in a third wave. This results in a relief of pressure on the upper parts of members 22; and they bend inward slightly, especially at their tops, releasing the seal in that region.

Friction, resulting in wear along the outer wall of the cup 25. is distributed over practically all of the outer wall of the flexible part of the cup.

This is true whether the area of friction be ne continuous area or band, spreading down the 'outer wall of the plastic cup in one wave, as pressure increases (on the structure shown in Fig. XIII), or whether there be found two or three separate bands, to slide down the outer wall of the cup employing the construction shown in Fig. VII.

One very important point in both types of reinforcing is that there shall be a lengthening of the life of the cup by causing the wear on the outer wall thereof to be distributed over as great an area as possible. This object is accomplished by both forms of construction. These two forms are separately indicated in contemplation of the load factors and the diameters of the required swabs. The construction disclosed in this specification has been abundantly proved by field tests. Less abrasion, distribution of fric tion surface and long life is now an established fact.

Conventional swabs. as heretofore known in this art, have been found to wear in a very narrow band around the outside of the swab cup. This wear is so pronounced that, after a short period of operation. the cup wall is worn too thin to be of further use. This is especially true where there is a solid band of reinforcing material in the lower part of a resilient cup (as disclosed in Patents Nos. 1,669,812 and 1,735,264 and 2,305,282, over which patents my present invention is an improvement). Localized wear has been found to be unusually heavy wherever fixed or solid bands of reinforcing metal have been used. Such construction produces a cup having brief life.

This appears to be so because there is'always found a cold-flow of rubber (or rubber composition) over and beyond and outwardly'from the upper parts of such solid bands of metal. A perfectly stiif cup is not very good. In fact, it is of little use. A solid band of reinforcing metal. around the lower part of a cup, as shown in the patents referred to. makes that region of the cup very stiff indeed; and it makes very pronounced the cold-flow of rubber outwardly above such reinforcing. This excessive outward movement makes the rubber composition to be so severely distorted as to be pressed against the tubing wall (or the casing wall) sufliciently to create terrific friction at a particularly narrow band around the cup. The cup is soon destroyed. The extra power needed to lift cups dragging such a friction load is wasted.

The use of a metallic base, or bowl, having side walls extending upwardly and outside of a rubber cup (as found in some earlier devices) results in excessive friction. wear and abrasion. This is especially true when such metal part is made almost as large as the diameter of the tubing in which it must move. Certain old cups examined have a base almost as wide as the outer wall of their rubber; and the rubber has substantially the diameter of the tubing. Such construction is wasteful both in power and materials.

These excessively wide bases and wide cups. once apparently eagerly sought after and used in the past, are now obsolete because they are no longer necessary. My cup does not fit the tubing as it goes into it. There is practically no touching of the tubing as the swab drops into the well. Friction is reduced to a minimum.

My construction presents a paradox. Although my cup appears too small for the tubing in which it is to work, it nonetheless immediately spreads its lip to gather in a load of fluid the minute it is started upwardly in the hole. As the load increases, the cup wall expands until it hugs the tubing wall. The initial sealing of the upper edge of my cup wall is in region A. This is closely followed by the continued sealing of the cup wall against the tubing in region 13. Still later, if the load be increased. there will be a complete and continuous seal between the lower part of the cup wall and the tubing in region 0. At n time during the loading and upward progress of my cup is there any breaking of this seal. For the first time in oil field history it appears that a cup has been presented which will lift out all of the fluid under which it is placed. There is no loss or lay-passing.

Also. my swab will pick up the very last bit of fluid in the bottom of the hole. This is so because my cup gets under" the fluid readily and quickly. The fluid passes easily upward behind the loose fitting cup (and through the enlarged conduit). My cup never turns this fluid loose once it is picked up. My present invention represents improvements over Patents 1,669,812, and 1,735,264 and 2,305,- 282, which improvements should be obvious; and such improvements include the following:

I have eliminated the use of solid or fixed steel or metal bands of reinforcing material embedded in or surrounding the lower part of the rubber cup. I have eliminated the rigid cup in the region of such bands. I have eliminated the cold-flow of rubber outwardly and over and beyond the upper edge of such bands and through any other reinforcing material thereabout. I have eliminated terrific friction and abrasion on the outer wall of the rubber cup. I have eliminated the short-lived swab cup.

'The cups'described in all three of the patents referred to have been found to wear in a very narrow band on the outer periphery of the. cup; and the seal made (or attempted) by such cups is very poor and soon lost.

' These old style cups become distorted by being bellied out or rounded out. Their thin outer sealing band is threatened from both top and bottom. There is formed a V-shaped opening both above and below such band of contact. These openings lie between the wall of the distorted cup and the pipe in which it moves. A partial vacuum below the band seeks to break the seal; and the pressure of a. heavy load of fluid above the band seeks to separate the cup from the pipe. When the seal is broken the load of fluid is lost. v

It has become tremendously important to minimize friction and wear on a swab cup. It also has become very important that the area i l of friction and wear be extended and spread over the outer wall of the cup as far as possible.

My construction and the operation of my invention result in a sealing band of relatively tremendous area (as compared with old cups). Such a band forms a seal extremely diificult to break.

I have also improved the mandrel of a swab cup. by simplifying it and increasing its bore. I have eliminated the corrugated spring band which formed the outer part of the thimble shown in Patent 2,305,282, referred to above. This member is unduly yielding. because made of spring steel; and it will not hold the reinforcing wires firmly. It is very expensive to make. as compared to my extremely stout and rigid pair of concentric members and 2|) forming my present thimble.

The cantilever action of my spring members 22 and 23. or 34 and 35. securely and lrremovably fastened in a rigid base, gives a uniform and evenly yielding resilience to the entire cup wall which carries these members. The firmly fixed and immovable nature of the lower ends of the companion cantilever members is essential to their desired function and operation.

The spring reaction to pressure on the cup wall begins immediately above the top edge of the thimble 28. This cantilever action extends upwardly for almost the entire length of my cup. which is unusually long.

The result of such construction is that there is a uniformity in the outward expansion of my cup. Such expansion describes a very gentle are, allowing a loaded cup to be gently but closely pressed against the tubing throughout a relatively great area.

Notwithstanding the complete seal made between my cup when loaded and the tube in which it works. the cup will immediately return to its natural shape when relieved of load. The cantilever members. above described. materially assist in this restoration to normal form.

The straight and free running threads 2 carried internally of the thimble of my cup engages complementary and free running threads along a considerable extent of the lower ends of both of the mandrels 3 and 5. This allows the cup assembly to be positioned on the mandrel at most any desired elevation. It is usual to first install the cup so that there is a slight clearance between the beveled shoulder of the mandrel H6 or I! as the case may be) and the upper edge of hp 2- of the cup 25. My cup assembly is run in this osition for a long time.

However. after extended use. the outer periphery of this lip will be worn away by friction and abrasion. as indicated in Fig. XII. When this comes about. it is only necessary to make a slight adjustment in the position of my cup on the mandrel in order to restore the tool to its original efllciency.

This adjustment is made as follows: The base member 20 of my swab cup assembly 2 is rotated about the mandrel until it moves along the free running threads described. This rotation can be made to result in the elevation of the cup until the inner face of lip 26 touches the lower face of beveled shoulder IE (or i1); and a little further rotation will cause this beveled shoulder to force the lip outwardly until it is in a position which will allow renewed contact with the wall of the tubing whenever a slight load of fluid accumulates in the cup.

My cup may always be adjusted to Pr perly impinge the inner wall of the tube in which it is required to lift a load of fluid, even though the original overhang of lip 26 becomes entirely worn away through use.

Another thing of importance in the adjustment mechanism is this: my swab cup can be made to fit various sizes of pipe in which it may be required to work. even to the extent of being expanded (when much worn or when quite new and unwom) until it fits a pipe slightly larger than that it was ordinarily designed to work in. This means that fewer sizes are required to be manufactured or carried in stock by distributors. or kept in the operating-field by users. than is the case with old style swab cups. This results in a great saving .of money, materials and labor. A worn lip is dwwn as at 29, in Fig. XII, after it has been adjusted to a position of renewed emciency.

In order to forestall the possibility that such adjustment as may be made, when elevating the swab cup. will force the inner face of lip 26 too tightly against the under race of the beveled shoulder, 16 or I1. I have provided the series of notches 21 around the inner periphery of lip 26. These notches will always remain open. and allow the flow of fluid therethrough to fill the cup initially, regardless of how far up against the shoulder the flexible cup may be forced. This is a practical matter of some considerable importance.

When desired, one or more or my swab cups may beinverted and used in well pipe as a packer. to seal oil and prevent the movement of fluid in the pipe and/or to-retain pressure therein.

The amembly and use or my invention as a working tool is extremely simple and readily carried out.

The operator simply secures a typical plair. mandrel 8. places a swab cup assembly 2 thereon. and runs the latter up on the free runnin threads. common to both members, until the lip of the cup is in proper position.

This will leave a threaded extension of the lower part of the mandrel below the cup assembly; and this extension will be sufficient to receive and secure the retaining nut is. When this nut has been made up, then the lower part of the tool is complete.

It only one swab cup is to be employed, the operation Just indicated is carried out with the use of mandrel 6 instead of mandrel 3. Where more than one swab cup is to be employed, addi tional plain mandrels 3 may be used to carry typical swab cup assemblies 2. as may be desired.

Where only two swab cups are required, as indicated in Fig. 11, then the next step consists of the employment ofmandrel 6, and the mounting thereon of a typical swab cup assembly 2. The lower end of mandrel 6 (extended below the cup assembly) will be securely made up into the open upper end of mandrel 3.

Then bail i3 is dropped into the opening at the top of mandrel 6; and the mandrel sub I is firmly made up into this opening until it is securely tight. The assembly of the tool is then complete. and the tool is ready for use.

A threaded steel cup (not shown). previously fixed into the end of a stout steel cable, may then be attached to the upper end of member I: and the swabbing tool may then be lowered into the hole by the use or this cable. which runs over a drum operated above ground by appropriate power (not shown).

A pipe coupling can be put on the upper end of member 7, and this coupling may be made to receive the lower end of any kind of pipe or rod which may be suited to hold the tool and allow it to be lowered in the well. The means used to raise and lower the swab assembly is to be left entirely to the choice of the operator. It constitutes no part of this invention.

In the operation of my device, after it is assembled as indicated above. it is lowered by gravity into the well. Because of the considerably enlarged bore of conduit 36, fluid will enter the tool and rush upwardly through it. displacing ball I 3. This ball will be kept pressed up against its confining root until the tool reaches the proper level for operation.

Because of the loose-fitting nature of my swab cup, as exemplified by the foregoing dissertation thereon, and as made more clear by drawings, and particularly Fig. VIII, a tremendous amount of fluid rushes upwardly around the swab cup assembly. (This is in addition to that which goes through the conduit 36.) Such dual arrangements for unusually large fluid passageways, result in the very rapid dropping of the tool to the position where it will begin to operate as a lift. Considering the great amount of overhead, time and labor saved, it is hardly possible to overstress the importance of the extremely rapid placement of the tool in position to work. Such is a most valued achievement of this invention.

When the tool is in static position, the ball i3 falls upon seat I! closing the valve of which it is a. part. Thereafter, no fluid may escape downwardly through this valve while the swab is being elevated.

No fluid may then escape outwardly or around the swab cup, for the reason that upon the initial upward movement of the swab, the lip of the cup contacts the inner face of the pipe in which it is working, as shown in Fig. IX. and this seals the cup against the pipe.

As the lift starts upward, a medium load of fluid will force the cup wall, in the region B, outwardly and against the pipe through which it is moving. During such movement, the initial seal is continued and expanded until there is a much larger surface of the outer contour of the cup pressing against the confining pipe. If the load be relatively light, then the impingement of the cup against the pipe will be limited to the lip 26 and the region B, until the fluid is delivcred from the top of the pipe.

If the load be heavy, then the seal between the cup and the pipe through which it moves will be extended down to and include the region C, meanwhile releasing from impingement part or most of the region B. The seal thus made will continue until the load of fluid is delivered at the top of the pipe.

Thus it will be seen that the region of wear and abrasion in this cup, first and last, includes and covers practically the entire outer wall thereof, from the lip 26 down almost to the steel base member 20. The cup has an extremely long life because the wear is distributed all over its outer face.

There is no break along the wall of this cup. because there is no weak region, no typical bending section, no hinge section. The whole cup veiy gently swells out to touch and reach and move along the tubing whenever the cup is fully loaded.

There is practically no wear on this steel base. because it need not touch the pipe going in or coming out. It is, so loose a fit that it is at no time required to be in frictional engagement with the pipe.

' when the cup is empty, and running into the hole, there is practically no friction at all. What little friction as may be found is usually on the outer peripheral face of lip 26. Even this face need not touch the tubing wall, because the fluid flowing upwardly around the cup will usually prevent such contact.

Depending upon the character of work done. and especially the load to be lifted, and more especially the size of the swab cup, either reinforcing of the character shown in Fig. VII or that shown in Fig. XIII will be used. The job to be done will dictate the kind of reinforcing to be used.

When the lip of the cup is worn, adjustment is made to re-establish the ready contact of the lip with the tubing or casing wall, by simply rotating the entire swab assembly on its mandrel until the lip comes in contact with the beveled shoulder of the mandrel immediately thereabove. The nothces 21 will prevent the closing of the lip against this beveled shoulder. These notches will always admit fluid, so that the cup may be filled.

From the foregoing it will be seen that I have achieved the invention of a simplified swab cup and assembly which is very strong and very rugged and which has a very long life. This invention saves a very great amount of time in operation because of the speed with which it can he run into the hole to gather up a load of fluid.

The invention has added value because it will quickly pick up a load of fluid, at the very bottom of the hole, and keep it (without leaking) until the load is delivered to the surface of the ground. Its efficiency in this respect is very pronounced. I have achieved a very long-lived swab cup. Its design, construction and operation (all as outlined hereinabove) make plain that when the swab is descending in the pipe, friction between the cup and the pipe is negligible or non-existent. This is very desirable.

In coming out of the pipe with a load, my swab presses evenly against the pipe with a relatively large surface of the cup. This distributes wear and makes the cup to last many times longer than cups heretofore used.

The cantilever action of the spring reinforcing material used in my cup not only materially assists in spreading the friction and wear over a large surface of the cup to increase its life and efficiency, but it also returns the cup to its original shape without any permanent distortion having been wrought in it.

The extreme ruggedness and strength of the two concentric steel bands which make up the thimble constituting the base of my cup should be apparent, as should be the speed, simplicity and low cost of assembling and uniting the reinforcing materials in and between these bands. by the quick use of great pressure.

I claim:

i. In a swab cup, a. thimble consisting of a. pair of rigid concentric rings; a series of flexible metallic loops having their lower ends fixedly secured by and between said rings and their upper parts disposed above the thimble in cantilever relation thereto; an elongated elastic cup wall so molded above said thimbie and about; said loops that the latter become resilient reinforcing means within the greater part of the length of said wall, the uppermost part of said wall being unreinforced and provided with an externally 15 overhanging lip and internally disposed notches about its rim.

2. In an elongated flexible swab cup, a rigid base; a series of short flexible reinforcing elements fixedly carried by such base and extending upwardly therefrom; a series of long flexible reinforcing elements fixedly carried by such base and extending upwardly therefrom; and a resilient cup wall molded to said base and about all of said reinforcing elements, the length of said wall being so related to the lengths of said reinforcing element that. the lower part of said wall carries more reinforcing elements than the middle part thereof. and the uppermost part of said wall remains unreinforced.

3. In a swab cup, a rigid base; a resilient and elongated cup body; a series or separate flexible reinforcing members rigidly fixed in said base and extending upwardly within the wall of the cup body for approximately half its length; a series of separate flexible reinforcing members rigidly fixed in said base and extending upwardly within the wall of the cup body for the greater part of its length.

4. In. an elongated swab cup, a rigid base; a. resilient cup body; a series of separate flexible reinforcing members fixed in the base and extending upwardly within the wall of the cup body for the greater part of its length; a series of separate flexible reinforcing members fixed in the base and extending upwardly within the wall of the cup body for a distance approximating half its length, both the long and the short reinforcin member being so arranged and interlocked as to coact simultaneously in resisting pressure within the cup.

5. In a well swab, a mandrel having an enlarged conduit therethrough and discharge ports in the walls thereof; a valve so arranged in said mandrel as to control communication between the conduit 4:

and said ports, whereby fluid may flow through said mandrel only while it is being lowered therein; an elongated swab cup assembly, rotatably carried on threads arranged about the lower end of said mandrel. the said cup assembly including a rigid base, a series of short flexible reinforcing elements carried by such base and ex* tending upwardly therefrom, a series of long flexiblu reinforcing elements carried by such base and extending upwardly therefrom. and a resilient cup wall molded to said base and about all of said reinforcing elements, the length of said wall being so related to the lengths of said reinforcing elements that the lower part of said wall carries more reinforcing elements than the middle part thereof, and the upper part of said wall carries no reinforcing, the upper end of the wall formin a lip which is provided with a series of notches about its inner rim.

6. In a. well swab, an elastic cup provided with a wall expansible throughout its length, said wall being provided with three areas of relative responsiveness to internal pressure, the uppermost being unreinforced, the middle area being reinforced with upwardly extending flexible reinforcing members and the lowermost area being reinforced with said members and a number of l ke members of shorter length.

'7. In a well swab. an elastic cup including a wall having therein three areas each differing from the others in flexibility, the uppermost area being unrelnforced, the middle area being provided with upwardly extending elongated flexible reinforcing members extending through the lowermost area, and the lowermost area being provided with like members of shorter length, the last named members overlapping the first named members.

RAYMOND G. TAYLOR. JR.

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

UNITED STATES PATENTS Number Name Date 1,596,353 Hartman Aug. 17, 1926 1,669,812 Crickmer May 15, 1928 1,735,264 Crickmer Nov. 12, 1929 2,264,741 Chamberlain Dec. 2, 1941 2,305,282 Taylor et a1 Dec. 15, 1942 2,336,090 Granger Dec. 7, 1943 2,358,908 Crickmer Sept. 26, 1944 2,360,577 Parrish Oct. 17, 1944 2,388,520 Bowie Nov. 6, 1945

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