US1596353A - Swab - Google Patents

Description

Patentedl Aug. 17, 1926.

l WILLIAM:A WALTER HARTMAN,

0F LOS ANGELES, CALIFORNIA.

swan

Appliation led April 27, 1925. Serial' No. 26,171.

This invention relates to swabs which may be inserted into oil or water wells to clean them, or Atop'ump fluid .out from them.

An object is to provide such a swab with a sealing cylinder or packer which retains flexibility radially but which strongly and effectively resists compression and distortion longitudinally, and is therefore exceptionally durable and powerful in practice.

Another object is to provide an effective metallic reinforcement for such sealing cyl-` inders or packers, which reinforcement 1s stiff o'r rigid longitudinally and thereby imparts to the packersthe above described 'qualities' L In swabs the resistance to` longitudinal 'compression or distortion of the packer-is of lutmost importance because it prevents the packers under load from being compressed or mashed down into the casing joints of the well at the couplings, and being cut away,at the bottom of the packer by the shearing action encountered when the swab is drawn up through the large number of such casingjoints in a well. This is particularly important inv my preferred types of packers which are characterized by having thick heavy walls that contact with the i i wardthe bottom of the latter.

casing for a substantial distance along their length to give good suction, only-a moderate amount of clearance being allowed between the casing joint and the packer. to-

Even heretofore when using such thiol; walled packers without -metallic reinforcement therein, no trouble was experienced /by their being cutaway or mutilated at the top, as these packers are usually suiiciently rounded at the top tofprevent their upper contour being in any way caught or .'dam- 'aged by irregularities of the casing, or at the casing .y joints. However, most such packers heretofore cut away very badly at the bottom because of the endwise compression of the load as above noted, and it is this bad cutting of the packers atthe bottom which my invention effectively elimi nate's, or at least very greatlyv reduces, bypreventing the longitudinal. compression` of the packer'to which this cutting or shearing at the bottom is due.L Obviously this reduces swabbing costs, and eliminates the f delays and trouble of frequently replacing the packers. t

My invention is broadly new in that I provide a simple .rugged and easily assembled swab structure in which the body of the' packers isyvery eifectively heldup against the load for the important purpbse of` protecting the' bottom of the packers against cutting as above noted.

In a structural way my invention broad"- ly consists of a swab having a tubular stem, a valve for lcontrolling the flow of fluid through such stem, a p acker or packers on the stem, and a metalhc supporting or reinforcing means, other than the stem, for

`eii'ectively upholdingthe packers against endwise compression without danger of the -reinforcement itself becoming caught in the sections at the casing joints. e

Exceptv as specifically limited in the claims, the precise form and structure of this support or reinforcement, and its mode] of association with the swab and packer, can of course be varied considerably without departing from the spirit of my invention, and such questions as to whether this support or reinforcement is'completely or only mostly concealed within the packer, or .whether it is permanently molded into the packer or removable therefrom, do not affect the broader aspects of my invention `even though some of the specific forms thereof illustrated in' the drawings, and showing Athe metallic support or reinforcement completely concealed and permanently molded within the'packer, possess additional merit that will be apparent to those-skilled in the art. This is particularly true of my wire cage reinforcement which is simple and in- .expensive to manufacture, and which posbenefits of yFigure 1 is a plan view of the swab, with l the stem shown in section.

Fi 2 is a sectional view taken on line m2, Fig. 1, and with the casing also shown in section. 1

Fig. 3 is a side elevation of my swab, the casing being in section.

Fig. 4 is a fragmentary side eleyation of my swab partly in section and with parts broken away to show the interior construction.

Fig. 5 illustratesV three slightly modified forms of reinforcing.

Fig. 6 is a side view of another modified form of reinforcement.

Fig. 7 is aside view of my preferred form of wire reinforcing.

FigVS is a section on line w8, Fig. 7.

The following is a detailed description of my preferred forni of the invention.

The bottom member 1 of the string of tools commonly used in wells is threaded at its lower end to' receive the threaded head or coupling member 2, which constitutes 'the upper extremity of my swab. A head 3 has a bore 4 extending longitudinally approximately the length thereof, and a pin 5 extends loosely through the end a uand is threaded into' the coupling 2, preferably permanently by a rivet c or other suitable expedient. K

The member 5 is formed withl an enlarged end 6 on which the head 3 rests, and about which said head swivels. A plurality of ports 7 extend through the wall of the head 3 into the bore 4.

'A tubular stem 8 is threaded into the lower end of the bore 4 and depends from the head 3, any desired distance.

To the bottom of this stem a. hollow tip or 'de member 9 is threaded, which is pre erably tapered towards the lower end thereof, and a bore 10 extends throu h the lower end in which a ball 11- seats to orm a downwardly closing valve.

A pin 12 extends through the tip 9 above the ball 11 to limit the upward movement of said ball. l

One or more sealing cylinders or packers l 13 are positioned between the tip 9 and head 3, and surround the stern 8. Each of these packers have in .conjunction with them a sleeve 14, which slides over thelstlem 8.

A downwardly facing shoulder 15 is formed on the exterior surface and adjacent the lower end of the sleeve 14, and the outer surface vof said sleeve approximately from the shoulder upwardly to the top may be liuted or corrugated as at 16, the purpose of which will be further described.

l The packer 13' is formed of a more or less yieldable or pliable material such as rubber, leather, fabric, etc.,^and surrounds the sleeve 14, the relation of the parts being preferably such that only a small space 18, or none at all, is provided between said packers and sleeve.

An annular seat 19 is formed in the bore of the packer 13, and the shoulder 15 of sleeve 14 rests firmly on this seat 19.

A metallic collar 20 is used below the lower end of packer 13. It embraces the-stem 8 andis preferablyy provided with a recess 21 in which the said packer rests. p

Flutings or corrugations 20 may be formed in the outer lower surface of the collars 20.

The lower end of sleeve 14, constituting a cylindrical skirt, rests against collar 20, and nin assembling, a nut 22 threads on the stem 8 against the lowermost collar 20. The lowermost sleeve 14 engages the 'collar 20 next above it, and so on up until the uppermost sleeve 14 engages the lower end of the head 3.

In this way when nut 22 is screwed onto the threaded stem 8, it butts all of the collars 20, and all the intervening sleeves or spacers 14, solidly against one another so as to make a continuous and rigid arrangement with the nut 22 at one extremity and the head 3 at the other extremity. As this is done it is obvious that the packers 13 all become securely fastened and locked in place on the swab longitudinally.

y A reinforcement 23 is molded or otherwise introduced int-o packers 13, andin my preferred form this reinforcement consists of a cage formed of 7wire loops provided with rounded upper loopedends as shown at 24.

Radially, this cage is preferably positioned in about the center of the packer 13, and should extend from below the top 'to a place in the vicinity of the-bottom thereof. This providesN a reinforced packer that is very stiff and strong vertically to resist compression under load, but is still expansible and contractible radially to compensate for the small differences vin the size of various sections of the rough well casing as the swab is raised or lowered through the well.

The top rounded ends or shoulders 24, of cage 23, hold' up the topof the packer without cutting or tearing out, and in this way the entire body of the packer is upheld,

-which in turn greatly reduces the cutting of the packer around the bottom by shearingof same under load at the casingjoints as previously described.

Besides, when wire loops are used for the reinforcement, the fabric or rubber texture of the packer itself lcan be thoroughly joined or vulcanized all around the legs' and be'- neath as well as above the upperasupporting shoulder 24, which complete knitting or vulcanizing of the. packer body around the reinforcement has further benefit in increasingl the strength and durability of the packer.

Of course whether the cross section of the wire is round, flat, square or of other shape, or whether the loops at the top. are rounded as shown or are of other suitable shape, is somewhat immaterial. v

,As shown in Figure 5, the reinforcement 23, instead of consisting of the looped wire cage above described, orof some modification of same, may consist of various other expediente of which the following are examples: As indicated in Figure 5 th1s reinforcement may consist of a plurality ofy very coarsely barbed posts 25 which may rise from a ring 26; or of posts 27 which may rise from a ring 28, and which` are provided with shoulders or caps 29 at the top thereof; or of very coarsely threaded posts 30 which also may or may not rise from a ring 31 as desired. This reinforcement may also consist of a metallic cylinder 32, see Figure 6, preferably provided with large perforations 33, also .with a substantial bead at the top, and also with longitudinal slits or slots 34 therein. It should be noticed that these modifications, like .the wire cage, are all disposed lengthwise of the packer and approximately parallel to the axis of the tubular stem 8, which makes them very sti and strong longitudinally. They also have their supporting shoulders or portions embedded or located within the packer below the upper end thereof, and this upper end is lapped or molded over the top of these supporting portions, or is otherwise supported by same, so -that the friction and downward crushing force of the fluid load cannot appreciably compress the packer longitudinally or strip it down during operation. As previously stated this tends to prevent the bottom of the packer from being` mashed out into the space between the casing sections and the coupling, and being cut away by the shearing" action set up between the casing and the collar 20, which action would otherwise cut the packer at the bottom, just above collar 20, yas the swab is pulled up through the well to lift the load. y

' Itr` should also be noticed that by arranging the length of the reinforcing means 23, substantially parallel with the axis of stem 8, the risk of this metallic reinforcement, if

`unduly expanded radially under excessive load, itself becoming caught in the casing joints, is practically eliminated, and the importance of this is obvious.

By forming collar 20 in `such manner that it has a projecting perimeter which embraces the bottom of the packer to a place above the bottom of the metallic reinforcement 23, additional rigidity is secured, as the bottom portion of the reinforcement and packer are further strengthened by lthis pro]ecting perimeter of the cup or collar 20.

In addition to the modifications of the reinforcement 23 above described, other modi- J fications may also be made without depart-v v ing from this invention.

- In operation the swab is lowered into the well casing m having the usual couplings y ybetween the joints, and as the swab passes down through the fluid, the liquid raises the ball 11 ofl:` its seat, yand passes upwardly through the tip 9, stem 8, head 3 and out of the ports 7 thereby becoming disposed above the swab in place of below it.

The packers or seals 13 are preferably of such diameter that they just pass down into the casing with practically no friction on the sides thereof.

Also I prefer that as nearly as practicable the packers should fill the space between the casing a: and the stem orsleeve 14, only enough space being allowed to permit the packer to accommodate itself in passing through a tight joint of casing.

Of course this prevents the packer from collapsing radially under the action of the fluid as the swab passes down through the fluid into the well. In other words by using rugged packers of this character with thick ysubstantial walls, I sacrifice the benefit of having collapsible packers to allow the fluid to rise around their outervsurfaces on the down stroke, but the loss of this benefit is much more than offset by the very exceptional durability obtained, and by the very heavy loads that these thick walled rein' of my swab, passes up through my tubular stem 8, I prefer to make the bore of this stem quite large so that my swab still sinks very rapidly even though none of the fluid rises around theoutside of the packer. Also by heavily rounding the thick top end of my packer, the same is spared, even in the absence of any metallic support 23, lfrom any cutting or mutilation at the top, this being solely due to its thick rounded shape. and in this respectmy invention is basically different from those other types of lightly constructed packers of Idistinctly flaring conical shape which have sharp upper edges at their top extremity to wipe tightly along the walls of the casing on the up stroke for more per-- fectly preventing leakage of the fluid. These lightly constructed packers with sharp delicate upperedges, must be externally embraced and protected by wires orA bands ,extending beyond thetop end thereof for the purpose of protecting their thin upper edges'froln mutilation, andy from being turned completely upside down by the weight of the load. and by the 'friction against Vthe casing. I am aware that the eX ternal fluid pressure at the top rounded end yof myy heavy packers tends to radiallycomfound that by thus allowing the pressures to '13.0

counterbalance one another in this way, the sealing function of my packers even with their rounded upper ends, is performed practically as well as with packers having a relatively sharp upper extremity that scrapes or wipes tightly along the casing. My iiutings or grooves 16, in sleeve 14, assist in' admitting the iiuid pressure to the inside surface of the packers. Also shoulder 15, on sleeve 14, prevents upward displacement of the packer while sinking.

When the fluid that is being raised reaches the top of the well, it either spills out of the well or is otherwise suitably discharged therefrom.

My invention relates to well swabs and well pumps as the construction of these is identical and the name interchangeable. j

In practice I have used a single packer on the stem 8 with very good results, but I have shown a multiplicity of these packers, sleeves and collars for the purpose of illustrating how effectively the structure lends itself to use of more than one packer on the stem.

, Attention 4is also called to my co-pending application filed May 16, 1.925, Serial No. 30,727, it being understood that subject matter of invention shown but not claimed in this application is reserved for and claimed 1n my cri-pending application just referred to. Furthermore the structure shown in my said co-pending application is but another modification of the broader invention which is shown and disclosed in this present application, and the broader claims herein are therefore intended to cover the same. Claims on the packer per se are in my said co-pending application Serial No. 30,727.

It is also understood that though swabs are normally and usually employed to lift fluid in the manner described in this speciiication, nevertheless they are sometimes used in the reverse manner for forcing the liquid down through the well to clean out the perforations in the well casing below., In this case either the entire swab may be turned upside down, or else only the packers may be reversed with a suitable change in the valve arrangement. However, my invention relates to swab devices used in this inverted manner as well as in their usual, normal, upright manner, and though the nomenclature which I have employed in the specifications and claims of this application, is necessarily directed to the normal upright assembly of the device for lifting fluid, nevertheless this nomenclature is intended to also cove-r and include the structure when reversed for swabbing downward.

I claim:

1. A device for operating in well casings composed of sections of jointed pipe, saidJ device comprising the combination of a tu- Abular stein, a valve permitting fluid to flow one way through said stem Vbut preventing fluid from flowing the other way through said stem, a thick-walled packer mounted on said stem, and longitudinally stiii' metallic reinforcing means embedded in said packer `for holding same up against longitudinal pressure, said metallic reinforcing means being located entirely below and terminating short of the top end of said packer.

2. A device for operating in well casings composed of sections of jointed pipe, said device comprising the combination Aof a tubular'stem, a valve ermitting fluid to ow one way through sa1d stem but preventing fluid from flowing the other way through said stem, a thick-walled packer mounted on said stem, and longitudinally stili1 metallic .reinforcing means embedded in said packer embedded in said packer for making said packer stiff longitudinally, the upright part of said metallic reinforcing means being substantially parallel to the axis of said stein and terminating below the top of said packer.

4. A device for operating in well asings composed of sections of jointed pipe, said device comprising the combination of a tubular stem, a valve, a packer ymounted on said stem, and metallic reinforcing means for said packer forming an integral part of said packer, said metallic reinforcing means having `a longitudinally rigid upright part substantially parallel to the axis of said tubular stem, and also having a supporting shoulder in said packer adjacent to but below the top end of said packer over which shoulder the upper part of said packer is formed to firmly hold the packer up against longitudinal pressure.

5. kA device for operating in well casings composed of sections of jointed pipe, said device comprising the combination of a tubular stem, a valve, a packer, longitudinally stiff metallic supporting means for upfor upholding the upper part of said packer,

said supporting means terminating below packer below the top eXtremit ing a longitudinally rigid upright part disposed substantially parallel to the axis of said stem andinserted between the internal and external surface of said packer and having a supporting portion engaging said of the packer, said top extremity of t e packer lapping over said supporting portion to prevent the top edge of said packer from pulling down olf said supporting portion during operation.l

A device for operating in well casings composed of sections of jointed pipe, said device comprising the combination of a `tubular stem, a valve, a packer mounted on said stem, said packer having its upper end unrestrained radially and its inner surface adaptedto be eXposed'to fluid pressure, and ,longitudinally rigid metallic reinforcing means molded into said packer between the internal and external surfaces thereof and forming an integral part-.fof said acker, said metallic reinforcingmeans having an erect part disposed lengthwise within the erect walls of said packer and extending substantially parallel to the axis, of said stem, said erect part of said reinforcing means having a supporting portion in said packer below the top end thereof over which supporting portion thev upper part of the packer is formed to hold said packer up against longitudinal pressure. v

8. A device for operating in well casings composed of sections of jointed pipe, said ly joined together near their upper ends and below the top extremity of vthe packer to form a supporting shoulder for upholding the top part of the packer.

9. A device .for operating in well cas-l ings composed of sections of jointed pipe, said device comprising the combination of a tubular stem, a valve, a packer mounted on said stem, said packer being adapted to vhave fluid under pressure admitted to the inside surface thereof, metallic reinforcing means-for resisting endwise compression of Said packer, ,said reinforcing means comprising wire looped up and down in an approXimately circular path around said packer, said reinforcing means being embedded `and practically concealed within said packer, and the upper looped shoulder of said reinforcing means being located below the top of the packer which is supported thereby.

l0. A device for operatingV in well casings composed of sections of jointed pipe, sald device comprising the combination of a head, a stem depending therefrom, a valve, a packer mounted on said stem and having an upwardly facing seat, a metallic collar supporting said packer from below, a sleeve within said packer, a downwardly facing shoulder -on said sleeve located above an engaging the said seat on said packer, said sleeve having a cylindrical skirt depending therefrom below said shoulder and adapted to intervene between the lpacker and the stem, and means for securing said packer, collar and 'sleeve to the stem.

Intestimony whereof, I have hereunto set my hand at Los Angeles, California, this 21st day of April, 1925.

WILLIAM WALTER HARTMAN.

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