US1563162A - Swab and packing for deep wells - Google Patents

Description

G. cH-RlsTENsoN SWAB AND PACKING FOR DEEP WELLS Filed May 22. 1924 l Sx Patented Nov. 24, 1925.'.

: uNrrEDI STATES f x 1,563,162- PATENT oFFicVE.

GE'oRGE cHmsTENsoN, 0E NORTH PLArNErELn, NEW JERSEY, -A'SSIGNOR 'ro JoHNs- MANVILLE, INCORPORATED, oF NEW Yonne. N. Y.A conrona'rioN 0E NEW Yonx.

sWAB ANDEACKING non DEEP WELLS. y

Application med May 2z, 1924. semi No. 715,159.

To NUM-'7mm 'it may/'concerm Be it known. tha't I, (luenen CnmsrnN- soN, a citizen of the United States of Amerira, and' resident of North Plainfield, in the county of Somerset and State of New Jersey, have invented. new and useful Improvements in `Swabs and Packings for Deep` ings by a mechanically imperfect cooperat- Vmg interior cylindrical surface; for eX- ample, by the ordinary casing of a deep tubular well.

In one form of deep well practice, liquids are retrieved from great depths by swabbing or hailing, the tubular well casing serving as the'cylinder of a lift pump during a long upward stroke of a fluid-tight piston. Such a swab, bail or piston ordinarily comprises a weighted tubular stem connected to a wire hoisting cable, and provided with multiple packings intended to bridge'the space between the stem and the interior surface of the Well easing. rllhis function is not usually well performed in practice, because of the inherent diticulty of packing against great pressures the variable clearance,space'between the stem of the'swa'b andthe rough and irregular wall of the easing. An opening through the swab controlled by' a cheekv valve (or an opening pastthe swab stem and collapsible packing cups) usually is relied upon to permit descent of the swab under gravity.

The4 pressures to which such swabs are subjected are very great; this and the often rough and broken surface-ef the well casing prevent ordinary packing devices from proper effect; the customary devices are notoriously unreliable and inefficient, and lack durability to .such an extent that a single stroke of the piston. frequently destroys the packing element; a score or less of strokes without renewal ofthe packing elements is regarded as a 'satisfactory performance of .the existing apparatus. f

Objects, amongothers, of this invention are therefore to provide a lifting plunger adapted to make a fluid tight connection with the interior walls of a-cylinder of variable a.ml}i1nperfect mechanical construction; -to provide for doing this means adapted toprolong the useful life of the plunger packing; to provide aswab packing protected against mutilationby projections and irregularities of the interiorv Walls of a well casing; and. in general .to improve the operative efiiciencyand durability of devices -for purpose mentioned.

I.The invention will be explained in connection with one preferred form shown in the accompanying drawings, in which,-

VFig'. 1 is a central vertical section in elevation of a well casing and swab;'

Fig. 2-isan enlarged vertical sectional elevation of a protective cap, packing and calyx showing the relationof the parts,

and

Fig. 3 'is an enlarged elevation'of an ex-.

the

pension-resisting protective cap .for packing clement. i

The well casing Vas shown may comprise the abutting pipe sections l, 2, etc., eX- teriorly screw threaded for the usual couplings '3, but not necessarily contacting at their abutting ends, which are often marred and blurred. Such easings charucteristically are rough, often dented, and seldom accurately cylindrical.

y The bailer or swab shown may comprise a tubular stem 4, preferably screw threaded on its` exterior surface throughout its length, having a tapered terminal nut 5 at one end' of the .stem and a protective retaining head (3 at the opposite end of the stem, one of these structures (as shown, the head 6) having annular surfaces to receive the seat l2, cage 9 and ball 11 of the usual check-valve controlling the central bore in stem 4. yA terminal threaded lug 10 provides an attachment place for the usual -swivelled hoisting cable couplingB.

hauled up withinthe casing by\hoisting on the cable, the superimposed column of liquid is lifted to the surface. It is obvious that the exterior attachments of stem 4 should be such as to pass the casing pipe joints and other obstructions, wit-hout leakage, or if deformed for this passage, to resume operative contact with the casing after passage. For these purposes the cups or annuluses 15 are preferably structures of rubber or rubber compounds adapted and mounted to bridge the clearanceb. space be tween stem 4 and casing 1,v 2 under circumstances permitting these packings to yield and protecting them from excessive abrasion and mutilation by the internal burrs and projections inevitably found in the well casing. In order to maintain continuity of liquid tight packing between the piston comprised of the swab and the cylinder comprised of the casing, the swab is built up of elements comprising a sutlicient number of the cups or annuluses 15 to insure operative sealing contact with the casing wall of one or more of them at any one time. The stem 4 for example, is provided With spaced `seats 17 for a sufficient number of the annuluses 15, (each of which com prises a heel section 1G, a median cylindrical portion, and a lip section 18), to insure the presence of one or more of the annuluses in a part of the casing with which goed sealing contact is possible.

Such a sealing cont-act is provided to be made by making the cups, annuluses or packings of a structure materially capable of expansion by longitudinally and outwardly acting forces tendingr to hold the median region of these packings in tight {iexible contact with the inner sui-tace of the casing, despite variations due to lack ot' cylindric tigure or the presence of local cavities or projections of minor sizes.

In order to provide for a reasonable wear only on these pac-kings, it is desirable to providerthat they'shall not expand into the grosser cavities of the casing, such as the space between pipe sections at the. couplings, and particularly to provide that the lips 18 shall be protected against expansion into locking contact with such cavities.

In the preferred construction, the seats 17 are the conical cavities of centrallybored calyx cups 14 engaging the stem 4 and positioned by lock-nuts 22. The heel sections 16 of the packing annuluses 15 tit the seat cavities 17 of the cups 14, and are each provided with an internal shoulder 21 for a tubular spacer 20. Above the shoulders 21, the packings 15 preferably have a tapered internal cavity, Figs. 1 and 2. Under longitudinal or internal pressure or both, the packings 15 tend to expand except as restrained by the cups 14, or by restrainingY means 19 adapted to prevent radial expansion of the lip sections 18 of the said packings.

The restraining means 19 may comprise a metal thimble or cup centrally bored for stem 4, restingon each spacer 20, and held from longitudinal motion by said spacer and the lower face otl one of the lock nuts 22. `Whatever the particular form of the restraining thimble 19, its annular or other extremity 7 overlies the lip portions 18 of the packings 15, and prevents expansion of the upper edge of the packing into contact with the casing walls.

Preferably the restraining thimbles 19 are shaped as indicated in the drawings and are provided with flow openings 23. The upper restraining means of the series used may comprise an integral skirt 27, Fig. 1, of the head 6.

Each of the described metallic parts G, 14, 19 is of .suicient diameter only to give free clearance in the well casing. Because of this, leakage of liquid past any of the series of packings is afforded a free path around'the restraining structures 27, 7 or through the openings 23'to act upon the packings 15 longitudinally and internally to cause them to expand. But the lips 1S can not partake otl this expansion, being restrained by the parts 7, 27, and are therefore protected from contact with cavities or internal projections ot the casing. l v these provisions, the swab as a whole is enabled to operate under great pressures with high efticiency against leakage, and with great durability of the expanding packings. ll'hen worn, the described structure enables new cups or annuluses 15 to be assembled rapidly.

I claim:

In a plunger for deep well pumps, the combination with a tubular stem of an ex pansible packing member having an exteriorly downwardly tapered heel portion secured to said stem, a lnedian bearing portion, a free end upwardly tapered exteriorly and downwardly tapered interioily, and means secured to said stem and adapted to restrain movement of the free end otl the packing member when the latter is subjected to forces tending to expand it.

Signed by me at New York city this 17th day of May, 1924.

GEORGE CHRISTENSON.

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