US 3104883 A
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Description (OCR text may contain errors)
Sept. 24, 1963 c. L. ENGLISH ETAL SEATING CUP 2 Sheets-Sheet 1 Filed Dec. 5. 1960 FjE.-1-
INVENTORS CHARLES A, /vau'sl-r 4* BY JOHN 5. 4M2005 ATTOIQNEY United States Patent 3,104,883 SEATING CUP Charles L. English, 2404 E. 25th Place, and john B. Woods, R0. Box 7157, both of Tulsa, Okla. Filed Dec. 5, 1960, Ser- No. 73,877 3 Claims. (Ql. 277205) This invention relates generally to devices for providing a hydraulic seal across an annular space, as between telescoped, tubular members. More particularly, but not by way of limitation, the invention relates to seating cups of the type which are responsive to a pressure differential for maintaining a deep well pump in fixed position relative to the production tubing of the well in which the pump is employed. Although the cup of this invention may be used in various ways, such as a valve cup, and we do not intend to be limited to any one use, the invention has particular use in the form of a seating cup and will be described with particular reference to seating cups.
In deep well pumps it is necessary to retain the pump in fixed position relative to the bore of the well while the pump is operating, as well as prevent leakage of pumped fluid afound the pump back into the well bore. This fixation of the pump must be of sufiicient tenacity to resist the tendency of the pump to move upwardly and downwardly in response to the impress of motive power to the engine end of the pump. In previous deep well pump technology, pumps of the sucker rod type have usually been retained in fixed position relative to the production tubing of the well by means of annular cups of resilient material which are carried upon a portion of the pump termed the hold down body and which are biased into contact with a surrounding seating nipple which is connected to, and forms part of, the production tubing. Generally, there are three or four of these annular cups, termed seating cups, which are secured around a portion of the pump and are spaced from each other by means of annular cup rings. The outside diameter of each cup is larger than the outside diameter of the remainder of the pump so that only the seating cups are in contact with the seating nipple when the pump is positioned in the well. An adjustable lock nut is provided below the lowermost cup so that the cups may be held fixed with respect to the pump and hydraulically expanded outwardly into tight engagement with the surrounding seating nipple. Such cups are also utilized in deep well hydraulic pumps where they are secured around the middle and/ or lower portion of the pump.
The types of seating cups which are usually employed in deep well pumps areof a configuration which permits advantage to be taken of the hydraulic head of pumped fluid to impose an outwardly biasing force upon the cups, thereby improving the seal between the cups and seating nipple. This configuration is generally L-shaped with the upper end of the cup tapered downwardly and outwardly from the pump toward the seating nipple at an angle of approximately 45 degrees. The foot portion of the L-shaped seating cup, which is termed the clamping flange, extends inwardly from the seating nipple toward the pump and is clamped between a pair of cup rings, or, in the case of the lowermost seating cup, between a cup ring and the lock nut to which we have previously referred. A space is provided between the remainder of the cup and the adjacent cup ring so that the pumped fluid standing in the production tubing above the seating cups may enter this space and bias the upright portion of the L-shaped seating cup outwardly into contact with the seating nipple.
The L-shaped seating cups of the prior art have been characterized by several undesirable features which have reduced their elfectiveness and shortened their operating 3,104,883 Patented Sept. 24, 1963 life. One of these features is the constant subjection of the clamping flange of the cup to the opposing forces of the cup rings and lock nut, which forces tend to weaken and eventually pinch off or sever the clamping flange from the remainder of the seating cup. Another undesirable characteristic of previous types of seating cups is the tendency for the cup to become worn unevenly along its outer surface by the escape of fluid downwardly around the cup. This uneven wear arises from the distribution of forces imparted by the column of production fluid in the well production tubing above the cup washers and usually is manifested by a wearing-away of the heel of the cup-that is, the outer periphery of the cup opposite the angle included by the L-shaped configuration. Wear at this position on the cup accelerates the weakening of the clamping flange and reduces the tenacity of the seal between the seating cup and the seating nipple.
Yet another disadvantage of the types of seating cups previously employed is their tendency to stick, or vulcanize, to the metal of the seating nipple with which they are in contact. This condition makes removal of the pump from the Well for repair, etc., quite difiicult and frequently results in the destruction of the cups during the process of pump removal.
.The present invention contemplates a seating or valve cup which is characterized by a novel configuration which permits the force exerted by liquid (as in the production tubing) to be distributed throughout the body of the cup in a manner which will assure even Wearing of the peripheral surface of the cup and which will bias the cup against the surrounding walls of the seating nipple or other tubular member in which it is located. The cup of the invention is further characterized by a composite construction in which a metallic sleeve is provided at the inner periphery of the cup and lends structural stability to the cup while eliminating the necessity to utilize a.
plurality of cup rings between the several cups. An annulus of resilient material, such as rubber, is molded around the metallic sleeve with a permanent bond being established between the metal and the elastic material. A layer of nylon mesh is bonded to the outer periphery of the annulus of resilient material and more effectively resists the wear to which the cup is subjected in contacting the walls of the seating nipple or other tubular member in which the cup is disposed. Thenylon rnesh also functions to prevent or reduce the adherence of the resilient material to a seating nipple, thus facilitating the removal of the pump from the well.
It is an object of this invention to provide a seating or valve cup which is characterized by a longer and more effective operating life than has been characteristic of previous types of cups.
Another object of the present invention is to provide a seating cup which does not require the utilization of cup rings for installation of the seating cups upon deep well pumps.
An additional object of the present invention is to provide a seating cup which is characterized by an outer pe; ripheral layer of plastic material which will not stick or vulcanize to the metal surface of the seating nipple against which the seating cup bears during its installation.
A further object of the present invention is to provide a seating cup which is characterized by a configuration which more evenly distributes acting hydrostatic forces throughout the body of the cup, thereby assuring more evenwearing of the seating cup surfaces during its service life.
-An additional object of the present invention is to pro; vide a composite seating cup having an annular efi'ective portion constructed of a resilient material, and an internal metallic sleeve bonded to the annular effective portion and providing reinforcement therefor. l v
These objects and advantages will be better understood,
upon reading the following disclosure in conjunction with a study of the appended drawings which illustrate our invention.
In the drawings:
FIGURE 1 is a plan view of a preferred embodiment of the present invention showing the configuration of the upper end thereof.
FIGURE 2 is a plan view of the seatingcup of FIG. 1 showing the configuration of the lower end thereof.
FIGURE 3 is asectional view of the seating cup, of FIG. 1 taken along lines 3-3 of FIG. 1.
FIGURE 4 is-an elevational view of the seating cup of FIG. 1.
FIGURE 5 is a. vertical sectional view through the center of a portion of the production tubing of an oil well showing schematically the manner in which a pump of the sucker rod type is seated in the tubing by means of the I seating cups of the present invention.
--FIGURE 6 is an enlarged sectional view of a portion of the seating cup of this invention showing the directions and points of application of forces acting on the seating cup and resulting from the hydrostatic head of production fluid above the seating cup. I
FIGURE 7 is a vertical section taken through one side of a modified embodiment of the present invention.
I FIGURE 8 is a vertical section taken through one side of another modified embodiment of the present invention, showing the manner in which the cup illustrated in FIGS. 1 through 4 is modified to adapt it to use as a valve cup.
Referring now to the drawings in detail, and particularly to FIG. 1, the seating cup of the present invention is designated generally by reference character 19. The cup comprises an internal metallic sleeve 12 which is bonded to a molded annulus of resilient material designated generally by reference character 14-. Although any suitable resilient and corrosion resistant material may be utilized for forming the annulus 14, we have found that synthetic rubber sold under the trade name Hycar functions especially elfectively. In referring to FIGS. 3 and 4, it will be observed that the annulus 14 is characterized by an outer peripheral portion 15 and by upper and lower ends 16 and 18, respectively, which are tapered at an angle of 45 degrees to the peripheral surface of the metallic sleeve 12. The upper end portion 16 of the annulus 14 is further characterized in having a flat annular surface 20 which extends normal to the metallic sleeve 12. The lower end 18 of the annulus 14 is also characterized by a flat surface 22 which extends normal to the metallic sleeve 12 and parallel to the flat surface 20.
The upper end '16 of the annulus '14 is provided with an annular recess 24, which extends axially into the annulus 14 for approximately one half its length. It should also be noted that in the preferred embodiment of the invention illustrated in FIGS. 3 and 6, the width of the recess 24 at its origin is approximately equal to one half the radial thickness of the annulus 14. The sides of the recess 24 taper inwardly toward each other from the origin of the recess toward the bottom thereof. The purpose of this rather specific recess configuration will be explained in conjunction with the description of the operation of the seating cup 210 set forth below.
A relatively thin layer 26 of a suitable plastic material, preferably nylon, is bonded to the outer periphery 15 of the annulus 14 for the purpose of providing a hard, Wearresistant surface for contact with theseating nipple against which the seating cup 10 bears when installed. The nylon is applied as a loosely woven mesh material which is impregnated with the same resilient material, such as rubber, as that of which the annulus 14 is constructed. The impregnated nylon mesh is thermally bonded or vulcanized to the resilient annulus 14 and covers the lower end 18 of the annulus "1'4 as well as the outer periphery 15 thereof.
The manner in which the seating cups 10 of the present invention are utilized to support a pump in the production tubing of a well is illustrated in FIG. 5. The metal sleeves 12 of the cups are fitted concentrically about a portion of the sucker rod pump barrel termed the hold down body, designated by reference character 28. The seating cups L10 abut each other and are retained in fixed axial relation to the hold down body '28 by means of a shoulder 30 formed on the hold down body, and a lock nut '32 which is threaded upon the lower end of the hold down body and which may be tightened to force the metallic sleeves 12 into juxtaposition with respect to each other. The resilient annuli '14 of the several caps 10 frictionally engage a seating nipple 34 of the production tubing 36 at their outer peripheries 15. As will be ap' preciated by those skilled in the art, an annular space 37 exists between the barrel of the pump and the production tubing 36, and during operation of the pump, this space P contains a column of the production fluid 38 which is being pumped from the well. Atits lower end, the column of production fluid 38 is supported by the upper most seating cup '19, and biases the periphery 15 of the resilient annulus outwardly against the seating nipple34.
The manner in which the hydrostatic forces exerted by the column of production fluid 38 act upon theresilient annulus '14, of the seating cup .10 is illustrated in FIG. 6. It will be noted that some of the force exerted by the column of fluid 38 acts downwardly andslightly inwardly upon the beveled upper end '16 of the resilient v annulus 1-4.- A considerable component of the hydro;
static force, on the other hand, is applied to the walls and bottom of the recess 24. The directions and points of application of the acting forces, as indicated by the arrows in FIG. 6, are such that the inner periphery of the resilient annulus 14 is urged against the outer periphery of the metallic sleeve 12, thus tending to reinforce the 7 I bond at the interface between the resilient annulus and the metallic sleeve and preventing the ingress of fluid between the annulus and sleeve. The hydrostatic forces also bias the outer periphery 15 of the resilient annulus 14 into contact with the seating nipple -34, thus enhancingthe tenacity of the frictional engagement established therebetween, as well as the seal between the cups and the I seating nipple. It should also be noted that the substantial thickness of material between the lowerend of the recess 24- and the lower end of the annulus 14 prevents distortion of the annulus by the hydraulic forces. In the event any of the production fluid bypasses the uppermost seating cup In, the same influence will be exerted by the fluid on the lower cups.
This characteristic of the seating cup of the present invention may be contrasted with the action resulting from the distribution of the hydrostatic forces which chare acterizes seating cups of the prior art.
(In such a comparison, the construction of the seating cup of the present invention may be seen to extend the effective operating life of such cups in three ways. First, by virtue of the utilization of the metallic sleeve 12, the seating cup is reinforced and rigidly supported at its inner periphery so that it is unnecessary to utilize seat ing rings as previously required. Thus, the pinching or compressive action of such seating rings, which tends to sever the clamping flange of the prior art seating cups,
does not constitute a problem when seating cups of the present invention are utilized. Second, the particular shape and location of the annular, axially extending recess 24 in the novel seating cup of this invention, and also the.
relative dimensions of the resilient annulus 14 and the recess 24 permit the forces exerted by the hydrostatic head of production fluid to be more evenly and effectively distributed, thus biasing the outer periphery '15 of the seating cup 10 into a tenacious frictional engagement f with the seating nipple 34 without undue distortion of 1 the cup. Lastly, the employment of the nylonmesh material 26, previously described, imparts a further advantage to seating cupsconstructed in accordance with the present invention in that the nylon layer greatly reduces the tendency of the resilient material of the annulus "14 to adhere to, or become bonded to, the internal surface of the seating nipple. The nylon also provides a relatively hard, wear-resisting peripheral surface on the seating cup.
In the modified embodiment shown in FIG. 7, the resilient material annulus 14- is further reinforced and supported by an outwardly extending lip 50- formed integrally with the internal metallic sleeve 12. The lip 50 is tapered upwardly at its outer end so that the lower surface of the lip is substantially conterminous with the outer curved surface of the nylon layer 26. The slight upward curvature of the lip 50 allows the annulus '14 to be supported against downward displacement under the influence of hydrostatic force and thus materially assists in preserving the bond at the interface between the metallic sleeve '12 and the annulus 14. Moreover, the lip 50 provides a seal preventing infiltration of liquid between the annulus 14 and sleeve 12 at the lower end of the seating cup.
The seating cup shown in FIGS. 1 through 4 may be modified to adapt it for use as a valve cup as shown in FIG. 8. It will be noted in referring to FIG. 8 that the upper end 145 of the annulus 1 4 is tapered upwardly and outwardly instead of inwardly as in the case of the seating cup embodiments previously described. This permits the resilient annulus to be flared outwardly more easily by the fluid pressure which is brought to bear on the cup during reciprocation of the plunger upon which such valve cups are mounted, and a more efiective seal is established between the cup and the barrel surrounding the plunger.
Although the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in details of construction and arrangement of parts or elements without departing from the spirit and scope of the invention as set forth in the ap pended claims. Moreover, although the seating cups of the invention have been illustrated and described by way of example in their application to sucker rod pumps, it is to be borne in mind that such cups may also be used in other environments, such as in the construction of hydraulic deep well pumps.
'1. A seating cup for use in deep well pumps and the like for retaining the pump in fixed position relative to a seating nipple and for preventing leakage of fluid downwardly around the pump comprising:
(a) an annular metallic sleeve having upper and lower ends and of a size to slidingly fit around the pump;
- and (b) a resilient annulus having upper and lower ends and surrounding the external periphery of said metallic sleeve and bonded thereto over the length of said metallic sleeve to preclude the entrance of fluid between said sleeve and said annulus, said annulus having an inner annular portion adjacent said sleeve and terminating in flat end faces extending normal to said sleeve, and said annulus further having an outer annular portion formed integrally with said inner annular portion at its lower end and radially spaced from said inner annular portion at its upper end to define therewith a generally V-shaped, axially extending recess in said resilient annulus, said outer annular portion having a downwardly and outwardly tapered upper end and an upwardly and outwardly tapered lower end, the tapered upper end of said outer annular portion being spaced axially downwardly from the flat upper end of said inner annular portion whereby a plurality of said seating cups may be axially aligned on said pump in abutting contact without obstructing the recess in the resilient annulus of each of said cups and said resilient annulus having a uniform outer diameter between the tapered ends of the outer annular portion.
2. A seating cup as claimed in claim 1 wherein the upper and lower ends of the outer annular portion of said resilient annulus are each tapered at 45 to the periphery of said metallic sleeve, the depth of said recess is equal to approximately one-half of the length of said metallic sleeve, and the width of said recess at its origin is equal to approximately one-half of the radial thickness of said annulus with the sides of said recess tapering toward each other from the origin of said recess to the bottom thereof, said seating cup being further characterized to include an elastic material impregnated nylon fabric covering bonded to the outer periphery of said annulus to provide a wear-resistant surface on said cup.
3. A cup as claimed in claim 1 and characterized further to include a curved lip portion formed integrally with said metallic sleeve and extending outwardly and upwardly from said sleeve in abutting contact with said annulus at its end opposite said recess to minimize distortion of the cup, said lip portion having a curvature conforming to the taper of said annulus and being tapered to a thin edge at its outer periphery.
References Cited in the file of this patent UNITED STATES PATENTS 2,013,903 Thaheld Sept. 10, 1935 2,400,533 Buffington May 21, 1946 2,597,976 Cousins May 27, 1952 2,686,092 Neesen Aug. 10, 1954 2,687,335 Bowerman Aug. 24, 1954 2,906,552 White Sept. 29, 1959 FOREIGN PATENTS 574,534 Great Britain Jan. 9, 1946