US3002466A - Swab cup support - Google Patents

Description

N. W. READ SWAB CUP SUPPORT Oct. 3, 1961 2 Sheets-Sheet 1 Filed March 25, 1958 INVENTOR Norman W Read 2 ATTORNEYS Oct. 3, 1961 I N. w. READ SWAB CUP SUPPORT 2 Sheets-Sheet 2 Filed March 25, 1958 INVENTOR Norman, W Read ATTORNEYS States 3,002,466 'SWAB CUP SUPPORT Norman W. Read, Dallas, Tex., assignor to The Guiberson Corporation, Dallas, Tex., a corporation of Texas Filed Mar. 25, 1958, Ser. No. 723,804 11 Claims. (Cl. 103-225) Swab cups for removing fluid from wells have customarily been mounted on a tubular mandrel or support having one or more tubular sections joined together by threads, with a swab cup mounted on each section. The support usually includes a ball check valve which opens ate nt I as the swab is lowered in a column of fluid to allow l by-pass of fluid through the mandrel, and closed by the weight of the column of fluid when withdrawn to trap fluid above the swab cups.

Such swab mandrels, as described above, are rigid and inflexible so that they may not bend and flex at the connections therebetween so as to pass through crooked or irregular places in the pipe, and often become stuck in the pipe for such reason. Furthermore, the threaded joints must be unthreaded for changing swab cups, requiring considerable loss of time in so doing. Many times the threads become frozen by reason of corrosion or undue stress thereon, making them diflicult to unthread and many times causing the threads to be stripped, requiring the mandrel sections to be discarded. Also such threaded joints are often stripped apart, leaving a portion of the swab in the well.

This invention overcomes these problems by providing a swab cup mandrel or support wherein the separate sections of the support are joined by quickly detachable joints, eliminating threaded connections between the sections, permitting free swivel action between the sections and limited lateral movement therebetween.

Such a swab support not only saves time in assemblying and disconnecting sections for changing cups, but provides a support for each individual swab cup which may flex and bend and rotate to pass through irregular or crooked places in the pipe. It also provides a strong joint between the sections which will not easily come apart until removed from the pipe and one section is rotated approximately 90v from the longitudinal axis of an adjoining section.

The mandrel is so made that a ball check valve is not required, but fluid is by-passed between the swab cup and mandrel as the swab is lowered in the well pipe, by means of grooves or flutes formed in the wall of the swab sup- I port body.

The separate sections have complementary interfitting ends so that as many swab cups may be added as desired by simply adding additional intermediate sections between the suspending head section and base section.

It is, therefore, a primary object of this invention to provide a swab cup support having joints between the sections thereof permitting rotatable and pivotal movement between the sections.

Another important object is to provide joints between separate sections of a swab cup support, which eliminates threaded joints and which may be quickly joined and disjoined by simply positioning the sections at substantially right angles to each other.

A still further object is to provide a quickly detachable 3,002,466 Patented Oct. 3, i961 joint between swab cup support sections which is strong,

' low fluid to by-pass between the cups and the supports through longitudinal flutes or channels formed in the outer face of the support as the swab is lowered in the well pipe.

A general object of the invention is to provide a swab L cup support which is easy to assemble and disassemble,

which is flexible, and which reduces the possibility of becoming stuck in the pipe.

Other andfurther objects will become apparent upon reading the detailed specification hereinafter following i and by referring to the drawings annexed hereto.

Suitable embodiments of the invention are shown in the attached drawings, in which,

FIGURE I is a side elevational view of the preferred form of the well swab employing the support assembly incorporating my invention, having two swab cups mounted thereon, wherein the cups are in upward position on the support being as they would be while the swab is being lowered through a column of fluid in a well pipe.

' FIGURE II is a view similar to FIGURE I showing the swab cups in lower position as they would be while the swab is being withdrawn from the well pipe.

FIGURE III is a side elevational View of one of the intermediate support sections, of the swab mandrel.

FIGURE IV is a cross-sectional elevational view taken a (in the'line IV--IV of FIGURE III.

- for joining or disjoining the sections.

FIGURE IX is an enlarged cross-sectional elevation of the universal joint between two sections of the swab support with the'male and female members in interengaged position.

FIGURE X is a partially sectionalized, elevational view of a modified form of joint to prevent accidental disconnection of the joint.

FIGURE X1 is a partially sectionalized, elevational view of another modified form of joint to prevent accidental disconnection of the joint.

In the drawings numeral references are employed to designate the various parts shown, and like numerals indicate like parts throughout the various figures of the draw- 1ngs.

The swab cup support assembly, incorporating the improvements disclosed and claimed herein, generally includes a suspending head section 1, an intermediate section 2, of which there may be one or more, and a base section B, said sections being joined together by the rotatable and pivotal joints, which will be hereinafter described in detail.

The suspending head 1 includes an exteriorally threaded pin 4 which may be threadedly engaged to a conventional sinker bar or weight (not shown) to facilitate the downward movement of the swab assembly into the well pipe.

The swab assembly, including the sinker bar, is usually attached to a wire cable, and is lowered into the well-pipe from the surface in the usual manner.

An enlarged shoe or female socket member 5 may be separately attached or made integral with the lower end of the intermediate section 2, said shoe 5 having an up wardly facing shoulder 6 thereon against which the upper swab. cup 7 may rest when the. swab assembly. is withdrawn from the well pipe to form a sealed connection between the lower end of the cup and the said shoulder.

The swab cups. 7' are merely illustrative. of suitable.

forms of swab cups which may be used with. the swab support assembly, it being understood that other forms of swab cups may be employed therewith.

The swab cups 7 are made of natural or synthetic rubber, reinforced by longitudinal flexible metallic ribs spaced thereabout, and having a supporting thimble molded in the lower end thereof, the said reinforcing wires and thimble being embedded and molded into the resilient cup body. A longitudinal bore extends through the cup 7 of slightly greater diameter than the support members 2 and 3, and the lower ends of the cups include a rubber cushion 7a of resilient material about the lower face thereof which comes to rest upon the shoulders 6 or 10, and the weight of the fluid above the cup when the swab is withdrawn upwardly in the well pipe presses such rubber cushion into sealing engagement with such shoulders so that no fluid may leak between said cups and such shoulders. The cups 7 are loosely mounted on the elongated stems 17 of the supports 2 and 3 so that they are free to slide up and down on the supports and are free to rotate thereon.

The detailed construction of cups, like those indicated at 7, is shown in the co pending application for patent of Thomas B. Losey, Serial No. 751,911, now Patent No. 2,887,347 filed July 30, 1958, to which reference is hereby made. It isnot thought necessary to illustrate. same in detail herein as they do not form a part of the invention claimed herein.

The base section 3 is provided on its lower end with. an enlarged guide shoe 8, which may be separately attached or made integral therewith. The guide shoe 8 is for the purpose of supporting the lower swab cup 7 and also provides a guide for the swab assembly as it is lowered in the well pipe. The guide shoe 8 includes spaced annular grooves 9 thereabout to permit the by-pass of fluid in the well pipe as the swab is lowered therein.

A shoulder 10 is provided on the upper face of the guide shoe 8 on which the lower swab cup 7 may rest when the swab assembly is withdrawn upwardly in the pipe. The resilient cushion 7a on the lower end of the lower swab cup 7 seals against the shoulder 10, as described above, to prevent leakage of fluid between the swab cup and the support section 3.

The head section 1, and the enlarged shoe 5, of the intermediate section 2, have formed therein a semispherical socket 11, which includes on its inner side, a spherical surface 12. The socket 11 is preferably formed medially of the head 1 or shoe 5, as the case may be, so that the diameter of the semi-spherical socket will win cide with the longitudinal axis of the head 1 or shoe 5. This relationship is preferably provided so that the sup.- port sections may be suspended along a common vertical axis when joined together.

The semi-spherical socket 11 is intersected by a hole 13, provided through the side wall of the head section 1' or shoe 5, said hole '13 being smaller in diameter than the diameter of the semi-spherical socket 11.

A slot 14 is provided in the wall of the head section 1 and shoe 5, intersecting both the hole 13 and the socket 11, and extending through the lower end of the head 1 and shoe 5, but having a back wall terminating short of the back extremity of the spherical surface 12 of the socket 11. The slot 14 is lesser in width than the diameter of the hole 13 or socket 11.

The intermediate section 2 and base section 3 each includes an elongated shank portion 17 in which longitudinal, annularly spaced, flutes or grooves 18 are formed, providing spaced ribs 19 thereabout. The upper ends of the ribs 19 are preferably champhered, as indicated at 20.

As will be seen in FIGURE I, as the well swab assembly is lowered through a column of fluid in a well pipe, the swab cups 7 will be displaced upwardly on the elongated 4 stems 17, so that fluid may by-pass the swab assembly through the flutes 18, between the stems 17 and the inner bores of the swab cups 7, to thereby facilitate downward movement of the swab assembly in the fluid column.

When the swab assembly is drawn upwardly under a column of fluid in the pipe; asshown in FIGURE II, the weight of the fluid will push the swab cups 7 downwardly againstthe shoes Sand 8. The rubber cushions 7a on the lower ends of the swab. cups form a seal against the shoulders 6 and 10 on the shoes 5 and 8, as hereinbefore explained, causing the fluid to be trapped above the swab cups and expand same into sealing engagement with the well pipe, thus permitting the fluid to be withdrawn from the well.

On the upper end of each of the shanks 17 is formed a male mating head 21 for engagement in the female socket 1 1. The male mating head is joined to the shank 17 by a section 22 of reduced. diameter. The diameter of the reduced section 22 is preferably less in width than the slot 14 so as to provide a clearance 23 between the slot 14 and such reduced section 22. This clearance permits limited relative sidewise movement between the sections 1, 2 and 3 of the swab support.

The male mating head 21 is preferably in the form of a cylindrical section of a sphere which includes an intermediate elongated cylindrical surface 24, providing a reduced radius, and spherical end surfaces 25 and 26. The spherical end surfaces 25 and 26 provide radii greater than the radius of the intermediate cylindrical surface 24. The cylindrical intermediate portion 24 is of such diameter that it will pass through the hole 13 when the radius of such surface 24 is presented substantially parallel to the radius of the hole 13, as shown in FIGURE VIII. However, when the head 21 is rotated in the socket 11 to cause the reduced diameter 22 of the shank 17 to pass through the slot 14, the greater radii of the spherical surfaces 25 and 26 prevents the head 21 from passing through the hole 13, as-shown in FIGURE IX. Thus the support sections 1, 2 and 3 are joined by a ball and socket joint when they are suspended together as shown in FIGURES I and II, and they cannot be separated until the head 21 is again rotated to the position shown in FIGURE VIII, in which position the head 21 may be withdrawn through the hole 13. The head 21 is suspended in the socket 11 and is free to rotate therein by 360 on its vertical axis and'on an axis inclined to a limited extent from the vertical, and may rotate laterally therein to a limited extent, depending upon the clearance between the reduced section 22 and the wall of the slot 14, and backward and forward movement of the. reduced section 22 is permitted through the slot 14. and the kerf 27, formed on the rear side of the suspending head 1 and shoe 5. The head 21 is longer than it is wide. It is less in width than passage 13, is greater in width than slot 14, and has a length greater than the height of the passage 13, but is less than the height of socket 12 so that it may be inserted through passage 13 in one position and turned to another position where it. cannot escape from the socket, as clearly disclosed and shown in the drawings.

Thus. there is provided a rotatable and pivotal joint between the separate sections of the swab support, permitting free rotational movement therebetween and limited sidewise movement, so that the joints therebetween may freely bend and flex, permitting the swab support to conform to crooked or irregular sections in the pipe in which it is used, and permitting the swab assembly to be bent, flexed and rotated. to free it from, and pass through, restricted places in the pipe. The swab cups mounted therein may also rotate on the supports therefor and may slide up andv down thereon to permit the swab to be worked free of tight places in the pipe, should it become stuck. By virtue of the rotation of the swab cups it will also increase the life of such cups by reason of distribution of the wear thereon.

The. swab support sections 1, 2 and 3 may be quickly assembled and disassembled simply by inserting or withdrawing the male head 21 into or from the socket 11 after the support elements have been rotated to substantially right angle position, as shown in FIGURE VIII. They may be quickly assembled or disassembled for changing swab cups by any workmen in the field, without the use of a wrench or any other tools, resulting in a savings of time and expense. The joint between the separate support elements is strong, yet flexible, and there is little likelihood that the joint will be pulled apart.

The operation and function of the swab assembly described, is believed to be obvious without further descrip' tion. To join the support elements, it is only necessary to turn one support element at right angle to the other, insert the male mating head 21 through the hole 13 and rotate the support elements into longitudinal alignment, the reduced section 22 of the shank 17 passing through the slot 14 as they are rotated. In order to disjoin the two elements it is merely necessary to reverse this procedure.

It will be understood that the male mating head 21 could be of different shape. For instance, the surface 24 does not necessarily need to be cylindrical. The only requirement is that the diameter of the intermediate portion 24 be not greater than the diameter of the hole. 13, but greater than the width of slot 14 so that it will pass through .the hole 13 but not through the slot 14, and that the overall length of the head 21 be greater than the diameter of the hole 13 so that it will not pass therethrough when turned to the position shown in FIGURE IX. The diameter of the intermediate surface 24 should be greater than the width of the'slot 14 so that the head will be suspended in the socket 11 as shown in FIGURE IX. The ends 25 and 26 of the head are preferably spherical in shape in order to provide ansuitable bearing surface between such ends and the spherical surface 12 in the socket 11.

In FIGURES X and XI are shown modified forms of the joint designed to prevent the joint from becoming accidentally disengaged as the swab assembly is being inserted in the well pipe at the surfaces.

Preparatory to inserting the swab assembly into the open upper end of the tubing, it is suspended to a wire cable extending through a pulley on a mast positioned over the well. The swab assembly must be guided into the pipe as it is lowered. There is a possibility that the swab assembly might strike an obstruction in the pipe before all of the joints are in the pipe, allowing slack in the line, thus permitting the swab assembly to buckle at the joint outside the pipe. If the joint bends to right angular position the joints might become accidentally disengaged, allowing the sections of the swab assembly already in the pipe to fall into the pipe, requiring it to be fished out.

The modifications shown in FIGURES X and XI are designed to prevent this occurrence.

In FIGURE X, a recess 28 is provided to extend upwardly from the socket 11. When the swab sections 2 or 3, as the case may be, engage an obstruction in the pipe, the weight of the sinker bar, attached at the upper end of the swab assembly, would cause the head 21 to move upwardly in the recess 28. The wall of the recess would prevent the head 21 from rotating sidewise with respect to the female portion of the joint (1 or thereby preventing the joint from becoming accidentally disengaged. In this modification the reduced stem portion 22 would be elongated to allow upward movement of the head 21 in the recess 28.

In the modification shown in FIGURE XI, the male mating head, indicated at 29, is provided about its cylindrical surface with male threads 30 and the hole 13 through which the male mating member 29 is inserted is provided with peripheral female threads 31 which are complementary to the male threads 30. 'In assembling the joint the threads 30 on the male member 29 are screwed through the threads 31 in the hole 13. The threads 30 and 31 will positively prevent the accidental disengagement of the joint in the manner hereinbefore described, yet will allow the joint to be quickly assembled and disassembled.

In both of these modified forms the joint would have the same novel functions and advantages described in connection with the preferred form.

It will be understood that other and further forms of this invention may be made without departing from the spirit and scope of the appended claims.

Iclaim:

1. A swab cup support comprising: ahead section; a

base section; and an intermediate section; a socket formedin the lower end of the head and intermediate sections, said socket being semi-spherical in shape and being intersected by a circular passage of less diameter than the socket and a slot of less width than the diameter of the passage; said slot extending through the lower end of said sections; a male mating head on the end of each of the intermediate and base sections in the shape of a cylindrical section of a sphere, the said head having a cylindrical mid-portion of less diameter than the passage so that it will pass therethrough, and spherical end portions of greater diameter than the passage; the said head being joined to its respective section by a portion of less width than the slot, whereby the head may be passed through the passage in one position and rotated in the-socket to another position so that it will not pass through said passage and said slot.

2. The combination called for in claim 1 wherein the cylindrical mid-portion of the head has male threads thereabout and the passage has female threads therein which are complementary to the male threads.

-3. The combination called for in claim 1 wherein a recess is formed in the head and intermediate sections extending upwardly from the socket arranged to receive the cylindrical mid-portion of the male mating head.

4. A swab cup support comprising, a suspending head; a substantially spherical socket formed in the head section having a wall thereabout; a circular passage through the wall of the suspending head intersecting the socket, said passage being less in diameter than the socket; a slot through the wall of the head intersecting the passage and socket, which slot is less in width than the diameter of the passage, said slot extending through the lower end of the suspending head; a cup support section; an enlarged shoe on the cup support section; a stem extending from the shoe of less diameter than the shoe; a head on the stem disposed in the socket, said head being in the shape of a cylindrical section of a sphere, and having a cylindrical mid-section and spherical end sections; the cylindrical mid-section being less in diameter than the passage so as to pass through the passage, and the spherical end sections being greater in diameter than the passage but less in diameter than the socket; alternate longitudinal ribs and grooves provided on the stem, the ribs terminating short or" the head to provide a reduced neck portion of less width than the slot so as to pass through the slot; a swab cup having a bore slidable over the ribs, said bore being less in diameter than the shoe and the suspending head, said cup being less in length than the stem so as to be slidable longitudinally on the stem between the shoe and the head.

5. The combination called for in claim 4 with the addition of a resilient seal about the lower end of each swab cup to seal against the shoes.

6. A swab cup support comprising, a head section; a base section and an intermediate section; a socket formed in the lower end of each of the head and intermediate sections, having a wall thereabout, each said socket being substantially spherical in shape and being intersected by a circular passage through the wall of the support section of less diameter than the socket, and a slot through said wall of less width than the diameter of the passage,

said slot extending through the lower end of each respective support section and intersecting the passage and the socket; a stem portion on each of the base and intermediate sections of less diameter than the lower ends of such sections; a head on the end of each stem in the shape of a cylindrical section of a sphere; each said head having a cylindrical mid-portion of less diameter than the passage so that it will pass therethrough, and spherical end portions of greater diameter than the passage, but of less diameter than the socket; each said head being joined to its respective stem by a portion of less width than the slot, whereby the head may be passed through the passage in one position and rotated in the socket to another position so that it will not pass through said passage and said slot.

7. The combination called for in claim 6 wherein a plurality of longitudinal ribs are formed on the stem which terminate short of the head.

8. The combination called for in claim 7 wherein a swab cup having a bore slidable over the ribs is disposed on each stem and arranged to rest on the respective bases thereof, said swab cups being less in length than the stems so as to slide vertically thereon.

9. As a subcombination, a support for a swab cup comprising, an enlarged shoe; a substantially spherical socket in the shoe; a substantially circular passage in the wall of theshoe communicating with the socket; a slot in the wall of the shoe intersecting the socket and the passage, the socket being larger than the passage and the passage being wider than the slot; a stem extending from the shoe of less diameter than the shoe; a head on the outer end of the stern which is in the shape of cylindrical section of a sphere; the stem having a section of reduced diameter adjacent the head.

10. Claim 9 wherein a plurality of longitudinal ribs are provided about the stem which terminate short of the head, thereby providing a reduced neck portion on the stem adjacent the head.

11. A swab cup support comprising: a head section; a base section; an intermediate section; a female mating member formed in the lower end of each head and intermediate section, said female member including a socket with a wall thereabout, a passage through the wall communicating with the socket, said passage being of less height than the socket, and a slot through the wall of less width than the passage, said slot extending through the lower end of the member and intersecting the passage and socket; a head on each intermediate and base section, said head being longer than it is wide and having a width less than the width of the passage so as to pass therethrough, but being greater in width than the width of the slot so as not to pass therethrough, and said head having a length greater than the height of the passage but less than the height of the socket so as to seat in the socket and not pass through the passage when the longitudinal axis of the head is turned toward alignment with the longitudinal axis of the sections; the intermediate and base sections adjacent the head being of less width than the slot so as to pass therethrough.

References Cited in the file of this patent UNITED STATES PATENTS 812,361 Pickles et a1. Feb. 13, 1906 1,562,235 Hoffman et al Nov. 17, 1925 2,176,231 Swortwood et a1. Oct. 17, 1939 2,224,916 McFarlane Dec. 17, 1940 FOREIGN PATENTS 393,090 Great Britain June 1, 1933

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