US2153843A - Well swab - Google Patents

Description

April 11, 1939. B PARmSH 2,153,843

WELL SWAB Filed July 22, 1935 4 Sheets-Sheet 3 M Z0 Z0 z 7,

C Z8 Z8 55 Aprilll,1939. I B.'E.PARR1SH I 2,153,843

I WELL SWAB Filed July 22; 1935 4 Sheets-Sh e t 4 w I Patented Apr. 11, 1939 UNITED. sT -T ss PATeNT OFFICE 24 Claims. (o1. 103-225) This invention relates to new and useful improvements in well swabs.

One object of the invention is to provide an' improved swab which is particularly adapted for use in oil wells, and which is so constructed as to descend rapidly in the well fluid, whereby theswab may be run in the well in a minimum amount of time.

An important object of the invention is to provide an improved well swab including a packing element constructed intwo halves, said halves being arranged to be displaced vertically out of horizontal alinement with each other so that fluid may by-pass said packing element; the halves being automatically displaced when the swab islowered in the well fluid on the downs'troke and arranged to fit together in packing position on the upstroke, the displacement of the halves provid ing a maximum by-pass which permits rapid 2O lowering of the swab.

Another object of the invention is to provide an improved well swab having its packing element made in two halves, one of which is slidable vertically with relation to the other to permit by' 25 passing of the well fluid on the downstroke of the swab, with means for alining the two halves into packing position on the upstroke with the weight of the fluid above the packing element, said means being arranged to cause the halves to be equally 30 distorted, whereby an equal peripheral packing action around the inner wall of the casing is had.

A further object of the invention is to provide an improved well swab having a split packing element the halves being arranged to be auto- 35 matically displaced vertically with relation to each other by the fluid pressure on the downstroke to permit a maximum of fluid toby-pass the packing element, the fluid pressure providing a positive actuating means for opening the bypass, whereby danger of the packing element moving into packing engagement during the down stroke'is' positively eliminated.

Still another object of the invention is to pro-- vide an improved swab having a resilient packing 5 element, with means for limiting the distortion of said element, whereby danger of distorting said element beyond its elastic limit is eliminated.

A still further object of the invention is to rovide an improved packing element for well swabs 50 which has its upper portion made of ordinary rubber or similar material, having its lower'por I tion suitably reinforced, which gives said lower portion increased toughness and durability, thereby preventing said lower portion from being- 5 damaged, when in packing position on the upstroke, by its engagement-with the couplingsand j collars in the well casing.' I i Still another object of the invention-is to provide an'improved packing element fora well swab which is constructed in two halves arranged to fit 5 around-the swab mandrel,- one half being slidable vertically on a guide rod and being constructed so that the halves may be removed from 'saidrod's for replacement or other reason without dis-assembling the entire swab. 10 A still'further-objeet'of the invention is to provide an'improved well swab which is constructed of bronze, whereby fire hazard is eliminated', and wherein allcheck valves are eliminated, the pack ing element serving as a valve to permit by pass- )5 ing of fluid on the downstroke; the entire assembly being simple in manufacture and arranged to be attached to any suitable lowering rod, cable, or device.- "A'construction designed tocarry out the inven; tion will be hereinafter described, together with I other features of the invention.

The invention will be more readily understood I Q from dreading of the following speciflcation and by reference tothe accompanying drawings in which an example of the invention is shown, and wherein: I

Figure 1 is an elevation of a swab constructed in accordance with the invention, and showing the packing element in its packing position,

Figure 2 is a view, similar to Figure 1 and showing the. halves of the packing element displaced vertically from each other,

Figure 3 is an elevation taken on right angles to Fi ure 1. Figure 4 is an elevation taken at right angles to Figure 2 Figure 5 is a transverse vertical sectional view I of theswab, taken on the line 5-5 of Figure 3.

Figure 6 is a transverse vertical swtional view taken on the line 6-6'of Figure 4,

Figure 7 is a horizontal, cross-sectional view, taken on the line l l of Figured,

Figure 8 is a horizontal cross-sectional view,

taken on the line 8 -8 of Figure 1,

Figure 9 .is a horizontal cross-sectional view, taken on the line ;99 of Figure 1,

Figure 10 is an isometrical view of the movable.

The upper end of the mandrel has 5 an enlarged neck H whereby an annular overhanging shoulder i2 is formed. This is provided with an upwardly extending screw-threaded nipple II, which is of such size as to receive the standard threaded box (not shown) at the lower end of the usual sucker rod, whereby the mandrel may be readily connected to said rod and lowered into the well casing A.

The lower end of the mandrel I6 is provided with an enlarged portion. oi the same diameter as the neck, whereby a lower annular shoulder II is formed. The enlarged portion H has its lower end screw-threaded, whereby the mandrel may beinverted and lowered by means of a pipe which screws onto said screw-threaded portion, This is done when it is desired to lower the mandrel by means of a pipe instead of a sucker rod and thus it is obvious that with the arrangement, specially designed couplings are unnecessary and the mandrel may be connected with any of the usual lowering devices.

Mounted on the mandrel l and confined between the shoulders I 2 and I6 is a packing assembly I6 which includes a pair of split collars l1 and 18 which encircle the mandrel l0 adjacent the shoulders l2 and I6. Each collar comprises semi-circular halves which are secured to each other by bolts IS. The bolt holes are preferably countersunk so that the heads of the bolts are flush and do not project outwardly from the connecting ears of the collars.

The collars are spaced apart vertically and'held in position contiguous to the shoulders 12 and i5 by elongated vertical tie rods 26 which have their ends screwed into threaded openings 2| in the collars. The upper end of the rods are provided with left hand threads while the lower ends are formed with right hand threads. Thus, the rods.

may be screwed into both collars simultaneously and also said collars may be spaced exactly a de sired distance from each other. Since each half of the collar I8 is connected to one half of the collar I! by one of the rods, and the other half oi the collar 18 is connected to the other half 01' the collar I! it is obvious that two units B and C are provided. By merely removing the bolts II which fasten the two halves of each collar it is possible to remove the units B and C from the mandrel quickly and easily. Similarly said units ,may be readily attached to the mandrel.

Mounted on the mandrel l6 and tie rods is a flexible packing element 26. The packing element is constructed of two semicircular sections 26 and. 21 which are arranged to fit around the mandrel I, as clearly shown in Figure 8. One of the sections 26 is carried by the unit B, while the other section 21 is carried by the unit C,

whereby when the units are separated and removed from the mandrel, the packing assembly is also removed.

Both sections of the packing element are exactly alike except that the section 26 is permanently attached to the collar l8, and is permanently fixed at the bottom of the mandrel, as will be explained, while the section 21 is slidable vertically on the rod of the unit C, whereby it may be displaced vertically out of horizontal alinement with the other section. The construction of the section 26 is clearly shown in Figure 11, and includes an upper semicircular head 28 having an upwardly directed flange 29 at its, inner upper edge. A raised boss 30 extends radially of the head and the boss and head have a vertical opening 3| through which the vertical rod 20 of the unit B passes. One section of the flexible packing element 25 is confined between the upper head 28 and alower head 33, and has a vertical passage 24 extending therethrough. .The lower head 33 is provided with an opening 35 through which the rod extends and, as is clearly shown in Figures 5, 6 and 11, this head is made integral with the half of the collar l8 which forms a part of the unit B. Thus it is seen that since the rod 20 screws into the collar, it also attaches to the lower head 33.

The heads 28 and 33 are secured to each other by vertical, elongated headed bolts 36 which extend upwardly from the bottom head, through the packing and are screwed into the upper head 28 (Fig. 1 It is obvious that when pressure is applied to the upper head 28, the same is forced downwardly on the rod 20. The lower head being integral with the collar l8 which is resting on the shoulder i 5 of the mandrel is held stationary. Therefore, the flexible element is depressed and distorted outwardly into engagement with the wall of the casing A.

It is obvious that under pressure the upper head and packing element 25 slide on the rod 20 and to prevent wear of the rubber due to frictional engagement of the rod, a tubular sleeve 31 (Figures 5 and 6) surrounds the rod within the passage 34 of the packing. This sleeve has its upper end screwed into the head 28 and extends entirely through the packing element, having its lower end terminating at the upper end 01' the opening 35 in the lower head 33, when the packing element is in a normal position. When pressure is applied above the head 28 and the same moves downwardly to distort the packing element, the sleeve being fastened to the head also moves downwardly along with the packing element. It is pointed out that due to the location 01 the lower end of the sleeve within the opening 35, the distortion of the packing element is limited. In other words, when the lower end of said sleeve strikes the bottom. of the opening 35, the downward travel of the upper head 28 is stopped, whereby further distortion of the packing element is prevented. This eliminates danger of the packing being distorted beyond its elastic limit.

To provide for easy replacement of the packing element, said element is formed with a vertical slit 32 (Fig. 8) which extends from the center of said-element to the passage 34. Thus, to remove and replace the packing it is only necessary to remove the elongated bolts 36, after which it is possible to spread the packing element laterally a sufficient distance to disengage it from the sleeve. The replacement may be accomplished in the same way.

From the above, it will be seen that the section 26 is positively secured to the lower end 0! the mandrel being immovable thereon. The other section 21, however, is slidable vertically on the rod 20 of the unit C, and is constructed exactly as is the section 26, including the upper head 28 having a flange 29, packing element 25 and lower head 33. The lower head of this section, however, is made separate from the collar I8 as is clearly shown in Figure 10. This lower head has a flange 38 at its inner side, this flange being similar to the flange 29 of the head 28 of the section 26, except that it is inverted.

The flanges 29 and 38 of the heads are beveled as shown at 28' and 38' in Figures 10 and 11. The upper edge of the flange 29' of the section 26 is further provided with a beveled seat 39 which is arranged to be engaged by beveled lugs made integral with the flange 29 of the section 21. Thelugs engage the seat when the section 21 is in a lowered position, and is disengaged therefrom when in a raised position.

In operation, the assembly is secured to a string of pipe, sucker rod or other lowering device and.

as to permit the section 21 to move upwardly to the position shown in Figures 2, 4 and 6, with the lower end of the flange 3.8 of the section 21 engaging and slightly overlapping the upper end of the flange 29 of the section 26.

Due to the bevels 29 and 38 ofthe flanges 29 and 38, it will be seen that an enlarged space E (as indicated by arrows, Figure 4) is provided between the sections to permit passage of fluid. This space is substantially equal to the crosssectional area of the casing A, whereby there is practically no resistance to the downward passage of the assembly in the well. The enlarged by-pass permits the assembly to be lowered rapidly and each run may be madein a minimum length of time. It is obvious that the displacement of the. sections of the packing assembly out of horizontal alinement act as a valve to permit by-passing of the fluid on the downstroke.

When the swab has reached its lowermost position and the raising operation is begun, the section 21 will drop by gravity being aided in. this downward movement by the fluid pressure above the assembly, whereby said section is immediately lowered. The lugs 40 will strike the upper beveled seat 39 of the flange 29 of the section 26, and from then on the pressure will be exerted equally on both sections 26 and 21, whereby an equal packing of both sections will be had. It has been found that since the section 21 travels downwardly on the rod some distance before it is in horizontal alinement with the section 26, this former section gains momentum as it moves downwardly and unless there was some way of connecting. the two sections when they become alined, the momentum of the moving. section would cause it to move into packing position first. The provision of the lugs and beveled seat assures the sections of the packing element 25 being dis- -torted simultaneously and equally in allradial lower portion which carries the load will not tend to shear oif when it strikes a joint or other obstruction within the casing A. To further reduce this tendency, the lower end of the element 25 may be inclined inwardly, as shown at 25'.

From the above, it will be seen that a swab wherein the packing element. is utilized as a valve, is provided. The structure is such that the "entire assembly may be quickly and easily attached to, or detached from the mandrel ill.

' The removal of the bolts l9 from the collars I1 and I8 permit the units B and C to be removed in their entirety. The slit 32 in the sections of the packing element 25 allows their replacement at any time without disassembling the swab. It is pointed out that since the rods 20 are provided with oppositely directed threads on their upper and lower ends, a positive adjustment so as to horizontally aline the sections 26 and 21 of the packing assembly can be accomplished. The bypass E is of such size as to eliminate any great resistance in the downward travel of the assembly, which makes for rapid lowering of the devicein the well casing A. Further, the particular structure of the sleeves 31 not only prevent wear of the packing element 25 but also serves as stops to limit the distortion of the packing, whereby it cannot be distorted beyond its elastic limit. It is noted that the provision of the nipple l3 at one end and the threaded portion H at the other, together with the reversibility of the mandrel, eliminates the necessity of special couplings and the assembly may be lowered by any suitable lowering device on the open market.

What I claim and desire to secure by Letters Patent is:

1. A well swab including, a support, a packing assembly mounted on the support, said assembly including a pair of sections which are arranged to be displaced vertically out of horizontal alinement with each other to permitthe well fluid to freely bypass the packing assembly on the downstroke of the swab, said sections also being arranged to move back into horizontal alinement and to be distorted into packing position upon the upstroke of the swab, and rigid means for.

connecting the two sections together just prior to their distortion into a packing position, whereby the sections are distorted equally and simultaneously.

2. A well swab including, a support, a packing assembly carried by the support, said assembly.

comprising a pair of units arranged .to be clamped around the support, and an elastic packing element constructed of two sections, .one of which is permanently attached to one of said units, the other section being carried by the other unit and movable vertically thereon, whereby it may be displacedvertically with relation'to the other section out of horizontal alinement therewith to provide an enlarged space to permit the well fluid to by-pass-the packing element freely on the downstroke of the swab, which makes for rapid lowering of the swab. V

for connecting the two sections together just prior to their distortion into a packingposition, whereby the sections are distorted equally and simultaneously. and means for limiting the distortion oi the sections of the packing element to prevent their expansion beyond their elastic limit.

4. A well-swab including, a support, a packing assembly mounted on the support, said assembly including a pair of sections one of which is in a fixed position on the support, the other section being arranged to be displaced vertically out of horizontal alinement with the fixed sec;-

tion to permit the well fluid to freely by-pass the packing assembly on the downstroke of the swab, the movable section being arranged to move back into horizontal alinement with the fixed section and to be distorted into packing position with said fixed section upon the upstroke of the swab, and means for limiting the distortion of the sections of the packing element to prevent their expansion beyond their elastic limit and to relieve the distortable packing members of the fluid load thereabove.

5. A well swab including, a support, a pair of split collars clamped to the support, diametrically opposite vertical tie rods connecting the collars, and a deformable packing element ineluding a pair of semi-circular sections arranged to fit together around the support to form a circular packing element, one of said sections being mounted in a fixed position on one of said rods while the other section is slidable on the other rod whereby the latter section may be vertically displaced out of horizontal alinement with the fixed section to provide an enlarged space to permit fluid to freely by-pass the packing element whereby the swab may be lowered rapidly, said sections being exposed to the well fluid as the swab is lowered or raised in the well, whereby the movable section is displaced vertically by the well fluid on the downstroke and is moved ,0 back into horizontal alinement with the fixed section and is then distorted with said fixed section into packing position by the fluid thereabove on the upstroke.

6. A well swab including, a support, a pair of split collars clamped to the support, diametrically opposite vertical tie rods connecting the collars, a deformable packing element including a pair of semi-circular sections arranged to fit together around the support to form a circular packing element, one of said sections being permanently fixed on one of said rods while the other section is slidable on the other rod whereby the latter section may be vertically displaced out of horizontal alinement with the fixed section to provide an enlarged space to permit fluid to freely by-pass the packing element whereby the swab may be lowered rapidly, said sections being exposed to the well fluid as the swab is lowered or raised in the well, whereby the movable section is displaced vertically by the well fluid on the downstroke and is moved back into horizontal alinement with the immovable section and is then distorted with the immovable section into packing position by the fluid thereabove on the upstroke, and means for connecting the two sections in horizontal alinement just prior to their dis tortion into a packing position, whereby the sections are distorted equally and'sirnultaneously.

7. A well swab including, a support, a pair of split collars clamped to the support, diametricah ly opposite vertical tie rods connecting the collars, a deformable packing element including a pair of semi-circular sections arranged to fit together around the support to form a circular packing element, one of said sections being permanently fixed on one of said rods while the other section is slidable on the other rod whereby the latter section may be vertically displaced out of horizontal alinement with the fixed section to provide an enlarged space to permit fluid to freely by-pass the packing element whereby the swab may be lowered rapidly, said sections being exposed to the well fluid as the swab is lowered or raised in the well, whereby the movable section is displaced vertically by the well fluid on the downstroke and is moved back into horizontal alinement with the immovable section and is then distorted with the immovable section into packing position by the fluid thereabove on the upstroke, means for connecting the two sections in horizontal alinement just prior to their distortion into a packing position, whereby the sections are distorted equally and simultaneously, and means for limiting the distortion of the packing element, whereby distortion beyond its elastic limit is prevented.

8. A well swab including, a support, a packing element including a pair of semi-circular sections arranged to flt together to form the cylindrical packing element, one of the -lections being fastended in a fixed position on said support while the other section is arranged to be displaced vertically out of horizontal alinement with the fixed section whereby the sections serve as a valve to permit by-passing of well fluid thereby on the downstroke oi the swab, said movable section being arranged to move into horizontal alinement with the lower section and to be distorted to pack oil with said section on the upstroke, means for guiding the movement. of said movable section, and rigid means for positively connecting the two sections just prior to their moving into packing position, -whereby both sections are distorted simultaneously and equally.

9. A well swab including support, a packing element including a pair of semi-circular sections arranged to fit together to form the cylindrical packing element, one of the sections being fastened in a fixed position on said support while the other section is arranged to be displaced vertically out of horizontal alinement with the fixed section whereby the sections serve as a valve to permit by-passing' of well fluid thereby on the downstroke of the swab, said movable section being arranged to move into horizontal alinement with the lower section and to be distorted to pack of! with said section on the upstroke, means for guiding the movement of said movable section, rigid means for positively connecting the two sections just prior to their moving into pricking position, whereby both sections are distorted simultaneously and equally, and means for limiting the distortion of the packing element, whereby dlstortion beyond its elastic limit is prevented.

10. A well swab including, a support, a separable packing element mounted on said support and provided with a displaceable section adapted to undergo vertical movement with relation to the remainder of said element to provide a by-pass for fluids on the downstroke of said swab, and rigid complementary members one on each section of the packing element and adapted to engage each other when the sections are in alinement to cause both sections to be distorted into packing position simultaneously.

11. A well swab including, a support, a separable packing element mounted on said support and provided with a displaceable section adapted to undergo vertical movement with relation to the remainder of said element to provide a bypass for fluids, said displaceable member being moved by the pressure of the fluid as the swab is lowered thereinto, and rigid complementary members one on each section of the packing element and adapted to engage each other when the sections are in alinement to cause both sections to be distorted into packing position simultaneously.

12. A well swab including, a rod, adapted to be lowered into a well bore, a shoulder on said rod,

a packing element seated on said shoulder, said element including upper and lower caps, are silient sealing member disposed therebetween, said caps and said sealing member being split in half along a vertical plane, and means on said rod to allow vertical sliding movement of one of said halves relative to the other.

'13. A well swab including, a support, a cylindri cal packing element including a pair of semicylindrical sections arranged to fit together to form the cylindrical packing element, one of the sections being fastened in a fixed position on said .support while the othersection is arranged to move in a straight vertical path so as to be displaced out of horizontal alinement with the fixed section whereby the sections serve as a valve to permit rapid by-passing of sufficient well fluid to allow the swab to rapidly fall on the downstroke of the swab, and guide means forming a part of the swab for guiding the movable section in its vertical movement. 14. A well swab including, a mandrel, a packing assembly mounted on the mandrel, said assembly including a stationary unit and a movable unit, said movable unit being arranged to be displaced vertically out of horizontal alinement with the stationary unit to permit the well fluid to freely by-pass the assembly on the downstroke of the swab, the movable unit being arranged to move back into horizontal alinement with the stationary member and to be distorted into packing position with said stationary member upon the upstroke of the swab, and means on each unit for limiting the distortion of the packing units.

15. A well swab including, a mandrel, a packing assembly mounted on the mandrel, said assembly including a stationary unit and a movable unit, said movable unit being arranged to be displaced vertically out of horizontal alinement with the stationary unit to permit the well fluid to freely by-pass the assembly on the downstroke of the swab, the movable unit being arranged to move back into horizontal alinement with the stationary member and to be distorted into packing position with said stationary member upon the upstroke of the swab and means on each unit for limiting the distortion of the packing units.

16. A well swab including, a mandrel having vertical grooves 'therein, a packing assembly mounted on the mandrel and including a pair of units which are arranged to be displaced out of horizontal alinement with each other to permit the well fluid to freely by-pass the assembly on the downstroke of the swab, each unit comprising an elastic packing member substantially semi-circular in cross-section so as to fit around the mandrel, confining elements at each end of the member for holding said member therebe- Q tween, and removable means for fastening said packing member to said confining elements.

1'1. A well swab including, an upright support, a swab element surrounding the support and including a plurality of registering sections having a elastic deformable members arranged to be deformed by the liquid lifted when in registration with each other, one of said sections being immovable and the other section being slidable vertically of said support whereby it is displaced 1. from the flrst section to provide a free by-pass for liquid along and between said sections, whereby the swab may be quickly lowered in a body of liquid in a well, guide means for the movable sec-v tion, and means onthe movable section coacting with said guide means to retain said movable section in registering position and for guiding said section into registering position with the stationary section.

18. A well swab including, an upright support, a swab element surrounding the support and having a section displaceable vertically of the support, and vertically extending guide means for the displaceable section for maintaining said section in vertical alinement with the support and arranged to prevent the displaceable section rotating over the remainder of the element when said section is displaced.

19. A well swab including, a vertical support, a swab element surrounding the support and having a vertically displaceable section, the upper vertically, the displaceable section being movable,

vertically approximately its length to provide amplified vertical fluid passages opposite the vertical faces of the element and the section.

21. As a sub-combination in a well swab having a displaceable section, an elongate elastic member substantially semi-circular in cross-section having its ends reduced and provided with elongate faces on its inner portion.

22. As a sub-combination in a well swab having a displaceable section, an elongate elastic member substantially semi-circular in cross-section having its ends reduced and provided with elongate faces on its inner portion, and rigid semicircular confining members at each end of the elastic member.

23. A deep well fast falling swab including, a support, and a packing assembly mounted on the support, said assembly including an elastic cylindrical sealing member which is split in half upon a vertical plane along its longitudinal axis, and means on said support to permit vertical sliding movement of one of said halves relative to the other to separate said halves and provide a by pass space therebetween while the sliding faces of said halves remain in vertical alinement.

, 24. A well swab including, a support, and a cylindrical packing element engageable around the support and split in half along a vertical plane longitudinally of its axis so as to provide two sections, each section being substantially solid in cross-section, one of said sections being displaceable longitudinally in a vertical line with relation to the other section to maintain said vertical alinement and provide a by-pass for fluids on the downstroke of the swab, said section being displaced by the pressure of the fluid as the swab is lowered therethrough.

BENJAIEI'N E. PARRISH.

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