US1715121A - Alvin b - Google Patents

Description

y 1929. A. B. CROWELL ET AL 1,715,1 1

SWAB

Filed Jan. 17 -l927 .IH 1m L 'I Y I I NV EN TORS'.

G, Lorre/x7e,

ATTORNEY Patented May 28, 1929 ALVIN B. CROWELL ANTTDAVID G. LORRAINE. OF DALLAS, TEXAS, ASSIGIN'ORS OF ONE-THIRD T0 ERD V. CRGNELL, 0F LOS ANGELES, CALIFORNIA.

SWAB.

Application filed January 17, 1927. SerialNo. 161,694.

This invention is a swab for removing paraffin and heavy oils tromfawell casing; and it is an object of the invention to combine a usual swabbing medium and a cutting means which is adapted to positively out heavy hydrocarbons from the wall of a well casing, the paraffin and the like which is thus dislodged passing into a hollow bore extending through the device, where it is trapped against back-flow during subsequent withdrawal of the swab, so that the tight engagement of the swabbing medium with the casing wall removes'all of the dislodged material from the'well. I

Itis a further object of theinvention to provide a cutting means above and below the swabbing medium so as to positively cut away heavy hydrocarbons as the, swab.

is either raised or lowered, and to arrange the cutting means so as to present a maximum cutting surface and automatically clear away the dislodged material without clog- 111 r i It? is a still further object of the invention to provide a valvular means automatically opening as the swab is lowered to permit passage'of the dislodged material into a hollow hereof the device, and automatically closing as the swab is withdrawn in order to prevent back-flow of the dislodged material. p

It is a still further object of the invention to provide for escape of fluid as the swab is lowered in a well, so that pressure in the well will notretard saidlowering movement, and to automatically shut-oft said escape of fluid when the swab is withdraw, the said automatic shut-oi? means being positioned above the cutting elements of the device where it will not hinder ready replacement of the cutters when they become worn.

is a still further object of the invention to arrange the swabbing medium which is positioned between the end cutters, so as to maintain a fluid tight engagement with the wall of the well casing without subjecting the swabbing medium to excessive wear. It is a still further object of the invention to arrange the swabbing medium so as to form a vacuum contact adapted to maintain a fluid tight engagement and cool the swab for preventing its burning when it is not submerged in fluid, the arrangement of the 7 ing.

swabbing medium also providing for collection of sand and cuttings so that such foreign matter will not score or cut the swab.

Further objects of the invention will be readily understood from the following description of the which:

Fig. 1 is a side elevation, partly in axial section, showing the swab in operation in a well with the device divided and its upper and lower ends shown alongside one another.

Figs. 2 and 3 are transverse sections on the lines 22 and3-3 of Fig. 1.

The swab is suspended from a usual string of cable tools lin the casing 2 of a well, a coupling 3 being provided at the upper end of the swab for engagement by a usual pin 4 on the end of the cable tools.

The coupling collar 3 is provided with a hollow coupling 5 depending therefrom, and an open ended, pipe 6 on which the swabbing elements are mounted is threaded into the coupling 5. Above the open end of pipe 6 the bore of coupling 5 is threaded to receive a valve seat 7, and an upwardly opening gravity valve 8 cooperates with the valve seat, to open or close the bore of pipe 6 to theupper portion ofthe hollow coupling 5,

'which is slotted as shown at 9 for open communication with the bore of the well cas- Pipe "6 supports upper and lower cutting means and an intermediate element forming a tight packing engagement with the wall of casing 2, the said intermediate element having a hollow bore and adapted for limited sliding movement of pipe 6' relative thereto to open or close its hollow bore.

The upper cutter for the swab may be mounted on-pipe 6 immediately below coupling 5, with the lower cutter preferably mounted on the extreme lower end'of the pipe; and each cutter is illustrated as comprising a sleeve 10 on pipe 6, with axially. spaced collars 11 -12 mounted on said sleeve and connected by outwardly bowed spiral springs formingcutting blades 13.

The ends of the springs are equi-distantly, circumferentially spaced, and may be fixed by pins 14 to rings 15; and the rings are illustrated as mounted in annular counterbores in the proximate ends of collars 16 which are threaded onto collars l1- 12, so

accompanying drawings, in

that the rings are held in place by abutment against shoulders 17 at the proximate ends of collars 11-12. v r

The sleeve 10 is fixed relative to pipe 6, and collar 12 at the lower end of the cutter is preferably fixed relative to the sleeve, as for example by common fastening means shown as rivets 18; and the collar 11 at the upper end of the cutter is adjustable along sleeve 10 to adjust the diameter of the bowed cutter formed by spring blades 13. 7 As an I instance of this adjustment, a threaded connection19 is provided'between sleeve '10 and collar 11, and the shouldered inner end 17 of the collar forms a nut 17 a for turning the collar. The collar may be locked in threaded adjusted position by a set screw 20 which may also extend through collar 16 for looking it on collar 11; and the collar 16 on the lower collar 12 may be locked in placeby a set screw 21.

The respective cutters at the ends of the swab function as the device is raised and lowered in a well, in order to dislodge paraffin and heavy oils from the wall of the well casing by the cutting engagement of the edges of spiral blades 13, and the blades of the respective cutters spiral in opposite directions so that each cutter will have maximum cutting efliciency when the swab is moved in the direction to cause it to function. The spiral disposition of the blades providesa maximum cuttingsurface, and in conjunction with the hollow construction formed by the bowed arrangement of the blades, affords a positive means for re1noving the dislodged material from the blades and passing it beyond the cutters.

The swab proper WlllCl'l is mounted on pipe 6 between the upper and lower cutter,

functions immediatel I after the cuttin acf) e tlon produced by raising or lowering the device, in order to complete the removal of heavyoils and the like from the wall of the well casing; andthis swabbing element has a hollow bore adapted to open for reception of the dislodged material as the device is being lowered in a well, but adapted to automatically close when the swab is withdrawn,

so that all of the dislodged material is removed from the well. 7

As ,an instance of this arrangement a sleeve 25 is slidable on pipe 6 between the cutters, and the sleeve is spaced from the pipe to form a hollow bore, by means of a guide nut- 26 threaded on the upper end of the sleeve and slidably engaging the pipe.

The nut 26 has bores 27 in alinement with The lower end of sleeve 25 has a valve seat 29"threaded thereon, which cooperates with a valve 30 fixed on pipe 6 in order to open or close the hollow bore of the sleeve when the pipe is lowered or raised relative to the sleeve. The valve 30 preferably has a guide head 31 extending into sleeve 25 for maintainmg alinement of the parts, and the guide head has axial bores 32 for unobstructed flow through the hollow bore of the sleeve.

Swab rubbers 33, preferably two in numher, are mounted on sleeve 25 and may have their proximate ends spaced by a ring 34, with their respectivedistantends abutting against the supporting annulus of valve seat in place; and the rubbers in addition to the v radial expansion obtained by tightening nut 35, are preferably subjected to fiuid pressure for maintaining a tight engagement with he wall of easing 2. v

For this purpose slots 38 open through V sleeve 25 inba'ck of the swab rubbers, so that. pressure in the hollow bore of the sleeve tends to radially "expand the rubbers; and in order to maintain a fluid tight connection between the swab rubbers and the casing wall without subjecting the rubbers to undue I wear, annular grooves 39 may be provided in forming vacuum recesses when the swab, is inuse, which tend to maintain a tight engagement between the rubbers and the casing wall. 6 j

Thegrooves 89 further tend to prolong the life of the swab rubbers'by providing of the swab rubbers thus prolongs their life and also increases their swabbing efficiency. j l j V In operation, the device islowered in casing 2,, the valve 8 readily opening to relieve pressure in the well through the hollow pipe 6, and the swab rubbers engaging the casing wall so that'pipe .6 is lowered relative to sleeve 25for opening valve 30. The open bore of pipe 6 together with the open valve 30 thus prevents a discharge passageway for dislodged material and for pressurein. the well which is substantially equal to the cross-sectional area of the 'swahbing medium, and the swab may thus be readlly lowered 1n the well lrrespective of 100 the contact faces of the rubbers, said grooves the pressure which is encountered. The lower cutter functions during downward movement of the device, for cutting paraflin and heavy oils fromthe casing wall, and the dislodged material is held against dropping by the spiral blades and isthus directed past open valve 30 into the hollow bore of sleeve 25. The swab rubbers engaging the casing wall in back of the lower cutter, completes the removal of the heavy oils.

When the deviceis subsequently withdrawn from the well, the swab rubbers tend to stick in the casing, sothat valve is immediately closed by elevation of pipe 6 relative to sleeve 25, and valve 8 is closed by the pressure above the swab. As a consequence, the dislodged heavy oils above the swab or in the hollow bore of sleeve 25, are trapped against back-flow, and-during elevation of the device-the upper cutterfirst dislodges any remaining heavy oils onthe wall of the well casing, and the fluid tight engagement of the swab rubbers then withdrawsall of said heavy oils from the casing.

In the event of the swab sticking during its withdrawal so that it is necessaryto unload the dislodged material 'WlllCh has been trapped, pipe 6 is lowered relative to the sleeve which will again be held against axial displacement by the swabbing rubbers engaging the casing wall, and the valve p is thus opened for unloading the dislodged material from the sleeve 25.

We claim: i v

1. A device of the character described comprising a medium adapted for swabbing engagement with the wall of a well casing and, having an open bore, means axially beyond said swabbing means'adapted for cutting engagement to dislodge paraffin and heavy oils from the casing wall, and a valve for the open bore of the swabbing medium between theswabbing mediumand the cutting means. i

2. A device of the character described comprising a medium-adapted for swabbing engagement with the wall of a well casing and having an open bore, means axially beyond each end of the swabbing medium adapted for'cutting engagement to dislodge paraffin and heavy oils from the casing-wall as the device is raised and lowered in the casing, and a valveiorthe open bore of the swabbing medium between the swabbing medium and the lower cutting means.

3. A device of the character described having means at its lowerend adapted for cutting engagement to dislodge paratfin and heavy oils from the wall of a well casing, and positively actuated valvular means above the cutting means adapted for downward movement of the device past the dislodged material and preventing back-flow of the dislodged material as the device is withdrawn from the casing. i

at. A device of the character described comprising means adapted for cutting en? gagement to dislodge paraifin and heavy oils from the wall of a well casing, a medium above said cutting means adapted for swabbing engagement with the wall of the well casing, said swabbing means having an open bore, and positively actuated valvular means for said open bore between the swabbing medium and the cutting means, said valvular means being adapted to be opened for reception of the dislodged material after the device is lowered in the casing and adapted to be past said discharged material so that said material enters the bore of the device, and means for preventing back-flow of thedislodged material through said bore during withdrawal of the device from the casing.

6. Adevice of the character described comprising means adapted for cutting engagement to dislodge parafiin and heavy oils from the wallet a well casing, said cutting means comprising axially spaced collars having exterior shoulders at their proximate ends,'ringsmounted on said collars and abutting axially against said shoulders, a plurality of spirally disposed, outwardly bowed, spring cutter blades fixed at their respective ends to the respective rings, and counterbored collars received over the ends of said springs and fixed to the shouldered collars.

7. A device of the character described comprising means adapted for cutting engagement to dislodge paraflin and heavy oils from the wallet a well casing, and means for adjusting said. cutting means for oper. ative engagement with the wall of the easing, said adjusting means comprising a threaded connection and a retaining means for locking said threaded connection in adjusted position. i

8. A device of the character described having a bore and a normally closed valve for said bore adapted to open upon lowering of the device in a well casing, and means be low said valve adapted for engagement with the wall of the casing for dislodging paraflin and heavy oils so that said material is supported by the dislodging means in order that it may enter the bore of the device past said open valve.

9. A device of the character described comprising a pipe adapted for suspension from a string of drill pipe, a normally closed valve for the upper end of the pipe adapted to open during lowering of the device in a well casing, means axially spaced on said pipe below said valve adapted respectively for cutting engagement to dislodge paraflin and heavy oils from the wall of the well casing during lowering and raising of the devicefin the well casing, a medium adapted for swabbing.engagement with the. wall of the well casing mounted on said pipe between said cutting means, said swabbing medium having a hollow bore, and valvular means for the hollow bore of the swabbing medium, said valvular means beingv positioned between the swabbing medium and the lower cutting means and adapted to open during lowering of the device in the well casing for reception of dislodged material in said hollow bore, said valvular means beceived over the ends of. said blades and fixed to the shouldered collars.

11. A device of the character described comprising a medium adapted for swabbing engagement with the wall of a well casing,

said swabbing medium having a hollow bore, valvular means for the lower end of the hollow bore, and a valve stem for said valvular means slidable in said hollowbore and adapted for suspension from a drill string, the swabbing medium being adapted for .irictional engagement with the wall of the well casing for movement of the valve stem.

relative thereto so that lowering the device in the well casing will .open the valvular means for reception of dislodged material in said hollow bore and withdrawal of the device from the well casing will close said valvular means. to prevent back-flow from said hollow bore.

12. A device of the character described comprising'a medium adapted for swabbing engagement with the wall of a well casing,

said swabbing medium having a hollow bore, valvular means for the lower end of the-hollow bore, and a valve stem for said valvular means slidable in said hollow bore and adapted for suspension from a drill string,

said valve stem having a hollow bore open to the vwell casing below said valvular means whereby said open bore, of the valve stem and the open valvular means presenta discharge passageway of substantially the,

cross-sectional area of the swabbing medium, the swabbing medium 7 being adapted for frictional engagement with the wall of the well casing for movement of the valve stem relative thereto so that lowering the device in the well casing will open the valvular means for reception of dislodged material in said hollow bore and withdrawal of the device from the well casing will close said valvular means to prevent back-flow from' said hollow bore. I v f 7 13. A device of the character describedcomprising a medium adapted for swabbing engagement with the wall of a well casing,

said swabbing medium having a hollow bore, valvular means for thelower end of the hollow bore, a valve stem for said val: vular means slidable in said'hollow bore and adapted forasuspensionfrom a drill string, said valve stem having a hollow bore open to the well casing below said lvalvular means and adapted for discharge into the well casing above said valvular means whereby said open bore of the valve stem and the open valvularnieans presenta discharge passageway of substantially the cross-sectional area of the swabbing medium, and an upwardly opening check valve inthe hollow hore of. the a valve stem, the swabbing medium being adapted for frictional engagement with the wall of thewell casing for movement. 01 the valve stem relative thereto so that lowering the device in the well casing will open the valvular means fol-reception of dislodged material in said hollow" bore and withdrawal ofthe device from the well casing will close said valvular means to prevent back-flow from said hollowbore.

In testimony whereof we have afiixed our signatures to this specification.

- I ALVIN B. CROWELL.

7 DAVID G. LORRAINE.

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