US2072859A - Wall scraper - Google Patents

Description

J. GRANT WALL SCRAPER March 9, 1937.

Filed NOY. 25, 1935 Y llll I .Ewen/far .Jb/UZ Grave/- ateute Mas., Q, w3@

.. air-Elo .STATES 'PATE attesta NT o1-Fica WALL scnaPEa .iohn -Grant, Los Angeles, Calif.

iapplication November 25,1935, seriales. 51,979' v e claims. (crass-7s) This invention relates generally to well reaming or scraping `tools embodying 'expansible reaming elements or cutters, and p articularly to tools of this type in which the cutters are' ac- 5 tuated by circulating fluid pressure. My invention is primarily directed to improvements in the luid circulating systemin the tool, and provisions whereby excessive wearand abrasion of y' the partslby the circulating iiuid is prevented. i While I have chosen as a typical and preferred embodiment of the invention, atype ofreamlng tool in which the cutters take the forni of bladesmounted within la transverse slotinthe body, it will be understood that inv its broad i aspects the invention is not limited to. any particular type of vcutters or cutter arrangement.

The-present teaming tooll may be 4generally described as comprising a tubular body contain-y ing a plunger connected to .the cutters and actuated by circulating fluid to move. the cuttersto expanded positions., As regards the 'general construction and arrangement` of the parts, the. present tool isv similar to that described in Patent No. 1,992,546, issued February 26, 1935, to

g5 James J. Santiago, on Beamers and well scrapers. In the operation of the tool the plunger is pressed downwardly by the uid pressure and, in order to maintain the -desired circulation of fluid into the well in propel; proximity to the cutters ora drilling tool carried below the reamer,` the circulating fluid' is Vconducted downwardly through passages in the plunger, the fluid pas' sages being restricted suiii'cientlyto maintain the necessary yoperatingpressure differential on the plunger. In practice, serious-dimculty has resulted -from excessive wear on the parts l through which the restricted uid passages exitend, due to the abrasive ,action of `the high velocity circulating uid andthe iine mud or Y 40 siliceous particles which it carries.

, My primary object is to provide improvements G in the construction of the cutter actuating .plunger and the positions and arrangement oi the circulating iiuid passages in' the plunger, to the end that ample pressure differentials may be ,maintained to operate the plunger,-without involving'excessive uid velocities through'the restricted passages and resultant excessive "and 4 4 0S Fig. 1;"and Y lar body III, into the box'end Illa of which is formed integrally with the body, although the as viewed in open position, are beveled to promade clear in thefollowing detailed description of. the invention in one of its typical and preferred forms. Throughout the description reference 'is hadto thel accompanying drawing, in.- which:

Fig. 1 is a longitudinal central section showing one'form o f the tool in collapsed condition;

Fig. 2 is, a similar view showing. the tool in expanded condition;

Figs. 3 and 4 are cross particular manner of attaching the 'bit to the body is inv no way limitative on the invention.- Cutters' I 4 are'mounted` within `a. transverse slot I 5 inthe b0dy,'the cutters consisting of blades lying alongside each otherface to face, in the 25 body slot and movable .pivotally o n the transverse pivot pin I6 between 'the collapsed position of Fig. 1 and the expanded position shown in 2. 'I'heends Ila and lower edges Mb of the blades,

vide sharp cutting edges, the bevels on the two blades being reversed, as illustrated, so that the bevels trail the cutting edges as the tool rotates. In fully expanded position; the-'cuttersswing into engagement with body shoulders I 1 at the upper end oi' slot I5, the shoulders serving'as stops to limit the cutter swing and also to take on the parts. The invention also provides a novel arrangement of fluid passages in the body oi the tool, which enable the circulating fluid' to be discharged at the most desirable-points for et; fective operationV of the tool.

The manner -in which these and additional ob-l the upward thrust transmittedthrough the cutters during operation. 4In their collapsed position, Fig. l, the cutters areswung into engagement with stop-pins Il. see Fig. 4,' having beveled ends Ila correspondingin angularityto the bevel at the cutter edges Ill,` so that the cutters are caused to bear flatly against the pins.

The cutt are actuated in their expansive movement ronil the position of Fig. 1 to that 9! Fig. 2, by iluid pressure applied to a plunger, generally indicated at I9, within bore 20 o1' the body.

-The portion 20a of the bodyv bore within the upper interior oil-the body is ofcomparativel'y large dian'ieterv and tapers at Zlib below shoulder 2| to a-relatlvely small diameter bore llc. ',/Anl guiar grooves 22 are forme/din the body at-'thQ lowernd of bore 20c to provide a downwardly .6 5 jects arev accomplished by the invention, will be l' ilarlng communication between the bore and the cutter containing slot I5. Circulating fluid is discharged into and through the body bores by way of the tool' joint bore IIb and the tubular drill string l2.

The cutter actuating plunger I9 comprises a head 23, preferably shaped substantially in the form of an inverted cup, as illustrated, and a rod 24 threaded at 25 into the upper end of the head and connected at 25a within a pair of links 26. These links, in turn, are pivotally attached at .21 toA one each of the cutters I4, the pivots 21 being offset sufficiently from the axial center of the body that downward movement of the links causes their respective cutters to swing oppositely as shown in Fig. 2. The connection at 25a between the plunger rod 24 and links 26% com-I prises a nut 28 threaded on the lower end of the rod and having a lower bifurcated portion 28a into which is inserted a pivot pin 28 passing through the links. Nut 28 is substantially cylindric in shape (see Fig. 3), having a substantially sliding t within bore 20c, and is provided with vertically extending channels or recesses 30 through which circulating :duid is discharged from bore 20c downwardly through grooves 22 into the slot I5.

As previously mentioned, the plunger is pressed downwardly by the circulating fluid pressure to swing the cutters from their collapsed to expanded positions. The cutters are returned to collapsed condition by a coil spring 32 encircling the plunger-rod'and bearing against body shoulder 2i and the lower end of plunger head 23. The plunger head 23 is designed particularly with the view of avoiding any serious wearuon the inner surface of the body bore wall 20a by abrasive action of the circulating iiuid, and with the further object of conining substantial wear caused by the circulation fluid, to the more inexpensive and easily replaced parts of the tool. By forming the plunger head in the manner illustrated, I am able to prevent extreme high velocity flow of circulating fluid along .the inner surface of the body and the severe abrasive wear on that surface that would otherwise result, by directing the flow of circulating iluid passing through the plunger head, downwardly and inwardly against therod 24, so that the relatively inexpensive and easily replaceable plunger yrod takes the wear, instead of the body. c

Y The hollow plunger 23 preferably is tapered upwardly to its point of connection with the rod 24, and may be provided at its upper end with an eye 35 to receive a tool for removing a plunger from the body in disassembling the tool after pin y lli-has been withdrawn to disconnect the cutters.

plunger head `is proportioned so as to have'a diameter suilioientiy large that the total iluid pressure acting downwardly against it will oper-I ate the cutters I4 without the necessity for particularly high fluid pressure per unit area, and

`also to enable the combined areas .of slots 31 to be sufllciently large to avoid excessively high iiuid velocities v`within the slots and resultant abrasive wear. Thus by giving the head a, tapered or conical shape, I am able to provide both the desired eiective plunger area and large total slot area to the end that the necessary cutter operating pressure on the plunger may be had without excessive uid velocities through the slots.

During operation, the circulating fluid being discharged downwardly against the plunger head is caused to flow inwardly through slots 31 in the directions indicated by the arrows, and thence downwardly and inwardly against the surface of rod 24 within the plunger head. It will be observed that by virtue of its downward and inward course of flow, the circulating uid is directed against a substantial length of the plunger rod surface. That is to say, the rod surface against which the circulating iiuid streams impinge is not ,confined to a small area, but is distributed along the length of the rod, s'o that any wear caused by the abrasive action of the circulating iluid is correspondingly distributed over the surface of the rod and excessive wear at a localized area avoided. In order to obviate any necessity for replacing the plunger rod in case it becomes worn to a substantial degree by the circulating fluid, a replaceable sleeve 38, see Fig. 5, supportedon flange 38 may be placed around the upper end of the rod to receive the wear. This sleeve may be made of metal or any other suitable material such as rubber or rubber hose, and may be replaced when the tool is withdrawn from the well, in case the sleeve shows wear. l

After passingi'down through the plunger head into the space 40 between rod 24 in the body I8, the major portion of the circulating uid is discharged outwardly into the well through passages 4| extending through the body above the cutter slotnl5. 'I'he remainder of the circulating fluid passes ldownwardly through the channels 38 in nut 28,'y and through grooves 22 into the cutter slot I5, wherein the fluid constantly washes the cutter blades to keep them free from accumulations of sand or mud. As will be seen from Fig. 2, the main discharge of circulating iluid through pasages 4l is directed toward the extremities of the cutters in expanded positions, so that during scraping or reaming operations, the uid constantly washes away the cuttings from the outer edges of the blades.

In the form ofthe invention shown in Figs. 1 and 2, it will be noted the ends 31a and 31h of the plunger slots 31 are formed by substantially vertical surfaces. If desired, as shown in Fig. V5, these end surfaces of the slots 31' may be curved inwardly as at 43 and 44 in order to increase the tendency of the circulating fluid to take an inward path of flow toward the plunger rod. l

1. A well reaming tool comprising a tubular body, a cutter mounted within a slot in the body. a vcutter operating plunger within the body and connected to said cutter, said plunger having a wall of the body above said slots and opening into the well, and means for discharging circulatr ing fluid downwardly within the body below'the last mentioned passage and into said slot.

2. A well reaming tool comprising a tubular body, acutter mounted in a--slot in the body, a cutter operating plunger within the body bore and including a head and a depending rod connected to the cutter, means forming within( said plunger head a iluid passage through whichcirculating iiuid is discharged into the space between said .wd and the body, said body containing a circulating fluid passage leading from said space through the wall of the body above said slot and opening .into the well and a passage through which circulating fluid is discharged downwardly from said space into said slot.

3. A well reaming tool comprising a' tubular body, cutters mounted in the body, a cutter operating plunger including an inverted cup-shaped head having a bore, a depending rod connected to said cutters and to the upper portion of said head, said head containing a fluid passage located below the connection between said rod and the upper portion of the head and through which circulating iiuid is discharged directly into a space between said 'rod and the body and inwardly toward the axial center of the body, and a coil spring encircling said rod and bearing against the lower end of the head outside said bore.

4. A well reaming tool comprising a tubular body, cutters mounted in the body, a body contained plunger including an inverted cup-shaped head having an inclined wall, a depending cutter actuating rod 'connected to the upper portion of said head and spaced from the lower portion of the head, and means forming within said inclined wall-of the head, a iiuid passage spaced from the wall of said body bore and through which circulating iiud is'discharged into the space between said rod and the body and inwardly toward the axial center of the body, and a coil spring encircling said rod and bearing against the lower end of said head.

5. A well reaming tool comprising a tubular body, cutters mounted in the body, a body contained plunger including an upwardly tapered inverted cup-shaped head and a depending cutter actuating rod connected to the upper end of said head and spaced from the lower portion thereof, and means forming within thev tapered wall of said head a fluid passage spaced from the wall of said body bore and through which circulating fluid is discharged into the space between said rod and the body.

6. A well reaming tool comprising a tubular body, cutters mounted inthe body, a body contained plunger including an upwardly tapered inverted cup-shaped head and a depending cutter actuating rod connected to the upper end of said head and spaced from the lower portion thereof, the tapered portion of said head containing a plurality of narrow vertically extending and circularly arranged slots spaced from the wallof said body and through which circulating uid is discharged downwardly and inwardly against the surface of the top portion of said rod contained within the plunger head.

'7. A well reami'ng tool comprising a tubular body, a cutter mounted within a transverse slot in said body, a cutter operating plunger within the body and including a rod connected to the cutter, said rod extending downwardly through a body bore directly above said slot, and means for conducting circulating iiuid through an open space between the plunger rod and the wall of said bore, straight downwardly around the rod into the top of said body slot.

8. A well reamlng tool comprising a .tubular body, a cutter mounted within a transverse slot in said body, a cutter operating plunger within the body and including a rod extending downwardlyV end of said body slot.

9. A well reaming tool comprising a tubular body, cutters mounted within a transverse slot in said body, a cutter operating plunger within the body and including a rod extending downwardly within and spaced a substantial distance from the wall of a body bore located directly above said slot to provide a iluid passage, and means connecting said rod with the cutters, the last mentioned means including a member carried on lthe lower end of the rod within said bore and having a pair of openings through which circulating iiuid is discharged straight downwardly through said bore into the upper end of said body slot.

JOI-1N GRANT.

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