US2238998A - Expansive reamer - Google Patents

Description

April 2z, 1941.

2 Sheets-Sheet l A J. GRANT EXPANS I VE BEAMER Filed Feb. 20, 1939 April 22, 1941.

y J. GRANT 2,238,998V

EXPANS I VE BEAMER Filed Feb. 20, 1939 2 Sheets-Sheet 2 Patented Apr. 22, 1941 UNITED STATES PATENT oFFicEl EXPANSIVE REMER John Grant, Los Angeles, Calif.

Application February 20, 1939, Serial No. 25'7i426' 3 Claims. (Cl. Z55-76) This invention relates to expansive well reamers; and it is among the objects of the invention to produce an effective and rugged reamer of large expansive capacity; to produce such a reamer in such form and of such strength and ruggedness that it can utilize, and will withstand the forces resultant from the use of, roller cutters; and further to produce such a reamer of large expansive capacity and cutting efficiency, which is actuated by hydraulic pressure and in which the cutting action of the mud laden circulation fluid is minimized. It is also an object of the invention to produce such a tool as herein referred to in simple and rugged form. And

there are many other objects and corresponding y accomplishments of the invention which, together with the foregoing, will be better understood from the following preliminary discussion and specific description of illustrative forms embodying the invention.

In the past expansive well rea-ming tools using blade type cutters, sometimes known as wall scrapers, have been designed to have an expansive capacity relatively large as compared with the more limited expansive capacity of the expansive reaming tools which are commonly known in the trade as underreamers and commonly use cutters of the roller type. These large expansive tools have commonly used expansive cutters of the blade or scraping type. They have commonly been actuated by hydraulic pressure. But their serious limitations have been due to their inability to utilize roller cutters with their accompanying superior and dependable cutting action, to their relative weakness of design particularly with relation to the thrusts and forces which would be imposed upon them if roller cutters were used, and to their lack of simplicity and ruggedness of structure with relation to their hydraulic actuation of the cutters, and as well their tendency to have their parts cut out by the abrading action of the mud laden circulating fluid. It may be stated as one general object of the present invention to overcome these priorly encountered diiiiculties. Among these objects I may, without minimizing others, particularly emphasize that of providing a tool using roller cutters but having large expansion. The prior blade cutters have large expansion, but they wear so quickly that they cannot be depended upon to enlarge any substantial footage of hole in hard formation to any definitely determinable diameter. In this connectlon. the object of the invention is to attain the desired expansion in a tool utilizing roller cutters. so that the enlargement of the hole to a definitely predetermined size can be relied In one aspect of my present invention, it may be regarded as an improvement upon the type of hydraulic cutter actuation which is the subject-matter of copending application Ser. No. 167,389, led October 5, 1937, by James J. Santiago. My present invention utilizes certain of the fundamental features of structure and function shown in said Santiago application, and further improves `upon that prior structure by simplifying the interconnection between the hydraulically actuated plunger and the expansively movable cutters, by making a part of the plunger directly contact the cutters both for purposes of their expansive movement and for forming an abutment for the cutters when expanded. And further, as compared with the type of tool shown in said Santiago application, my present invention further improves the mounting of the cutters, vparticularly as to solidity and strength and ability to take the thrusts and forces which are developed upon roller cutters.

The invention in its various aspects will be best understood from the following detailed description of certain illustrative and typical forms of expansive reamer illustrated in the accompanying drawings in which Fig. 1 is a vertical central longitudinal section of an expansive reamer illustrative ofthe invention;

Fig. 2 is a fragmentary elevation of the same;

Fig. 3 is a section taken on line 3-3 of Fig. l;

Fig. 3a is a cross section on line 3cr-3a of Fig. 1;

Fig. 4 is an enlargement of certain portions of the sectional view of Fig. 1;

Fig. 4a, is a similar view showing the parts in contracted position;

Fig. 5 is a diagrammatic perspective showing the inner end of acutter arm; l

Fig. 6 is a similar fragmentary section showing adaptation to a diffe-rent type of roller cutter, the cutter in this view being shown in contracted position; and

Fig. 'l is a section showing adaptation to another type of roller cutter.

In the drawings the tool is shown as having a hollow body IIJ adapted at its upper end for attachment to a sub, or drill stem or the like, indicated at Il. In its upper part this body Ill has a main plunger bore l2 in which a plunger head reciprocates, indicated generally by the numeral I3. Immediately below the plunger bore I 2 there extends a somewhatl smaller plunger guide bore I4, in which the depending plunger I5 reciprocates. The lower end of the guide bore I4 opens into a larger body bore I6 which extends to a point near the lower end of the tool where the body carries the usual bit I'I. In the drawings this bit is shown as being integral with the body, although it need not be so.

t is preferred that a tool of this character have three cutters, and accordingly the body is provided with three cutter-receiving slots 20, of which the lower portions 2i are of suicient width to take the roller cutters hereinafter described, and the upper portions 22 are of narrowerjwidth and adapted snugly to take the thicknesses of the swinging cutter arms 23. As Ashown "in the present illustrative design,` the upper ends of the lower and wider portions of slotsuZI ektendto'the line shown at 26 in Figs. 1 and 4, this line also demarking the lower extremity of the narrow -upper slot portions 22. As shown inthe cross sections of Figs. 3 and 3a, the upper narrower slot lower ends of the narrow body slots 22. The purpose'of this arrangement, as will become more clearhereinaiter, is to provide certain shouldering faces on the surface oftheupper p art ofthat large body bore adjacent the swinging cutter'arms 23.. .In the design as here shown, the transverse Apivots .for the swinging cutter arms Y2? are mounted approm'mately at the level of the said shoulder 2l. And this shoulder 21, in such posi- Vtion relativeto the cutter pivots, also demarks the lowerend of'the'plunger guidenbore I4.

Each swinging cutter arm23 carriesatits outer end a roller cutter '321, of which the details and f variations will be consideredlater. At the instant it is sufficient tonote "that, the swingingarms of .i

the present illustrative tool have been designed to take expanded positions swung outwardly to about the 60 angle yshown for instance in Figs.

' 1 and 4, although this particular angle isfnot neci essary, and to take contracted 4positions hanging vertically downwardly in the body slots 20, as

' shown in '.Fig. 4a. It is thegeneral-purpose and function of the parts now'to bedescribedto cause and allow expansive and contractive movements of the cutter arms, and to ruggedly support the Acutter arms and cutters against all the forces and thrusts which are imposed upon'them.

The plunger head I3 shown in Fig. 1 is substantially similar to the corresponding plunger head shown in the said Santiago application, and

to it in itself I make no claim. This plunger head hasa relatively large hollow interior 35, and an upper preferably conical end 36 having two or more narrow'entrance slots-31 through which the circulation fluid flows downwardly and inwardly, and in restricted high velocity str eams'into the large plunger interior in opposed relation so that the high Yvelocities are broken up by interbe used.

extension of plunger head I3, and this plunger I5 plays in the plunger guide bore I4 with a sufciently close fit to guide the plunger fairly accurately and to enable it to form an interior central and common abutment for the several cutter arms, as hereinafter described.

At the same time, the plunger I5 lits bore I4 with suiiicient clearance that fluid circulation may be maintained through the clearance if desired, :as hereinafter explained. In the operation of the device lthe plunger I5 moves between its lowermost position shown in Fig. 1 and its uppermost position shown in Fig. 4a. To prevent the plunger from rising much beyond its uppermost position, any suitable motion limiting means may be used. In the present instance I have shown a stop sleeve lI depending from the sub II and adapted to form a stop to limit the upward move- 'ment of -plunger head I3 to a position that corresponds to, or a little above, the upper position of plunger I5 shown in Fig. 4a. To limit downward movement of the rplunger and prevent it from `moving on vdown and'locking the cutter arms in expanded positions, any suitable stop means vmay For instance in Fig. 1 stop lugs '4I are show-n on the plunger, engaging the shoulder 42 at the lower end of bore I 2.

The interior chamber 35 of plunger head I3 is continued on downwardly through plunger 'I5 by the plunger bore `42's. Thelower part of -thisbore is diminishedin size, as at 46 and loosely Vtakes the upper end of the circulation pipe 41 which is mounted at its lower end in vbore 43`in the'lower end of the body. From bore '4.8 circulation ducts, such vas 49 and 5U, lead off to deliver circulation to bit Il andoutwardlyjand upwardly under the cutters '30. The use of an interior central-circulation pipe, as here described, ob-viates-the necessity of carrying circulation to the -lower `part .of the body by Vpassages leading down through the l outer parts of the body, as is usually done in. tools vof vthe kind described here. Such circulationpassages materially weaken theibody at its slotted portion The central pipeobviatesall such weakening.

Bore 460i the plunger I5 is recessedjrat-a'to -provideanV annular channel in which packing may :be inserted if it is desired-not to have downward "circulation through the clearance in bore #I6-surrounding pipe '4`I. V.The'stop'sleeve '40 prevents plunger I5 from rising high enough vtolmove out the tool is otherwise'liable to move'the plunger u up outof proper engagement.

impingement of the streams. The back pressure set up by these restricted slots 3'I is the pressure which tends to force the plunger head I3 downwardly. The plunger head-carries apacking ring 38 engaging the wall of bore I2 to-prevent leakage direct ciwntvrd Before explaining Ythe details ofv the cutter 'mountings and abutme'ntsv I will first explain the modes of circulationthat may beha'd. As `s'hown in thedrawings thealower part of 'the plunger head VI3 has large Aopenings .i'fin its lwall, fso vthatV circulation Vmay pass from Ythe interiorfchamberf 35 .of the 'head into the 1 bore '.I 2 belowpackin'g'.' Ifxthe'se openings-55 are used, Ythen a part lof the circulation'passes idown through the annular 'clearance -around plunger I5 in Abore lidia'nd is delivered r`at the lower -end of bore I4 directly over-theinne'r endsfofwthe cutter arms "213, :and thus 'serves as'circulation to the immediate'vicinity o'f,orvr above, the lcutters. jI-Iowever I note particularly vthat the openings "V55 may be dispensedjwith, andi-the'walliftthe charriberr 35 "made solid, in `whic'hfcase there will be no circulation around the outside of the plunger.

As is seen in the drawings, the upper end of circulation pipe 41 communicates directly with the plunger lbore 45 and head chamber 35, so that circulation from the chamber interior takes place through that pipe to the circulation ducts at the lower part of the body. Furthermore the annular clearance around pipe.41 in plunger bore 45 also communicates directly. with bore 45 and head chamber 35, so that circulation may be maintained through that clearance if desired. This circulation, if used, discharges at the lower end of plunger I near, or directly under, the inner ends of the cutter arms 23, and thus discharges in the direct vicinity of the cutters.

Like the circulation around the outside of plunger I5, that around the outside of pipe 41 may be dispensed with if desired, by inserting packing in the channel 46a. On the other hand, if circulation is maintained around the outside of the pipe, it may either be comparatively small or large in quantity, as the clearance is made small or large. Either one or both, or neither, of the above circulations may be used; and if used they may be made to be of any desired relative volumes by constricting or enlarging the clearances.

In any case, regardless of which circulation passages are used, it will be seen that all of them are fed from the large interior chamber 35 of 62, Vand the walls Bl of the recesses bear closely the plunger head, and that that chamber can only receive circulation through the restricted ports 31. These restricted ports are preferably so dimensioned that their total area is less than the smallest total ilow area beyond the head chamber 35. For instance, if only the circulation pipe 41 is used for circulation, then the total area of ports 31 is preferably less than that of pipe 41, so that the highest velocities are set up at the ports '31 and substantial actuating pressure is applied to the plunger head, and also so that substantially all the cutting and wear due to high velocity streams is localized at ports 31.

Once the high velocity streams enter the large chamber in the plunger head, all high velocity flow ceases. From that chamber the flow, by whatever routes it travels, is relatively slow and quiet.

Each cutter arm 23 has in its inner end a recess whose back face 6| is cylindric and of a curvature to fit the cylindric face of plunger I5. This recess is so aligned in the cutter arm that its cylindric wall is vertical when the cutter arm is in expanded position, as shown in Figs. 1 and 4. The bottom 62 of recess 60 is located and shaped so as to t the conical end surface 63 of the plunger. In the expanded position of the arm the recess bottom 62 is below the swinging center of the arm on pivot pin 28, and the end portion of the plunger is somewhat relieved at 64 above conical surface 53 so that the conical surface 63 may keep in contact with recess bottom 62 as the arm swings between the expanded position of Fig. 4 and the contracted position of Fig. 4a. In the contracted position, shown in Fig. 4a, the conical seating end of the plunger may still rest on the recess bottom 62, although not flatly. When the plunger is forced downwardly by the hydraulic action, downward pressure of the plunger end on the recess surfaces 62 forces the cutter arms to the expanded positions of Figs. 1 and 4. In that position the lower end of the plunger seats on the recess bottoms against the cylindric surface of the plunger. By

this arrangement all the cutter arms are given mutually a solid internal backing against the central plunger so that inward pressures on the arms are sustained. In case the lower walls of the recesses B0, at the lower wall surfaces 62,

should break off or wear away, the previously explained stops 4l on the plunger prevent the plunger from moving on down below its proper lowermost position and locking the cutter arms so that they could not be swung downward for retraction. Retraction is effected by pulling the tool up into the well casing, the arms contacting the casing shoe and being swung down and in. When the arms are thus swung down they raise the plunger to its upper position.

In the expanded positions of the arms, their upper surfaces, at points outside the pivot centers 28, bear upwardly against abutment surfaces 65 which are located on the body at the upper ends of the body slots. In the particular design as here shown, where the upper surfaces of the arms are at an angle, the abutment faces 65 are likewise at that angle, so that flat seating is attained. The function of these abutment surfaces is to form a stop, located at one side of the pivot 28, to limit upward swinging of the cutter arm.

The stop lugs 68, with their shouldering faces B1, form other abutments at the opposite sides of the pivots 28 to limit upward swinging of the cutter arms. These stops are formed on the opposite faces of the arms at their inner ends, in such positions that their faces 51 bear outwardly against the faces 16a of the bore I6 when the cutter arms are expanded. See Figs. 3 and 4. These rotational stops being located opposite to the rotational stops $5, they take all or substantially all the thrusts which are generated by forces tending to rotate the arms upwardly, and thus take the resultant shearing stresses off the pivot pin 28. The major forces to which the cutters and cutter arms are subjected are upward forces, inward forces and circumferential forces. The upward forces acting on the outer ends of the cutter arms are here taken care of by the stops above described and also by the recess surfaces 6I bearing against the central plunger. These bearing faces and stops take off the pivot pins shearing stresses that would otherwise be placed upon them. The inward forces that would also otherwise have to be carried by the pivot pins are taken by the inward bearings of the arm faces 6l on the central plunger. Circumferential forces acting on the outer ends of the cutter arms are taken care of by the lateral bearing of the side faces of the arms against the side walls of the upper narrow portions 22 of the body slots 23. The cutter arms are thus solidly supported at their inner ends against all thrusts, and accordingly they can be made long enough to carry roller cutters at a considerable expansion diameter, and still carry all the thrusts to which the roller cutters located at such a cutting diameter are subjected in heavy service.

Various forms of roller cutters may be carried on the outer ends of the cutter arms, the particular form being dependent upon the service required. Figs. 1 to 4 show roller cutters 3l! arranged on axes longitudinal of the arms. As shown in Fig. 1, the outer end of the arm may be shaped to form a tapering pin 10, and the cylindric cutter body 1| has a corresponding bore. The outer end 12 of the cutter may be conical, and provided with cutting teeth, as is the cylin- Adric surf-ace.

The outer lend of `the cutter bears back; against an end-thrust .bearing ball 13. Near the inner end, the cutter may have bearing on balls 14 which, running in races 15 and 1.6 in the cutter and the bearing pin 1|, also serve to hold the cutter endwise on the pin.

In Fig. 6, a roller cutter 30a is `shown mounted on an axis pin 80 whose axis is at an angle to the length of the arm 23a and at right angles to the axis of pivot pin 28. Axis pin 8D is held in arms 8l at the outer end of the cutter arm 23a. And thrust washers 82 are provided at the ends ofthe roller cutter; the cutter runs on roller Y bearings 83, and the pin 8U is secured solidly in In Fig. '1 another type of roller cutter is shown,

a crown cutter 30h, Here again the cutter rotates on an axis longitudinal of the cutter arm 23h. Ther outer end face 85 of this cutter is frustowonical and has teeth 86. The outer part of the cutter has a central bore 81, and the inner part of the cutter a large bore 88. This `inner large bore takes a ball race ring 89 and ball bearings 90 which take both radial and end thrust. pins 9|. Between bores 88 and 81 the cutter has an internal iiange 92 which surrounds a reduced portion 93 `of an ,axial boss -94 integral with arm 2319. A retention screw 95 has its head 95 overlying the ange 92, and the screw is looked against loosening by the lock pin 51.

These and various other forms of roller cutters may be utilized, in fact any roller cutter form that can effectively be mounted on the outer end of such arms as I describe. My invention is f not limited to any particular form of cutter, being characterized by its provision of rugged and solidly mounted cutter arms' capable of giving large expansion regardless of the type of cutter used, but capable of utilizing roller cutters.

I claim:

l.. In an expansive reamer, an elongate body having in its upper portion a plunger receiving bore, a plunger with an upper plunger head reciprocabie vertically in said bore, said plunger fhaving a longitudinal bore open at its lower end and the plunger head being hollow and in cornmunication with the plunger bore, .a restricted fluid entry port in the upper end of the plunger n head, a packing surrounding Athe plunger head The race ring is held non-rotative by aeaaooe an opening through its wall below the packing, a circulation pipe mounted in the lower part of the body and entering the lower end of the plunger bore to receive fluid therefrom, the body having cutter larm receiving slots immediately below the plunger bore, and cutter arms pivoted in said slots and adapted to take the lower end of the plunger between them.

2. In an expansive reamer, an elongate tubular body having longitudinally extending radial cutter arm receiving slots through its walls, swinging cutter arms in said slots mounted to swing on pivots which extend transversely of the body and across the slots, said arms adapted to Swing from positions longitudinal of the slots to positions extending outwardly from the body, stop means on the body adapted to engage the arms at a point radially removed from the arm pivots and adapted to limit outward swinging of the arms, and other stop means on the arms at the opposite side of their pivots and adapted to engage the body to limit outward swinging of the arms, the pivoted ends of the arms having plunger receiving recesses which recesses have side walls lying in a cylindric formation when the arms are vexi'iended and which recesses also have end walls, and means in the body for swinging the arms outwardly, said means including a cylindric plunger movable longitudinally of the body to engage its end with the said recess end walls .and adapted to be received in the several recesses to form a central abutment between the arms.

3. In an expansive reamer, an elongate tubular body having longitudinally extending radial cutter arm receiving slots through its walls, said slots terminating at their upper ends at downwardly facing wall shoulders, swinging cutter arms ,in said slots mounted at their upper ends to swing on pivots which extend transversely of the body and across the slots near their upper ends., the arms adapted normally to hang downwardly from the pivots and to swing upwardly and outwardly from the body, each arm having a stop surface at its outer side near its top adapted .to engage a wall shoulder, each arm having a projecting stop shoulder adjacent its inner side near its top and adapted to engage the inner surface of the tubular body, the upper pivoted ends of the arms having plunger receiving recesses which have side walls that lie substantially vertically when the arms are swung outwardly and which also have bottom walls, and a downwardly movable plunger in the body adapted to engage its lower end with the several recess bottom walls and adapted to be received in the several recesses to form a central abutment bey

Images