US1843668A - Underreamer - Google Patents

Description

` Feb. 2, 1932.

F. c. FARMER UNDERREAMR Filed Maren A18, 1930 A TTORNEYS.

FitnNois C. FARMER, or Los' Y ik Los 'ANeELns, oAL1roi-ti\iin be safelyV subjected to heavy Patented Feb. 2, 1932 ANGELES, CALIFORNIA, essie-Noia TO `TOI-11T GRANT, OF

' L UNDERREAMER Application' inea nalen 1t, 1930. seriaii'N. 436,760.

i This' invention relates to an underreainer drill adapted for use in general*l in drilling operations whereverit is desired to'enlarge.

the diameter of the Well. borefbeneath "the lower end ofthe well casing. v

Amongtheobjects of the invention are'tol y being `shown inv the drawings., QJThese reprovide a tool of the character stated which will be an improvementup'on others -ofits class withl respect to'efliciency and dependability'of operation; one in which the vcjiu'sting elements may be more readily and'conveniently inserted, and removed after they have become' worn in order that "new-cutting 'ele'- ments may be inserted; and a general con.- struction which improves upon the prior devicesof theV` class with respect to various other' details. y j f f Among theobjects of the inventionl are -to provide improved means for' supporting the cutter shafts in such a manne'rthat they may strain during drilling operations. Y

lYet another object of the invention isi-to provide superior means for moving the reamel ing elementsA from anormal sheltered, retracted, inoperative position outwardly intocontact withthe portion ofthe well bore which isto'bereamed away.y y

Referring in detailto the accompanying drawings7 which illustrate what is at present deemed to be a'preferred embodiment of the invention, f 'f i `Fig. 1-is a side elevation of the complete tool mounted inposition for use, laportion of the view beingshown in mid-section. Fig. 2' is a side elevation ofthe centrall portion ofl Fig. 1, looking at said Fig. 1 from right to left, Y 'the cutting' elements being shown in afdiflerentvposition. f f f `Fig. 3 isxa sectional detail-showing'one of thecutting elements inthesame position as in Fig. 2.5 v

ytig. 4 isa cross sectionon line of Fig. 1. f i' u F ig. 5 is' a cross'section on line5-'5 of li`i,g.2l"V

Figu is a sectionaldetail of one of the reaming elements together'wi-th its shaft and adjacent parts. Y 'y f Referring in detail'V to-thedrawi-ngs, thel it is united to the usual tool joint'13.` The A.body portion of the tool is provided with a l 'plurality ofrecesses 15whichl are equally spacedfrom each other, three of said recesses cesses are eachad'apted to shelter one' of fthe composite reaming elements 16 which will laterbe described. ySaid recesses 1 5 are desirably,"y as viewed in cross section7 of a broad shallow nature as shownin Fig. 5 to avoid clogging, but the'invention is not limitedv to 'any particular shape of recess 15.

Each ofthe composite reamers 16 com prises a main central cutter 17 a frusto-coni cal upperv cutter 18 and a cylindrical-lower Icutter19,the central cutter 17 being bevelled at 20/adjacent to said cutter 19.17T-hese cut* The upper @mi of 'Shaft 22 is .provided .with

va flattened head 23 lwhereby,-by means of a pin-24, it is pivotally secured to the outer bifurcate'd end "of a link 25,'th'e upper end of said link 25 being in turn'pivotally secured to the body of the tool by means of a pivot-pin or bar 26. Each link 25 hasa swing through a limited arc, the upward rmovement of said 4link being 'limited by a shoulder 27 which is positioned toy arrest the movement of. said link after thepivot pin f ,tool is provided with a cylindrical bodyfporl Vtion 10 yhaving a shank portion 11 whereby 22 whereon they f 24 has reached ya point kslightly lalcove the level'o'f thepivot-pin 26. 'The outer end portion'of said link isv preferably provided with a curved face 29.V f f f The inner end portion of' saidA link is 'pro- "vided with a curved face 30;` These. curved faces 29 nand 30 are formed as a'rcs having Lforth'eir respective centers the pivots A24and 126.r The face is shaped to have a working lit upon a curved facev or recess81 formed 'at the upper end'of the recess 15 in order to provide an abutment to support' thelink "and relieve pressure from the pivot rpin y26 during reaming, as will hereinafter more fully appean At the lower end of each cutting device 16 is locatedva follower whichlis seated with el. l

a working lit in a circular recess or pocket 36 provided therefor in the body portion of the tool beneath the main recess 15. rlhe lower end of follower 35 is recessed at 35a to receive a compression spring 37. The upper end of follower 35v is recessed at 352) to rece'ive'vthe lower portion of shaft 22 which projects beneaththe composite cutting element 16 mounted thereon. This recess 35?) is widened toward its mouth so as to permit 'the yshaft 22 to swing from one to the other of the positions shown in Figs. 1 and 3.`

Longitudinally through the entire tool eX- tends a water supply passage ed At the lower end of the tocl a fish-tail bitfll is shown attached by a conventionalshank a2, or other drilling n ieans'inay be substituted for said fish-tait bit. With said passage 10 communicates-radial ducts or. passages 413, there being a passage. 413.; tofsupply waterto eaclrof the Inainrecessesl., A .Y I

YReferring to; further details regarding the 'means for pivotally attaching the linlis 25,

each of the VpiVQt pins of the links 25 fits -iirto a hole. 2671, provided therefor as indi-l cated inFig. 41, said hole being bored in the direction of a chord with respect tothe cylindrical body-of the tool,'but not being drilled quite-through vthe tool', there being a diavmetricallyreduced hole 262' which leads from thebase. of hole 26h to the adjacent side of -theitoo1- f f Thepin, 26 is driven tightly into the hole 261i sothat it wilt not be accidently displaced. -Vllli n 'it-is, desired to remove the pin 26, a

n mail orothor suitablotool is inserted through the hole 26a' and is then driven against the .ond olfI Said pnin order to loosen 'it'.

Afterv the/pin has thus been loosened it may. readily be removed permitting the link 25- together with shaft 22 and composite figeaming element 16 to. be completely` remoyed soI that zthe cutters 19, 17 or-18, may one. or all be removed and replaced;withl new cutters,

. 1in addition, toJ the ducts or passages 4:3 which havealready been described, addition- .al ducts orfpassages 5 0 are provided, one vof 'lower end-portion otsad` roces-S in. order to v.supply liquid pressure thereto from. the pas- ;Slg'e 410; thus to` aid the Spring iii-moving '.thereamlg elellnt 1,3 up tothe operative yposition,shown in Figli The upper passage lili-is,desi-rably madel smaller than the lower o ssaoe 50because said lower assaoe is desig-ned to, freely supply hydraulic pressure beneath tho follower 35but the u )per l P sage L13 will perform its cleansingl function morel effectivelyifg Water. passes 4therethrougi1 in morerapidly moving stream.

lessees The spring element 37 which has already been described, comprises a spring` of as greatacompressive power as can be used'with` out interfering with the lowering of the tool into the well, that is to say, the rotary reamu ing elements 16 mustnot be forced Jtoo violently into .engagement withftheisides of the welll casing and yet the spring 37 should be strong enough to b e depended upon to move said elements up to the operati-ye "position when said spring` isA aided by the hydraulic pressure supplied through passage 50 beneath the follower 35.

The frustrofconical cutter 18 around its baseportion is ofthe same diameter as the main Cutter 17, and normollyseats uponfthe yupper end; of sai-d cutter17. This construction adaptsthe reaming element as@ ywlfiolie to smoothly and effectively engage the ignaterial to be roamed. as eachreamging device Y isforced upward: to its operative; position. A

The short cylindricalcutter; 19 isv of' a smaller diameter than the mehr cutter 17 in order that said :cutter 19i'may, as ,nearly as.

possible .llf the upper end of the roeoss and may therefore, more .effectively koop saidrecess from becoming clogged up with materials detached vby, the ream-ing operaertending therearound filled with a pack-ing of anyapproved kind, in, orderto causevv the hydraulic pressure belowf the follower tofact thereupon effectively.

vided adjacent its lower end witha deepened lportion15a in order tofsa-feguard against 1n operation, the tool is 'lowered into vthe well casing and as therotary roaming elements 16 enterlthe top `of the wellcasing they ,areinanually depressed, if need be, against the opposition ofsprings37 in order that the 'toolmaybesmootyhly fedy into the well; cas- The tool Visf-then completely lowered into the well Yuntil the reaming elements 1 6 arrive at the position to. beA used for underreaming. Then liquid pressure is supplied through the maiii,passage 10v andg ductl 50 thus to aid the spring 37 inraising the follower; 3,5,y of" eachv of said. reainingdevices 16,

.thereby foroiI-15-tY Marthe-'drill shafts. y'22410 the position shown in Fig. 1 wherein the pivot U in4 theouter portion; of each link25occu 'The follower 35 a circularvr recess- 3511L loo of the recesses 15 isdesire-bly,proi the other end portion ofsaid link.

pies a higher position than pivot 26 through position of the links the upper edges of the links abut against the shoulders 27 while the inner ends of said links rest aga-inst the` face 30 provided therefor. Hence when the tool `is'rotated the reaming elements 16 are supported in avery substantial manner attheir upper ends and no mattery `howrheavy a force is applied to them in a. radiallyinward di' rection, they maintain their operative position by reason of the pivot pins 24 being positioned above dead center with relation to the pivot pins.

When a follower 35 is inthe depressed position illustrated in Figpk,4 the pressure of the spring37 thereagainst is the greatest.

n Therefore, since said spring safeguards against the follower becoming stuck fin its most depressed or starting position, the

springvand hydraulic pressure means cooperate to improve thefunctioning of the device. Y

Claim:-

An underreaming tool comprising an elon` gated body portion adapted to be lowered through a well casing, a cylindrical cutter mounted adjacent said body portion and po'- v sitioned to perform an yunderreaming operation7 said cutter being mounted upon ay shaft which extends lengthwise of said body, a

link pivotally connecting said shaft with said body, a spring to force said shaft'length-v` wise of said body and thereby cause said link to force said shaft radially outward from said body, a follower against which said spring operates to move said shaft in the direction of its length as aforesaid, and means to supply hydraulic pressure to said follower to supplement the aotionof said spring thereagainst. v

In testimony whereof I hereunto aiix my signature.

5 FRANCIS C. FARMER.

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