US2642267A - Apparatus for initiating and drilling deviating curved bores from existing vertical wll bores - Google Patents

Description

June 16, 1953 J. A. ZUBLIN APPARATUS FOR INITIATING AND DRILLING DEVIATING CURVED BORES FROM EXISTING VERTICAL WELL BORES 5 Sheets-Shet 1 Filed Jan. 17, 1951 JhAZMha a W ATTORNEYS June 16, 1953 J ZUBLIN 2,642,267

APPARATUS FOR INITIATING AND DRILLING DEVIATING CURVED BORES FROM EXISTING VERTICAL WELL BORES Filed Jan 17, 1951 5 Sheets-Sheet 2 v r lllfflllllllllllll pl!Ill!!!lllIlllfllIllll/ll/IfllIll/f!llIll/IIIIIIll/IIIIIfl/lfllll/f'lIllll/fIl/I/IA Ill 8 VII II! as VII/IY \QHW IIIIIIIIIII IIII i:

III III! I i lllllll'lii ATTORNEYS J1me 1953 J. A. ZUBLIN 2,642,267

I APPARATUS FOR INITIATING AND DRILLING DEVIATING CURVED BORES FROM EXISTING VERTICAL WELL BORES Filed Jan. 17, 1951 B SheetS-Sheet 5 JMIMW ATTORNEYS Patented June 16, 1953 UNITED STATES PATENT OFFl-(ZE.

. 254L267 1 APPARATUS FOR- INITIATING AND DRILL- ING DEVIATING CURVED BORES FROM EXISTING VERTICAL WELL BLORES John. A. Zublin, Los; Angeles, I Calif;

Application January 17, 19'51, Serial No; 2063364 The present invention relates toz-an. apparatus forinitiating and' drilling lateral curvedzbores: detrvi'ating from an existing: vertical wellibore;

More particularly; it is an o.bject: and. purpose ofthe presentinvention to provide an apparatus whichis particularly efficacious inothedrilling of lateral bores deviating; from: existing .wellib'ores in hard formations such as. limestone and like hard formations. p

More: specifically, it1is; an: obj ect; and. purpose. of the. present invention to provide an apparatus which: constitutes amimprovementt-on: an appara tus hereriofore developed. Icy-me; such, for: exam;- ple; as disclosed; and. claimed in. my Unitedi States Batenti2;382,9.&3z The prior: apparatus developed by; mehas. great; value. and. is. particularly: well suited for useirr drilling, inrelatively. softform'ae tions. Hwever; limestone; formations? which are formed: in nature: asga solid block are: difficult to penetrate and; the improvements: presented-by the present: invention renderthe drilling of; deviating bores, in such formations economical and: practicali.

' In its more specific: aspects; the-presentinven- .tion contemplates pressing a drilling, bit' sidewardlyinto the? walk of. an existing well.- bore with energy furnished by reaction ofa-nelongated normally curved. resilient? flexible drill guide. forcibly flexed to: a. lesser curvature: within the: existing well boreand inaugmenting the :forcewit-hwhich the bit-is pressed sidewardlyintothe-wall of. the exist ngwell: 'borerby the; deflecting forces" imposed; on the bit as. the resilient drill. guideis lowered; over. the inclined: surfaceoi, av whipstock insertedin thewell borein; advance ofthe normally curved. flexible resilient. drill guide;

Further and: more. detailed; objects and; advantages of the. invention; will become apparent, as the; description) proceeds,- V which will be. given by reference to -the accompanying drawings, wherein Figure 1.is.a side. elevation. of one formofi an paratus showingparts, broken. away tor, clarity.

Figure.- 2 is. a. front. elevationiof. theilower. portionoii the, embodiment. of'Figure 1.v

Figure 3 is, a planview taken on line 3-3 of Fi ure 2'.

Figured isa crossesectional view albngtheline 4j-4 of. Figure 2; V

Figure 5 is a side" elevation with parts shown in section at a second embodiment ofan apparatus oonfcccming tothe present invention.

Figure Gisa fronirelevational view-of the-lower portion of the embodiment shown in Figure 5:

Figure 7 is: atransverse sectional view on the 1ine T-'l orF-igure fi taken imtlie direction of the arrows;

' 2=Glaims. (Cl..255.--1'.6)

Figure 8 is: aside elevation. with-parts; shown in section of a third embodiment of. apparatus; cor:- responding to the present. invention.

Figure 9' is atransverse sectional; view: on the line 99 of'Figurei8k taken imthe direction of the arrows.

Figurel'O is a sideelevationaliview With parts shown in sectionof a fourth embodiment of; an. paratus conforming. toe the invention:

I Figure. 1'11 is a d'etailedicrosseseotional view of the apparatus of Figure I05 showingz'the: position a-ssumed bythe- Vfi-fiOlJSielEIIIBDItSTQf? the apparatus during initiating of. the: drilling. of: a. deviating bore. 1

Figure 121 is; a. transverse sectional. viewon. the line l 2-42 of Figure 10 taken inithe directionof the arrows;

Figure: 13': is a: transverse sectional. view. onthe line l3l3 of Figure 10 takeninlthed'irection of the. arrows;

Referring" to the embodiment; oh the invention illustrated inFigures .1 to 4.; thezcombinationapparatus shownin Figure 1 is-adaptedzto: be carried in its entirety at the lower endloffasubstantially rigid drill string such as indicated at I 0 in Figure 8, which substantially rigid: drill. string: extend'seto the surface -of the-well and is adapt'ed to be. driven Figurelembraces the flexible n0n-resilientidrill string-section- I l", the-upper end ofwhich isoroken 'figurationoi' thedrill guide; [:2 is; such as to'canse away in Figurel but which it: will be understood is; connected to the rigid drill string in. the same manner that the flexible non-resilient drill string section bearing the same reference numeral H in Figure 8-- isillustrated in that figure as con nected to the normally rigid drill string Hit The flexible'non resilient drill string section ll may" preferablytake the form of the non-resilient flexible drill pipe more par ticularly disclosed in my priorUnited States Patent 2515366 issued on July= 18, 19501 It will-be appreciated thati depending upon the length of the deviating bore desired to be drilled; one or more non-resilient flexible? drillpipesections l=lmay be employed in the apparatus. g Below=the fi'exiblenon resili'ent drill string section l 'l thereis positioned the normally curved flexible resilient" drill guide I92 It. will be under stiood that: the. normal: unstressed: curved: com

the: same; to? be; flexed to a. substantially lesser curvahira an insertion: into, an. existing; well; bore to thereby storezenergn in saididrill guide: effective tosf'orce the; bit, is; carried: at t-he: lower end: of the drill guide I2 sidewardly against the wall of an existing vertical well bore.

The flexible non-resilient drill string section I I in reduced form as indicated at Ila in Figure extends downwardly through the interior of the hollow normally curved flexible resilient drill guide I2 and the reduced portion I Ia of the flexible non-resilient drill string section I I constitutes the rotating means for driving the drill bit I3 to which it is connected at its lower end. Both the flexible non-resilient drill string section I i and the reduced extension. I Ia thereof are made up of small independent units interconnected by dovetailed slots in the manner more specifically described in my United States Patent 2,515,356 hereinabove referred to. The normally curved flexible resilient drill guide I2 is preferably of the type disclosed in my United States Patent 2,515,365 issued July 18, 1950. This normally curved flexible resilient drill guide is formed of tubular metal pipe having a slot through the wall thereof extending in a generally helical path along and around the pipe. The sides of the slot are provided with intermeshing and interlocking dovetailed teeth. By way of illustration it is advantageous to employ a normally curved flexible resilient drill guide I2 which has an over-all length of about It feet and a curvature in its unstressed condition that lies on a radius of about 16 feet. Under such conditions the height of the are formed by the guide when in unstressed condition will .be found to be about 30 inches. When such a drill guide is inserted into a well bore, depending somewhat on the diameter of the well bore, the lower end of the drill guide will be forced against the side wall of the vertical bore in the absence of the augmenting force provided by the whipstock under a pressure of the order of from 100 to 700 pounds.

The specific manner in which the reduced portion Ha of the flexible non-resilient rotating drill string section II is mounted for rotation within the outer normally curved flexible resilient drill guide I2 is illustrated in greater detail in my copending application Serial No. 189,591 filed October 11, 1950, now Patent 2,585,207.

In the embodiment of the invention shown in Figures l-4, the lower end of the normally curved flexible resilient drill guide I2 extends through the casing-like collar I I at the upper end of the whipstock member indicated generally at I5. The opening I6 through the casing-like collar I4 is preferably in this embodiment slightly inclined from the vertical axis extending through the whipstock member I5 and the opening I6 is of a b diameter only slightly greater than the diameter of the normally curved flexible resilient drill guide I2. The arrangement is such that the bit l3 positioned below the casing-like collar I4 will not pass through the opening I6. Thus the entire whipstock member I5 issuspended from the drill string and may be lowered into and withdrawn from the well with the drill string. The lower end of the whipstock member I5 carries the fishtail bit-like member l1 and the length of the intermediate coupling I8 will determine the elevation from the bottom of the well at which the inclined face I9 of the whipstock member I5 will be positioned. It will be appreciated that when the drill string is lowered into the well it can be oriented to insure the drilling of a deviating bore such as indicated at 20 in Figure 1 in any desired azimuth and the fishtail bit-like member I I when it strikes the bottom of the Vertical bore will act to hold the Whipstock 4 member I5 in such desired oriented position. The screw 2i is employed to interlock the lower end of a normally curved flexible resilient drill guide I2 and the casing-like collar I4 so as to hold the bit I3v substantially wholly within the the teeth of the cones 22 of the bit I3 are held out of contact with the walls of the well bore 23 as the apparatus is inserted into an existing well bore thereby avoiding wear on the teeth and unwanted gouging against the side wall of the existing vertical well bore. When the fishtaillike bit member i1 carried at the lower end of the whipstock member I5 strikes the bottom of the existing vertical Well bore, the release at the surface of the well of the weight of the drill string shears the pin 2| which allows the normally curved flexible resilient drill guide I2 to be lowered through the opening I6 in the easing-like collar Id and to advance over the inclined surface I9 of the whipstock member"). It will be observed that the bit I3 carrying the cones 22 is thus forced against the side wall of the well bore I3 by the energy stored in the nor= mally curved flexible resilient drill guide I2 which has been forcibly flexed to a lesser curvature by insertion into the well bore which is augmented by the wedging forces created through the advancement of the drill guide I2 over the inclined face I9 of the whipstock member I5. It will be appreciated that the release of weight of the drill string at the surface of the well will insure the creation of very substantial augmenting forces as the drill guide l2 moves over the inclined surface I9 tending to force penetration of the formation by the driven bit I3.

The several embodiments of the invention have in common the feature of augmenting the lateral directing force imparted to the bit by the energy stored in the normally curved flexible resilient drill guide I2 through passage of the latter under controlled pressure over the inclined surface of an associated whipstock.

Referring to the embodiment of Figure 5, it will be observed that the flexible non-resilient drill string section II'a is of substantially lesser diameter than the normally curved flexible resilient drill guide I2 so that the flexible nonresilient drill string section I Ia can extend downwardly completely through drill guide I2 as indicated in dotted lines and be connected at its lower end to the drill bit I3a. In this embodiment there is provided an elongated casing or sleeve 24 carrying a collar 25 at its upper end. The opening 25 in the collar 25 has a diameter only slightly greater than the diameter of the flexible non-resilient drill string section Na and thus considerably less than the outside diameter of the drill guide I2. The arrangement is such that the upper end of the drill guide I 2 abuts the shoulder 21 of the collar 25 and prevents upward withdrawal of the drill guide I2 through the collar 25. The sleeve 24 is substantially longer than the over-all length of the drill guide I2 and the bit I30. so that the sleeve 24 completely encases the guide I2 and bit I30; during insertion of the apparatus into an existing vertical well bore. It will be appreciated that the friction developed between the casin 24 and the normally curved flexible resilient drill guide l2 created by forcibly flexing the drill guide I2 from its normally curved configuration to the straight configuration occupied thereby in the position shown in Figure 5 will be wholly adequate to ti'onshipshown in Fig-ure 5' during theinsertion of" the apparatus intoan existing well borer It Will'be'further observed that thebit l3a= carrying cones 22a is house'd within the hollowcasing: 24 during insertion of the apparatus in the verti car well bore sothat-contact of'the teeth of the cones with the wall of the vertical well bore is completely'avoided. I

A portion of the wall of the casing 24: near the bottom thereof is cut away as-indi'cated: at 2'8 to provide a-- window through whichfthe bit l3a, the drill guide 1-2 and the flexible noneresilient drill string section Ha may be; projected. Opposite the window: providedv by the cut-out portion; 28- isdisposed the inclined surface 28 of they whipstock' member 30 welded: as indicated at 3] to the casing 24; The whipstockg member 3-0 is connected through coupling 32'. with the fishtail-like bit member 33: which functions in altogether a similar manner to: the functioning of the fishtail-like bit member H of" the embodiment: of Figure l. Rib- like members 34,35 and 36 are welded to the outer wall= of the casing; 24 ("see Figure 7:) and serve the two-fold purposeaof acting as sled runner-like members during the insertion of the apparatus intoan existing well boreand-iurther actin conjunction: with the fish:-

tail-like bit member 33-" inholding: the apparatus in at desired position of orientation during; the drilling of a deviating bore.

In the embodiment exemplified: by Figures: 54 no shear'pin: is requircd; The entire combination is insertableinto and Withdrawable: front a well here as a unit; In this embodiment when the fishtailelike bit member" 33- strikes the: bottom of the existing well bore, the release of weight on: the drill string at the surface of the well will be suihoient to force the normally curved flexibleresilient drill guide l-2 carrying the bit 13 down through the upper closedi portion of the casing 24 and over the inclined surface as oflthewhipstock member. 353., As soon as the normally, curved flexible resilient drill guide. I12: begins to emerge through the window provided; by theJcut-outportion 28', the energy storedlthe'reindue to. itsl-havi'ng been flexed 't'o a lesser curvature isreleased and" effected'to force the bit [3a against. the. side Wall of the existing we'll; bore and the force thus applied; to. the bit is. augl ment'edlby the wedging actionoccasionedlthrough passage of the drill" guide f2 downwardly :over the inclined surface 29 of the whipstock; The embodiments of Figures 5-7 have some advantages over certain other embodiments herein disclosed in that no elongating strain is placed on the normally curved flexible resilient drill guide 12 in withdrawing the apparatus from the well bore which of course is not the case with the more simplified embodiment of Figure 1 which has, however the advantage of being more economically produced.

The embodiment of Figure 8 presents a variant of the embodiment of Figure 5 in that in Figure 8 the casing 24a is provided with a much larger cut-out portion 28a than is the case in 24 of Figure 5. Thus in the embodiment of Figure 8" the normally curved flexible resilient drill guide [2 is held in interlocked relationship with the casing 24a by the shear pin 3'1, the arrangement being such that the drill bit I3b is held wholly within the confines of the circumference of the casing 24a when the apparatus is inserted into an existing vertical well bore. When the 'fishtail-like bit member 38 strikes the bottom a oii'the existlng vertlcal bor the pin 31 is sheared ofij the weight of the drill string and the bit I 3 together with the drill guide l2 then pass downwardly over the inclined face 39 of the whipstoch member 40 with the result that the laterals force upon the-bit l3b represents the energy stored" in the drill" guide I 2 as; augmented bythe wedging force incident topassing the same over the inclined surface 39 of the whipsto'c'li- E0 When the apparatus of the embodiment of Figure 8 withdrawn from the well, the coupling member 4* l carries laterally extending ribs 42 which engage the shoulder 43"0f the collar 25w at the upper end of the casing 24a.

Thus; inthis embodimentno longitudinal strain is imposed on eithertheflexible nonre'silient drill string sect-ion l il or'the' drill guide l2 during' withdrawal of the apparatus' from the well since" the coupling 4 lis directly connected to the lower end of,-the substantially rigid drill Referring to theembodiment illustrated in Figures/ 110-13 inclusive, it will be; observed that this: embodiment is primarily intended for the drillingof relatively 'sharp deviating bores from a vertical well" bore; that is, deviating bores of no greater length than the length" of the normallycurved flexible resilient drill guide l2. It will be understood that in this embodiment an inner: flexible-non-resilient-drill string section of smaller diameter than the drill guide l2- extends down througntne drillguide l2 for driving the drill bit l3c. The upper end of the inner flexible norr-resilienti drill string member is connected through the; tubular" rigid coupling 44 to the lower end of the substantially rigid drill string H! The rigid: tubular coupling 44 isprovided Wlththe annulanshoulde'r'45' for a-purpose which will be. presently: described. The casing 24bin this embodiment ispro'vid'e'cl with an extended cut-out portion; 28b and wi th a collar 255 at the movement with respectto the casing 24b. 'The lowen end of the casing 24b is provided with a tubular" collar 4 8* having a-key-way 49 extending along one side: of the tubularopening 5t.- An

elongated coupling member 51 interconnects the 'wl' lipstock member 4i. and the fishtail-like bit member 52. The elongated member 5| is provided with a key 53 which moves through the keyway 49 in the collar 48 and prevents relative rotation of the whipstock member 4! with respect to the casing 44b. The member 5| is of a length substantially equal to the over-all length of the casing 241). When the fishtail-like bit member 52 strikes the bottom of the vertical well bore due to the fact that coupling 44 can move down through the tubular collar 25b for a distance equal to the space between the top of the collar 25b and the shoulder 45, the shear pin 46 will be sheared off by the limited down- I ward movement of the drill guide l2 with respect to the casing 241). When the shoulder or tubular coupling 44 strikes the top of the collar 25b no further relative longitudinal movement between the drill guide l2 and the casing 24b will occur. move downwardly around the whipstock member 41 and downward pressure by weight of the drill string through shoulder 45 on the top of the However, the casingl24b is free toshown in Figure 11.

collar 251) will force the casing 24b downwardly over the whipstock 4! and cause the latter to move into a position between the flexible drill guide 12 and the casing 24 as more particularly As the casing 241) and the dl lll guide 12 move downwardly with respect to lth'e whipstock 41, the bit l3c is forced laterally linto the formation by the energy stored in the (drill guide 12 as augmented by the passing "thereof over the inclined surface 54 of the whipstock 41. In this embodiment when the apparatus is withdrawn from the well, the upper end of the drill guide 12 strikes the lower face of the -collar 25b and thus there is no longitudinal strain on the drill guide 12 during withdrawal of the apparatus fromthe well- From the foregoing it will be appreciated that the basic method of the present invention is susceptible of being practiced by any one of numerous apparatus embodiments. In all instances the laterally directing force applied to the bit represents the energy stored in a normally curved flexible resilient drill guide which has been forcibly flexed to a lesser curvature as augmented by the additional forces developed through passage of the drill guide under pressure downwardly over an inclined surface of a whipstock, through which medium lateral deviating bores may be effectively drilled in hard formations of the character of limestone and the like.

Having-thus described claim is:

1. An apparatus adapted to be carried in its entirety at the lower end of a rotary drill string for drilling curved bores deviating from an existing well bore, comprising in combination a 1'0- tatable flexible drii'i string section made up of a plurality of units so interconnected as to per mit of limited relative angular movement of adjacent units in all directions, a normally curved metallic flexible resilient drill guide surrounding at least a portion of said flexible drill string section said guide having a slot in the wall thereof extending in a generally helical path around and along said guide, the upper end or" said flexible drill string section being connectable to the lower end of the rotary drill string, a drill bit carried at the lower end of said flexible drill string section for rotation therewith, an elongated sleeve surrounding at least a portion of said rotatable flexible drill string section and said flexible resilient drill guide and insertable my invention, what I therewith into an existing well bore, a whipstock having an exposed camming face secured at the lower end of said sleeve said normally curved flexible resilient drill guide being effective to exert pressure on the bit in the same direction as that of the wedging action of said whipstock whereby upon relative vertical movement of said bit and said whipstock the bit is forced sidewardly, by the wedging action of said whipstock, and the action of said normally curved flexible resilient drill guide against the wall of the existing bore to initiate and thereafter drill a deviating bore.

2. An apparatus adapted to be carried in its entirety at the lower end of a rotary drill string for drilling curved bores deviating from an existing well bore comprising, in combination, a rotatable flexible drill string section made up of a plurality of units capable of limited relative angular movement in all directions; a sub having a laterally extending shoulder carried at the upper end of said flexible drill string section, the upper end of said sub being connectable to the lower end of a rotary drill string; a drill bit carried at the lower end of said flexible drill section; an elongated rigid sleeve substantially entirely surrounding, within the confines of its circumference, said flexible drill section, sub and bit during insertion of said apparatus into an existingwell bore; a collar carried at the upper end of said sleeve for engagement with said shoulder of said sub when said flexible drill string section is raised to permit withdrawalof said apparatus as a unit from a well bore; and a whipstock having an exposed camming face carried at the lower end of said sleeve.

JOHN A. ZUBLIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,814,601 McCaskey Sept. 2, 1919 1,886,820 Lee Nov. 8, 1932 2,170,284 Eastman Aug. 22, 1939 2,207,920 Hughes July 16, 1940 2,296,161 Hall, Jr Sept. 15, 1942 2,336,338 Zublin Dec. 7, 1943 2,338,788 Walker Jan. 11, 1944 2,498,159 Gammill Feb. 21, 1950 2,506,799 Livingston May 9, 1950 2,571,644 Zublin Oct. 16, 1951

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