US2084421A

US2084421A - Well drill

Info

Publication number: US2084421A
Application number: US689896A
Authority: US
Inventors: Jesse C Wright
Original assignee: Globe Oil Tools Co
Current assignee: Globe Oil Tools Co
Priority date: 1933-09-18
Filing date: 1933-09-18
Publication date: 1937-06-22
Anticipated expiration: 1954-06-22

Description

J. C. WRIGHT June 22, 1937.

WELL DRILL Filed sept. 18, 19:53

3 Sheets-Sheet 1 J. C. WRIGHT June 22, 1937'.

wELL DRILL sheets-sheet 2 Filed Sept. 18, 1933 a k .,HWWMW Q L A J. C. WRIGHT June 22, 1937.

WELL DRILL Filed Sept. 18, 1933 3 Sheets-Sheet 3 W .97 Y W Patented June 22, 1937 PATENT OFFICE WELL mm1.

Jesse C. Wright, Los Angeles, Calif., assigner to Globe Oil Tools Company, Los Nietos, Calif., a corporation of California Y Y e Application september 1s, 1933, serial No. 689,896

7 Claims.

This invention relates to well drilling tools, and relates more particularly to well drills for use in the rotary method of well drilling. It is a general object of the present invention to provide a practical efficient well drill having a simple eective bearing means and guiding means.

Another object of the invention is to provide a well drill that is operable to drill a. straight vvertical bore.

10 It is another object of the invention to provide a well drilling tool'having improved bearing and guiding-parts that are effective in guiding the tool to make a straight vertical bore and in stabilizing and steadying the tool during operation.

l5 Itis another object of the invention to provide a well drill having bearing and guiding parts that stabihmnd guide the drill to make a straight vertical bore without causing it to bind or stick in the bore.

It is another object of the invention to provide a well drill having guiding parts that engage the wall of the well bore at points above the cutting parts to guide the drill to make a straight bore, which guiding parts wear away as the cutting 25 parts become reduced in active diameter or size through wear so that they continue to be eiective in guiding the drill throughout the life of the cutting parts without causing the drill to jam or stick in the well.

It is another object of the invention to provide a well drill including guiding parts that are effective in stabilizing and guiding the drill without scoring or cutting into the wall of the well bore and without interfering with the free circulation 35 of fluid or rotary mud through the well.

40 the tool so that they may be easily and quickly replaced.

Other objects and features of the invention will be best and fully understood from the following detailed description of the invention, throughout 45 which description reference is made to the accompanyin'g drawings, in which:

Fig. 1 is a longitudinal detailed sectional View I. of a well drill embodying one form of the present invention. Fig. 2 is a transverse detailedsec- 50' tional view taken as indicated by line 2 2 on Fig. 1. Fig. 3 is an enlarged transverse detailed sectional view taken as indicated by line 3 3 on' Fig. 1. Fig. 4 is an enlarged fragmentary exterior view of one of the enlargements for carrying 5 a bearing part with the bearing part removed.

Fig. 5 is a longitudinal detailed sectional view of a double barrel core drill embodying another form of the invention. Fig. 6 is an enlarged transverse detailed sectional view taken as indicated by line 6 6 on Fig. 5. Fig. 7 is an enlarged fragmentary exterior view of one of the enlarged parts of the body for carrying a bearing part. Fig. 8 is a longitudinal detailed sectional view of a single barreled core drill or core receiving drilling tool embodying another form of the invention. Fig. 9 is a transverse detailed sectional view taken as indicated by line 9 9 on Fig. 8, and Fig. 10 is an y enlarged fragmentary view of one of the body 1 enlargements for carrying a bearing part of the character illustrated lin Figs. 8 and 9.

The present invention maybe carried out or embodied in Well drills of various types, for example, it may be embodied in rotary well bits of various forms, single barreled core drills or core receiving drilling tools, double barreled core drills, etc. Throughout the following detailed description, I will discloseseveral typical forms and applications of the invention, it being understood thatV the invention is not to be considered as limited or restricted `to the specific details or applications about to be'described, but is to be taken as including any features or modifications that may fall within the scope of the claims.

The form and application of the invention illustrated in Figs. 1 to 4 inclusive of the drawings, includes generally, a body I0, a pilot bit 4or cutter II on the lower end of the body, a reaming or bore enlarging cutter I2 on the body spaced above the pilot cutter II, bearing parts or guiding parts I3., and means I4 for removably attaching the parts I3 to the body I0 to project therefrom for engaging the wall of the well bore.

The body I of the drill is an elongate member adapted to be attached to the lower end of an operating string of drill pipe, or the like. In the particular case illustrated in the drawings, the

body Il) is integral and includes an upper portion I and a lower portion I6 of reduced diameter. The. lower portion I6 of the body is preferably comparatively long as illustrated in the drawings. A screw threaded pin Il is provided on the lower end of the reduced portion I6. A central longitudinal fluid passage A extends through the body I0 from one end to the other to carry the circulation iiuid or rotary mud to the pilot cutter II at the lower end of the drill.

The pilot cutter II which is attached to the lower end of the reduced body section I6 is provided to make a bore B of comparatively small shoe I9 and cutting parts I9. The upper portion ofthe shoe I8 is in e nature of a box having a threaded socket 2 for receiving the pin I1.

vIn accordance with the broader principles o! the invention, any form of cutting parts may be provided on the pilot cutter II. In the simple form of the invention illustrated in the drawings the cutting parts I9 are in the form of bladesprojecting downwardly and outwardly from the shoe I9. Certain of the cutting blades I9 have upwardly and inwardly stepped lower cutting edges while others oi the blades have comparatively narrow straight lower edges. Central blades 2| are provided on the lower end of the shoe I9 tor removing or cutting away the core lett by the blades I9. The shoe I5 of the pilot .cutter has an internal chamber 22 in communication with the lower end of the iiuld passage A. Ports 23 are provided in the shoe I9 to discharge iiuid lilromV the'chamber 22 at or adjacent the cutting blades I9. The cutting blades I9 o! the pilot cutter II4 have comparatively long outer or reaming edges 25 and are operable to out the bore B to pass the lower portion I5 of the body with substantial clearance. l

The cutter I2 is provided on the body I9 at a point spaced a considerable distance above the pilot cutter II to enlarge the well bore so as to freely and safely. pass the upper portion of the body and the drilling string. The reaming cutter I2 is carried by the large upper portion I5 of the body II) and includes a body or shoe 24 and cutting parts 25. The shoe 24 is tubular or annular and surrounds the lower end of the body part I5. In the particular case 'illustrated in the drawings, the shoe 24 is screw threaded on the body part I5, it being understood that it may be attached to the body inA any suitable manner. In the particular drill illustrated the cutting parts 25 of the reaming cutter are in the nature of blades and project downwardly and outwardly manner clearly illustrated in Fig. 1 of the drawings.

'I'he bearing and guiding Vparts I3 are provided to engage the wall of the well bore to maintain the body of the drill stabilized in the bore and thus guide the drill to make a straight vertical hole, and through their engagement with the wall of the bore, stabilize the drill during operation. In accordance with the broader aspects of the invention, the bearing parts or guiding parts I3 may be located on any suitable Portion of the drill body III. Where the drill has a pilot cutter II spaced from and operating in advance of a reaming cutter' I2, the guiding parts I3 are very effective when mounted on the body I9 at points between the the two cutters. It is al feature of the invention that the bearing parts and guiding parts I3 are formed oi.' a material that provides for the proper positive bearing and guiding action and yet wears away at a rate equal to the rate of reduction of the active diameter of the cutting parts I9 without scoring or cutting into the wall oi the well bore. In practice. the parts I3 may be formed of a metal having a relatively -body llbythemcans I4.

The means I4 for removably mounting the guideparts I3 onthebody lllssuchthattbe parts I3 are dependably held in their operative positionsduringthedrillingandallowstheparts I3 to be easily and quickly removed from the v body for replacement etc. The means I4 includes a boss or enlargement 29 on the exterior of the body I9 for carrying eachotthe guideparts I3..

The enlargements 29 -are arranged in a circumferential. series on `the lower or reduced body portion I5. In the particular form o! the invention being described. there are three equally spmd enlargements 29. The enlargements 29 are preferably spaced a substantial distance above the pilot cutter II. A recess or socket 39 is provided in each enlargement 29 to receive or carry a bearlng'part I3. The sockets 39 have comparatively large open outer sides and their forward ends, relative to the direction oi rotation of the drill, are open. The rear endsof the sockets 39 are closed and their rear walls `3I form abutments for the bearing and guiding parts I3 as will be subsequently described. `The upper and lower walls of the sockets 39 are under .cut or provided with longitudinal grooves 32. The outer walls oi' the grooves 32 are preferably sloping as clearly illustrated in Figs. 1 and 4 of the drawings. The bearing and guiding parts I3 are shaped and proportioned to be slid into the open forward ends of the sockets 39. `The parts I3 have flatinner ends or shoulders 33 adapted to bear against the abutment shoulders 3I at the rear ends of the sockets. Tongues 34 are provided on the upper and lower sides o! the parts I3 to t in or cooperate with the grooves 32.

In accordance with the invention, the guiding parts I3 project radially outward from the body enlargements 29 and their outer sides or ends are operable to engage the wall ot the bore B. The opposite vertical sides 35 of the parts I3 may be flush with and form continuations of the sides o! the body enlargements 29. The means I4 for removably attaching the parts I3 to the body III includes screws 35 for clamping or retaining the parts I3 in the sockets 35. There may be one screw 35 ior retaining each part I3 in a socket. The screws 35 pass through openings 31 in the parts I3 and thread into .openings 33 in the 'body I0. The heads of the screws 35 are preferably counter-sunk in the outer endfportions of the openings 31. 'I'he outer end portions of the cutting parts I3 may be peened over into the outer ends of the openings 31 as at 39, to lock the screws against displacement. Theretaining screws 35 may be formed oi thesame material as the guiding parts AI 3 or may be formed of a material having substantially the same qualities and characteristics as the material of the guiding and bearing parts. It will be obvious how the screws 35 are operable to securely and dependably hold the guiding parts I3 in their proper positions in the sockets 30. The screws 35 are not subjected to severe strains or pressures during operation of the drill, as pressures due to turning or rotation of the drill are directly transmitted from Ithe shoulders 33 to the abutment shoulders 3 I. In a like manner, the upward forces on the guiding parts I3 due to the downward feeding of the Adrill are directly transmitted to the upper walls of the sockets 30.

The guiding and bearing parts I3 in projecting radially outwardV from. the enlargements 29 of the body are adapted to engage or cooperate with the wall of the bore B and in accordance with the invention,l the parts I3 are proportioned to have their outer formation engaging faces 40 spaced the same distance from the axis of rotation of the drill as' the outer edges 26 of thecutting blades '|9. The outer sides or faces 40 of the bearing and guiding lparts `Iii are smooth and curved concentrically about the central vertical axis of the body I0 andare of considerable area so that the'parts I3y do not cut or bite intd the formation. The bearing and guiding vparts I3,- .in being located at circ'umferentially spaced points around the exterior of the body, effectively center the lower portion I6 of the body in the borev B and thus stabilize the. drill and guide to th drill to make a straight vertical bore.

It is believed that the operation ofthe embodi-` ment of the invention illustrated in Figs.'1 to'4 inclusive of thedrawings will be vreadilyfunderstood from the foregoing detailed description.

As the bearing and guiding parts I3 are carried l on the reduced lower portion I6 of the Abody IIl.

they do notv engage the wall of .the large major portion of the well 'bore asthe drill is run into the well. When th'e lower portion vI6 of the body enters the reduced lower bore portion B, or follows the pilot bit, I I into the bore B, the bearing and guiding parts I3 come into engagement with the wall of the reduced part B of the bore. The outer faces 40 of the bearing and guiding parts I 3, in being spacedthe 4same distance-from the axis of rotation of the drill, engage or bear against the wall of the bore B, while the drillis rotated during the drilling operation. The pilot bit or cuttervl I cuts into'the formation far in advance of the reaming cutter I2 and thus operates to guide the drill to make a straight bore.

The circumferentially spaced bearing and guiding parts I3 are spaced between the pilot cutter II vand the reaming cutter I2 and effectively prevent the drill from taking an inclined course.

Further, the lcircumferentially spaced bearing and j guiding partsv I3 stabilize vthe drill during opera.-` tion, preventing it from wobbling, etc. The pilot cutter II is effective in rapidly cutting the small lower portion B of the bore as it acts on a comparatively small surface, and the reaming cutter I 2, in making an annular cut at the upper end of the bore B is also rapid and eicient in operation. It is a feature of the invention that the bearing and guiding parts I3 are formed of a material having a relatively low resistance to abrasion so that they wear away as the blades I9 The parts I3 present comparatively large outer surc faces 40 for contacting with the formation and f become reduced in width through wear.

the blades I9 of the pilot cutter II operatevto space the lower portion I6 of the body from the Wall of the bore B so that the bearing parts are not worn away or reduced in thickness more rapidly than the blades I9. In this manner, the bearing and guiding parts I3 remain in active guiding vengagement with the wall of the boreB during the life of the cutting blades I9. parts I3 present large smooth surfaces 40 for engaging the formation and therefore do not cut into or score the wall of the bore B. It will be apparent how the three point contact of the spaced parts I3 with the wall of the bore B points between the cutters II and I2 positively guides a minimum of expense.

The

the drill to makev a straight .vertical boreA and effectively. stabilizes the drill tov prevent it from wobbung. 'rne'circmauon nuiddischarging from the lpilot' cutter II flushes the blades I3 and the blades 2I .and is free to ow upwardly around thev lower portion I3 of the bodybetween the parts I3 and'- then washth'e blades 25V of the reaming 1 cutter. VThe reaming cutter blades 25 project inwardly ,at lthe upper vend of the reduced bore B, I

thus overlapping the blades I 3' invtheirjaction on the formation so that their inner portions may assume a part of. thecutting function'when the blades vI9 become materially reduced throughv wear. The screws 3 6 vfor retaining the parts I3 in position are formed of a material having a relatively low resistance to abrasion so that they may wear away together with the partsv I3 without biting into the formation.

YWhen the cutting parts of the drill .and the bearing and guiding partsl I3 become worn, the

4 drill is removed from the well so that the cutting parts may be replaced-and repaired, and so that the guiding parts I3 maybe replaced. The parts the openings 33 which allows the parts I 3 to be I3 maybe readily detachable from. the vbody ofthedrillby merely unthreading the screws 36 from 25 slidout of the socketsA 30. Asdescribed above, I

the bearing parts I3 are .effectively supported against the thrusts and pressures to which they are subjectedduring operation of thedrill. The

inner-'ends of the parts I3 bear against the inner Walls 32-of the`sockets'30 and the rear sides of I thefparts bear against the abutment` faces 3| so pressures andthe pressures imposed on them due tofthelrotation of the drill. Vertical forces on thev parts I3 are.' transmitted directly to -the upper and llower walls of the sockets 30. The bearing and guidingparts `I3 are inexpensive of manufacture and therefore may bereplaced'at The form of the invention illustratedin Figs.

f5, 6 and '1 of the drawings 1s in menature of a. double barreled core drill'andincludes, generally, f -an outer barrel or body 4I, a bit head 42 on the lower end of the body, an linner core receiving barrel 43, bearing and guiding parts 44, and means 45 for removably attaching the -parts 44 to the that the parts I3 are supported against inward 35% 4'I. The members 41 and 48 are tubular and are preferably of the same external and internal diameters. A threaded pin49 is provided on the lower end of the member 48 to facilitate connection with thebit head 42.

The bit head 42 is attached to the lower end of the body 4I and is operable to make an annular cut in the earth formation, andthus form a corel` C to be received by the inner barrel 43. The bit head 42 includes a tubular bodyl or shoe 50 and cutting parts 5I. A threaded socket 52 is-provided in the upper end of the shoe 50 for receiving or cooperating with the pin 49. An annular internal channel or recess 53, is provided in the shoe- 50 at'the lower end of the socket 52. The 'cutting parts 5I may be inthe nature of blades projecting downwardly and outwardly from the trates, the inner barrel 4r has'itslower euriI the drill is removed from the-well bore. In acfao u 'extends through tne'b'ody u with substantial' clearance providing an annular passage for the downward ow of the circulation tluid or rotary mud. .,In' the particular drill structure illimrotatably supported in thebitjhead 42 so that it may4 be held against rotation with respect to thecore C during drillingwhen the frictional engagement with thefcore- ,is sumcient to hold it 'against turning. -An enlargementv or collar 55 is\ provided on the lower end of the inner barrel 4I and is rotatably supported in theannular recess s: or tneshoe sa.' Ports se are provided in theL collar 55 to connect the annularV space between thevinner barrel 43 and the body- 4iwith an annular space on the upper endsof the ports 54.A The core drill includes a corecatcher for retaining or supporting the core C in thedrlll when cordance with the broader aspects ofthe invention, any suitable or practical form of core catcher may be provided in the The particular core catcher illustrated in the drawings includes an annular body 5l rotatably supported in the annular recess 53 of the shoe lil and extending into the lower end of the 'collar 55. Pivoted dogs 5l The bearing and guiding parts44 are provided 4 on the exterior of the body 4i to engage the wall of the well bore X to stabilize the drill and to guide Vthe drill to make a straight vertical hole. In accordance with the invention, the bearing and guiding parts 44 are mounted on the-exterior of the body a considerabledistanceabove the cutting parts or blades 5I. It is a feature ofthe invention that the boring and guiding parts 44 wear away or become reduced in effective diameter as the cutting blades 5l become reduced in size through wear so that they effectively guide the drill throughout the life of the'cutting parts without causing-the drill to bin'd or stickin the bore. 'I'he parts 44 are formed of a material having a relatively low resistance to abrasion to readily wear Vaway as the cutting parts 5I become reduced in width through wear, so that they do not ate to dependably hold the` parts 44 in their proper positions during operation of the drill, and

are such that the parts 44 may be easily removed for replacement. A plurality of circumferentially spaced body bosses or enlargements v59 are ineluded in the means 45 for carrying the parts 44.

I'he enlargements 59 are provided on the exterior of the body 4| and in the form of the invention being described, are provided on the coupling or i "connecting member 4l. In the particular construction il1ustrated, there Aare three equally t spaced prolections `or enlargements Il von the member 44. o yA V socket 0l isl provided in each enlargement to receive or carry a bearing and The sockets 44 extend upwardly guiding part 44. y from the lower ends of the yenlargements 5l having open lower ends and open outer sides. The

upper endsor walls .Ilv of the sockets l form abutments for the parte. The sockets III are substantially rectangular in cross sectional configuration and their vertical side walls are Vpro.- vided withl grooves 42. The outer walls .of the -grooves'll are preferably outwardly convergent as clearly illustrated in Fig. 6 of the drawings. 'I'he bearing and guiding Darts 44 are shaped and proportioned to fit into the sockets Ii. In assemblingthe parts 44 on the drill. they are slid or passed upwardly into the' lower ends of the sockets 60. Tongues .l are provided on the opposite ver? tical sides of the parts 44to' fit the grooves 62. The upper. ends ofthe bearing and guiding parts 44 are nat and seat upwardly against the abutment shoulders l The means 45 includes screws 54 threaded through horizontal or transverse openings in the parts 44 and extending into sockets or openings l5 in theinner walls of the sockets 60. 'I 'he inner ends of the screws 64 react against the ends of the openings I5, clamping the parts 44 outwardly so that their` tongues 63 are tightly held or wedged'in the grooves 62. The screws 64 may be socket-headed and their heads are preferably counter-sunk in the outer end portions of the parts 44. The screws 64 are preferably formedof a relatively soft metal or a metal having the same characteristics as the parts 44.

Theouter faces or surfaces of the enlargements 59' are preferably curved concentrically about the central vertical axis of the body 4I. In accordance with the invention, the guiding and bearing parts 44 project radially outward from the enlargements 59 and their outer faces 61 areroperable to engage the wall of the well bore X to guide and stabilize the drill. If desired, the outer projecting portions of the bearing and guiding parts 44 may be formed to overlie the outer faces of the enlargements 59. 'I'his provides the parts 44 with large bearing or formation engaging surfaces `6". 'I'he surfaces '81 are preferably concentrically curved about the central vertical axis of the drill. In accordance with theinvention, the active or formation engaging surfaces 61 of the bearing and guiding parts 44 are spaced thev same distances fromv the axis of rotation of thedrill as the outer or teaming edges of the blades 5|.

In the operation of the form of the invention illustrated in Figs. 5, 6 and 7 of the drawings, the cutting parts 5i of the bit head operate to make an annular cut in the earth' formation providing the core C which is received in the inner barrel 43. 'Ihe circulation uid is passed downwardly between the inner'barrel and the body to diso charge from the ports 54 of the bit head to flush the cutting parts 5I and to provide the necessary turbulence in the lower end ofthe bore. The

circulation 'fluid is free to flow upwardly around the body 4I between the bearing and guiding parts 44. As the outer faces B1 of the parts44 are through wear without causing the drill to stick 60, the member 11.

or bind in the well. The parts 44 are spaced a considerable distance -above the cutting parts 6| and are circumferentially spaced to insure the eective centralizing" of the drill in the bore and to stabilize the drill. #As the cutting parts 5| become reduced in effective size through wear, the bearing and guiding parts 44 likewise become reduced in size so that they at all times are capable of having bearing and guiding engagement with the wall of the bore X without cutting into the formation and without causingthe drill to bind. The abutment shoulders 6| effectively support the bearing and -guiding parts 44 against upward thrusts, while the rear side walls of the sockets 6| support the parts against the strains` imposed upon them due to the rotation of the drill.- The screws 64 clamp the parts 44 outwardly so that their tongues 63 are securely wedged in the grooves 62 and the screws may take the inward thrusts or pressures imposed on the parts 44.v When the cutting parts 5I and the bearing parts 44 become worn to an appreciable extent, or when a core of sulcient length has been received, the drill is raised, causing the dogs 58 to bite into the core to break it from the formation and the drill may then be withdrawn from the well. The parts 44 may be easily andl-quickly detached from the body 4| by unthreading the screws 64 which allows the parts to be slid downwardly out of the sockets 60.

Figs. 8 to 10 inclusive of the drawings illustrate another form of the invention embodied in a single barreled core drill or core receiving drilling tool. This form and application ol the invention includes generally, a tubular body,10, a cutter head or bit head 1| on the lower end of the body, core catching means 12, and replaceable guiding and bearing parts 13 on the exterior'of the body 19 for guiding and stabilizing the drill.

The body 18 is adapted to be attached to the lower end of the drilling string and is an elongate tubular structure including an upper portion or barrel 14. A sub or tubular connecting member 15 is threaded on the lower end of the barrel 14 and is provided at its lower end with a threaded pin 1 |..v A tubular member 11 is threaded on the pin 16 and forms the body of the core catching means 12, Aand can'ies the bit head 1|. As illustrated in the drawingsl the member 11 is comparatively long.

'Ihe cutter head or bit head 1| is attached to thelower end of the member 11 and is operable to make an annular cut or bore Y, and provide the core Z. The bit head 1| includes a tubular body or shoe 18 threaded on to the lower end of Cutting parts 19 are provided on the body or shoe 18 of the bit head. In the particular drill illustrated -in the drawings, the cutting parts 19 are in the nature of blades, it being understood that any suitable form of cutting parts may be provided on the bit head. The cutting parts-'19 project downwardly and outwardly from the lower end of the shoe 18 and have comparatively long outer or reaming edges 80 for engaging the side wall of the bore Y. In the single barrelledcore receiving'drill illustrated in Figs. 8 and 9, the circulation fluid is passed downwardly through the body 1|) around the corey Z to discharge from the bit head 1| at the point where the core enters the drill. The vcirculation fluid then ows upwardly around the drill body 1li-to ultimately flow from the upper end of the well bore.`

The core catching or retaining means 12 includes a tubular body member 11 attached to the lower end of the member 14 and carrying the bit head 1|. Elongate blocksA 8| 'are set in slots 82 in the wall of the member 11. Core gripping and supporting dogs 83 are pivotally mounted in recesses 84 in the inner sides of the blocks 8| and are adapted vto project into the interior` of the body to engage the core Z. 'I'he dogs 83 are adapted to pivot upwardly and outwardly to retracted positions as the core Z enters the drill. Upon an upward movement of the drill the pointedinner ends of the dogs 83 bite into the core Z and cause the core to be broken away from the formation. The dogs 83 thereafter support the core Z in the drill asvthe drill is removed from the well bore.

The bearing and guiding parts 13 are remova-bly mounted on the exterior of the body 1|) a substantial distance above the bit head 1| to engage the wall of the well bore Y and guide and stabilize the drill. In accordance/with thel form of the invention being described, the guiding and bearing parts 13 are provided on the coupling or connecting member 15. The parts 13 are formed of a relatively soft material vsuch as bronze, brass, or a like metal having a relatively low resistance to abrasion. In accordance with the invention, the bearing and guiding parts 13 are detachably mounted on the member 15 so that theymay be readily replaced. A plurality of cilcumferentially spaced' enlargements 86 are provided on the exterior of the member 15 to carry the parts 13. In the particular case illustrated in the drawings, there are three equally spaced enlargementsl 86. Slots or sockets 81 are provided in the enlargements 86 to carry or hold the guiding parts 13. The sockets 81 extend vertically through the enlargements 86 from their lower ends to their upper ends and the outer sides of the sockets are open to pass the projecting end portions of the guiding parts 13. Vertical key-ways or grooves 88 are provided in the side walls of thesockets 81. The walls of the grooves 88 taper or converge upwardly as clearly illustrated in Fig. 10 of the drawings. y

The bearing and guiding parts 13 are shaped and proportioned to be passed upwardly into the lower ends of the sockets 81. Tongues 89 are provided on the opposite vertical sides of the parts 13 to cooperate with the grooves'88. The faces of thetongues 88 are upwardly convergent so as to wedge against the walls of the grooves 88. In accordance with the invention, the bearing and cutting parts 13 project radially outward from the enlargements 86 to engage the wall of the bore Y and project beyond the upper and lower ends of the slots or sockets 81. The projecting upper end portions 9| of the parts 13 are preferablypeened over to prevent the parts 13 from becoming displaced from the sockets 81. If found desirable or necessary, the projecting lower end portions ,92 of the parts 13 may alsoA be peened over or may be initially formed to bear upwardly against the lower ends o'f the enlargements. The outer formation engaging faces 93 of the parts 13 are comparatively large in area and are concentrically curved about the central vertical axis of the drill.' The outer surfaces 93 of the bearing and guiding parts 13 arespaced the same distance from the axis Aoi? rotation of the drill as the outer vedges 80 of the cutting parts IS-so that they may at all times enme the wall of the bore Y.

In the operation of the form of the invention disclosed in Figs. 8, 9 and 10 of the drawings. the drill is rotated in the well bore so that the cutting parts 49 make the annular cut or `bore Y and form the core Z. 'I'he core Z is-received by or extends upwardly into the body of the drill, and the circulation fluid ows downwardly through the body around the drill to discharge at the bit head 1I. During the drillingoperation, the outer faces 93 of the bearing and guiding parts 13 slidably engage the walls of the well bore Y'to eil'ectively guide the drill and to stabilize the drill. In being spaced substantial dissocket in each enlargement bavingan open outer side and an open forwardend relative izo-the direction of rotation of the drill. guideV blocks adapted to be passed into thev forward ends. of

the sockets to bear on the rear. endsof they sockets and project outwardly-through the outery sides of the sockets, and screws 'passing through openings in the guide blocks and lthreadedinto the body to removably attach the blocks .tov the tances apart, the guiding parts I3 and the enbody largements 86 do not interfere with the free upward ilow of circulation. iiuid around the body 1li. The bearing and guiding parts 1l, in being formed of a relatively soft material having a low resistance to abrasion and wear away as the cutting parts 49 become reduced in `eil'ective size through wear and do not score orcut into the wall of the bore Y. The formation engaging faces 93 of the parts Il continue to be spaced the same distances from the vertical center oi' the drill as the outer edges Il of the cutting parts throughout the life ofthe cutting parts so that the cutting parts are at all times active and effective in stabilizing and guiding the drill. When the drill is pulled or removed from the well bore, the dogs el bite into the core Z to break the core free from the formation and to thereafter sup-r port the core in the drill as the drill is removed from the well. 'I'he worn guiding parts 'Il may be easily detached from the drill and replaced. To remove the worn parts 13, the peened over upper portions 9| are cut on or removed so that the parts 13 may be readily driven downwardly outof the sockets I1. During operation of the drill the bearing and guiding parts 'Il closely nt in the tapering sockets 81 so that theyare dei. pendably held and supported against the pres- "sures and forces to which they are subjected 45 K Having described only typical forms' and ap- `piications of the invention, I do not wish to be limited or restricted to the -specinc forms and applications herein described, but wish to reserve to myself any lvariationsjor modifications that may appear to those skilled in the art or fall within the scope of the following claims: Having described my invention, I claim:

1-.1n a wen drm, a bodyl adapted to be ecn-` nected with a bit head, a projecting enlargement on the exterior of the body to be spaced above the head, the enlargement having a socket having an open outer side, a closed end wall and a normally open end opposite said wall and grooves in its side walls, a guide part adapted to be passed into the open end of the socket to bear on said end wall and project from its open outer side to engage the wall of the well bore, and tongues on the guide part cooperating with the grooves to hold the guide part ln the socket. 4

2. In a well drill, a body adapted to be connected with the bit head of the drill, there being circumierentially spaced sockets in the exterior of the body to be spaced above the head. each socket having an open outer side and an open end and grooves in its walls, guide blocks adapted to be passed into the open ends of the sockets to project from the open outer sides to engage the wall of the well bore, tongues on the guide to the bit head of the drill,'-external enlargements on the body, there being a socket in each guide parts adapted tobe passed intothe lower' ends of the` sockets to projectfrom the .outer sides of the sockets, tongues on the guide partsy cooperating with the grooves, there beingopenings in the inner walls ofthe sockets, and. screws threaded through the guide parts andreacting.`

4. 'In a wen anu, a body adapted to, be attached against the walls -of said Openinas to detachably 'i clamp the tongues against the outer walls of the grooves to lock the guide parts in position.

5. In aweli drill, a body to'be attached to the bit head of the drill, there being circumferentiaily spaced sockets in the exterior of the body, each socket having an open outer side and anl open lower end, the vertical side wallsof the socketsbeing upwardly` convergent,` and guide parts adapted to be passed into thelower ends of the sockets to project outwardlyl through the outer ends of the sockets, the opposite sides of the guide parts being upwardly convergent to wedge against the convergent walls of the recess. the guide parts including upper portions projecting from.Y the upper ends of the sockets and peened over to prevent displacement of the parts.

6.Guide .means for use with a well drill r.in-v cluding'a tubular member having a thread at one end for connecting with a part of the drill` and a thread at the-other endfor connecting with another-part of the drill, spaced projections on the member each having a socket anda passageway leading from an external surfaceto its socket, there being grooves in opposite side walls Y of the sockets, guide parts adapted to be passed through the passageways into the sockets to project therefrom to engage the well bore, tongues on guide parts for cooperating with 'the' grooves, and

means for detachably locking the guide parts in the sockets.

'1. In guide means for a well drill, abody adapted to be connected with cutting means for making a bore, a projection on the body, the pro- `jection having a socket with an open outer side and grooves ink its walls, a guide block` adapted to project through said outer side of the .socket to engage the wall of the bore, tongues onthe guide block cooperating with the grooves, the projection having a passage-leading from an external surface of the projection to the socket to pass the guide block into the socket, and a screw locking the guide block in the socket.

c. WRIGHT.