US3539024A - Apparatus for drilling inclined boreholes with drill bit support - Google Patents

Description

O United States Patent 1 1 3,539,024

[72] Inventors John D. Irons; 2,692,059 /1954 Bolling 175/85X Ray W. Hester, Jr. and Donald L. Bleyl, 2,828,024 3/1958 True 214/ Houston, Texas 2,966,994 1/ 1961 Wolff 214/25 [21] Appl. No. 751,437 3,186,499 6/1965 Bullard et a1. 175/5X [22] Filed Aug.9,1968 3,254,776 6/1966 Brown 214/2.5 145] Patented Nov. 10, 1970 3,390,654 -7/l968 Bromell et a1. l/5X 3] Assignee Brown 8: Root, Inc. 3,443,647 5/1969 Jenkins et a1. 175/85 Houston, Texas 3,451,493 6/1969 Storm l75/220X corporation of'lexas OTHER REFERENCES Rogers, Leslie C. Unique Rig Cuts Costs Off Peru In Oil & [54] APPARATUS FOR DRILLING INCLINED Gas (32% Aug 1967,

BOREHOLES WITH DRILL BIT SUPPORT Primary Examiner--Marvin A. Champion 12 Claims, 16 Drawing Figs. Assistant Examiner-Ian A. Calvert [52] US. Cl..... 175/85, Doane Benedict Swecker and Mathis 173/44, 175/9, 175/220, 214/25 [51] Int. Cl...... E21b 7/04,

15/0032") 14 ABSTRACT: A drilling apparatus including a skid-mounted [50] Field ofSearch 175/5-10, base d a platform mounted f pivotal movement about a I 85, 61, 195, 220; 173/43, 44; 214/25; 52/1 16; horizontal axis and supporting a mast and a rotary drive unit. The platform is supported on horizontally spaced, relatively large, arcuate, force distributing, bearing walls. The bearing [56] Referenges Cited walls project downwardly from the platform, generally on op- UNITED STATES PATENTS posite sides of a trackway. The trackway serves to convey a 46,673 3/ 1865 Hyde /85X large bit to a position of alignment beneath the tilted platform, 491,164 2/1893 Forker 175/85X with the bit being disposed in coaxial alignment with a drill 2,079,449 5/ 1937 Haldeman ,175/220X string section supported by the mast.

2 I e 3 7 3| fi 3 L 1 6 fiT 14 L 15 WATER LINE 4 3b 5a Patented Nov. 10, 191 0 3,539,024

Sheet Z of 7 WA'TER LINE 4 INVENTORS JOHN D. IRONS RAY W. HESTER,JR. DONALD L. BLEYL BY flan/M, QM, W

ATTORNEYS Patented Nov; 10, 1970 3,539,024

Sheet 2 of? HARD ROCK LINE WWW INVENTORS JOHN D. lRONS RAY W.- HESTER, JR. DONALD L. BLEYL I ATTORNEYS Pat ented Nov. 10, 1970 7 j 3,539,024

JOHN D. IRONS RAY W. HESTER,JR. DONALD L. BLEYL BY Bun/w 7 QM, M 9 W ATTORNEYS INNENTORS 1 Patented Nov. 10, 1970 Sheet j: of 7 00 ooqouoooooooo INVENTORS \JOHN D. IRONS RAY W. HESTER,JR. DONALD L. BLEYL BY 7 8M ATTORNEYS INVENTORS JOHN D. IRONS Sheet Patent d Nov. 10, 1970 RAY W. HESTER,JR. V DONALD L. BLEYL BY My 190M E -M ATTQRNEYS Patentc d Nov510 1970 I 3,539,024

INVENTORS JOHN D. IRONS RAY W. HESTER,JR. DONALD L. BLEYL BY Bun/-4 0M, W,

ATTORNEYS Patented Nov 10, 1970 Sheet 1 of? INVENTOR. JOHN D. IRONS RAY W. HESTER,JR. I DONALD L. BLEYL J m ML m ATTORNEYS yl- APPARATUS FOR nmrunomcunsn BOREHOLES 1 wrmmuu. BIT SUPPORT." GENERAL'BACKGROUND, OBJECTS AND SUMMAR or INVENTION Y I 'In nearshore, and offshore drillingwoperations it is often necessaryto drill relatively large diameteredholesfor the purconduit portions of a 'drillstring, a-hinged mast supporting ark rangement in the "contextof the pivoted-mast'supporha conduit storage arrangement, and a transfer system comprising a":

pose of-installingpiling.The function of this piling is to support andstabilize drilling platforms. 7 Often it is necessary to drillsuchboreholes so that-they are inclined-relative to a vertical aXisJThe-inclination-requirements vary from installation to installationtand may alsovary as to a particular, single'installation;

The large diameter of boreholes which receive piling is such as to require relatively large.diametered drilling bits. .Such

drilling bits, of course, require -ruggedtsupporting arrangements.

The problems associated .with the. handling of large diametered bitsare compounded by 'the .necessity' of being .able to drill at an inclination and'by the necessity' of being. able to manipulate and position a drilling tapparatus at an offshoreor 1 It is likewise an objectof the 'inventionto provide such "an improved drilling instrument including a bitchanging system:

disposed beneath the main floor of a rigand laterally shielded by bearing plates whichsupport a pivoted. mast.

It is also an object of the invention to providean improved portion of the conduit handling and-storage system.

DRAWINGS In describirige'the invention, reference will bemadeto a;

preferredembodimentshown in the attached drawings: In The Drawings: 1

FIG; I providesaiside elevation'view of a portable'drilling: rig of the presentinvention, illustratinga mast'of the rig in a i pivoted position; As shown'in FIG. 1, the drilling rigis sup-S.

portedon an offshore platform above a water surface;*

FIG. 2 provides'a end-elevation view of the FIG: 1 assembly} viewing the FIG.=1 assembly from the right, with the-rig'mast I raised to a vertical position;

FIG. 3 provides a perspective view, in an "exploded." for mat, illustrating structurai'relationships' between a mast-sup'j portingplatform-anda-rig base of theFIGJ rig. In FIG.-3, in I order to clarify these relationships,-components other than the rig base.andmast-supporting:platformhave not been illus'-. trated;,-

FIG. 4 providesanenlarged, side elevational view of a'portion of the FIG. 11 assembly,- illustrating the manner in which; the mast of the assembly may be supported in either an upright;

' or inclined position, and pivoted at an intermediate pointfor system for manipulating drillstring conduit'sectionsbetween a storage station and a rotary driveunit associatedwith a pivoted mast and a systemfonracking drillstring sections without imposingloadson' an inclinedmast." A

In accomplishing at'least someof theforegoingsobjectives,

there is provided, through the invention adrilling apparatus which includes portable -base means :and platform means adapted to support rotary -drivenmeans.= The rotary drive means isoperable "to impart rotation-to drillingimeans such as a drill string. A mastmeans .is supported 'on the platform means. This mast means includes meansfor support-ing the drilling means for" substantially axial movement through the rotary drive means. 'Arcuatezsupport'.means. is interposed between the platform means and the base1means..This arcuate support meanssis operable .to rotate abouta generally horizontal axis. Arcuate bearingmeans,.mountedonrthe base means, serves to support the arcuate support means' for rotarymove ment about the aforesaidhorizontalaxis. Thearcuatesupport I 'rneans'provid'esperipheral means-engaged with the bearing a means. This peripheral means is generally aligned with a cylindrical 'plane which encircles the rplatform'means. A drill bit slipper: mea'nsis provided which is'operable to support adrill bit for attachment' to the fdrilling meanss The drill bit support mea parti beneath a portion of the platform'means.

Ahotlir 'inde endently significant facet: of the invention it 'to 'specrfic structural details ofthe :arcuate support and the arcuate bearingameans. These details involve 'r 'wall .means which'-both shield albit changing stasim la in is mounted on the vbasezmeans,andiis disposed at least.

'tion and provide stress-distributionfor apivoted -mast. This stress istransmitted exteriorly around the rotary drive means.

Another significant facet of -the' invention pertains to a piv'oted' track and dolly arrangement: defining :the aforesaid drill bit support means;

Other facetsiof the invention; worthy'of'individualcon-- sideration, include a: unique actuating means for unscrewing storage-or transportationpurposes;

FIG. 5 providesa perspective view of a pipe ,storageand' transfer system included in the FIG. 1 assembly;

FIG. 6 provides a transverse, sectional view of 'a pipe storage bin of the FIG: 5 assembly, as viewed along the section line 66.of FIG. 5;

as viewed along the sectionline 7-7 of FIG. 5; I 7

FIG. 8 provides an enlarged, fragmentary, side elevational view of a transfer mechanism, mounted on the mast ofthe FIG. 1 assembly, and operable to move a drill string portion away fromthe mast: and toward the pipe storage system shown j in FIG. 5; V

FIG. 9 provides an enlarged, side elevational viewofadrill bitsupporting; track and dolly system incorporated in the HQ;

1 assembly;

FIG. 11 provides a transverse sectional view of a traveling block, stabilizing system incorporated in the FIG. -1 assembly,

as viewed along the section line 11-11 of FIG. 2;

FIG. 12 provides an enlarged, side elevational viewof the FIG. 1 assembly, illustrating a fluid actuated, cylinder and pistonzmechanism: operable to effect the unscrewing of conduit sections of a drill-string;

FIG. 13 providesan enlarged, fragmentary, sideelevationalview of thef'FlG; I assembly, illustrating the manner in which the track anddolly system of FIG. it) serve to support a drill bit' beneath a rotary 'drive means; while the bit is being mounted on a drill string;

FIG. 14 illustrates the disposition of the components shown in FIG. 13,,after the drill 'bit has been attached to the drill stringand the dolly removed from a position beneath 1161:0-

tarydrive unit, so as to enable the drill bit to be lowered into a surface casing defining the entry of a borehole to be drilled; 1

FIG. 15 illustrated the disposition of the FIG. 13 com ponents, with the drill bit lowered onto a borehole and'with a rotary drive 'unit'positioned on the platform of the pivoted and FIG. 16 provides a transverse sectional view, of the FIG-'8 pipe transfer; mechanism, as viewed along the section line 16-16 ofFlG. 8.

FIG. 7 provides a transverse sectional view of =a-ramp mounting arrangement incorporated in the FIG. 5 assembly,"

FIG. 10 providesa top plan view of the dolly shownin mast and disposed for driving engagement with the drill string; I

MAJOR COMPONENTS OF APPARATUS FIGS. 1 and 2 illustrate, in a somewhat schematic format, the principal components of a slant drilling rig l embodying the present invention.

Rig 1 includes a portable or skid-mounted base 2. Base 2, as shown in FIG. 1, is supported on a portion of an offshore platform 3. Platform 3 supports base 2 above a water surface 4.

Platform 3 comprises a series of easing sections 3a. These sections 3a are interconnected by horizontal framing members 3b to form a towerlike structure. This structure is positioned offshore so that the lower ends 3c of the casing sections rest upon an unconsolidated or mud layer 3d underlying a water surface 3e. The weight of the towerlike unit 3f, comprising the casing sections 3a and their interconnecting framing 3b, may be such as to cause the casing ends 3c to partially penetrate the unconsolidated or mud layer 3d.

Following conventional practice, once the towerlike unit has been positioned as shown in FIG. 1, it functions as a template to facilitate the placing of piles.

Prior to the placing of piles, sections of surface casing 33 may be installed. Each such section 3g may be lowered through a casing 3a and may be then driven through the unconsolidated layer 3d to a consolidated or hard formation 3h.

Tower 3f may be provided with a temporary deck 3i, detachably supported on framing 3b as shown in FIG. 1. Rig 1 is supported on this temporary decking 31' at an elevation disposed above the upper extremities of the casing sections 3a and the upper ends of the surface casings 33.

Temporary decking 31' is supported on framing 3h so as not to provide horizontal obstructions interposed between the rig l and the upper ends of casing sections 3a, or the upper ends oftheir telescopingly received surface casing 33.

In order to extend piling through the surface casings 3g, so that these pilings penetrate the hard formation 3h, it is necessary for the rig l to support a drilling mechanism so that pile receiving holes may be formed in the hard formation 3h in axial alignment with the surface casings 3g and the surrounding template casings 3a.

In the usual installation, some of the casing sections 30 will be inclined relative to a vertical axis, while others may extend more or less vertically. Thus, it is necessary for the rig 1 to provide a drilling apparatus having a capacity to drill either vertical or inclined pile receiving holes. In drilling these holes, a rotary drilling string" (Le. conduit supporting a bit) is projected downwardly from the rig 1 through the interior of the casings 3g to the hard formation 3h. The drilling mechanism then forms elongate boreholes defining continuations of the interior passages of the surface casings 3g.

After these boreholes have been formed, the drilling mechanism is withdrawn, the rig I removed from the temporary decking, and conventional pile placing equipment is moved into place. This pile placing equipment is employed to lower piles through the surface casing 3g and into the boreholes which-define a continuation of the interior passages of these surface casings.

This inventionv is concerned specifically with the structure of the rig 1 whichenables the pile receiving boreholes to be formed.

Rig 1 includesa platform 5 mounted for pivotable or rotata- *ble movement above a horizontal pivot axis 6. Platform 5 is supported for this arcuate or rotary movement by arcuate and convex, generally semicircular, wall-like, support means 7. Support means 7 conformingly engages arcuate bearing means 8. Bearing means 8 is mounted in base means 2, is concave in configuration and faces generally upwardly as shown.

Rig 1 includes a mast 9 which is carried by, and projects generally upwardly from, the platform means 5.

A drill bit handling mechanism 10 is contained within base 2 and is located generally beneath the elevation of the platform 5. This bit handling apparatus includes a trackway 11 and a drill bit supporting dolly 12. Dolly 12 is supported on trackway 11 for shuttlelike movement between a bit loading station 13 and a bit changing station 14. As illustrated, bit changing station 14 is locatedgenerally beneath the pivotal platform 5.

A pipe rack or storage crib 15 is, detachably connected to one end 16 of the rig base 2, as shown schematically in FIG. 1. This storage unit 15 projects downwardly and outwardly of the baseend f A pipe pushing or transfer mechanism l7-is mounted on the mast 9. This pipe transfer mechanism serves to push a drill string portion, disengaged from the rotary drive unit of platform 5, away from the mast 9 and generally toward the storage unit-15. This push serves to facilitate the movement of drill string portions from the platform 5 to the storage unit 15.

Unscrewing of conduit sections of the drill string is facilitated by a drill string disconnecting mechanism 18.

Base 2 supports a conventional drive mechanism 19. Drive mechanism 19 provides a hoisting unit for causing a conventional traveling block 20 to traverse vertically along a trackway'2l mounted on the rearmost end framing 22 of the rig 9.

A conventional hoisting cable system 23 extends from a winch drum 24 in drive unit 19, upwardly to a conventional crown block assembly 25. The hoisting cable system 23 then extends down to the traveling block 20. Traveling block 20 supports conventional, pipe engageable elevators 26.

Platform 5 provides framing for detachably supporting a conventional, drill string rotating, drive unit 27. Structural details of rotary drive systems for rotary drill strings are well known and discussed, for example, in Chapter 6 of the History of Petroleum Engineering published by the American Petroleum Institute in 1961.

It is sufficient to here note that the conventional rotary drive unit 27 is detachably mounted on the platform 5 and includes a main drive shaft 28. Drive shaft 28 is coaxially aligned with the pivot axis 6 when the drive unit 27 is supported on the platform 5. Conventional drive belts or drive chains 29 extend from the drive shaft 28 to a drive shaft of the drive unit 19. The drive belts or drive chains 29 may project generally upwardly from shaft 29 through an opening in platform 5 to the drive unit 19.

With the drive shaft 28 of the rotary mechanism 27 being aligned with the pivot axis 6, pivoting of the platform 5 about the axis 6 will in no way impair the driving connection 29 between the rotary drive unit 27 and the power unit 19.

STRUCTURAL DETAILS OF BASE, PLATFORM AND BEARING UNITS Platform 5 comprises an upper deck 34, supported by conventional, beam-type underframing 35. Top deck 34 has a generally l-shaped configuration, in plan view, thus yielding longitudinally spaced, but transversely extending, rectangular recesses 36 and 37.

Arcuate support means 7 comprises a pair of generally identical, semicircular, wall- like support structures 38 and 39. Units 38 and 39 are displaced horizontally and transversely of the longitudinal median plane of the base 2, which plane extends between the base ends 16 and 40. Each arcuate unit 38 and 39 includes a semicylindrical web segment 41.

Each such segment 41 is connected to beam components 42 and 43 of framing 35 by a heavy, or thick-walled, semicircular wall plate 44. Beams 42 and 43, as generally shown in FIG. 3. are mutually parallel and extend perpendlculur ol' the median longitudinal plane of the base 2. Plate 44 may be welded to web 41 on its lower edge and welded to the ends of thebeams and 43, plate 44, and segment 41.

Arcuate bearing means 8 comprises a pair of generally identical, horizontally spaced, arcuate bearing units 45 and 46 Units 45 and 46 are displaced-horizontallyand transverselyof the rigs longitudinal median planeand are operable to conformingly engage the webs 41 offisupports 38 and 39.

Each of the bearing units 45am includes a semicylindrical web segment 47. Each such web segment 47 faces upwardly and is operable toconformingly and concentrically-engage a web 41 of its superposedarcuate support. Securing flanges 48 project generally .radially inwardly of each of the webs 47, toward the axis'6fThese flanges 48 are paired as shown in FIG. 3, so as toextend generally vertically on opposite sides of each web 41. Thus,the flanges 48 serve to prevent lateral disengagement of the webs 47 and 41, when the support 38 is seated on the 'bearing45 and the web 39 is seated on the bearing 46.

If desired, one or more abutmentstops49 may be carried by the periphery of the webs 41."T-hese abutrnerrtstops may be engageable with abutment stops,. such asjthestop 50 on webs 47, so as to limit pivotal movement of the platform 5 to a predetermined increment.

Platform 5 includes a generally centrally located,

framework defined, rotary drive unitseat 51. This seat prothrough the opening 33 in the lower floor 32 throughout the pivoting range of the platform 5.

With the platform 5 seated on the base 2, as shown generally in FIG. 5, a rectangular extension 52 of platform deck 31 is operable to project into, andtsu-bstantially fill, the

recess 36 when-the platform deck 34 is horizontally disposed.

As shown in FIG. 5, the recess 37 may remain open to facilitate-the transfer of drill string sections between the location of the platform means 5 andthe conduit storage unit 15.

' As shown in FIG. 5, vertically extendingwall means 53 may be associated, in a general coplanar fashion, with each of the wall means 44. Thus, the wall means53, in combination with the wall means 44, define substantially continuous walls ex tending between the elevations of deck's'31 and 32, on opposite sides of the opening 33.

STRUCTURAL oarArLsor MAST l l I .Structural details ofthe mast9 are illustrated, for example,

G8. 1, 2 and 4. v in Mast 9, as shown in FIG. 4, includes a lower section 54 fixed y secured to the platform 5 As'shown generally in FIGS. 2 and 4, the coplanar corner legs55 and 56, disposed on the left side of mast section 54 when the apparatus is viewed as shown inFIG. 2,are spaced laterally outwardly of the rotary drive unit 27. a

Similarly, the corner legs 57 and 58 of the other side of the mast; section '54 are disposed laterally-outwardly of the drive .-unit 27, when it issupported by seat51 as shown generally in FIGS. 2 and 5. l

With this leg arrangement, loads are transferred from the bearing means 8, into the mast'9, through the locations of the legs 55, 56, 57 and 58, i.e., through force transmission paths generally circumscribing and spaced from the rotary drive system 27 associated with the platform 5. This beneficial force transmission path results from the interface of bearing means 8 and arcuate supportmeans 7 being aligned with a cylindrical plane which encircles platform 5 and is spaced from drive unit 27.

Mast 9 includes an upper section 59 which is pivotally connected to the lower section 54 by conventional pin connecting. means 60. Other detachable general. connecting means 61 provide a detachable connection for securing the front end 62 of mast portion 59 to the lower mast portion'54.

When the connecting pin means 61 is removed, the upper mast portion 59.may be pivoted rearwardly toward the base means 2. Downwardly pivoted upper mast section 59 may be supported in ahorizontallyextending position shown in phantom line in FIG. 4, on an upright framework 63. With the mast portion 59 thus supported, it is contemplated that the mast section 54 will be oriented so as to project vertically upwardly, with the platform means 5 beinghorizontally disposed. As llf lustrated in FIG. 4, the support 63 is operable to support the mast section 59 above the drive unit 19.

As shown in FIGS. 2 and 11, upper mast section 59 is provided with a backing plate 64, extending along and connected with, rear end framing 22. Backing plate 64 supports a pair of vertically extending, mutually parallel and laterally outwardly facing, channel members 65 and 66.

Traveling block 20 includes a base 67 and a pair of guide rollers 68 and 69. Guide rollers 68 and 69 are supported intermediate the base 64 and the traveling block body 67 by mounting brackets 70 and 71, respectively. As shown in FIG. 11, guideroller means 68 and 69 are guidingly received within the channel members 65 and 66. Each of the guide roller means 68 and 69 may comprise a plurality of superposed rollers, so as to prevent pivotal movement of the traveling block body 67 relative to theguidechannels 65 and 66. With the rollers and channels thus engaged, the traveling block 20 is stabilized for guided translation along the rig face 62.

As will be apparent by reference to FIGS. 1, 2 and '11, trackways 68 and 69 and plate 64 are supported by the rearor leftmost end 22 of the upper rig portion 59, between the rig sides 72a and 72b. With this support arrangement, the traveling block is stabilized for movement along a path so as to support a drill string for axial movement through the rotary drive means 27, with the axis of this movement intercepting the pivot axis 6.

The SUPPOl'tIfOI' plate and channel-defined trackways 68 and 69 maybe provided, as shown in FIG. 11, by framing 73 extending between corner posts 74 and 75 of mast portion 59. In this connection, itv will be understood that these corner posts 74and 75define essentially vertical continuations of the comer legs 56 and 58, respectively, of the lower mast unit 54.

As shown in FIG. 2, elevator unit 26 is connected to traveling block 20 by a pair of links 76 and 77. Links 76 and 77 are supported by a hook 78, secured in turn to the lower end of traveling block 20.

The length, or vertically elongate dimension, of the links 76 and 77 is such as to permit the elevator 26 to be displaced from the axis of reciprocation of the drill string toward the base end 16'. The unusually long links 76 and 77 enable these links to pivot on hook 78, toward base end 16, so as to connect with a conduit section in the general vicinity of the platform recess 37. This. long link arrangement thus facilitates the coupling of the elevator with a drill string section, with the traveling block 20 disposed in its lowermost position but restrained by the trackways 65 and 66.

STRUCTURAL DETAILS OF DRILL BIT HANDLING SYSTEM FIGS. 1, 9, l0, l3 and 14 illustrate structural details of the system 10 for handling'drill bits, as incorporated in the rig assembly l.

This drill bit handling system 10, as previously noted, includes the track system 11 and the dolly 12.

As shown in FIGS. 8, 10 and 13, track 11 includes a portion 79 which is fixedly connected to base framing members 80. The leftmost extremity of trackway 11, as viewed in FIGS. 1 and 9, terminates at the bit loading station 13. The rightmost extremity of trackway l1 terminates at bit-changing station 14.

Fixed track section 79 includes a pair of horizontally spaced and mutually parallel rails 81 and 82, which extend longitudinally of the rig base 2.

Track assembly 11 includes a movable track portion 83.

Movable track portion 83 includes one side rail 84 defining a continuation of rail 81. Rail section 84 is pivotally connected to rail 81 by a pivot connection 85, having a horizontal pivot axis. Another rail section, not shown in FIG. 9, is incorporated in the movable assembly 83 and is pivotally connected to rail 82 so as to define a longitudinal continuation of rail 82. The pivot axis between this other rail portion of rail component 83, and rail 82, is coaxial with the pivot axis of pivot connection 85.

Pivoted rail section 83 is provided with a lifting attachment 86. A cable or chain 87 may extend upwardly from connection 86 to a hoist 88 mounted on the base 2. Hoist 88 may be remotely operable if desired. Alternatively, hoist cable 87 may extend through a conventional sheave network, through the base 2, and upward to a cat-head" 89, conventionally included in the drive unit 19.

Thus, by way of either the cat-head 89 or the winch 88, the pivoted track section 83 may be elevated or pivoted upwardly so as to dispose it in parallel alignment with the pivoted or inclined platform surface 34. This ensures that the dolly 12, when supported on the track 83, is operable to support a bit with its longitudinal axis coaxially aligned with the travel path of a drill string portion supported by the traveling block 20.

Dolly 12 includes a bit supporting platform 90 and four wheels 91. These wheels are engaged with the two elongate tracks defined by the pivotally connected rail portions. With this arrangement, and with the dolly 12 disposed at the bit loading station 13, a hit may be loaded on the dolly platform 90 by conventional hoisting means. The dolly 12 may then be translated along the track system 11 until the dolly is supported upon the pivoted platform section 83. This translation may be effected by a draw cable 92 extending from the for ward end of the dolly 12. This cable 92 may extend to a sheave 93 mounted on the forward end 16 of the base 2, between the floor levels 31 and 32. The dolly movement inducing cable 92 may extend from the sheave 93 either to a power hoist or winch 94, or to another cat-head on the power unit 19. In either event, the movement inducing cable 92 will serve to fixedly position the dolly 12 on the pivoted track portion 83. The positioning of the cable 87 and winch 88, and the positioning of the cable 92 and its associated sheave 93 and winch 94, have been only schematically illustrated in FIG. 9. Obviously, these components will be mounted on the rig base 2 in a mutually noninterfering relationship, with the controls for the winch units being accessible to operators at the bit-changing station 14 and/or the loading station 13.

Similar positional criteria apply, of course, where the track unit 83 and the dolly 12 are manipulated by lines extending to cat-head units on the power unit 19.

With the dolly supporting a bit on the track portion 83, the track portion 83 may be pivoted so as to align the bit axis with the axis of a drill string portion extending downwardly from the travel block 20, and intended to be coupled with the bit.

As shown in FIG. 10, bit supporting surface 90 may be provided with an opening 90a to enable lead" or pilot portions of the bit to project through the platform 90, with the annular periphery of the bit serving to stably support the bit on the platform 90.

Platform 90 may provide sufficient space for an operator to work from, while the dolly 12 is being manipulated and the bit installed.

STRUCTURAL DETAILS OF PIPE STAGE SYSTEM Structural details of the pipe storage system 15 are illustrated in FIGS. 5, 6 and 7.

As shown in FIG. 5, storage system 15 includes a bin or criblike unit 95. This unit includes a base 96, horizontally spaced side walls 97 and 98, and a lower end wall 99.

Base 96 includes a central ramp or skid 100 interposed between laterally displaced, pipe-racking means, i.e., surfaces 101 and 102. Racking surfaces 101 and 102 may be foraminous in nature so as to permit fluid to drain from drill pipes stacked thereon.

End wall 99 may be provided with a series of generally vertical extending framing members 103 operable to provide abutment stops to support the lower ends of stacked conduit sections.

Storage unit 15 is connected to the forward end 16 of rig base 2 by detachable pin connections 104, 105, 106 and 107. This pin connection arrangement enables the storage unit 15 to be connected to the rig base, after the rig base has been separately positioned. With the pin connections 104 through 107 secured, the pipe supporting base 96 extends outwardly and downwardly from the lower level 32 of the rig base 2.

A "pipe-tailing" ramp means 108 provides an upward extension of central ramp portion 100, terminating in the general vicinity of the platform recess 37.

Ramp extension 108 includes a floor portion 109 connected to ramp section 100 by a detachable pin connection means 110. A beam 111 extends transversely of, and supports, an upper portion of ramp unit 108. Beam is connected to base framing members 1120 and l12b by detachable pin connecting means 113.

As shown in FIG. 7., each detachable pin connecting means 113, disposed at each end of beam 110, comprises a pair of beam carried flanges 114 and 115. These flanges are telescoped over a flange 116 carried by each base framing member 112a and 112k. A connecting pin 117 detachably interconnects the flanges 114, and 116.

Thus, once the storage unit 15 has been installed, the platform extension 108 may be positioned and locked in place with the detachable pin connections so as to provide a pipetailing" ramp having an uppermost, pipe-receiving end and extending from the platform surface 34 to the racking surfaces 101 and 102.

PIPE TRANSFER MECHANISM FIGS. 2 and 8 illustrate structural details of the pipe transfer mechanism 17.

Mechanism 17, as shown in FIG. 2, is carried by upper mast section 59. Mechanism 17 is supported by rear rig wall 22 so as to be operably aligned with, and disposed at, the lower end of the guide tracks 65 and 66.

Transfer mechanism 17, as shown in FIGS. 8 and 16, includes a pair of piston and cylinder assemblies 117 displaced horizontally along the rear rig wall 22.

Each such assembly includes a cylinder means 118 which is pivotally connected by a pivot connection 119 to frame 22. Pivot connection 119 has a horizontal pivot axis. Thus the cylinder 118 undergoes pivotal movement in a plane generally parallel to the longitudinal median plane of the rig 1.

A piston 120 is telescopingly mounted within the cylinder 118. Pressurized fluid, supply lines 121 and 122 control the supply of pressurized fluid passing to, and issuing from, the cylinder 118. This fluid serves to induce reciprocation of the piston 120 within the cylinder 118.

A pair of generally vertically extending bracket arms 123 and 124 are connected to framing 22 by pivot means 125. Pivot means 125 has a horizontal pivot axis generally aligned with the plane of rear rig face 22.

Arms 123 and 124 support a roller 126 at their lower ends. As shown in FIG. 2, roller 126 is supported beneath the guide channels 65 and 66. A shaft 127, carried by the roller 126,

provides pivot connection means between this roller and the arms 123 and 124. This same shaft 127 is pivotally connected with fitments 128, carried by the outer extremities of .the piston rods of the piston means120.

moving roller 126.

In the retracted, full-line-position, oflroller 126 shown in FIG. 8, this roller is: retracted 'betweenthe axial movement path of the drill string D and the. rig face 22..This position of drill string D conforms to the position-resulting from drill P string D being supported byqelevators26 and traveling block 20, with .the drill string D .passing axially through the rotary drive unit 27.

By supplying pressurizedfluidfthrough line 121, the piston 120 may be extended so as to cause-the roller 126 to move the string D outwardly of the rig, to thepha'ntom line position shown in FIG. 8 ..ln.this phantom line position,-the lower end of the conduit string D is displaced toa position in the general vicinity of the upper: end of the ramp 108. By then lowering the drill string, the string may be guided downwardly along the ramps l08 and-100, disconnected-.fromwthenelevators, and

stored or racked in one of the areas 101 or 102.

It will here be understood thatthis function of the transfer mechanism 17 takes place when a conduit string is being withdrawn from a borehole.

Inasmuch as sections of the conduit string are unscrewed immediately abovethe rotary unit 27, the upper portion of the unscrewed conduit string, supported at its upper end by the elevator 26, is free to be displaced outwardly by the transfer 'mechanism 17. The lower portion of. the conduit string, still extending into the borehole, may besupported temporarily by conventional slip mechanismswithin the rotarydrive unit 27.

DRILL STRING UNCOUPLING vFIG. 12 illustrates, in. a-more or lessnschematic format,

19, to a guide or deflector post l33. Fromthe guide or deflector post 133, the cable or chain 131 extends to the drill string D above the rotary drive unit 127. By attaching the free end of the cable or chain 131 to a pipe tang; or by wrapping this free end about the drill string D, and then'retracting the piston of the cylinder 129, an uncoupling torqueiis applied to the drill A i string D. This torque will tend to separate the upper drill string portionA from the lower drill string portion B at the threaded coupling C.

Q Pistort and cylinder assembly 129 is disposed in generallongitud ip'a ignment with one side wall of the rig 1 so asto provide m interference with operations on eachof floor levels 31 and 32.

:ADZJUSTING OFINCLINATION OFMAST FIGS. 1 schematically illustrate structural details of a K systern134 whichserves to' adjust and maintain the inclination t jofmast 9.

' Adjusting system 134 comprises, on each side of the mast 9,

' an extensible,hydraulically actuated, piston and cylinder assembly 135 and a pin mounted strut 136.

F The extensiblepiston-and cylinder 'assembly is pivotally connected at pivot points 137 and-138to the rigbase and mast, respectively.

Each strut 136 is pivotally connected to mast 9 by a pivot connection 139 disposed at the upper strut end. A detachable pin connection 140 serves to detachably secure the lower end of the strut 136 to'one aperture of a mounting bar 141. As shown in FlG.-4,' mounting bar 141 is fixed to the base -2 and includes a series of horizontally spaced and longitudinally ex'- tending pin connection apertures 142. I

In order to adjust the inclination of the mast 9, the pin connections 140 on each side of the rig 9 are separated or disen-i I gaged. The piston and cylinder assemblies 135, on each side of the mast 9, are then actuated to move the mast to the desired inclination position. Once this inclination position has been attained, the locking struts 136 are reengaged with appropriate apertures 142, so as to lock the mast 9 in its inclined position; In this connection, it will be recalled that abutment means such as the abutrnents 49 and 50 may be provided in the arcuate bearing arrangement, which supports the mast platforms 5,

to limit the inclination position of the'mast 9.

When the mast section 59 is pivoted by the folded orphaiitom line position shown in FIG. 4, the piston and cylinder as: semblies 135 will contract to-the phantom line position shown in' FIG. 4. It is contemplated that the struts 136 may remain attached to the rig section 59, although freed from pin couplings 140, and extended rearwardly of the mast 9 so as toalso be supported on the support framework 63 of the rig base 2.

OVERALL MODE OF OPERATION OF APPARATUS 14. The movable track section 83 has been pivoted upwardly so as to. support the bit E in coaxial alignment with a drill string D, extending centrally through the seat 51. As shown in FIGS. 13 and 14, the rotary drive unit 27 may be removed from the seat 51 to facilitate the connection of the lower end of the conduit stringzD to the trolly supported bit E.

In order toinstall the bit B, it may be necessary to remove ing space provided by the removal of drive unit 27 will .materi-r' ally facilitate the bit securing operation.

With the rotary drive unit 27 removed, workmen may attach the bit-E to the drill string D, with access being provided through the opening in the seat 51 and by the workingplatform onthe dolly 12.

Once the bit E has been secured, the dolly 12 may be moved away from bit changing station 14 to an intermediate position along trackway 11. The dolly 12 may be removed byfirstalifting the traveling block 20 so as to raise slightly the. interconnected drill string and bit. It will here be understood thatthe roller 126 of the transfer mechanism 17 may serve to support the lower end of the drill string 16 in the longitudinal alignment position, shown in FIG. 14, i.e., generally axially aligned with the borehole.

With the dolly l2 removed, the bit E is able to. pass downwardly between the side rails of the track section 83 and through the base floor opening 33.

Either before or after the removal of dolly 12, the rotary drive unit 27, if removed for the bit installation, will be reinstalled on the seat 51 as shown, for example, in FIG. 15.

With the rotary drive unit 27 installed, the drill string D. may be lowered progressively into the borehole F and its associated surface casing G. Additional conduit sections may be added to the drill string D by chucking" a lower portion of the drill string in conventional removable slips 143 associated with the rotary drive unit 27 With the slips 143 in place, the lower portion of the conduit string is supported. Thus, the elevators 26 may be freed from the drill string and moved from thelowermost position of the traveling block 20, horizontally toward platform aperture 37, and engaged with the upper end of a drill string section projecting upwardly from the ramp extension 108. The traveling block 20 may then be raised so as to enable the lower end of the new drill string section to be moved into coupling alignment with the drill string portion chucked in the drive unit 127 by conventional, wedgelike slips 143. After the new section has been coupled with the chucked drill string, the slips 143 may be removed, and the traveling block 20 lowered to effect the lowering of the bit E further into the borehole F.

This process is continued until the bit E comes to rest on the base of the borehole.

With the bit E resting on the base of the borehole, and with the slips 143 removed, the rotary drive unit 127 is disposed to impart rotary movement to the drill string D while permitting axial advancing of the bit E as drilling progresses.

When it is necessary to change a bit, or when drilling has been completed, a drill string D and bit E are withdrawn from the borehole, by reversing the procedure above described.

During the retrieval of the drill string the transfer mechanism 17 facilitates the movement of conduit sections from the platform to the tailing ramp 108.

SUMMARY OF ADVANTAGES AND SCOPE OF INVENTION A principal advantage of the invention involves the overall compactness of the rig and ease and reliability with which its various components may be operated.

The arcuate supports and bearings cooperate to provide a dispersion of stress over a large area without interfering with the rotary drive of the drilling mechanism. In a unique fashion, the arcuate supports and bearings cooperate to shield a bit changing station.

The force-transmitting walls 44 provide a structurally simple, but highly effective mechanism, for radially distributing force between the mast 9 and the wide surface area afforded by the segments 41. Because of the extremely large bearing area provided by the segments 41, the level of forces acting between the segments 41 and 47 is of unusually low intensity. Because of this low intensity, minor imperfections in mating cooperation between the segments 41 and 47 will be of minimal adverse consequence. Thus, the necessity for precision manufacture in this bearing arrangement is avoided.

The dolly and trackway afford an efficient system for handling large diametered, heavy bits.

The pipe transfer and storage mechanisms significantly reduce the problems associated with manipulating drill string sections between a storage area and a mast.

Another advantage of the invention involves the manner in which the pipe storage area provides a conveniently accessible storage area for pipe, without placing a pipe load on the inclined mast 9.

In this connection it will be appreciated that where the mast 9 is operated in a vertical position, pipe may be stacked vertically in the rig, following conventional techniques. This pipe may be supported between a temporary decking installed on the rig framing 30, to the right of the platform means 5, when theapparatus is viewed as shown in FIG. 1. When this temporary decking is installed, the tailing board or ramp extension 108 will be removed.

The upper ends of pipe sections, extending vertically upwardly from this temporary decking, may be secured by bracket means associated with a conventional stabbing board". This stabbing board, of course, would be mounted on a portion of mast section 59, intermediate the lower mast section 54 and the crown block 25.

The pipe decoupling system is blended into the platform structure so as to provide virtually no significant obstruction of working areas. broadest exploratory While the invention has been described in the context of drilling boreholes to facilitate the installations of piling in an offshore environment, it will be recognized that the invention,

in its broadest ramification, is of basic utility of the drilling art generally. For example, the invention may be useful, in drilling boreholes on shore and in drilling explanatory and production holes.

In describing the invention reference has been made to one preferred embodiment. However, those skilled in the drilling art and familiar with the disclosure of the invention will envision deletions, additions, substitutions, or other modifications which would fall within the purview of the invention as set forth in the appended claims.

We claim:

1. A drilling apparatus comprising:

portable base means;

platform means adapted to support rotary drive means, with said rotary drive means being operable to impart rotation to drilling means;

mast means supported on said platform means, said mast means including: means for supporting said drilling means for substantially axial movement through said rotary drive means; arcuate support means pivotally mounting said platform means on said base means, said arcuate support means being operable to rotate about a generally horizontal axis; arcuate bearing means mounted on said base means and supporting said arcuate support means for rotary movement about said generally horizontal axis;

said arcuate support means providing periphery means engaged with said bearing means and generally aligned with a cylindrical plane which encircles said platform means; and

drill bit support means operable to support a drill bit for attachment to said drilling means, said drill bit support means being mounted in said base means, said drill bit support means being disposed at least partially beneath a portion of said platform means operable to support said rotary drive means.

2. An apparatus as described in claim 1:

wherein said arcuate support means comprises first and second arcuate supports disposed generally on opposite sides of said drill bit support means, with each of said first and second arcuate supports including first semicylindrical web means carried by said platform means, facing generally downwardly, and having an axis of curvature coinciding with said generally horizontal axis,

generally semicircular wall means connected with said first semicylindrical web means and defining, therewith, semicircular wall means disposed generally on one side of said drill bit support means,

wherein said arcuate bearing means comprises first and second arcuate bearings, engageable, respectively, with said first and second arcuate support means, each said first and second arcuate bearing means including:

second, semicylindrical web means supported by said base means and disposed in supporting and conforming engagement with one of said first semicylindrical web means of said arcuate support means;

wherein said platform means includes mounting means for said rotary drive means, said mounting means being spaced radially inwardly from said cylindrical plane; wherein said base means includes:

generally horizontal floor means projecting into a radial space between said cylindrical plane and said mounting means; and said base means cooperating with said platform means to provide aradial space between said mounting means and said cylindrical plane, through which radial space portions of said drill means may be transferred.

3. An apparatus as described in claim 1:

wherein said drill bit support means includes:

fixed track means fixed in position on said base means,

movable track means carried by said base means and 1 disposed generally beneath the portion ofsaidplatform means adapted to support said rotary drive means, said movable track means being disposed in pivotable relation to said fixed track means and defining a continuation thereof, with said movable track means being operable to pivot so as to be perpendicular to the axis of rotation of said rotary drive means, through a range of pivoting movement of'said arcuate support means, means operable to pivot said pivoted track means and support said pivoted track means at a pivot position to which it is moved, dolly means movably mounted on'said-fixed and movable track means, and means operable to move said dolly means along said movable and fixed track means and secure said dolly means in a fixed position on said movable track means while a drill bit is being attached to-said drilling means. 4. An apparatus as described in claim 1 further including: actuating means operable to unscrew threaded conduit pordons of said drilling means, saidactuating means comprising: wall means disposed on one side of saidbase means, fluid actuated piston, and cylinder means supported by. said wallmeans in general'longitudinal alignment, with saidpiston and cylinder means andlocated generally beneath the elevation of said platform means, said piston and cylinder: nteans comprising cylinder means i p and piston means telescopingly received within said cylinder means, said cylinder means being anchored to said wall means, flexible, force transmitting means connected with said piston means, and guide means operable to guide'saidflexibleforce transmitting means, through a defined path, to a position disposed above said platform means, with said flexible force transmitting'means being operable at said position to circumferentially engage a threaded conduit portion of said drilling means and impart torque force thereto in response to "fluid .pressure induced movement of said piston means within said cylinder means. 5. An apparatus as described in claiml: wherein said mast means includes:

a lower mast section fixedly secured to said platform means, an upper mast section pivotably attached to said lower mast section, means for releasably securing said upper mast section in axial alignment with said lowermost section, with said aligned upper and lower mast sections projecting generally upwardly from said platform means, wherein said apparatus further includes:

support means carried bysaid 'base means and horizontally displaced from said platform means, and said support means being operable to support said upper mast section when said upper mast section is pivoted relative to said platform means toward said base means. 6. An apparatus as described in claim 1 further including: ramp means operable to support conduit section portions of said drilling means, said ramp means including: conduit storage means, v detachable mounting means operable to detachably secure said storage means to one end of said base means, with said storage means being inclined downwardly and outwardly from said base means, and ramp means detachably connected with said storage means and operable to project'upwardly from a base portion of said storage means, through said base means, to the general vicinity of said radialspacebetween said platform means and said cylindrical plane. 7. An apparatusas described in claim 1 further including: transfer means adapted to move a conduit portion of said drilling means from said platform meanstoward a conduit storage means, said transfer means including:

cylinder means pivotablymounted on said mast-means,

piston means telescopingly mounted within said cylinder means,

means adapted to supply piston motivating fluid to said cylinder means and thereby induce reciprocal movement of said piston means,

conduit engaging means pivotably mounted on said mast means,

said piston means being pivotably engaged with said con- 7 duitengagingmeans, and

said conduit engaging means being operable to move away from said mast means in response to reciprocation of said piston means, to thereby move a conduit 7 portion of said drilling means, supported by said mast means, and disengaged from said rotary drive means, generallyaway fromsaidmast means and toward said conduit storage means. 8.. A drilling apparatus comprising: base means, platform means adapted to support rotary drive means,-with said rotary driverneans being operable to impart rotation to drillingm'eans'; I mast means supported on said platform means;

arcuate support means pivotallymounting said platform means on said base means,

said arcuate support means being operable to rotate.v

about a generally horizontal axis;

arcuate bearing means mounted on said base means and supporting said arcuate support means for rotary movement about said generally horizontal axis; said arcuate support means providing periphery means engaged with said bearing meansand generally aligned with a cylindrical plane which encircles said platform means; drill bit supporting, means operable to support a drill bit support means, being mounted in said base means, said drill bit support means disposed at least partially beneath aportion of said platform means operable to support said rotary drive means;

said arcuate support means including first and secondarcuate supportsdisposed generally on opposite sides of said.

drill bit support means;

said arcuate bearing means including first and second arcuate bearings, engageable, respectively, with said first and second arcuate support means;

said platform means including mounting means for a rotary.

.drive means; said drill bit support means including:

fixed track means fixed in position on said base. means,

movable track means carried by said base means and disposed. generally beneath the portion of said platform means adapted to support said rotary drive means,

said movable track means being disposed in pivotable relation tosaid fixed track meanstand defining a continuation thereof, with said movable track means being operable to pivot so as to be perpendicular to the axis of rotation of said rotary drive means, through a range of pivoting movement of said arcuate support means;

said mast means including:

a lower mast section fixedly secured to said platform means, 1

an upper mast section pivotably attached to said lower mast section,

meansfor releasably securing said upper mast section in axial alignment with said lowermost section, with said aligned upper and lower mast sections projecting generally upwardly from said platform means; and

' ramp means operable to support conduit section portions of ramp means detachably connected with said storage means and operable to project upwardly from a base portion of said storage means, through said base means, to the general vicinity of said radial space between said platform means and said cylindrical plane. 9. A drilling apparatus comprising: portable base means; platform means adapted to support rotary drive means, with said rotary drive means being operable to impart rotation to drilling means; mast means supported on said platform means, said mast means including: means for supporting said drilling means for substantially axial movement through said rotary drive means; arcuate support means pivotally mounting said platform means on said base means, said arcuate support means being operable to rotate about a generally horizontal axis; arcuate bearing means mounted on said base means and supporting said arcuate support means for rotary movement about said generally horizontal axis; said arcuate support means providing periphery means engaged with said bearing means and generally aligned with a cylindrical plane which encircles said platform means; drill bit support means operable to support a drill bit for attachment to said drilling means, said drill bit support means being mounted in said base means, said drill bit support means beingdisposed at least partially beneath a portion of said platform means operable to support said rotary drive means; ramp means operable to support conduit section portions of said drilling means, said ramp means including: conduit storage means;

detachable mounting means operable to detachably secure said storage means to one end of said base means, with said storage means being inclined downwardly and outwardly from said base means, and ramp means detachably connected with said storage means and operable to project upwardly from a base portion of said storage means, through said base means, to the general vicinity of said radial spaced between said platform means and said cylindrical plane; and transfer means adapted to move a conduit portion of said drilling means from said platform means toward said conduit storage means, said transfer means including: cylinder means pivotably mounted on said mast means, piston means telescopingly mounted within said cylinder means, means adapted to supply piston motivating fluid to said cylinder means and thereby induce reciprocal movement of said piston means, conduit engaging means pivotably mounted on said mast means, said piston means being pivotably engaged with said conduit engaging means; and said conduit engaging means away from said mast means in response to reciprocation of said piston means, to thereby move a conduit portion of said drilling means, supported by said mast means, and disengaged from said rotary drive means, generally away from said mast means and toward said conduit storage means.

being operable to move l6 10. A drilling apparatus comprising: portable base means; platform means;

mast means supported on said platform means;

arcuate support means pivotally mounting said platform means on said base means, said arcuate support means being operable-to rotate about a generally horizontal axis;

arcuate bearing means mounted on said base means and supporting said arcuate support means for rotary movement about said generally horizontal axis;

said arcuate support means providing periphery means engaged with said bearing means and generally aligned with a cylindrical plane which encircles said platform means; said arcuate support means including first and second arcuate supports disposed generally on opposite sides of said drill bit support means, with each of said first and second arcuate support including: first semicylindrical web means carried by said platform means, facing generally downwardly, and having an axis of curvature coinciding with said generally horizontal axis; said arcuate bearing means including first and second arcuate bearings, engageable, respectively, with said first and second arcuate support means, each said first and second arcuate bearing means including: second, semicylindrical web means supported by said base means and disposed in supporting and conforming engagement with one of said first semicylindrical web means'of said arcuate support means; and said platform means including mounting means for a rotary drive means, said mounting means being spaced radially inwardly from said cylindrical plane. 11. An apparatus for manipulating conduit sections of a drill string, said apparatus comprising:

base means;

mast means projecting upwardly from said base means; pipe storage means disposed laterally of said mast means and extending downwardly and outwardly of said base means, pipe transfer means pivotally mounted on said mast means, said'pipe transfer means being operable to displace a conduit section of a drill string from said mast means to the general vicinity of said pipe storage means; said pipe storage means including: pipe receiving means carried by said base means,

pipe racking means disposed at least in part beneath said base means, and ramp means for guiding movement of conduit sections from said pipe-receiving means to said pipe-racking means,

at least a portion of said ramp means being inclined relative to said base means, and at least a portion of said pipe-racking means being inclined relative to said base means and disposed 5 5 laterally of said at least a portion of said ramp means.

12. An apparatus for manipulating conduit sections of a drill string according to claim 11 wherein:

said at least a portion of said pipe-racking means comprises foraminous racking surface means for permitting fluid to 0 drain from conduit sections located in said pipe-racking means.

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