US3554298A

US3554298A - Breakout apparatus for a sectional drill stem

Info

Publication number: US3554298A
Application number: US852537A
Authority: US
Inventors: Harold T Klein
Original assignee: Robbins & Assoc James S
Current assignee: JAMES S ROBBINS AND ASSOCIATES Inc; Robbins & Assoc James S
Priority date: 1967-08-07
Filing date: 1969-08-25
Publication date: 1971-01-12
Anticipated expiration: 1988-01-12

Abstract

A drill stem section having breakout wrench receiving depressions or flats formed on its outer surface substantially immediately axially inwardly of an end located threaded tool joint component. A reversible rotary drivehead including a threaded tool joint component connectable to the stem section tool joint component and a breakout wrench including a jaw wrench on the drivehead and a torque transmitting insert element insertable between the breakout wrench receiving depressions or flats on the drill stem section and the jaws of the jaw wrench. Means for holding the stem section second from the drivehead during reverse rotation of the drivehead and first stem section through the insert element.

Description

United States Patent inventor Harold T. Klein Bellevue, Wash.

Appl. No. 852,537

Filed Aug. 25, 1969 Division of Ser. No. 658,674, Aug. 7, 1967, Pa; No. 3,463,247.

Patented Jan; 12, 1971 Assignee James S. Robbins and Associates, Inc.

Seattle, Wash. a corporation of Washington BREAKOUT APPARATUS FOR A SECTIONAL DRILL STEM [56] References Cited UNITED STATES PATENTS 306,588 10/1884 Cronin 166/775 3,291,225 12/1966 Foran 173/164 3,446,284 5/1969 Dyer et a1. 175/85X Primary Examiner-Ernest R. Purser Attomey-Graybeal, Cole & Barnard ABSTRACT: A drill stem section having breakout wrench receiving depressions or flats formed on its outer surface substantially immediately axially inwardly of an end located threaded tool joint component. A reversible rotary drivehead including a threaded tool joint component connectable to the stem section tool joint component and a breakout wrench including a jaw wrench on the drivehead and a torque transmitting insert element insertable between the breakout wrench receiving depressions or flats on the drill stern section and the jaws of the jaw wrench. Means for holding the stem section second from the drivehead during reverse rotation of the drivehead and first stern section through the insert element.

PATENIEHJANI 2 l97| sum 1 or 4 INVIL'NTUR. T. KLEIN HAROZD KW,

A T TORNE Y5 PAIENTEU JAN 12 Ian v 3 sum 2 or 4 INVIiN'In/e HAROLD I KLEl/Y PATENTEB mg i am sum 3 BF 4 66 ,5 INVENTOR.

HAROzD I KlE/N a l ws .444?

Afro/mere PAIENTEUJAMMQ?! SHEET R []F 4 I INVENTOR. l/AkOlD I KZE/N prising plural pipe -sections joined by threadedpin'and box-.

type tool joints. More particularly, it relates to apparatus for rotatively coupling the drill stemto'the-drivehead atatime 15 when the threaded tool joint betwee'nthe two is loosefso. that the drivehead can be rotated in reverse to 'invturn rotate the drill pipe threaded to it, without unscrewingthe tool'joint between such drivehead'and the pipe. It alsov relates to a breakout technique-in which such apparatus is used to loosen mechanisms to breakout tightly set 'up' threaded tool joints. 2 5 J drivehead wrench and the recesses or flats carried by the drill pipe.

According to the breakout technique of the present invention, the portion of the drill stem connected to the upper section is held against both rotational and axial movement. This may be done by anchoring it to a wrench table situated relatively close to the entrance to the drill hole-,by means of a horseshoe wrench or the like engaging holding wrench surface depressions formed in side areas of the drill pipe at a location axially inwardly of, and preferably immediately adjacent to,- the turning wrench receiving recesses or flats. The drivehead is then reversed to randomly loosen-one or. the other of the two tool joints at the opposite ends of the first section of drill pipe; If the tooljoint at the drivehead end of the first section of pipe is first to loosen, then the turning :wrench carried by the drivehead is coupled to the turning wrench receiving recesses or flats, and the driveheadis rotated in reverse to first loosen and then decouple the other tool joint. The first section is then removed and the drivehead is lowered or raised, depending upon the direction of drilling, in order to place its-tool joint component. in position to be loosely coupled to the tool joint component of the second section; A new tool joint is then Manipulation ofsuch tongs and power mechanisms requires hard manual work, andin additionthey-make the breakout operation both-hazardousandtime-consuming;

Alexander,- US. Pat. No, 3,239,016 proposes a breakout method and apparatus in which'tongsiand manually applied thelower joint loosens first, the upper section of-pipe is rotated until the threadsaareicompleteiy decoupledL-flhemthe drivehead and the upper' section of pipe attached: thereto are raised until the squarehea'dzofi theextensioniis-engaged inlthe: square socket of EhESEC OHdSflZIlOIIrThBD, the driveheadis again reversed to causezfirst'aloosening andithen-a complete decoupling of the jointatthe-upper end of theupper sec tion. If the upper tool jointis the first to loosen; thedrivehead is reversed untilthethreads of such joint*are:e ntirely disengaged, and'then theydriveheadis moved axially upwardlyrto place the square head of-a'naxialxtensionofthedrivehead. inside the square socket'at theuppenend' ofthezupper -section .ofi drill pipe. Themuthedrivelheadsis reversed to'first: loosen. and then entirely disengagertheathreads of the lower tool joint;

Thornburg, U.S. Pat;No.2,972,388 andForan, U.S. Pat. No. 3,29-l,225*disclose, drilling machines-whii:h:includeauxiliary, wrench mechahisms actuatab le to directly. grip-portions of'thedrillpipe. I 7

SUMMARY 'OFTHEINVENTION The drill pipe of theipresent invention coruprisesa threaded"! 50":

pin atone end, a. threaded. box atith'elother end, and externally located axially inwardly bfthe ztooljoint component at such. end. v

In preferred for'm the iauxiliary torque transfer means comprises diametrically opposedirecesses or wrenchaflatsft'ormedi on the-drill pipe-axially -inwardly ofltheathreaded'pin. Thel.

@ power mechanismsare" not used. lnstead,;the pipe 'sections: are

, reached. auxiliary torque:- transfer 1 means at one? end. only,

drivehead includes ax'threadedrboicand'auxiliarytorque 'transferring means in 'the*-forrn-:of :aturningwrench which extendsaxially outwardly beyondthe bomand. is positionable radially outwardly of the" recesses or flatsion the drill pipe when; the

threaded pin of the-drill pipe-=isiat least partially in ;the

threaded box of the drivehead .wrenchjf jaws'," which maybe;

in the 'form of removablemetal barsor blocks arei-snuggly fittablein spaces formed-between inner surface portions of the;

loosely made up between the drivehead and the second section and. the holding wrench is removed from the second section. Then the'drivehead is moved axially with the axial forces being carried by the-threads of the loosely madeup tool joint until the: holding wrench receiving surface depressionsof the third section are at the holdingrwrenc'h table and the second section is in position for removal.

Also'accordingto the breakout technique of the present in-' vention, if the'tool joint at the end of the first section opposite from the drivehead is the first to be loosened, then with-suchjoint loosely madeup, sothat thethreads thereof can'carry the weight of the portion of the drill stem still in the drill hole, the drivehead is moved toward the drill hole until the holding wrench receiving means of the first section-is in a position to be engaged and held by the holding wrench'at the wrench ta-' ble. Thenethedrivehead is rotated in reverse until the tool joint between it and the upper section has; been'loosenedi 'lhe' joint is loosened but not decoupled, sogthat the threads can carry the weight'of the drill pipe. Then the holding wrench is removed and-lthedrivehead is moved axially awayfrom the drill hole so as to return the first section to a position-for removal. The holding wrench is refitted to the second section,

and then the first section, which now has a-loosely coupled' joint'at eachofits ends, is easilyunthreadedand removed;

- Anotheraspect-of the inventionis the provision of 'alengtli- 'or section of drill pipev that comprises a. major part having" identical: tool joints-at itstwo' ends, and a relatively short" minorpart having identical tool joints atits=two 'ends.The=tool jointsiof-oneof the partsare threaded-boxes and the tooljoints on "the: other part are complementary threaded pins.-1lriitiall'y' theminor part is threadablyconnectedby-either 'on'e ofit-t'ool jointsto eitheroneofthetool joints of the major'part'; so as-to' provide a'length of drill pipe with a threaded'pin at one end'" thereof and-a threaded box at the oppositeend thereoff Then;- when'such pinand"box have become womtoa-pointlthat 'one or both of themshould bereplaced, the are mat! g; the wom pin with the wornbox, was to :providethe jle'n'gtli of drill pipewith' a'new' pin anda'new box 'at its two&ends: Ac cording tothe invention, theminor part compriseswpair ot" substantially identical wrench receiving" means -whichiare' aiti separated where originally joined and are rejoined by ally spaced and symmetrically-arrangedtbetween-theitwoneol joints for therninor part.=ln preferred form-the ntinor part hasthreadedtpinsat its two ends and the'rnajor-part' hasthie'aded boxes at its two ends.

tionwith'the accompanyingillustra'tion:

BRIEF DESCRIPTION OF THE DRAWING In the drawing like element designations refer to like parts, and:

FIG. 1 is a small sca e front elevational view of a traveling head-type drilling machine and a sectional drill stem, both of which embody features of the present invention;

FIG. 2 is an enlarged scale perspective view of one of the sections of drill pipe that make up the drill stem, shown partially in section to better illustrate the construction thereof;

FIG. 3 is a fragmentary perspective view of an upper section of drill pipe interconnected between the drive head and a second length of drill pipe, showing wrench completion blocks in position between the wrench forming extensions of the drivehead and the turning wrench receiving recesses of the upper length drill pipe, and showing the second length of drill pipe anchored to a table by a horseshoe wrench, with the drivehead being in partial section to better illustrate the construction thereof;

FIG. 4 is a view partially in section and partially in elevation of the components of FIG. 3, but minus the horseshoe wrench and showing tight engagement of the threads at both the upper and the lower tool joints;

FIG. 5 is a view similar to FIG. 4, but showing the horseshoe wrench holding the second section, the upper threaded joint decoupled, and the turning wrench completion blocks spaced radially outwardly from their recesses in the upper section of drill pipe;

FIG. 6 is a view similar to FIGS. 4 and 5, but showing a loose engagement of the threaded joint at the upper end of the upper section of drill pipe, the turning wrench completion blocks in place, and the threaded joint at the lower end of such upper length of pipe decoupled;

FIG. 7 is a view similar to FIGS. 4-6, but typifying a situation wherein on reverse rotation of the drivehead, for random breaking of the threaded joints, the lower threaded joint breaks first, and showing said lower joint decoupled;

FIG. 8 is a view similar to FIGS. 47, but showing the upper length of drill pipe lowered to a position adjacent the wrench table, with the horseshoe wrench engaging the holding wrench surface depressions of such upper length of drill pipe, and showing the drivehead being ready for use to loose the upper threaded joint;

FIG. 9 is a cross-sectional view taken through the upper length of drill pipe at the holding wrench receiving surface depressions, substantially along line 9-9 of FIG. 7;

FIG. 10 is a cross-sectional view taken substantially along line 10-10 of FIG. 6, and showing the cross-sectional configuration of the drill pipe in the region of the turning wrench receiving surface depressions, and showing the turning wrench completion blocks in their position of use; and

FIG. 11 is a view partially in section and partially in side elevation of a modified form of drill pipe, characterized by a minor part, or sub, of symmetrical construction which is relocatable in position from one end of a longer major part to the opposite end of the major part, to provide new tool joints at the ends of the pipe sections.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS Referring to FIG. 1, the drilling machine 10 is shown to comprise a base portion 12 which may be firmly anchored to a concrete pad 14 which is in turn anchored to the ground 16. Base portion 12 is shown supporting guide column means 18 for a traveling drive or drill head assembly. The drivehead assembly includes a carriage 20 having guide sleeves 22 at each of its ends which surroundingly engage the guide column means 18. Hydraulic cylinder column means or the like (not shown) are provided for moving the carriage 20, and a drivehead 24 canied thereby, up-and-down along the guide column means 18. Carriage 20 also carries motor and gearing means, indicated generally at 25, for rotating the drivehead 24. The motor and gearing are adapted to rotate the drivehead 24 in either direction at the selection of the operator. Base portion 12 also supports a holding wrench table 28, the function of which will hereinafter be described in greater detail.

The drivehead 24 includes an upper neck portion 30 by which it is attached to the motor and transmission means 26. It also includes an internal collar 32 (FIGS. 3-8) which is internally threaded to provide a box-type tool joint component. The sleeve 32 is surrounded by a husky annular portion of the head 24, and is supported within said annular portion for limited axial movement by means of a plurality of circumferentially arranged, axially extending splines 34, or the like. The splines 34 hold the sleeve 32 against rotation relative to the head 24, but as previously mentioned, permit a limited amount of axial movement of the sleeve 32 within the head 24. Head 24 further includes an axial extension which in the illustrated embodiment is of two

parts

36, 38 occupying diametrically opposed positions on the head 24, and each extending axially outwardly from the axial station of the sleeve 32 and the tool joint component carried thereby. As will hereinafter be described in greater detail, the two

portions

36, 38 of the extension are positionable generally radially outwardly of specially constructed portions of the drill pipe. As shown by FIG. 10, in the illustrated embodiment the two

portions

36, 38 of the drivehead extension are provided with diametrically opposed, flat, parallel surfaces 40, 42, which will hereinafter be termed wrench surfaces.

The drill stern S is of sectional construction. Each section or component is a length of pipe, and more accurately a length of drill pipe." The drill stem S may consist of standard section 44, such as illustrated in FIGS. 1-3, for example, or special sections (not shown) such as stabilizer sections, collars, subs,

etc.

According to the present invention, the standard sections 44 comprise a threaded pin 46 at one end thereof and a threaded box 48 of complementary character at the opposite end thereof. The type of threads used on the pin 46 and in the box 48 may differ somewhat in construction depending on the magnitude of the torque forces which the made up tool joints must carry during normal drilling.

As best shown by FIG. 2, the drill pipe is internally upset for a considerable distance axially inwardly of the pin 46, to provide a substantial wall thickness in that region. A first set of exterior surface depressions are formed on the drill pipe 44 at a location axially inwardly of, and substantially immediately adjacent, the pin 46. In the illustrated embodiment these surface depressions are shown in the form of a plurality of arc-tochord cuts in the exterior wall of the upset portion. The pipe 44 is shown to include a second set of surface depressions 52 formed in the upset portion at a location spaced axially inwardly of, and substantially immediately adjacent the first set of depressions 50. In the illustrated embodiment the

depressions

50, 52 are shown to be identical in construction, but this arrangement is not absolutely necessary, as will hereinafter be explained in some detail. Except at the regions of the

depressions

50, 52, the drill pipe 44 has a generally round exterior shape. Radial flanges 54 are located between the pin 46 and the first set of surface depressions 50, and similar flanges 56 are located between the first set of depresions 50 and the second set of depressions 52.

According to the present invention, the first set of depressions 50, which provide the drill pipe with a noncircular cross section at their location, are a part of auxiliary torque transfer means which also includes the

drivehead extension

36, 38, and which is employed during the breakout operation. The second set of depressions 52, and the radial flanges 56, constitute a part of means for restraining or anchoring the drill pipe against both rotational and axial movement.

In the illustrated embodiment the wrench surfaces 40, 42, carried by the

axial extension

36, 38 of the drivehead 24, are spaced apart a distance that is greater than the outside diameter of the drill pipe in the region of the flanges 54. Thus, they offer no interference to easy passage of the pin 46 into or out the drill pipe by means of the wrench defined by the drivehead defined on the sides bythe

surfaces

50 or 42 and 50, and on top and bottom by

theflanges

54, 56. As clearly shown by FIG. 10, these blocks 58 are sized tosnuggly fit within such nooks. In the illustrated embodiment the

drivehead extension

36, 38 and the wrench completion blocks 58 together form a radially adjustable wrench means, operable as an auxiliary torque transfer means between the drivehead and the drill stern S. v

The wrench table 28, which is located'in close proximity to the entrance 60 to the drill hole Dl-I (FIG. 1), includes an opening or slot 62 through which the drill stem S passes. The table 28 includes asquare sided (for example) box 64 adapted to snuggly fit the outside dimensions of a holding wrench 66. As shownby FIG. 3, theholding wrench 66 may be of the horseshoe wrench type, composed of a pair of laterally spaced, parallel tines68, interconnected by astem'portion 70 which may be equipped with handle. means 72. The horseshoe wrench 66 is in the nature of an open ended wrench, and the open area between the tines 68 and outwardly of the stem 70 is sized to snuggly receive the drill pipeat the surface depressions 52. The horseshoe wrench 66 is restrained against rotation by the square sided box 64, and it in turnholds the drill pipe and prevents it from rotating relative to the table 28. In a down drilling operation gravity prevents upward axial movement of the drill pipe, and the overlapping engagement of the radial flanges 56 with the holding wrench tines 68 prevent downward axial movement of the drill pipe.

FIG. 1 l discloses a modified form of drill pipe 44 embodying features of the present invention. It comprises a major part 74 and a minor part or sub 76. In this forrn'the major part 74 is formed to include identical threaded boxes at each of its two ends, and the minor part 76 is formed to include identical threaded pins 46 at each of its two ends. Initially the minor part 76 is threadablyconnected by either one of its too] joints to either one of the tool joints of the major part 74, so as to provide the drill pipe section 44' with a threaded pin at one end thereof and a threaded box of complementary character at the opposite end thereof. Then, when the threads of such v pin and box have become worn to apoint that one or both of them should be replacednhe two parts 74, 76are separated where originally joined and are. rejoined by mating the worn pin and the wornbox. This ineffect provides the drill pipe section 44' with a new pin and anew box at its two ends. This is because during the first life of the pipe section 44' the mated inner pin and inner box are always together anddonot encounter the type of wear that, the end located pin and box experience, through "repetitious coupling and decoupling of them with other tool joint components. Besides plain wear the end place pin and box (particularly the pin) are subjected to thread damage, such as. by an inadvertent bumping of them.

against other pieces ofdrill pipe, the ground, or portions of the drilling machine proper.

A single section with damaged'or substantially worn tool joints can have a serious damaging effect on the entire drill stern S and must be repaired or replaced. The reversible sub 76v provides an easy and inexpensive way of repairing or rebuilding a drill pipe section, soas to prolong its useful life. Owing to this construction, it is also possible, following use of both sets of pins and boxes, to rework theends of the major part 74 to provide itwith a new box at. each of its ends, and then use with it anew sub or minor part 76. This is a very economical manner of remanufacturing the drill pipe. section 44, because the sub'76 isrelatively economically manufac* tured, and it is a relativelyeasy operationto form new boxes at the ends of the major part 74.

The

wrench receiving depressions

50, 52, and the cooperar. 'ing

radial flanges

54, 56 are all formed on the sub 76. In this situation it is necessary to make these parts identical, because when the sub 76 is reversed from its initial position at one end of the major part 74 to its drill pipe life-extending position at the opposite end of the part 74, the depressions which were once the turning wrench receiving recesses 50 become the holding wrench recesses 52, and the depressions which were originally the holding wrench recesses 52 become the turning wrench recesses 50. The radial flanges 54 are provided at each end of the sub 76. The radial flanges 56 are centered between the ends of the sub 76, and functions as the means for restraining the drill pipe againstaxial movement in the gravitational direction regardless of the end of major part 74 to which the minor part 76is attached. As shown by FIG. 11, the sub 76 is of symmetrical construction end-to-end- (the center of symmetry being a radial plane bisecting the flanges 56).

The breakout technique of the present invention will now be described.

Let it be assumed in the drilling operation depicted by FIG. 1 that the carriage 20 and the drivehead 24 carried thereby are in the process of being moved upwardly along the guide columns 18, and the drill stem S is being withdrawn from the drill hole DI-I. When the upper or first section 44 is wholly above the wrench table 28, and the-holding wrench receiving depressions 52 of the second section 44 are in position at the wrench table 28 to receive the holding wrench 66, axial movement of the carriage 20 is stopped (FIG. 4). The holding wrench 66 is then inserted in place, within the square sided box 64, about the second pipe section atthe region of the depressions 52, and below the radial flanges 56. The portion of the drill stern S below the first section 44 is then restrained or anchored against both rotational and downward axial or gravitational movement.

The drivehead 24 is then reversed, i.e. rotated in a tool joint loosening direction, for the purposeof. randomly loosening one of the tool joints at the opposite ends of the upper section 44. FIG. 5 relates to the situation when the upper tool joint loosens first, and for the sake of clearer illustration. shows the two upper joint components actually separated. FIG. 7 depicts the lower tool joint having loosened first, and also shows the two

joint components

46, 48 separated.

Let is be assumed that the random loosening operation caused the upper joint to loosen first. The threads are preferably not totally separated, but rather are maintained loosely joined. The flat and parallel chord surfaces of a diametrically opposed pair of the depressions 50are oriented,

by rotation of the drivehead 24 relative to the upper pipe section 44, to substantiallyplace them in parallelism with. the drivehead wrench surfaces 40, 42. Then the wrench completion blocks 58 are slid into place (FIG. 10) as previously described. After this has been done the drivehead is again rotated in the thread loosening direction. The portion of'the drill stern S below the upper section 44 is still'restrainedby theholding wrench 66, and now the wrench completion-blocks transmit torque from the driveheadto the upper section. 44,. resulting in a loosening of the threads at the lower tool joint. With the tool joints at both ends of the upper sectionnow loosened, the upper section can be easily unscrewed and removed from the drill stem S. After this is done thedriwel'tead 24is lowered and coupledto the. next pipesectionMbyrlooseP ly screwing together its box and the upstandingpimof theznext section 44. The drivehead 24 is then raised, with thezweight of the drill stem S being carried by the loosely engaged threadsof the loosely made uptool joint, until such next section issin. a position for removal wholly above the: holding wrench table 28, and the holding wrench receiving depressions 52 of the following section are at the holding wrench station of the table 28. The wrench completion blocks. 58 are again inserted between the drive head surfaces 40, 42 and the surfaceszofanopposed pair of the turning wrench receiving depressions 50, and the drivehead 24 is operated as before to .loosenthe threaded tool joint which is now at the wrench table. This latter stage is repeated with the subsequent sections until all sections of the drill stern S have been removed from the drill hole DH.

lf during the initial reversal of the drivehead 24, to cause a random loosening of f re tool joints, the lower joint was the first to loosen, then an added stage must be added to the technique in order to effect loosening of the tool joint between the upper section and the drivehead 24. This stage involves maintaining the loosened lower tool joint components coupled, so that their threads may carry the weight of the drill stern S, then removing the holding wrench 66, and then moving the drivehead 24, with drill stem S attached, downwardly until the holding wrench receiving depressions 52 of the upper section are at the holding wrench station at table 28. As shown by FIG. 8, the holding wrench 66 is then set in place and used to support the drill stem S and prevent its rotation. The drivehead 24 is then rotated in the joint loosening direction until the threaded tool joint between it and the upper pipe section 44 is loosened. When this happens the joint components are maintained loosely coupled, again so that the threads can carry the weight of the drill stem S, and then the drivehead 24 is raised to relocate the upper pipe section 44 in a proper position for removal. The holding wrench 66 is reinstalled on the second pipe section 44 and the first section 44, now having both of its tool joints loosened, is easily unscrewed from the second section and from the drivehead 24, and then removed from the drill stem S.

lt is to be understood that the character of the auxiliary torque transfer means, the turning wrench receiving depressions and the holding wrench receiving depressions may vary from what is illustrated and described. For example, it may be desirable to make the axial extension of the drivehead 24 annular in shape and provide it with a radially extending bore or passageway that is alignable with a radially extending bore or passageway formed through the drill pipe in the region thereof immediately axially inwardly of the tool joint component and radially inwardly of the drivehead extension. in this situation a rod or large pin may constitute the wrench completion element and be inserted through the aligned bores. in some installations it might be desirable to use a cross pin for anchoring the drill pipe to the wrench table 28. in the illustrated embodiment the wrench completion blocks 58 in effect serve as keys," ie they key" the drivehead to the drill pipe. in other installations it may be desirable to use keying" elements of a difierent shape or character. Although the drivehead 24 is shown and has been described as including a threaded box type of tool joint component, in some installations it might be desirable to provide it with a pin type of tool joint component, in which case the box ends of the pipe sections would be directed toward the drivehead, rather than the pin ends as is illustrated. Also, it is to be understood that the present invention is applicable to a drilling operation in which the drill stem 8 extends generally upwardly from the drilling machine.

Iclaim:

1. Drilling apparatus comprising:

a sectional drill stem composed of a plurality of sections joined together by threaded box and pin tool joints, each said section having a threaded pin at one of its ends and a threaded box at its opposite end;

a rotary drivehead including a threaded tool joint component connectable to the drill stem tool joint components which face the drivehead;

means for moving the drivehead axially both towards and away from the ground being drilled; and

breakout apparatus for forcibly loosening the threaded connection between a given first drill stem section connected to the drivehead and the drill stem section second from the drivehead, said apparatus comprising side located wrench element engaging meanson said first stem section, adjacent the end thereof connected to the drivehead, breakout wrench jaw means on said drivehead having wrench surface means which in use at least is spaced radially outward! from the wrench element engaging means on said firs stem section, a torque transferring wrench insert element sized to snugly fill the radial space between said wrench surface of the breakout wrench jaw means and the wrench element engaging means on the first stem section, means for holding the second stem section and restraining it against both rotational and axial movement, and means for rotating said breakout wrench jaw means in a joint loosening direction, resulting in a joint loosening rotational torque being transferred from the breakout wrench jaw means to the first stem section through the torque transferring wrench insert element and a loosening of the threaded joint between the first and second stern sections.

2. Drilling apparatus according to claim 1, wherein said breakout wrench jaw means generally surrounds the tool joint component of said drivehead and said tool joint component is movable axially with the first stem section while such first stem section is being rotated in the joint loosening direction for unscrewing it from the held second stern section.

3. Drilling apparatus according to claim 1, wherein said breakout wrench jaw means generally surrounds the tool joint component of said drivehead and each is axially movable relative to the other.

4. Drilling apparatus according to claim 1, wherein the wrench element engaging means on the first stem section is a substantially flat surface, the wrench surface of the breakout wrench jaw means is also a substantially flat surface, and said insert element has a thickness dimension substantially equal to the radial distance between said surfaces and it has substantially flat inner and outer surfaces.

5. Drilling apparatus according to claim 4, wherein said breakout wrench jaw means generally surrounds the tool joint component of said drivehead and said tool joint component is movable axially with the first stern section while such first stem section is being rotated in the joint loosening direction for unscrewing it from the held second stem section.

Disclaimer 3,554,298.Har0ld T. Klein, Bellevue, Wash. BREAKOUT APPARATUS FOR A SECTIONAL DRILL STEM. Patent dated Jan. 12, 1971. Disclaimer filed June 21, 1973, by the assignee, James 8. Robbins and Associates, Inc. Hereby disclaims the portion of the term of the patent, subsequent to Aug. 26, 1986.

[Ofic'ial Gazette April .9, 1.974.]

Claims

1. Drilling apparatus comprising: a sectional drill stem composed of a plurality of sections joined together by threaded box and pin tool joints, each said section having a threaded pin at one of its ends and a threaded box at its opposite end; a rotary drivehead including a threaded tool joint component connectable to the drill stem tool joint components which face the drivehead; means for moving the drivehead axially both towards and away from the ground being drilled; and breakout apparatus for forcibly loosening the threaded connection between a given first drill stem section connected to the drivehead and the drill stem section second from the drivehead, said apparatus comprising side located wrench element engaging means on said first stem section, adjacent the end thereof connected to the drivehead, breakout wrench jaw means on said drivehead having wrench surface means which in use at least is spaced radially outwardly from the wrench element engaging means on said first stem section, a torque transferring wrench insert element sized to snugly fill the radial space between said wrench surface of the breakout wrench jaw means and the wrench element engaging means on the first stem section, means for holding the second stem section and restraining it against both rotational and axial movement, and means for rotating said breakout wrench jaw means in a joint loosening direction, resulting in a joint loosening rotational torque being transferred from the breakout wrench jaw means to the first stem section through the torque transferring wrench insert element and a loosening of the threaded joint between the first and second stem sections.

2. Drilling apparatus according to claim 1, wherein said breakout wrench jaw means generally surrounds the tool joint component of said drivehead and said tool joint component is movable axially with the first stem section while such first stem section is being rotated in the joint loosening direction for unscrewing it from the held second stem section.

5. Drilling apparatus according to claim 4, wherein said breakout wrench jaw means generally surrounds the tool joint component of said drivehead and said tool joint component is movable axially with the first stem section while such first stem section is being rotated in the joint loosening direction for unscrewing it from the held second stem section.