GB2330609A - Drilling apparatus with dynamic cuttings removal and cleaning - Google Patents

Abstract

A drilling apparatus has a cuttings or debris removal structure to reduce balling thereof and comprises an apparatus body having a connection thereon, and structure for contacting cut portions of the earth formation or other debris and which is movable in the flow of drilling fluid. The contacting structure may include chip breakers, flexible cables, rotating nozzle assemblies, rotating turbine wheel assemblies, rotating vane assemblies, flails or combinations of these. The apparatus may include elastomeric portions and/or movable portions. The drilling apparatus may comprise a drill bit, drilling stabilizer, drill collar, reamer, downhole motor, etc.

Description

2330609 1 DRILLING APPARATUS WITH DYNAMIC CUTTINGS REMOVAL AND CLEANING

This invention relates to improvements for drilling accessories, drill bits and the like, the improvements having t h e abil ity to break cuttings produced from drilling operations and to prevent or -remove cuttings or mud solid material accretlon on such drilling accessories, drill b'Lts and the like. More specifically, this invention relates to drilling accessories, drill bits and the like having the io dynamic capability, either mechanical, hydraulic or both, to break drill cuttings produced from the formations being drilled into smaller, more easily transported cuttings in the drilling fluids, to remove the drilled material and/or solids therefrom or to prevent accretion of material or sollds thereon. The invention is particularly useful with drilling accessories, drill bits and the like used in either plastic and sticky rock - formations or formations and drilling fluids which tend to build up or accrete on the drilling accessories, bits, and the like.

The clogging of the various fluid courses, surfaces and cavities of drilling accessories, drill bits and the 12'.ke by the highly ductile cuttings produced -from drilling onerations in plast-ic formations, or solids from the formations, o_r solids from the drilling fluid, is typically referred to as "balling, " or "bit balling" if it is a drillbit. The drilling of shales or other plastic types of rock formations has always been difficult for all types of downhole drill bits and particularly when using drag type drill bits. The shales, when under pressure and in contact with drilling fluLds, tend to act as a stIcky mass, and tend to ball or clog cutting surfaces and cavities of the drill bit, thereby reducIng the bit's cutting eff- ectiveness. Other formations, when contacted with particular types oil drilling fluid systems, can also cause seve--e balling problems by L-he drilling fluid system 2 enhancing or enabling the cuttings from the fo---,1a--ion to accrete on the drill bit and drilling accessories.

Also, certain types of formations being dr-:.11ied w,-A-r, subjected to high hydrostatic drilling fluid pressure, suc,-, as in highly weJLgn'zea drilling _fluids used at greaz depths, are highly plastic ceneratJLng long, ductile cuttJnc:s dur.J.na drilling operations. Unless such cuttings are e-.f.ecz-ive-,y broken into more manaceable, smaller cuttincs, the va---ic.us fluid courses, surl aces and cavities of the drill bit and drilling accessories become clogged, thereby reducing their effectiveness.

one typical pr:Lor art approach wh_ich deals such- a drag bit balling problem has been to provide large cutters on the bit with strong drilling fluid hydraulics in the proximity of the cutters in an a-L-temDt to remove the cuttings from the cutter faces with high-volume, high-velocity hyd-raullc Jet flow of the drilling fluids. For example, see U.S. Patent 4,116,289.

Another prior art attempt to deal wIth such drag bilt balling problem is illustrated in UK Patent GB 2181-173A, to Barr et al., entitled "Improvements in or relatJ.ng to -r-o-ka--y drill bits." it illustrates a bladed drag bit with a Plurality of cutters on each blade in combination with a nozzle which creates a vortex flow having a peripheral stream extending across the cutting elements and exiting into a gage region, of the bit. The cutters are shown in a spaced relationship and a nozzle is azimuthally disposed in front of each blade. The flow from each nozzle is isolated from the flow of other nozzles on the bit by the solid mass of the adjacent blades.

This tends to cause isolation of the hydraulics of each vortex pattern, presents a non-cutting bit surface between the c'-'tters to the sticky formation, and does not provide for a U - J_ hydraulic impingement on the chips, which impingement has a tendency to peel the adhered chips from the cutter faces.

1 3 Yet another prior art drag bit for cutting plastic rock formations comprises a plurality of large polycrystal line diamond cutters with each large cutter having a nozz-'.,e directing the 'flow of drilling fluids to each larce cutter zo 5 apply a force to the chip which is cut by the larce cutter. The force tends to neel the chip from the face of zhe _large cutter thereby minimizing the tendency of the b'.-, to ball. Such a bit is illustrated in U.S. Patent 4,913,244.

Still another prior art drag bit for drilling shales and sticky formations comprises a bit body, a plu--a".ity of blades.formed with the bit body extending therefrom, and at least one cutting element, pre-ferably a plurality of cutters, on each blade. Each cutter has a diamond cutting face to -reduce t-he probability of adhesive contact between the cutters and the olastic, sticky rock format_ions. Each blade defines a cavity between the blade and the body of the bl. t, thereby permit- tinc: the flow of material therethrough. -in this manner, hydraulic removal of cuttings is enhanced to avoid bit balling. To.further enhance the hydraulic fluid flow across the b-;.t--, one or more nozzles are di sposed in the bit body below each of the blades to direct the hydraulic f- low of drilling fluids across the cavity and the plurality of cutters disposed on the corresponding blade. Preferably, each nozzle is d--SQosed in the bit body behind the diamond faces of the corresponding plurality oZE cutters on a blade with respect to the direction of normal rotation of the bit during drilling. in this manner, the chip being sheared from the -formation being d_rilled extrudes upwardly across the diamond foace of the cutter to be caught at the upper edge of the cutter by the hydraulic flow from a nozzle located behind the cutter, to effectively peel away the chip from the diamond face into the various waterways and junk slots of the bit. Such a bit _Js illustrated in U.S. Patent 4,883,132.

While such bits may be effective in the drilling of 35 shales and sticky, plastic rock formations, bit balling may 1 1 4 still be a probler,-. in so,-,ie instarl.ces as the bit hydraullc f low may not effectively deal. w.Lth chic removal from the faces of the bt. In some ins-ances, the hyd-aul-c 'low not be sufficient zo peel the chips off the cuzzer faces, may not be sufficient- to break the chios a-fter leavincr the cutter faces, c-- may noz- be sufficient to cause the _removal of larce ch:os, or the inszan--aneous re.,-,iova-l of a high volume o-i.- c'-1-i:-, s -from the water-wavs, face iunk slots and junk slots of 7-he biz during drilling operations.

in. other ins-.ances, zll-,e adhes'm on procerties of t'-e com)onents of various drilling fluid systems are su_fj..-cienz to cause accretion of the fluid solids and at--enda-n--.

formation cuttincs on the dri.11 bit surfaces, t h e r e bv affecting the drilling performance of the bit drilling tools and initiation of bit balling. These problems can similarly affect the performance of dri-llir.c: accessories used drilling operations.

A,nother p-r-io- art bit L-1-1ustrated in United, States Patent 4,727,946 utilizes brush-11ke rubbing pads having a plurality of bristles, ?--c provide sea-l.';_ng around the nozzles of. the biz face a,-,d channel the drilling fluid the nozzles past the cutting elements of the bit, to helc, clean the cutting elements.

A drill bit described in United States Patent 5,199,511 utilizes an expanding pad to sealingly engage the side of the borehole to seal freshly cut, portions of the bottom of the borehole from drilling fluids. The expanding cad of the bit body is formed of an elastomeric material which is reinforced with wire or other reinforcing material and which may have an abrasive-resistant grit embedded therein and/or abrasion resistant pad thereon.

The present invention relates to drilling accessories, drill bits and the like having the dynamic capability, either mecha.-.-ical or hydraulic, or both, to break cuttincs produced from drilling operations and to prevent the accretion of material from eL-kher the drilling foluids or the being drilled material, or both, on s..,ch drilling accessories, 5 drill bits and the like.

The present invention as -5 t relates to accessories comprises an apparatus body connected in. a string and having a cleaning apparatus connected to a oo--t.;_on 0.. the apparatus body having the capability, e i zi- er -,0 meclanicaliv, hydrau'ically, or both, to break cuttings from drilling ooeratlons and to prevent the accretion o_.F thereon, or both.

The present invention as it relates to a drAJ-1-1 bIt comprises a bit body having a connection at the uppe-r end and a fluid passageway --herel.-'.rough,, a nozzle, and contacting means associated with the bit for contacting cut oortions of the earth formation to cause the cut portions to be removed from the bit body and prevent accretion thereon to prevent balling of the bit, as well as to prevent the accretion of sollids -,i:rom the drilling fluid on the bit body. Th-e contacting means comprises movable chip breakers having breaker members thereon, if desired; articulated members; springs; flex-.b-le members; flexible cables having 'Arayed ends; weights and/or chio breakers thereon; rotating nozzle assemblies where the energy from the fluid flow.Lng therefrom breaks the chips; rotating vane asse.nblies or turbine-driven assemblies, where the assembly and/or the energy from the fluid flowing therefrom or the mechanical action of a portion of the assembly breaks the chips, clears accre,'--,ior. of solids from the drilling fluids or combinations thereof.

The contacting means may be used on any drilling adcessory, such as drill collars, drilling stabilizers, reamers, downhole motors, etc., as des. Lred, in any desired fluid course, surface, cavity or area to keep them free of the 6 accretion oil materiall and to promote b--ea'.-c.5ng of the fo-r chips into smaller, more easily transported solids the drilling fluid.

The present invenzion also includes the use of 'Jo-lex-ble elastomeric members, re.'.n-.:oreed as desired, in fluid courses, surfaces, areas and cavities of the drilling accessories, drill bits and the like w'i-l-ich may be moved by the fluid to prevent the accretion of solids thereon or to helo break the chips.

Examples of the invention will now be described with re-.e--ence to the accompanying drawings in which:- Figure 1 is a drawing of a drill string having the present invention used on various components thereon; Figure 2 is a drawing of a bit having a first embodiment 15 of the present invention; Figure 3 is a part-ial cross -sect _Jonal view of a bit-having a second embodimenz o-E the present invention the-reon; Figure 4 is a partial cross-sectional view of a bit having a third embodiment of the present invention thereon; Figure 5 is a partial cross -sectionalview of a bit having a fourth embodiynent of the present invention thereon; Figure 6 is a partial cross - s ect, _Jonal view of a bit having a fifth embodiment of the present invention thereon; Figure 7 is a cross -s ectional view of a bit having a sixth embodiment of the present invention thereon; Figure 7A is a view of a bit having a seventh embodiment of the present invention thereon; 7 Figure 73 is a view of a portion of a seventh enbod.'.i,,en-kof the present invention for use in a bit; Figure 7C is a view of a portion of an eighth embodiment of the present invention for use In a bit,- Figure 8 is a cross-sectional view of a bit having a ninth embodiment oil the present invention, Figure 9 is a cross-sectional view of a bit- having tenth embodimenc of the z)resent invention; a Figure 10 is a cross-sectional view of a bit having an io eleventh embodiment of the oresent invention; Figure 11 is a cross -sect lonal view of a portion of a bic having a twelfth embodiment of' the present invention; Figure 12 is a qua_-ter cross-sectional view of a portion of a bit having a thirteenth embodiment of the present iS invention; Figure 13 is a cross -sec t ional view off a portion of a bit having a fourteenth embodiment of the preseit invention; Figure 14 is a collection of different types of flaills for use in the present invention; Figure 15 is a view of a bit having further embodiments of the present inven'Ion thereon; Fig,ire 16 is a front quar-t-e: section view of the il.l-eenth embod;men'- of the oresent inven-ion; Figure 16A is a cross-sectional view along line A-A of a bi-k having the fifteenth embodi:nent of the invention thereon; 8 Figure 17 is a front cuarter section view of z--sixteenth embodiment of the Present -invent'Lon; and Figure 18 is a cross-sectioria, qua_-ter section view alonc line A-A of the sixteenth embodiment of the p-resent.

Referr'Lng to drawing F-J-gure 1, the P--ese.- invenzion Ls shown. being used on various components of a drill As shown, a drill bit 1-0 is drilling a formatior borehole 2. The drill bit 10 is connected to the lower end of a i string 4. The drill string is comprised of a series of dri.11 io collars 200 having a plurality of stabilizers 204 located thereon. Each st-abilizer 204 is a gene_rally cylindrical annular member connected to a drill collar in the drill string 4. The stabilizer 204 comprises a series of fluid courses or passages 206 on the exterior thereof- to allow the flow o:E drilling fluid and chics and debris contained therein to flow upwardly past the stabilizer 204 in the borehole 2 in the annular space 210 betweeh the drill string 4 and borehole 2. Contained in each 'LluLd Passageway 206 of each stab--1-ize-- 204 is one or more flails 212 of any suitable type described 20 herein to prevent the clogging of the passageway 206 by the chips and debris from the drilling operation and/or solids from the drilling fluid being used in the drilling operation. Similarly, a plurality of flails 214 are secured to the exterior of the drill collars 200 to prevent the accretion of 25 chips and debris from the drilling operation aid/o-- solids from the drilling fluid thereon. The flails 21-2 and 214 may be secured to the stabilizers 204 and collars 200 by many suitable means as described herein. Also, as shown, the drill bit 10 includes a plurality of flails 216 located thereon to 30 break chips formed during the drilling operation and to prevent the accretlon of chips and debris from the drilling 'operatlon and/or solids from the drilling fluid on the bit. In this manner, the portion of the drill string 4 located near the bit 10 during drilling operations may be used to break 9 chips formed during drill-ing opera--,4.ons, keeping relatively f ree of material bu:.1d-up and thereby increasing the effectiveness of the d--- iIiing ooeration.

Alternatively, --ather than havLng Elails 21-4 located on a drill colla-200 located between two stabilizers 204 in a drill string 4, the folails 214 mav be located on -,-he exte-;oo-f a downhole motor connected to drill bL-L 10 having stabilizers 204 'Located above and below the motor in an arrangement similar to tha-- shown wherein t-he downhole motor is substituted for the drill collar 200.

Ref erring to Figu_re 2, drill bit 10 having a threaded pin connection 8 and a plurality of cutters 12 is shown having a first embodiment of th.e present invention comorising a plurality of tethered cable type flexible flails 14 thereon. The flail 14 are secured to the bit 10 in various desired areas to be dLsplaced by the flow of the drilling fluid to prevent chips and cuttings from the formations being drilled, and/or mud solids from drilling fluids, from building up on the bit 10. The flan's 14 may be of any suitable material, such as metal cable, chaLn, spring wire, plastic, polymeric materials, etc., and may be secured at one end -L-he-eo-1 by any suitable means, such as welding, brazing, adhesion, mechanical a t t a c hm e n t, e t c. If desired, the flails 14 may include suitable members, such as weighted balls, washers with spikes thereon, twisted members, kinked members, sp:- rally wound members, etc., to aild Jn preventing the build-up of cuttings on the bit 10 and to assist in breaking up the formation chips and cuttings formed during drilling operations and the accretion of drilling fluid solids on the bit body.

Referring to F_.gure 3, a second embodiment of the present invention is shown on a drill bit 1-0. Mounted in or adacent J -an opening or cavity 16 on the drill bit 10 _Js a rotating chIP breaker 18. The chip breaker 18 comprises a p--vot-ing a--m 20 having chip breaker members 22 located on the ends thereof to break chips 2 being formed during the d-rilling of subterranean formations by cutters 1,21 of the bit 10. The ch:.p breaker members 22 may be of' any suitable and des-Lred conf.cu--ation to break the chiz)s 2 and to clean the ocenina or cavity 1.6 in the bit 10. The chio breaker P;. .votina arm 20 pivots about pivo- member 24. The pivot member 24 may be integrally formed with the arm 20 and mate wi th a suitable recess in a nortion of the bit 10 or may be -formed on the bit 1-0 and mate with a suitable recess in arm 20. If desired, th.e chip breaker 18 may be formed as a closed -rectangular member o-ivot-ing about its elongated sides 20 w-;::hi,-i the cavity 11.6, with the chip breaker members 22 being secu--ed or -integ--aj'_ly formed on the ends as well as other portlons of the rectangular member.

The chip breaker 18 is caused to rotate th--ouch the cavity 16 of the bit 1-0 by the flow of drilling fluid exiting from nozzle 26 of the b.:Lt 10. The hydraulic forces generated by the dr-i-ll- iig fluid exiting nozzle 26 also act to help break the chio 2 and clean the cavity 16 of the bit 10. If desired, the nozzle 26 may be a rotating type nozzle assembly as hereinafter described to generate a fluid flow pattern around the cavity 16 of the bit 10.

Referring to Figure 4, a third embodiment of the present;nvention is shown on a drill bi- 10. Mounted in or adjacenan opening or cavity 1-6 of a drill bit 10 is a closed rectangular shaped rotating chip breaker 30. The chip breaker 30 comprises a pivoting arm 32 having chip breaker members 34 formed by the ends of the closed rectangular shaped chip breaker to break chips 2 being formed during the drilling of subterranean formations by the cutters 12 of the bit 10. The chip breaker pivoting arm 32 pivots about member 36. As oreviously described, the pivot member 36 may be integrally. formed with the arm 20 and mate w.;th a suitable recess in a portion of the bit 10 or may be formed on the bit 10 and mate with a suitable recess in arm 32. The chip breaker 32 is formed as a closed rectangular 15 member pivoting about its 11 elongated sides 32 wIthin the cavity 16, wIth ends closed rectangular member breaking the chips 2. breaker 30 is caused to rotate through the cavity bit 10 by the flow of drillIng -Eluid exiting from 3 A- of the The ch -o 16 o f zh e nozzle 26 c--= the bit 10. if desIred, the llozzle 26 may be a rotating zvz)e nozzle asser-kb-ly to generate a fluid flow pattern a--Cund the cavity 1- 6 of the bit 10.

Re.ferring to Figure 5, a fourth embod-Lment of the crese:,-invention is shown within an opening or cavity 16 of a drill- b-;z 10. The chip breaker 40 comprises a Aflexible cable 412 having a weight 44 secured to one end thereof while the other end thereof is secured at 46 to a wall of the ooen,.nc or cavity IL6 c-L- the bit 1-0. The cable 42 may be secured az 46 to the wall of the bit 10 by any suitable means, such as we', d 4 nc, brazing, mechanical roastener, etc. The cable 42 as well as the we:Ight 44 on one end thereof may be of any suitable zy-pe. The chip breaker 40 is caused to flail about cavity 16 by the -flow of drilling fluid from the nozzle 26 of the bit 10. In this manner, chips and drilling debris 2 are broken and are prevented from accumulating with the cavity 16. As previously described, if desired, the nozzle 26 may be a rotating type nozzle assembly to generate a fluid flow pattern within cavizy 16. Also, if desired, the cable 42 may be formed as a loop having one or more weIghts 44 attached thereto (either fixed or slidable thereon) and each end of the loop secured to a wall of the cavity 16 of the bit 10.

Referring to Figure 6, a fifth embodiment of the present invention is shown in the cavity 16 of a bit 10. The chio breaker 50 comprises a cable loop 52 having one end 56 secured to a wall of the cavity 16 while L-he other end of the cable loop 52 is secured to another wall (noz shown) of cavIty 16 O.LO bit 10. The cable loop 52 includes a plurality off chip breakers 58 thei-eca. The breakers 58 may be in zhe for-m of toothed washers, star shaped mem.bers, etc. as desired. The breakers 58 may be spaced from each other by suitable spacers 12 installed on the cable loco 52. if- desired, a we.-c'-,-- 54 -av be included as well. As p--ev;_ousl,.y described, the c-;:) brea".-,e:

is caused to rozate in the cavzz-.,7 16 b, v the flow of drilling fluLds from the nozzle 26 -.c break chips 2 be-;.-.c cuz from the subterranean formatior bi cutters 12 c= Z 10 ' and ,,-.c helo prevent the bu,' I d-t,n o. cl, z z)s and deb-s cavity 116 thereby prevenzing ba ling of the bz 10. desired, the nozzle 26 may be a rotazina z-,i-je nozzle asse.-.b--to generate a fluid f low pattern within cav;.--y 16.

R ef e rr J;- n g ' c --- i qu r e 7, a b -i z 10 _; s sh- c wn c c 0 r a:: n C a sixth embodiment of the oresent invenzion. _he bit _S formed having one or more Lnternal cavities 16 wi a rotating nozzle assembly 60 provides hydraulic forces -:o clear cavity 16 of debris and break chips ceie:-al--.ed during operations. The roza-;.ric: nozzle assembly 60 comlD-Y-.;-ses a rotating nozzle body 62 having one or more nozzles 6-1 therein 'Led by fluid passages 66 in the nozzle body 62, which receive drilling fluid from plenum 69. The rotating nozzle body 62 rotates via bearing assembly 68 and sealingly engages suitable annular elastomeric seal member 70 installed in b-:z 10. if desired, the rotating nozzle body 62 may include a plurality of flails 63 Secu.-ed thereto by any suitable means to clean and break chips and drilling debris from the formations being drilled into smaller chips for removal f-rom the bit body and to prevent L-he accretion of chips, debris c.drilling fluid solids from building up on any portion c,-- the bit 10.

As the rotating nozzle assembly 60 having flails 63 rotates within the bit 10, L-he drilling fluid flowing -from nozzles 64 clears debris and prevents the debris from accreting within the cavity 16 of the bit 10. At the same time, the hydraulic Zzorces generated by the drilling fluid within the cavity 16 and mechanicall forces generated by the,Ola;'s 63 either acting independently cr together tend zo f.L - I_. - L 3 break chips formed during the drilling operation thereby enhancing the chic) removal from the area of the bit 10.

Referring to Figure 7A, a seventh embodiment of the present invention is shown. A portion of a bit 1-0 is shown having a rotatIng nozzle body 62' having fluid passages 66' therein to cause of the nozzle bodv 62' when L"lu;.d flows thereth-rough. --"xzend-:ng from the central ocr--.-Lon of t,-le body 62' are a plurality of cutters, blades or flails 63' to clean and break chips and drilling debris -for removal from the bit body and to -revent accretion of chips, debr,-s and drilling fluid solids from building up on interior portions of the bit 10. The drilling fluid -flowing through -fluid passages 66' helps clean the interior of the drill bit body and break chips, as well as the mechanIcall action off the flails 63' assisting in the cleaning of the interio:- of the drill bit body and the breaking of chips. The nozzle body 62' rotates via bearing assembly 68' and sealingly engages suitable annular elastomeric seal member 70' installed 1.n bit body 10.

Referring to Figure 73, the rotating nozzle body 62' off the seventh embodiment of the present invention is shown. The nozzle body 62' is shown having fluid passages 66' therethrough at the upper portion, and cutters, blades or flails 63' at the lower portion thereof connected to the upper portion via a post portion. Rotation pin 65' is shown on tIne bottom of nozzle body 62'.

Referring to Figure 7C, an eighth ernbod'-men- o_fthe present invention is shown. A portion of a modified nozzle body 62', is shown. The modified nozzie body portion 62" includes a cent.ral fluid passageway 6C. The nozzle body portion 62" includes one or more turbine blades and stators -61" secured therein so that drilling fluid flowing through passageway 6C causes rot-atior of the body portion 62". The nozzle body portion 62" further includes cutters, blades or 14 f lails 63" on the exterior thereof to prevent accretion c.,= drilling fluid solids within a bit body and to break ch"_js and drilling debris for easy removal. -- Referring to Figure 8, a ninth embod-i--,ient of the oresenz invention is shown in a bit 1-0. The bit 10 is formed having one or more inter-a-1 cavities 16 within wnich a nozzle 78 directs the f low of drilling f luids in t.he bit 10 Into a rotatable vane assemblv 80 instal- led within the cavity 16 of the bit. The rotatable vane assembly 80 comp- rises a vine body -10 82 having a pluralizy of vanes 84 and channels 86 therebetween. The vane body 82 is rotatably mounted wit'.-respect to the bit 10 by bearing assembly 88 retained within recess 90 of bit 10.

As the drilling fluid flows from nozzle 78 of bit 10, the vanes 84 and channels 86 cause the stream of drilling fluid impacting thereon to change direction and change the crosssectional geometry thereby causing the fluid stream to cut a.nd break the chips and debris formed during drilling by b.it 10 into smaller chips and debris and to sweelp the same from cavity 1-6 of the bit thereby preventing balling of the bit 10. Again, if desired, a;Dlurality of flails or cutters 79 secured to the vane assembly 80 may be used to cut or break the chips and debris formed during drilling into smaller chips and debris and to prevent the accretion of chips, debris or drilling fluid solids from building up on any portion of the bit 10.

If desired, the nozzle 78 may be made stationary within the bit 10 so that the energy of the drilling fluid as it exits the nozzle 78 breaks or cuts the chips and debris from 30 the drilling operation and sweeps it from the cavity 16 of the bit 10 to prevent balling thereof. The nozzle 78 may also direct the drilling fluid throughout the cavity 16 of the bit 10 to prevent accretion of sol--ds from the dzilling fluid or is from the ch-ins and debris of the drilling operation in the cavity 16.

Referring to Figure 9, a tenth embodimert of the present invention is shown in a bit 10. The bit 1-0 Is for-med having one or more internal cavities 16 within whIch a nozzle 90 directs the flow of drilling fluids in the bit 10 to sweep the cavity 16 free of chips, cuttings and deb----s and to break zhe chios, cuttings and debris Into smaller chios. The nozzles 90 are rotatable or movable in the directilons of the arrows 92 to efficiently sweeo the cavity 1-6 thereby preventing balling of the bit from either dr-i-].!,ing ch-Jos and debrIs, or from the accretion of drilling fluid solids. I.E desired, flails 93 may be secured to movable nozzles 90 by any suitable means to help keep cavity 16 free of material and to brea-k. chips, cuttings and debris into smaller nortions.

The nozzle 90 of the bit 10 com.Drises a central sha-j"--k rotatable in bit 10, --he shaft having a central -fluid passageway there.through commu. -i-,'ca-l-.,L,-ic wIth laterally extending nozzles extending therefrom. The drilling fluid -flows from opposite sides of the laterally extending portions from the central shaft to cause rotation thereof. Also, the -Eluid f lowing therefrom sweeps drilling chips and debris from cavity 16, and accreting solid material's are broken or swept by L-he drilling fluid from the interior of the bit 10. Further, the energy of the drilling fluid exiting the lateral nozzles helps break the drilling chips and debris.

Referring to Figure 10, an eleventh embodiment of the present invention is shown in a bit 10. The bit 10 is formed having one or more internal cavities 16 within which a rotating nozzle assembly 100 Is mounted on centre post 1-02 of the bit 10. The nozzle assembly 100 is rotatably mounted about centre post 102 by any suitable means. The nozzle assembly100 comp---;ses a hou-sing 1C4 having a plurality of -iozz.'a..es 1,06 mounted the--eor. which are, in turn, directed at varying angles 16 to cause the flow of drilling fluids from the fluid passageway 108 of the bit 10 to sweep chips, cuttings and debris from the 'ty 16 and cause rotation of the housing 104 within the bit cavi. L- io thereby preventing balling of the bit 10. if desired, a plurality of flails or fixed blades or cutters 112 may be attached to the housing 7-04 to helo break ch;L;Ds, cuttings and debris as well as clean the cavity 16.

RelEerring to 1Figure 11, a twelfth embodiment of the present invention is shown with respect to a portion of a bit 10. A rotatable nozzle assembly 120 is shown mounted in a b i t10 in f- ront of a blade having cutters 12 mounted thereon. The nozzle assembly 120 is free to rotate in the direction of t h e arrow 122 to cause drillinc fluids flowing the--ei.--on, to swee) in front of the cutters 12 to break chips, cuttings and debris as well as to sweep the blade and cutters 12 to prevent balling of the bit. The nozzle assembly 120 may also include a plurality of flails 124 attached thereto to assist in breaking the chips, cuttings and debris, and sweeping the blade area to prevent balling of the bit 10. The r-oz:le assembly 120 is oil the same type of construction as described hereinbefore with resnect to the nozzle 90 in Figure 9A.

Ref erring to F Lgure 12, a thirteenth embodi-ment of the mresent invention is shown with respect to a portion of a bit 10. The bit 10 is formed having one or more internal cavities 16 within which a nozzle 90 directs the flow of drilling fluids in the bit 10 as described hereinbefore to sweep the cavity 16 free of chips, cuttings and debris as well as break the chips, cuttings and debris. Fluid flows through the central rotating shaft out through nozzles 90 to cause rotation of the central shaft and nozzles. Secured to the rotating central shaft at each end thereof are rotating cutters 91 havirg flails 93 secured thereto to clean the internal cavities 16 and to break any chips, cuttJ.ngs or debris. The rotating cutters 91 may be of any suitable shape to conform with cavity 16 to rotate therein.

17 Referring to Figure 13, a fourteenth ernbodiment of' the present invention is s',-own with respect to a po--t-;on of a bil. 10. The bit 10 as shown Is a type of drill bit illustrated in United S,:ates Patent 5, 199,511. The bit 1-0 has been to have a suitable turbine 130 mounted on shaft- 132;.n the centre bore 134 of the bit 10. Secured to the ends of shaft 132 are cable type 136 having flayed ends 138 thereof to break drilling cl,,-;os and debris into small-ler pieces and to clean cavity 140 of the bit- 10 zo prevent the accretion oil drilling ch-Los and debris and drilling fluids therein. ALs drilling fluid flows through bore 134 of bit 1-0 the flu-'d causes turbine 130 to rotate which, in turn, causes sha_z i32 to rotate flails 136. Al-_hough cable type flails 136 have beer, shown, any suitable structure, such as cutters, blades, flails, turbines, etc. -,iay be used to break drilling chips, cuttings, and debris and clean cavity 140.

Refer:ring to Figure 14, a numbe-r of differing types of flails suitable for use on the various types of drilling apparatus are shown. Flail 150 is a cable type flail having frayed ends 1.52 thereon. Flail 154 is an articulated ZElail comprising a plurality of rigid members 156 movably secured at points 158 by any suitable means, such as a pin connection.

Flail 160 is a spiral wound spring type flail.

Flail 162 is a shaped piece of spring wire which, when secured by an end, will flutter. in the flow of drilling fluids.

Flail 164 is a combination type flail of a rigid member 166 having a cable type flail portion 168 secured thereto.

chain.

Flail 170 is a cha.n type flail of any suitable type 18 Flail 172 is a piece of spring wire of any desired le--g--.-, which, when secured by an end, will flutter in the flow of drilling fluids.

Referring to Figure 15, a bin 10 is shown having a portion 11 of the junk slot of the bin 10 containing a plurality of spring wire flails 172 mounted in high densicy to provide a carpet of flails 172 to prevent the accretion of solids from the drilling fluid therein or the accretion of cuttings and debris from the borehole thereon. The bit A further comprises an area of flexible elastomeric material 300 which is flexed by the flow of drilling fluid to prevent the accretion of solids from the drilling fluid thereon or the accretion of cuttings and debris from the borehole thereon.

Referring to Figure 16, a fifteenth embodiment of the present invention, is shown con a blade portion of bit 10 having an enlarged area 300 of flexible elastomeric material, the flexible elastomeric material 300 comprising any suitable type, such as urethane, rubber, neoprene, etc.

material may be reinforced with wire or reinforcing material and may have abrasion embedded therein and/or an abrasion resistant portion thereof. The elastomeric material cavity within bit 10 to allow flexing of material by the drilling fluid therearound.

The elastomeric other suitable resistant grit pad of metal on is mounted over the elastomeric The elastomeric material may be secured to the bit 10 by any suitable means, such as adhesive bonding, mechanical attachment means, etc. If desired, the cavity in the bit 10 behind the elastomeric material may have drilling fluid directed thereto to assist in the flexing of the elastomeric material by the variation in the pressure of the drilling fluid in the bit 10 and the pressure of the drilling fluid in the borehole.

Referring to Figure 16A, the elastomeric member 300 is shown in crosssection in relation to a bit 11. The elastomeric: member 300 is caused to flex by pulsing drilling 19 fluids flowing through passageway 302 in bJt 10 into cavity 304 located behind elastomeric member 300. As drilling fluid pressure is increased, the pressure causes elastomeric me-mber 300 to flex, --'mereby removing any accretion of solids 5 therefrom.

0 A- Referring to Figures 17 and 1-8, a s-Jxtee,-z.n. embodiment the present invention is shown on a portion of the blade of a bit 10 havina cutters 12 thereon and a nozzle 26 to direct drilling fluid across the cutters 12. The blade of the 0 bit 10 is formed hav--.ng a cavity 1-50 therein, the cavity 150 being covered by an expandable opening member, such as p-ivo---.rig plate 152. The pivoting p-7a,e 152 is held in its closed position by resilient member 154, such as a U-shaped wire spring membe: having the ends of the spring member secured to a portion of the bit 10 by any suitable means, such as welding, blazing, etc. The pivoting plate 152 pivots about pivot pins 156 retained in suitable cavities in a portion ofthe bit 10.

The cavity 1-50 in the blade of the bit 10 is connected v-;a passageway 158 to be supplied with drilling fluid. When it is desired to remove any material which may have acereted on pivoting plate 1-52, the flow of drilling fluid through the bit. 10 is increased. thereby increasing the fluid pressure in cavity 150 to force the plate 152 to pivot about pins 1-56 and open, thereby causing the U-shaped spring 154 to scrape across the plate 152 removing material therefrom. When the flow ofdrilling fluid is decreased, the U-shaped spring 154 biases the pivoting plate into its original position in the blade of the bit 10 covering the cavity 150. The spring 154 may contain suitable types of scraping members thereon to enhance its scraping ability.

Rather than use a U-shaped spring Mewer 154, any suitable shaped resilient member which -'s capable of closing pivoting plate 152 and scraping material from the surface of the plate 152 may be used, such as a resilient T-shaped member.

a b-Lt 10. For instance it should be understood that various comb -naz..;Lons of the different embodiments of the present invention may be used in 1. the flails 14 maybe used in combination with the ch-iQ breakers 18, 30, 40, 50, nozzie assembly 60, vane assembly 80, nozzles 90 and nozzle assemblies 100 and 120 as described hereinbe-fore wherever desired so long as no interference exists. S-im-iia--1v, the rotating chip nozzle assembly 60 may be used with any of zhe chip breakers such as 18, 30, 40 a n d 50 f or areater effectiveness.

Also, while the present invent or. has beer. desc-ri bed wJ th respect to drag type bits, it is ap-ol icable to any type drill bit, such as tri-cone rock bits, coring bits, e t c. Additionally, the present invention may be used on various drilling accessories to clean passageways thereon and to help prevent the accretion of solids from drilling operations as well as from drilling fluids thereon. Such ty L pes of dr-1ling accessories upon which the present invention may be used are drill collars, drilling stabilizers, reamers, downhole motors, etc.

it should be understood that various changes, additions, deletions, and modifications to the present invention may be made which will fall within the scope of the cla-Lmed invention hereafter.

2 1

Claims (3)

Claims:

1. A drilling apparatus used in a drill string for drilling a borehole in an earth formation, saild drilling causing said earth formation to be broken or cut into chips and debris which are transported by the flow of drilling fluid in said borehole, said drilling apparatus comprising: an apparatus body having at least one connection structure thereon adapted to connect said body in said drill string and an interior passage for said flow of said drilling fluid therethrough, said apparatus body having a surface area contacted by said chips and debris transported by said flow of drilling fluid in said borehole; and a closed member secured to a portion of said apparatus body having a portion moveable in said surface area.

2. The drilling apparatus of claim 1, wherein said closed member further comprises: a chip breaker member attached to a portion of said closed member.

3. A drilling apparatus used in a drill string for drilling a borehole in an earth formation, substantially as hereinbefore described with reference to and/or substantially as illustrated in any one of or any combination of the accompanying