CA2437519A1 - Hydraulic optimization of drilling fluids in borehole drilling - Google Patents
Hydraulic optimization of drilling fluids in borehole drilling Download PDFInfo
- Publication number
- CA2437519A1 CA2437519A1 CA002437519A CA2437519A CA2437519A1 CA 2437519 A1 CA2437519 A1 CA 2437519A1 CA 002437519 A CA002437519 A CA 002437519A CA 2437519 A CA2437519 A CA 2437519A CA 2437519 A1 CA2437519 A1 CA 2437519A1
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- Prior art keywords
- drilling
- drilling fluid
- fluid
- hydraulics
- well bore
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- 239000012530 fluid Substances 0.000 title claims abstract description 74
- 238000005457 optimization Methods 0.000 title description 2
- 238000000034 method Methods 0.000 claims abstract description 17
- 238000006073 displacement reaction Methods 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims 1
- 238000012544 monitoring process Methods 0.000 claims 1
- 230000003247 decreasing effect Effects 0.000 abstract description 2
- 230000015572 biosynthetic process Effects 0.000 description 4
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/60—Drill bits characterised by conduits or nozzles for drilling fluids
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/62—Drill bits characterised by parts, e.g. cutting elements, which are detachable or adjustable
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
- E21B21/08—Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
- E21B21/10—Valve arrangements in drilling-fluid circulation systems
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Earth Drilling (AREA)
- Drilling And Exploitation, And Mining Machines And Methods (AREA)
Abstract
A method for optimizing drilling fluid hydraulics when drilling a well bore is disclosed. The drilling fluid is supplied by a surface pump through a drill string to a drill bit. The method has the step of adjusting the flow rate of a surface pump and a fluid pressure drop across the drill bit while drilling such that the drilling fluid hydraulics are optimized for a given drilling condition.
In order for the flow through all the devices in the drill string to also be optimized, the flow through the devices is adjusted, thereby setting the pressure drop and the fluid flow rate through each device. As required for the overall system, the flow from the surface pump is increased or decreased as necessary.
In order for the flow through all the devices in the drill string to also be optimized, the flow through the devices is adjusted, thereby setting the pressure drop and the fluid flow rate through each device. As required for the overall system, the flow from the surface pump is increased or decreased as necessary.
Description
y~-~u~0c ptiiz~ttioc~ ~ ~°illir~g Fluids ii.~ o~°~~oc ~°iil~~~~;
This invention reiates to the h~dr~.ulic c~p~zatio~A of~hc Ii~uid driiii~g quid ~r~ud) used when drilii~xg orel°~oles i~a:o the earth for ex~~~,tio~.
of ~ni~~cr~Is.
particular, the presc~~~'. i~veEior~s ~I'~ows the p~vssure d flow rite of the mud to be set ~s desired ~t di.ffcre~~t Ioc~tionc; i~~ the devilling string ~o op ' ize the drilling o-ocraor~.
den drilling boreholcs to the earth, ~. liquid drilling :~Iuid, now well owra silk a,s "~~." o~° "pilling mud", is oft~;use~e. to gush the cuttir~;s from the bottom of the well bore to tie surface. -igjnally, the mud was used o~al~ for flusl~i~~~, ~~ut one c~.~ttgs. It was nc~~; Ionhowever, -before the 1~ drillia~g d~stry rc~.Iiz~ed that the chilling mud, oc~n supplicd ~t~ high pressures d high f oar r~tcs~ could he used to power other devices iaa the drill s ° g that support the d~°illi~g oper~tio~~5 inclu '- g for ~-eleme~
pressure pulses, power, d fog- prim~r~=~ well con'~ol.
This invention reiates to the h~dr~.ulic c~p~zatio~A of~hc Ii~uid driiii~g quid ~r~ud) used when drilii~xg orel°~oles i~a:o the earth for ex~~~,tio~.
of ~ni~~cr~Is.
particular, the presc~~~'. i~veEior~s ~I'~ows the p~vssure d flow rite of the mud to be set ~s desired ~t di.ffcre~~t Ioc~tionc; i~~ the devilling string ~o op ' ize the drilling o-ocraor~.
den drilling boreholcs to the earth, ~. liquid drilling :~Iuid, now well owra silk a,s "~~." o~° "pilling mud", is oft~;use~e. to gush the cuttir~;s from the bottom of the well bore to tie surface. -igjnally, the mud was used o~al~ for flusl~i~~~, ~~ut one c~.~ttgs. It was nc~~; Ionhowever, -before the 1~ drillia~g d~stry rc~.Iiz~ed that the chilling mud, oc~n supplicd ~t~ high pressures d high f oar r~tcs~ could he used to power other devices iaa the drill s ° g that support the d~°illi~g oper~tio~~5 inclu '- g for ~-eleme~
pressure pulses, power, d fog- prim~r~=~ well con'~ol.
2~ ~'oday, it is now co onplace" to have n erous tools in the drilling string which use the drilling rnud to supply power for their oer~.tio~. such tools include drill bits, d~Il~~g motors, drilling biases, rott~y directional 'ping de~ncesj ;thud drwen eiec'~ac gcner~tors, hope o~!~enmg dcv~ces, ~.~e~su~g while drilling tools, downhoie cou~cation devices, and many others.
.~5 ~Ithough the drilling operation is e~ ced bar the us~~ of these tools, it is well knows that the h~~~raudcs of the ~ ° g quid editing flee drib bit is one factor which most often de.te.i~es c:-illing pro ,messes and effaciec~r. 'phe drill bit ~aycie-aulies detern~es how ~-~.ii the i°o~r~~atio~ cu~ir~gs ~~~; cle~.:~ed frog the di~illg bit and transported to the surface.
~ primary factor ire the cost df drilling the borehole l the dr~il~~~; rate of penetration. ~inee this a-~te of pene-a~.~on is larofoundly affected by tl~e drill bit h~r~~lics~ it is ~je~r ~~npor~a~~t to prs~~ride prolrer pre6ssure and fl~~v rite of the drilling fluid ~s it c~~ts tlm d~111 bit t~-oglr di~u;,h~rge; orifices.
~rili bits ically i~~~r~~ ~~ed size nc~~z~es ~'~r discharge orifices., daring ~
single r~g~ into the hol,~. ~inc~~ o~~e bit ~~ be r~sed in ~ Tide range o:~
applications, and ~a~ d~il1 thro~gl°y differing litl~o~og~.es, it is necessary to be able to change the h~dr~~alic d~iscl~arge: clxaracteristics t~~o~gl~ those nozzles.
t~ °l~e need for ~nultlple ori.~ce sizes in drill bits is t~rical~~r addressed by g~a~°ing interchangeable nozzles of differermt sizes for the bits, or orif ce arrar~gen~ents, such as sizo~rn in ~~~ patent ~o. 6,L~ i'~,31~, that are adjustable.
In eiti~er case, the orifice size is set at the sm~'ace and remains the sane until the bit is once again ret~eri to the s ace.
t~
often, l~o~rever, as drilling progresses flee ~,hanges in the formations berg drilled affect hog yell the forrnat~o~a cuttgs are cleaned and transported.
'1'he nozzle size i~itia~~~ selec°~ed rr~a3~ no longer b~~ tl~e best _~or these clanging formations. 'order mo corxapensate, 9J~e o~ rate c~f the drilling 2~ r~.~id supplied to the, bit gf often changed at tl~i.e surface.
Ljnfortunatel~9 because optimizing the h~dra~.lics of the dell bid in~rol~es 'both the area of the discharge orifice ~.nd the o ~ rate: of the drilling Maid, tree optimization seldom ~~appens. ~'~Tic«ll~r, to fully optimize #:he hydraulics, the drill bit would hare to be ret~vd tc~ the surface and the nozzles replaced ~vitl~ ones With different orific° areas. T leis ~.s a very expensive process$
so a op ' anon rarely is a.~rhieved.
To complicate the issue:, if there are other n°~ud-poer~~d deices x~
the drill string, their operation is affected by tie ova rate cha~.ge. since each nud-powered device in the dr~~l st~-~~g 'robs' a po~~oof ties total hydraogic er~erg~r of the drilli_~g ~i~id, ~ e~~ar~ge in the i'lo~r rate may profot~diy affect the perfoa~~;: ;~~ th~t~ ~e~r~~;~. ~~.s a ~c~x~se~~e~~e, there is ~fte~~ ~.
~ ~aggi~~g pct in pro~,~css to supple tbge ~~rc~pcr ~o~;v of o~~r to ~~1 the u~~~
powered devices i~ tire d~~~~ str~r~g god also to tif~e d..~ii bit. grade-these conditions, providing =~~k~ optimnna pressures and flows to sash mud-powered device a drill stri_~g is di~'t~c~.it at best. ~fte~~tie:;, one or o~~e of the rnudvpowered devices cur left ~:o operate ~.rgin~~ll~r.
~ddi~o~~, because it v~.y be d~f~~;,uit to date n ~ a how cha~g$a~g the press~zre and flow rate of the drilling ~a .aid 1 af~~e~: tlmse the mud-po~rered devices, many decisions on ho~v to op~:rate these devices adversely a~'ect t_he overall d~ilhag perfor-~n~;.nce.
? 5 an~j of ve devises s~;d do~oie b~ve val - g andj~ar orifices that relieve the drilling ~.t~id frog wi the d~-~'ii st~~.g to the well bore, saxch as the reliet° valve described ?~ ~.1~° ~~.te~~t I~Tc~. ~,~ l i.:~~.~.
Cane type of device ntili~~g v~.ivia~g to vs.~io~s types. ~f ~~ed orificesc .~.t can be switched on as the deuce is ~.ctivated~.ri~.g d~-i~g is 'on s~$.ean~d' hole oper~e~. ~~~ii other de~~ices provide taxed ~~~~aees, for "eh~~es'7 as they are sometimes cahed~ in the drill sung to create ~. pressure drop 'long -the ~ 1 string with~~t venting to the borehole.
~Ithongh these devices a~-e ~peil Known, it is ~aot presenltl~ possible t~~
adjust 25 th.e flow rate and pressure dr~p t"_n-o~gla them.
it is e~efore desirable to be ~bie t~~ ~ci~nst~blyr select the p~-essu~: a drop andJor how rite ~.ca-oss e~cb m~a~~-poG~rered device in a drill stri~~g ~'e independently cf c~ci~ ether. ~t ~h~: s c ti~~,, ~t is ~is~ dcs~~-~~ie tc ~d~ust~.bry c~a~t~°c~i the sip;e c~f the ~~~.id ~iischa:~°gc c~,ificc.s in drib bits.
he present i~~~eaaticn ~s ~, r~cthc~ axed ~.p~r~t~s r:~. cct~ci the pressures and fi~ws ~crcss fluid ~sir~~ deices used it drill st~i~~gs ~~br drilling ~~>rehcles.
~ method for eptizis~~; d~-iiii~g fluid ~~.~rdrauiics ~~rhe~ driliir~g ~ ~eii bore is disclosed. ~'he driliir~.g fluid i~.s supplied by ~ su~g~~ce p p thr~u~,h ~
drill s g to ~ drill bit. °Thc rnethcd has ~e step ef ~d.~ust;~ the ~~ rite of the s ace p p d ~ fi:~id press=mare drop ~cr~ss t:e drt:il bit while drilling, such th~.t the drilling ~~uid hydraulics °e op ~ . ed for ~ gives driiiimg c~~aditi~n..
~.isc~ disci~sed is ~ dpi bit ~vh disch~rgc orifices c~r nozzles v~hich are ~5 adjustable such that the orifice size ~.y be changed while drilling, without reading the drill s ~ g fr~n°~ t~°~d hole:. 'here ~y be ~.
plurality of nozzles on the face ~f the bit th~.t ~n~y selec~~ely~ ed can or ~ff° such the total flaw rate alnd pressure drop dough the bit is ~.dj~.~sted.
Esc disclosed is a dc~nitaole ru~t~r with ~.dj~astable interference fit. she fit is adjustable by ~r g the ~cw rate; aid press~.,~e d~r~p across -0re n~ot6r w ° a in operation. ~.dditie~r~, the pr~;ssures end texnpera~ares of the drilling laid ab~~e and bel~~~ ve otcr rr~~~y be or~atc~red so th~.t the interference gay be optin~~.liy ~.djusted. ~~ce the naot~r hydr~.i~s ~.re optin°:ized, the how then pr~ceeds to e~~:her devices, and ~aliy to the drill bit.
h~ o~°der for the 11~~~ t:rt~x~gh iii the de~rices i~~ d~c drill string t~ ~iss~ be optin°~ized, the flog th;~ough ti~~, ~c5,or ~o~° othe°,r de~~ice~ is ~dj~stein ~
r~aer selected from the grc~~co~~.sisti~.g ~f rest~°icting the fi.:~id fio~, bypassing the fluid ~~~~~r a.r~d r~ii~~aa~~~; the fluid ~~~rv, thereby s~tti~yg t~
press~-e drip ~.a~d the ~~d ~lt~~a ~~te t:.r~~g~. e~~,h eee. ~ s reci~y~~ed ~~r the ~~rer~.li system, tree ~~~~r ~'r~~~ tl~e s~ce p p is ~~,re~sed ~r decreased as recess.
i'1-~e i~~e~ti~r~ gill f~~ ~°r die describe~~., by gray ~c~~
ex~~t~aple7 pith reference t~ the ~cc~pa~yig ~'r~~,~i~gs, ~,~ adh~cl~:
F'igrre 1 is a p ~a1 se~a~~~ ~rles~~ a drill rig th-illi~~; ~ '~~reh~le its the earth.
~zg~e 2 is partial secti~s~ ~f a side ~ie~~ s~f ~. 'wed canter bit.
:~ 5 ~i a 3 is a perspective e~f ~ rolling c~er drill bit..
Figure 4 is a sect~~~ ~v~r c~~ a wed ~~~.tter drill ~~it fitted ~rith a s~%~archable select~r ~al~'e.
~'ige 5 is a section vri~;~ ~~ ~. drill bit t~e~. ~i~~ c~ntr~ll~.ble ~a~~iable ~l~~r restxicti~n deices.
~i a 6 is a schern~.tic; ~ie~~ ~~ ~ fluid ~sir~g de~rice 1°~r d~ ale drilling ~perati~r~s ~f the preset iauer~t~n.
~ig~sxre 7~. is ~aa er~d s~.;et~c~~ ~ricr e1° ~. ~~~ine~~:c tyrpe drilling ct~r ~~' the preset irwer~tl~~.
~~~~a~o 7F3 is ~ side s~°~~s~~ ~r~e~E~ of ~ I~ic~i~~~u ~:~p~ dz-illing motor ~f tl~~
p~°~s~~t vo~tion.
.ofeg ~o~ t~ Figwc l ., u~~h.~~ ~ril~h~g bc~r~hol~~s 1 ~ ~o ~ho~
~°°~rm~.tio~s i2, i~ is ~~r~~~ora pr~.~tio~ t~ use a. bc~'s~~
hole ~.ssebly i4. as shop i~ g'iga~re l . ',he bottom hole ~.sse~nbi~r ~;~ 4. is typicali~
I.~ coamected. t~ the end of ~:l~e ~zbul~r drill s g 16, ~~hi.el~ is typicall~r r otatably drive lag~p ~ drill~g rig l~ ~~r~a she su~~aeea T~ ~c~ui~o~ t~ providing motive ford for rots ° g the drill string ~~, the; drilling rig- l.also supplies ~ ~.rilli~g fluid ~0 ~~der pressure, amd float created by ~. soiree mvd pu~~p ~~9 through the t~bul° 1 str~g l.~ to tee boo~~ hole ~.ssembly 14-. ~'l~e drilling fluid ~~l is ically- laden ~~iih drilled ~.b~°~sive f~rm~ti.or~ material, as it ret s to ~ mid 24 and is ~;~ rep~.~.tedl~r r~;-~ei~-cul~ted ~l~-ou~;h the borehol~. 10.
the i-i.~ i~-, m~.y b~; d.~illi~g fluid ~,siug devises ~~~ eliding ~. drill bit 2~. ese fluid using devices ~~ m~~~ be ore ~~- r~~re off' d~-illiug ~raotors, drill~g t~bines, rote directiona..l dolling devices, ~~d. driven electric generators, hole ope ° g devices, mess 'ng while drilling to~1 s, ~:~d doahole co ~c~.~xs~de~~~ces.
'fhe preset i~ve~ti~~~ is dr~x to ~ method ~d ~.pp~.r~~s t~ co~~ol the 2~ pressures d fl~~rs acs oss ese fluid using devices G~ used in drill strings l~ fc~r drilling borehol~;s ~~fl tv optimize the dri.~.lig fluid h~rdr~ulics vahe~
drilling ~ veil bore t. 'fhe r~~et~~od ha~,s the step c~~°~d~~isti~~g vhe r'~o~F rate of tl~=e ~u~~.ce Bump 22 ~~d ~. uipres,yre drola across the drill 2~ bit ~ahiie drilling, such that the drilling fluid l~.~dr~ulics arc optbnlzed for a given drilling condi~-ic~~~.
~'o optia~izc the quid i~~dra~wlics for a given dolling co~adition the flog through i~uid using de~rices ~~ ~s ~.d~vsted in ~. ~~acr selected ~rodie group consisting of rcstucting vie ~'~~id cw, b~passg tl~c quid ~loend relieving the fluid ~ov~ry thereby sct~~~; the prcss~~ae d~~~~p a.iid the quid $~ov~
rate through each de'ric~:. A,s rc~uired for tl°~e overall s~rste~n, the flog frornn the s ace p p 22 is ~.u~creased or de~:reased actor ° gzy, as necessary.
~0 Ione enibodirnent, the drill bit ?~ may be ~. e~cutter type drill bit 3f1 as shorn in figure 2. ~ he ~~ed cutter drill bit 30 has a longitu ' al axis 32, a bit body ~4 dvitli ~. n°s~~ arid ~~ i°~icb is. adap°~ed t~~ be se~deared to the ~3~14.
'typically, eads 3 ~ ire used for the attac~r~~ent, but other morons of t 5 attac er~t gnat' also be udlieed~ ~t the second, oppovaite end 4C of tae bit body 3~- is the cutting face ~.2 of the axed cutter drill bit 3~.
~ °ng operation, die bra bode 3~ is r~;~tated by ~~~ external means ~rl~ile the cu ' g face 42 of the fibbed cutter ' I bit 3~ is forced into the formation i2 2Q being drilled. 'I"lie rcaatiora ~der load causes cut~::ing elements .4 to penetrate into the for~~ir~tion l~ ~,nd rcn~.ove it ire a scrapping dlor gougbig action.
'lie bit body 3~ lips ~ntcrn~~ ~ass~~3in~; ~6 ~~~rth ~.l~o~s the press~ari~ed :~S drilling iiuid 2~ s~~ppl3ed fro~~ tl~e surf~c:e p~..a~ip ~'<~ t~~
i°lo~sr tba°o~gi~ a plurality of nozzle or-i:~ices ~-~. 'fbese nozzle orifices ~-& discharge the drilling fluid 2~ to clean a~~id cool die ~;utt~g ele~r~ents ~4 as they engage the material 12 being d~°~ll~~d. 'Te drii~iiig u~d ~~~ also transports tine drilled material to the surface f~~- dispos~,~.
P~ mother ennbodger~t the driii bit 2~ tray be a roiii~P; cutter type drib bit ~~
as shop iu ~'~~atre 3. ~. ~-ollir~~ otter drill bit 50 is also cooa~y c~l:~ed a rock bit, a rol~ir~~ cutt5:,r ~-ec~ dr~iP bit a>r aoiPf~;~d drift bit.
~i~r~l~r to the ~'~xed otter driil bit ~a,Phead~r described, the r~P1~_~ otter drill bit 5~
nas a ior~gir~ud~~aP axis 5~, a b_~t ~Sody ~~f ~ritl~ ~. ~'.rst cad ~E which is adapted to be secured to the lid i:~. ~ypic~PPy, threads 5~ are used the attar sot, but other forms ot° attar ~ e~~t ~n~.~~ also b~; utiPized. ~'ypically, the body of the rollick cutter drilP bit 5,~ has three Pe;s ~~. ~,t~ached to each lei ~~ is a a~tat~bly daunted roP~:~~~ cutter ~2. l~ttached t~> each roPliotter ~~ are hard, gear resistant c~t~t~ i.se~ts ~~~, which awe cap&~bl~; o~ e~~.~~ the earth formation P2 to effect a, dr"~Pl~ a~,tior~ arid c~.~se ~~ota~.o~ of the rolP~
c~.tte~- 6~.
~'he bit b~dy ~~ h~.s teraP pass, y ~ (of, sh~s~r~~ with ~.~lo~s the.
pressurized - Iir~~ i'yv~.d ~~ s~~~plied. °othe s~.u-f~c;e to ~fo~a t~~~ro~gh pPorality of ~aozzPe ori~'~~ces ~., 'these nozzle orifices 6~ discha.~~e the drglPhag ~.uid 2f~ ~enera~_ly to~~rard the roll~.~ otters ~2 a~pd the ~ate~aP
1~
be~~ drilled, i~ a ~ er similar to that off' tl~e fixed cutter ' 1 bit 3~
~t~st described.
P~ practicing owe er~~~odie~t of v.e preserbt inception, it is desirabPe to adjr st ties hydraulic fi~~~~ th~-o~the nozzle orifices c~~' a dr°iPl bit ~~, J(~, 5 as the opti~ehydrauPic horsepower of the driPl~ ~~uid i'iowir~g ti~rough these ori~c; s often char~bes d ~ driili~~.
~~s shop irg ~'~ge ~, o~c ~~a~, to :~d,~ust the lydra~~Iic flog thro~~.~h the ~zzic orifces iu ~ d~-ii~ bit 3g~ to ~t a seiecto~~ ~~an've °~0 irlt~ a bit body i4.
~s drilPin~ progresses, the s~;pector ~al~e '7~ a~~ be eEpe~~ated to such the flow f-~oa~n one see csf aa~czzle oai~aces ~~ to one or ~~~e ~lrea~ate a~ozzie orifices 7~.. The seiect~sr~ ~~e '~an~.~ i~~de see~ea~~~ open°atiaag positioaas such that ruazaerous cozafjgu$~.~.~ons ~.re possible. ~°he c;onf'aga~ration chosen ~ouPd be the one best sited fo~° the preseaat drilling conditioaz. ~7nce the selector ~~~ive 70 h~.s been set :~.~ ~ aa~~ic~ia.~ coa~ig~r~a~oaa, the flow ~~t~, of the saa~f~ce mud paaa~p ~~ is ~dja~sted to the proper va~~.e fc~a~ t~h~t coaaf'r~~~~~ioa-~.
tlvs m er, tl~e opaiz~~.i presswre gad flodv ~~te for the drill bit nndea° ~
given set of drilg co~~dit~o~~s m~.~r be ad~aasted. it" ~:hea~e ~.re other fluid usia~g devices 26 ixa the ~~-i~i s ' g i~9 ~~~ch of these a~~y~ ~iso be ~d,~~sted for i~ opt~°~~.1 opea-ation ~s ~r i~., ~s 1~ be described.
~s shop iaa F'igaxa~e ~, ~a~~ ~ltea~n~:~e ~r~..~3 to adjust ti-ae h~drsuiic f~o~i tough t~~e nozzle orifaces in ~ drill bit 5is to f'at v~i~.bie ~esta~ctions ~0, g~
into the nozzle orifices ~4, ~6 in ~ bit body ~~.. 'phase vaa~i~.ble restrictions ~~, ~2 ~-e opea-~.ted by servo type motor devices ~~, 9a, ~oa° other suitable devices ~rhich a controlled °oa~ a. sui~~.ble ~~ tool e,lect~°~~uics device through short hop co ualica.~'~o~a~s9 or other l~aao~systex~s suitable ~~°or this ~ a of con~ol. As indicated by aaurner~.l ~2; in ~ iga~re ~ the servoanotor end the restc~ctioai array he coanbiaaed into ~, single pac~~.ge ~vhifdh is inserted into ?C~ e~is - g flow p~.ss~ge ~ a ~n ~ dell hit. Ag~.ia~, once the aaozzle oa~i~~.es ~.a-e ~djo.sted to the optinaa~a-~r value, die flcwr r~.te of t~.e sua~~ace and pump 2~ is adjusted to the pa~ope.~ v~.l~ae for th~.'t coa~°agua~~rtion. in this ~aaa~er, the opth~~'pa~essure aaad ~~~~r a~~.te for the drill bit ua~der ~ givea~ set of da'illing coaaditions araay be ~.d~usted.
o~eve~, once the ' 'i1 bit pa°essure end flow is ~d~a~~sted, y other ~ui~
.sing devices 26 in tl°~e drib string t6 rn~y also need ~to be adjusted ~'or optismal operation as well. 'pl~~s ~s don~° i~ refea-e~.c~e to i=i a ~.
higure G is ~ scbcstic ~.iagraa~ of ~Io~ ~r!-~.ngements possible in other ~I~id using devices 2G. The device itself is i~~c~c~tcd by nnn~c;al l~~ as a v~~~.ble fio~r resti-ictor. ire ose, it is desh-~ble to ad~ost the press~f~e drop and ~:he ~lo~
~vte ti~o~gh the device itsclf ~ ~Q~. ~ir~ce it is ~.lso ~ece;~sa~gr to set the _~o S rite at the exit &~~ of tic; .~~d ~~swng, de~~gce 2G, it ~r~~~~a b~:, necessa~~~ to eitlacr d~-~ert ~lo~r a~od tbc device itself ~~0 e~ith ~ variable fio~ restrictor 1~4, res~ict the ~1~~r into the, de~Tice itself ~ ~~t~ pith a va~~ble fio~r restrictor ~ OG, or rcstrict the flog ont of the device itself ~ ~~ with ~. variable flog restrictor i~~, or to divert flog into the borehole above the dev3~ce itself' ~~~ With a t ~ varyable flog restrictors 1. ~ and j 1 ~.
1~.~ practice only on.e or a.~ro oi° these ~r~~ri~bie fio~v restrictors ~~4, i~G, ~ 0~, i hand i I2 would ge~~c~all~r be ~.sed, depc~~ding iapu~:~ tl~e type of ~.evice ~.nd the desirable acc~.cy level.
tS
In a~~ case, in ordcr to properly set the va~~iable f~o~v restrictors ~~~, I~6, ~~~, ~ ~~3 it is neccss~~~ to isno~~~ one ~r yore of r~e tepc~°~!t~.re, i~oratc and p~°esse through ~~e ~'~uid n.sin~ device 2G. ~~rde~° to ~~e ese rea ~ gs, one or Snore keenso~~s s i~-, 1.16, ~ 1.~, i:~~.re used to provide the rcquired te~nperat~~res, flower rates df.cr pressures i~ tile opassages ~~~
of t~hc device required to optimise tl~e tool. tJnce tie optyrnurn pressure drop and o~ rate is calc$~a~,ted, and lCno~ng the t~lorate which ~nn.st be maintained by c fla~id eti~g the fh~id using device ~G, tl~e variable flog restrictors t, t ~G, t ~~, l. t ~ any 1. ~ 2 -- and if' r~ecessar~r the fio~
rite of the '<?S surface pump 2~ - ~.re ~~~en set ~s red~i~:-ed to pro~ra~ce tlne;se vales.
~~ch fh~zid using device ~G ~~ tl-~~s be ad~nsted tc, opt~r~auhydraulic operating values and still permit the drill bit 2~ to be operated at its opt~~mu l~ydraolic setting.
~l C7ra such quid using de:~ce 2~ is a positive dispiaceL~t do~ole motor ZO~. positive d~spiace~r~,r~t motors 2~~, as sore ~._~ cress sec~ior~ wick's in ~i~ es '~~ and '~ dominate ~il~~eld o,~eraor~s and over distinct o~er~~ion~.l d economic advantages over cot~ve~~.-io~al ro' ' drilling i~. ~riax~yr conditions. Do ole h4~~o9:ors ~~C o~~er tle option of~ drilling erg e~tber ~.
traditional rotary ~aodd or a sl=ding ~:node in ar~hici~ tbae hole follo~rs tl~e di~ect~ioa~ off' the gent ~Eor~sir~~ o~~ t;~ motor ~~~~. In directior~~.l drilling applications, do ole t~°~otor4 ~~a pewit contrc>l ~~ .~e ~rellbore direction 1G and tf~us, more e~'fecti~Te deviation cor~~rol tiara conventional rotary mends.
oea~ type positive displacement motors X02 ~~onsis~: o~° three major suh-assemblies, a power secr~ion, compr~fsi~~g ~. rotor ~:~~ ~~ a stator ~~~, ~rl~ich ~co~~rerts hydraulic er~e~~gy into mechanical rotary power, a tr~~asrmission IS section (not shop), ~rb~ich transmits rotar~r drive tom the powcr section to vhe bearing section and also i~corpor.tes the adj~.~s~~bl~: ~~ent lousing end a be g section knot sl~~.), A~lxich supports axi~.~ anc~ radial loads d g drilling and transmits ~: rs~tar~J~ d~°ive to the bit through <~ drive sl~a~~.
~0 'The poorer section the motor 2~2 converts h~rdr~.ulic power Trom the drilling Tluid into mecl~~cal po~~ev t~~ . tl~e b~~i~-:. 'his is accomplished by reverse application of z.e oine~,u pup p ~ ciple. ~rillir~g fluid i_s pimped into e'~eotor's 2Q2 poker section at a pressure that carases the rotor 2~~ to rotate wi the stator ~ ~C~. ~°l~is rot~.R:ion~.l force is den traJ~smit~ed ~bro~.gh a ~ansrnission sh~Tt and drive sl~~Tt to tl~e bit.
Typically, die rotor Z~~ is na~~~u~a,ct~r~;d o~'corro:9lo~~-resgstaa~t st~i~.less steel.
It ~zsuall~~ has a chro~_e pl~.tir~g applied to reduce ~.~ction and abrasion.
T"ungster~-cirbide coated rotors 7C~~= ~.~°e also ~.vail~~le for reduced ~b~-asion e~~ and corrosion d~ag~. 'i'~ st~~c~ ~~~ cons:ists c;~ ~ steel Vibe pith ~~
e~as~a~nae~- ding oid~d ~~tc the bore. T'he ei~stc~~ur in thge i~~~.~ ~s ~c~.iated specif~caii~ ~~ resist ~.b~~sicn ~~-~d i~yd~cca~be~a~~~~d~ccd deterioration.
The rotor ~0~- and stator ~J~ have si~.ilar helical p~c~~~les, b~.t the rotor Z~~.
has c~~e less spiral, or i~~be 2f~~, thin the stator 2~:~~. lrn an ~sse~cabied po~e~
section, the rotor 2a~- and the stator '~~ ~°o~ ~ co~~r~~~~s seal ~._~
their c.ont~.ct points al~n~ a sc~ai~~~t li~~e, ~rbych produces ~. robber of independent cages. l~s aid ~,ai~, ~~a~d or vva~er~~ is ~'orce~ ~o~s~h these pro~~essi~,re cages, it cases the ~~to~- ~~~ ~~s ~-at~:het around ~~sid~; the stator 20~.
'1'~~is ~o~rement o~the rotor :~~~~ inside die stator ~~S :is c~.ll~;d n~ta.tior~..
:~o~ e~eh ~.ut~~.on cycle, the rote 24 t~~s the distance of ~~~e s~ats~~° lobe ~
1 ~ width.
'~he ~°otor 204 .gist nuta:e for each ~o'os~ ~ ~~ in the stator 20~ to complete one revc~l~t~on of the bid b~~. ~ motor 26~ critic a '~:~ rotor/stator 1~be coal anon a~.d a sp~;ed o~ 1 ~ rp at the bit boy gill have a nutati~n speed of 703 circles per ate.
'the lobes 2~~, Gtr on the rotor ~~~ ~.nd stator ~.~~ ac~: Pie a gear bob. ~s .e~ nbers increase; fdr ~. ~iv~;n oto~° ~~~ see, the ~voto~°~s torque o~.tp~.t generally increases arid its ox~tp~t shift speed ~~,~~e~:all~~f decreases.
eca~se power is de~'~aed as spe~;d ~~°~~1~.~iied b:y the torque;,., ~ eater ~
ber o~ lobes ~0, 2(~ ~ in a motor ~.;~~ does ~~o'~ necessarily ~,~~°o~~~°
more hors~;ovr6er.
motors ~~2 ~th yore lobes ~~9 ~l~ are ac~all~~ Hess efficient because t~°~e :2~ seal ~.rea between the raptor ~~~ end s~:ator 2fl6 i~n~,reases with the nur~~be~° o~
lobes.
otcrs ~a2 are us~.ail~~ assembled vvh the rotor ~fl.~ sued larger tan the stator Zc~6. 'his produces a stroa~g positive i~ne'er~~nce seal, casing a posive tit. motors ~QG r~s pith ~, ~°~t~r Z4 e~~ di~etcr r~c~rc dm~~
~0.~~
greater th~.~ the stator ~f~& nor dia~etvr at do~nhol.e co~dit~orls a.re very strong (capable of prt~d~~cir<g ~~r~;e pressure, drops, but t~ae~ usa~~~~y~
have ~
reduced fife because :~°c~t~re uhn~~~~g o~ the ~~3~b-~er pouion o1° t~~e stator 2~~ oecurs.
~f increa.sed do~mho~e tepe~-a~~res -c anticipated, thc~ a,a~ount of positive fit is re~uccd d g ~~~ator ~~z asser:r.bly to alla;,Yw nor the s~el~ir~g of the eia.stoer ~' g in the; stator ~a~. ~avers~e staror ~0~ is usually rc~uircc~
to obtain the correct got o~° inter~'c~rence bet~ve~a t~:~e rotor ~(~~-~~d the stator 20~ f~r ten2per~t~i~res ~~c~ve 2fl~:~ deg~". ~~ thhe ~t~cipated circ~.dating teperat°~re of a ~reli is ~bovc ~.pp~o~~atei~r 22~ dcgg-0, the ia~ter~~,recc ~t must be ~. ash or ~~e~;avve ~i~, vahich thc. rotor 2~. :mew die~;er as ire see size as, or sa~~'er the ~~he stator 20c~ ~o~- di- star when a motor 2(~~ is assembled iti the shop.
Ch 'ng dcscribes ~. sda.tor :~0~ ~~hich tire r~~bcr across the top of the lobes 21.t~ his ~pparenti~,~ ripped a.~~.~. ~ha~g occu~°s whey the s~er~gth of the frictior! force between the ~°otor ~(~4 lobe ~fl~ ~:~d the stator 20E lobe 2 ~ (~
exceeds the strcngth of tshe rbher ~vhe st~.tor ~(~6. The a 't~d.e of the f~ct&on force bet'veer~ vhe rc~vor 2(~~ and the stavor ~(~~ is erected ~ tire lubricity of the mud, h~ter~erence t bet~.veen the rote>r ~(~~- d the stator 2~~, nu~~tior~ speed and pressure drop.
?S ~h:.ng prevention ~;~ a. s;o~~.bi~stion of tec roes ivol~~ing rotorfstator fit, botto~~hole tepesate, dr~ll~g r~.d select~_on, proper oper~.tyon, lost cinc~alat~on ax~ateri~I, ~o:~zled k otors 2(~4, dogleg severity d stator ~6 age t~-~ clsi~g.
'4 '~bc irdteri'erencc ~~t or'~ tic rotor 20~ a~ad stat~~r X06 is critic~i to ~i~e per~orr~aarlcc arid o~cr~xi iify o~~ ti°~c ci~.s~:orncr ire tho si~to206 tube. ~ motor 2D2 ~rith. too ~c~~ i~:~tc~~ererqce itbc ~wto~ 2t~4 ~~~ggcr tba~ the st~.tc~~-2t~6~
s ~itb a iaigb di~'fcro~t~a~ p~-css~.rc, i;9~z~ ~r~i.i gcn~ra~c c;i~~ing a~cr o~l~ a ~evv circ~iating boaxrs ~i.c,., 6-~ ~~s~. ib.~ ci~~ing .q~a~ ~c ~~ito~~, or ~oilo~
a spi~-~l patters tbro~g~ talc o4or 2~2.
,~ rotor/stator i~tcrf~rc~~cc fit that is thvo loose p~rodces ~. ~ca~ r:~otor ~~~
that stalls at io~r dif~e~c~~ti~3 prcssv. ~'~otor 202 stalizrig is ~c c~~~di~.io~ in t~3 ~rbicb the torq~ze req~ircd to c bit is gryater tlaar~ tbc ~ao'cor ~~L is capably o~ producing.
ya motor 2~~ stays, ti.y rotor Z~~- ~s p~.sbyd to o~y side o~d~y stator 2d6 at~d ~~.d is pumpyd acrswss a sy~.l lacy o~x vc op:~sosite side o~ y rotor 2~G~.
?5 '1'he lobs 210 profile o~ the stator 2()6 mist dyt'or~a :for the fluid to piss across the: sc~i f°~cc. "~~~i:~ ca~s~~~;s ~yr~ l~gh ~.id w~iocaty~
across tbc °~.y~'~ora~od top o~thy stator 206 loba~s ~i~g a~~d lc~c~s to clx ~ vg.
'i'he circulating typ~,raturc dictates the opt op i~tyr~~crer~cv in assyra~.blig the rotor ~t3~. and tb.c stator 206. "shy hrghcr tt~y a~~ticip~.tyd do olc tc~apera ~ e, vc less ~~opryssior~~. req~~~ry. ~c eyn the ~°otor 2~~
arid stator 2~6. "i'he ryd~ctic~_~ iu i~teyre~~cc d ~ g rotor 2~2 ~.ssybly co~perlsates for the s~~e 11 do~oly o:~~ tby elastor~aer because of tyr~perat~rc aid mud proper~.es. l~ there is too ~~cb iuterfere~.cy ~~et~rey~a fihy rotor aid tie stator 2~6 ~t op~ r~ti~~; co~.ditio~s, tbe~ th.o stator 206 ~rie~bpyr~te~ce high shearing stressys, rcs~.lt~.g ire fatigue da~~~ge. ~~ bis ~'~.tiguc lc~.ds to pre~~ature clog ~a~i~.tv. ~iaiir,~e to compensate f'or stator 206 selling res~.lting firo~ the ara~;ip~te~~ do hole øepyra y ~.s ~. lyadir~g case o~
~to~- 2~? faiiures.
t5 ~t is ~er~~~re desirable ~~ adjust ~ int~'er~~~,:~ <~'~ e~~ ~~~ rat~r :~~~ aid s~tat~r 20~ d~r~~~ dril~i~~~ ~~ ~~~.imrm v~l~~~s t~ a~~~t~~~dat~ cb~~~~es n~~
drillings conditions.
°rhe ~r~per it~ter~ere~~~~ ~~t a~~ die rya~t~r 2~2 ~~ b~ caic~lat~d ~sir~g i~c~ati~~r~~, press-up ser~s~rs aid t~p~r~~ s~gas~rs 11~-, ~lE~, 11, 1 ~.~ as described ~~~i.~sly, rid tu,~ v~ ir~~t~;r~~~~~r~~~ a~ b~ set b~
~ntr~iiir~~ the ~ress~.~r dr~~ ~~r~ss tb~ r~.~t~r 20~ bar ad~~sti~~~ ~~~ ~r ~b~
~~~ariabh ~1~~ ~-~stri~t~~rs 10~, 1~6, 111, 11~, as pry~vsl~ described.
'h~~-~as tt~~ g~r~s~nt ~;~t~~~r~ ~s b~~d~s~ribed. ~~ l~a~ti~~lar r~lati~r~g t~
~~~
dra~i.gs atta~b~d b~~-~rt~, ~t sl~~~d ~~ rd~rs~s~~that ~tber and ~r ~~di~~~a~.~~~s ~~art -~a~ t~~s~ s~c~~. ~r s~~~~st~d ~~r~., a~ b~ made dvith~~ the sc~pe and s~i~-it ~~° tb~ ~r~seat i~~~nti~~~.
.~5 ~Ithough the drilling operation is e~ ced bar the us~~ of these tools, it is well knows that the h~~~raudcs of the ~ ° g quid editing flee drib bit is one factor which most often de.te.i~es c:-illing pro ,messes and effaciec~r. 'phe drill bit ~aycie-aulies detern~es how ~-~.ii the i°o~r~~atio~ cu~ir~gs ~~~; cle~.:~ed frog the di~illg bit and transported to the surface.
~ primary factor ire the cost df drilling the borehole l the dr~il~~~; rate of penetration. ~inee this a-~te of pene-a~.~on is larofoundly affected by tl~e drill bit h~r~~lics~ it is ~je~r ~~npor~a~~t to prs~~ride prolrer pre6ssure and fl~~v rite of the drilling fluid ~s it c~~ts tlm d~111 bit t~-oglr di~u;,h~rge; orifices.
~rili bits ically i~~~r~~ ~~ed size nc~~z~es ~'~r discharge orifices., daring ~
single r~g~ into the hol,~. ~inc~~ o~~e bit ~~ be r~sed in ~ Tide range o:~
applications, and ~a~ d~il1 thro~gl°y differing litl~o~og~.es, it is necessary to be able to change the h~dr~~alic d~iscl~arge: clxaracteristics t~~o~gl~ those nozzles.
t~ °l~e need for ~nultlple ori.~ce sizes in drill bits is t~rical~~r addressed by g~a~°ing interchangeable nozzles of differermt sizes for the bits, or orif ce arrar~gen~ents, such as sizo~rn in ~~~ patent ~o. 6,L~ i'~,31~, that are adjustable.
In eiti~er case, the orifice size is set at the sm~'ace and remains the sane until the bit is once again ret~eri to the s ace.
t~
often, l~o~rever, as drilling progresses flee ~,hanges in the formations berg drilled affect hog yell the forrnat~o~a cuttgs are cleaned and transported.
'1'he nozzle size i~itia~~~ selec°~ed rr~a3~ no longer b~~ tl~e best _~or these clanging formations. 'order mo corxapensate, 9J~e o~ rate c~f the drilling 2~ r~.~id supplied to the, bit gf often changed at tl~i.e surface.
Ljnfortunatel~9 because optimizing the h~dra~.lics of the dell bid in~rol~es 'both the area of the discharge orifice ~.nd the o ~ rate: of the drilling Maid, tree optimization seldom ~~appens. ~'~Tic«ll~r, to fully optimize #:he hydraulics, the drill bit would hare to be ret~vd tc~ the surface and the nozzles replaced ~vitl~ ones With different orific° areas. T leis ~.s a very expensive process$
so a op ' anon rarely is a.~rhieved.
To complicate the issue:, if there are other n°~ud-poer~~d deices x~
the drill string, their operation is affected by tie ova rate cha~.ge. since each nud-powered device in the dr~~l st~-~~g 'robs' a po~~oof ties total hydraogic er~erg~r of the drilli_~g ~i~id, ~ e~~ar~ge in the i'lo~r rate may profot~diy affect the perfoa~~;: ;~~ th~t~ ~e~r~~;~. ~~.s a ~c~x~se~~e~~e, there is ~fte~~ ~.
~ ~aggi~~g pct in pro~,~css to supple tbge ~~rc~pcr ~o~;v of o~~r to ~~1 the u~~~
powered devices i~ tire d~~~~ str~r~g god also to tif~e d..~ii bit. grade-these conditions, providing =~~k~ optimnna pressures and flows to sash mud-powered device a drill stri_~g is di~'t~c~.it at best. ~fte~~tie:;, one or o~~e of the rnudvpowered devices cur left ~:o operate ~.rgin~~ll~r.
~ddi~o~~, because it v~.y be d~f~~;,uit to date n ~ a how cha~g$a~g the press~zre and flow rate of the drilling ~a .aid 1 af~~e~: tlmse the mud-po~rered devices, many decisions on ho~v to op~:rate these devices adversely a~'ect t_he overall d~ilhag perfor-~n~;.nce.
? 5 an~j of ve devises s~;d do~oie b~ve val - g andj~ar orifices that relieve the drilling ~.t~id frog wi the d~-~'ii st~~.g to the well bore, saxch as the reliet° valve described ?~ ~.1~° ~~.te~~t I~Tc~. ~,~ l i.:~~.~.
Cane type of device ntili~~g v~.ivia~g to vs.~io~s types. ~f ~~ed orificesc .~.t can be switched on as the deuce is ~.ctivated~.ri~.g d~-i~g is 'on s~$.ean~d' hole oper~e~. ~~~ii other de~~ices provide taxed ~~~~aees, for "eh~~es'7 as they are sometimes cahed~ in the drill sung to create ~. pressure drop 'long -the ~ 1 string with~~t venting to the borehole.
~Ithongh these devices a~-e ~peil Known, it is ~aot presenltl~ possible t~~
adjust 25 th.e flow rate and pressure dr~p t"_n-o~gla them.
it is e~efore desirable to be ~bie t~~ ~ci~nst~blyr select the p~-essu~: a drop andJor how rite ~.ca-oss e~cb m~a~~-poG~rered device in a drill stri~~g ~'e independently cf c~ci~ ether. ~t ~h~: s c ti~~,, ~t is ~is~ dcs~~-~~ie tc ~d~ust~.bry c~a~t~°c~i the sip;e c~f the ~~~.id ~iischa:~°gc c~,ificc.s in drib bits.
he present i~~~eaaticn ~s ~, r~cthc~ axed ~.p~r~t~s r:~. cct~ci the pressures and fi~ws ~crcss fluid ~sir~~ deices used it drill st~i~~gs ~~br drilling ~~>rehcles.
~ method for eptizis~~; d~-iiii~g fluid ~~.~rdrauiics ~~rhe~ driliir~g ~ ~eii bore is disclosed. ~'he driliir~.g fluid i~.s supplied by ~ su~g~~ce p p thr~u~,h ~
drill s g to ~ drill bit. °Thc rnethcd has ~e step ef ~d.~ust;~ the ~~ rite of the s ace p p d ~ fi:~id press=mare drop ~cr~ss t:e drt:il bit while drilling, such th~.t the drilling ~~uid hydraulics °e op ~ . ed for ~ gives driiiimg c~~aditi~n..
~.isc~ disci~sed is ~ dpi bit ~vh disch~rgc orifices c~r nozzles v~hich are ~5 adjustable such that the orifice size ~.y be changed while drilling, without reading the drill s ~ g fr~n°~ t~°~d hole:. 'here ~y be ~.
plurality of nozzles on the face ~f the bit th~.t ~n~y selec~~ely~ ed can or ~ff° such the total flaw rate alnd pressure drop dough the bit is ~.dj~.~sted.
Esc disclosed is a dc~nitaole ru~t~r with ~.dj~astable interference fit. she fit is adjustable by ~r g the ~cw rate; aid press~.,~e d~r~p across -0re n~ot6r w ° a in operation. ~.dditie~r~, the pr~;ssures end texnpera~ares of the drilling laid ab~~e and bel~~~ ve otcr rr~~~y be or~atc~red so th~.t the interference gay be optin~~.liy ~.djusted. ~~ce the naot~r hydr~.i~s ~.re optin°:ized, the how then pr~ceeds to e~~:her devices, and ~aliy to the drill bit.
h~ o~°der for the 11~~~ t:rt~x~gh iii the de~rices i~~ d~c drill string t~ ~iss~ be optin°~ized, the flog th;~ough ti~~, ~c5,or ~o~° othe°,r de~~ice~ is ~dj~stein ~
r~aer selected from the grc~~co~~.sisti~.g ~f rest~°icting the fi.:~id fio~, bypassing the fluid ~~~~~r a.r~d r~ii~~aa~~~; the fluid ~~~rv, thereby s~tti~yg t~
press~-e drip ~.a~d the ~~d ~lt~~a ~~te t:.r~~g~. e~~,h eee. ~ s reci~y~~ed ~~r the ~~rer~.li system, tree ~~~~r ~'r~~~ tl~e s~ce p p is ~~,re~sed ~r decreased as recess.
i'1-~e i~~e~ti~r~ gill f~~ ~°r die describe~~., by gray ~c~~
ex~~t~aple7 pith reference t~ the ~cc~pa~yig ~'r~~,~i~gs, ~,~ adh~cl~:
F'igrre 1 is a p ~a1 se~a~~~ ~rles~~ a drill rig th-illi~~; ~ '~~reh~le its the earth.
~zg~e 2 is partial secti~s~ ~f a side ~ie~~ s~f ~. 'wed canter bit.
:~ 5 ~i a 3 is a perspective e~f ~ rolling c~er drill bit..
Figure 4 is a sect~~~ ~v~r c~~ a wed ~~~.tter drill ~~it fitted ~rith a s~%~archable select~r ~al~'e.
~'ige 5 is a section vri~;~ ~~ ~. drill bit t~e~. ~i~~ c~ntr~ll~.ble ~a~~iable ~l~~r restxicti~n deices.
~i a 6 is a schern~.tic; ~ie~~ ~~ ~ fluid ~sir~g de~rice 1°~r d~ ale drilling ~perati~r~s ~f the preset iauer~t~n.
~ig~sxre 7~. is ~aa er~d s~.;et~c~~ ~ricr e1° ~. ~~~ine~~:c tyrpe drilling ct~r ~~' the preset irwer~tl~~.
~~~~a~o 7F3 is ~ side s~°~~s~~ ~r~e~E~ of ~ I~ic~i~~~u ~:~p~ dz-illing motor ~f tl~~
p~°~s~~t vo~tion.
.ofeg ~o~ t~ Figwc l ., u~~h.~~ ~ril~h~g bc~r~hol~~s 1 ~ ~o ~ho~
~°°~rm~.tio~s i2, i~ is ~~r~~~ora pr~.~tio~ t~ use a. bc~'s~~
hole ~.ssebly i4. as shop i~ g'iga~re l . ',he bottom hole ~.sse~nbi~r ~;~ 4. is typicali~
I.~ coamected. t~ the end of ~:l~e ~zbul~r drill s g 16, ~~hi.el~ is typicall~r r otatably drive lag~p ~ drill~g rig l~ ~~r~a she su~~aeea T~ ~c~ui~o~ t~ providing motive ford for rots ° g the drill string ~~, the; drilling rig- l.also supplies ~ ~.rilli~g fluid ~0 ~~der pressure, amd float created by ~. soiree mvd pu~~p ~~9 through the t~bul° 1 str~g l.~ to tee boo~~ hole ~.ssembly 14-. ~'l~e drilling fluid ~~l is ically- laden ~~iih drilled ~.b~°~sive f~rm~ti.or~ material, as it ret s to ~ mid 24 and is ~;~ rep~.~.tedl~r r~;-~ei~-cul~ted ~l~-ou~;h the borehol~. 10.
the i-i.~ i~-, m~.y b~; d.~illi~g fluid ~,siug devises ~~~ eliding ~. drill bit 2~. ese fluid using devices ~~ m~~~ be ore ~~- r~~re off' d~-illiug ~raotors, drill~g t~bines, rote directiona..l dolling devices, ~~d. driven electric generators, hole ope ° g devices, mess 'ng while drilling to~1 s, ~:~d doahole co ~c~.~xs~de~~~ces.
'fhe preset i~ve~ti~~~ is dr~x to ~ method ~d ~.pp~.r~~s t~ co~~ol the 2~ pressures d fl~~rs acs oss ese fluid using devices G~ used in drill strings l~ fc~r drilling borehol~;s ~~fl tv optimize the dri.~.lig fluid h~rdr~ulics vahe~
drilling ~ veil bore t. 'fhe r~~et~~od ha~,s the step c~~°~d~~isti~~g vhe r'~o~F rate of tl~=e ~u~~.ce Bump 22 ~~d ~. uipres,yre drola across the drill 2~ bit ~ahiie drilling, such that the drilling fluid l~.~dr~ulics arc optbnlzed for a given drilling condi~-ic~~~.
~'o optia~izc the quid i~~dra~wlics for a given dolling co~adition the flog through i~uid using de~rices ~~ ~s ~.d~vsted in ~. ~~acr selected ~rodie group consisting of rcstucting vie ~'~~id cw, b~passg tl~c quid ~loend relieving the fluid ~ov~ry thereby sct~~~; the prcss~~ae d~~~~p a.iid the quid $~ov~
rate through each de'ric~:. A,s rc~uired for tl°~e overall s~rste~n, the flog frornn the s ace p p 22 is ~.u~creased or de~:reased actor ° gzy, as necessary.
~0 Ione enibodirnent, the drill bit ?~ may be ~. e~cutter type drill bit 3f1 as shorn in figure 2. ~ he ~~ed cutter drill bit 30 has a longitu ' al axis 32, a bit body ~4 dvitli ~. n°s~~ arid ~~ i°~icb is. adap°~ed t~~ be se~deared to the ~3~14.
'typically, eads 3 ~ ire used for the attac~r~~ent, but other morons of t 5 attac er~t gnat' also be udlieed~ ~t the second, oppovaite end 4C of tae bit body 3~- is the cutting face ~.2 of the axed cutter drill bit 3~.
~ °ng operation, die bra bode 3~ is r~;~tated by ~~~ external means ~rl~ile the cu ' g face 42 of the fibbed cutter ' I bit 3~ is forced into the formation i2 2Q being drilled. 'I"lie rcaatiora ~der load causes cut~::ing elements .4 to penetrate into the for~~ir~tion l~ ~,nd rcn~.ove it ire a scrapping dlor gougbig action.
'lie bit body 3~ lips ~ntcrn~~ ~ass~~3in~; ~6 ~~~rth ~.l~o~s the press~ari~ed :~S drilling iiuid 2~ s~~ppl3ed fro~~ tl~e surf~c:e p~..a~ip ~'<~ t~~
i°lo~sr tba°o~gi~ a plurality of nozzle or-i:~ices ~-~. 'fbese nozzle orifices ~-& discharge the drilling fluid 2~ to clean a~~id cool die ~;utt~g ele~r~ents ~4 as they engage the material 12 being d~°~ll~~d. 'Te drii~iiig u~d ~~~ also transports tine drilled material to the surface f~~- dispos~,~.
P~ mother ennbodger~t the driii bit 2~ tray be a roiii~P; cutter type drib bit ~~
as shop iu ~'~~atre 3. ~. ~-ollir~~ otter drill bit 50 is also cooa~y c~l:~ed a rock bit, a rol~ir~~ cutt5:,r ~-ec~ dr~iP bit a>r aoiPf~;~d drift bit.
~i~r~l~r to the ~'~xed otter driil bit ~a,Phead~r described, the r~P1~_~ otter drill bit 5~
nas a ior~gir~ud~~aP axis 5~, a b_~t ~Sody ~~f ~ritl~ ~. ~'.rst cad ~E which is adapted to be secured to the lid i:~. ~ypic~PPy, threads 5~ are used the attar sot, but other forms ot° attar ~ e~~t ~n~.~~ also b~; utiPized. ~'ypically, the body of the rollick cutter drilP bit 5,~ has three Pe;s ~~. ~,t~ached to each lei ~~ is a a~tat~bly daunted roP~:~~~ cutter ~2. l~ttached t~> each roPliotter ~~ are hard, gear resistant c~t~t~ i.se~ts ~~~, which awe cap&~bl~; o~ e~~.~~ the earth formation P2 to effect a, dr"~Pl~ a~,tior~ arid c~.~se ~~ota~.o~ of the rolP~
c~.tte~- 6~.
~'he bit b~dy ~~ h~.s teraP pass, y ~ (of, sh~s~r~~ with ~.~lo~s the.
pressurized - Iir~~ i'yv~.d ~~ s~~~plied. °othe s~.u-f~c;e to ~fo~a t~~~ro~gh pPorality of ~aozzPe ori~'~~ces ~., 'these nozzle orifices 6~ discha.~~e the drglPhag ~.uid 2f~ ~enera~_ly to~~rard the roll~.~ otters ~2 a~pd the ~ate~aP
1~
be~~ drilled, i~ a ~ er similar to that off' tl~e fixed cutter ' 1 bit 3~
~t~st described.
P~ practicing owe er~~~odie~t of v.e preserbt inception, it is desirabPe to adjr st ties hydraulic fi~~~~ th~-o~the nozzle orifices c~~' a dr°iPl bit ~~, J(~, 5 as the opti~ehydrauPic horsepower of the driPl~ ~~uid i'iowir~g ti~rough these ori~c; s often char~bes d ~ driili~~.
~~s shop irg ~'~ge ~, o~c ~~a~, to :~d,~ust the lydra~~Iic flog thro~~.~h the ~zzic orifces iu ~ d~-ii~ bit 3g~ to ~t a seiecto~~ ~~an've °~0 irlt~ a bit body i4.
~s drilPin~ progresses, the s~;pector ~al~e '7~ a~~ be eEpe~~ated to such the flow f-~oa~n one see csf aa~czzle oai~aces ~~ to one or ~~~e ~lrea~ate a~ozzie orifices 7~.. The seiect~sr~ ~~e '~an~.~ i~~de see~ea~~~ open°atiaag positioaas such that ruazaerous cozafjgu$~.~.~ons ~.re possible. ~°he c;onf'aga~ration chosen ~ouPd be the one best sited fo~° the preseaat drilling conditioaz. ~7nce the selector ~~~ive 70 h~.s been set :~.~ ~ aa~~ic~ia.~ coa~ig~r~a~oaa, the flow ~~t~, of the saa~f~ce mud paaa~p ~~ is ~dja~sted to the proper va~~.e fc~a~ t~h~t coaaf'r~~~~~ioa-~.
tlvs m er, tl~e opaiz~~.i presswre gad flodv ~~te for the drill bit nndea° ~
given set of drilg co~~dit~o~~s m~.~r be ad~aasted. it" ~:hea~e ~.re other fluid usia~g devices 26 ixa the ~~-i~i s ' g i~9 ~~~ch of these a~~y~ ~iso be ~d,~~sted for i~ opt~°~~.1 opea-ation ~s ~r i~., ~s 1~ be described.
~s shop iaa F'igaxa~e ~, ~a~~ ~ltea~n~:~e ~r~..~3 to adjust ti-ae h~drsuiic f~o~i tough t~~e nozzle orifaces in ~ drill bit 5is to f'at v~i~.bie ~esta~ctions ~0, g~
into the nozzle orifices ~4, ~6 in ~ bit body ~~.. 'phase vaa~i~.ble restrictions ~~, ~2 ~-e opea-~.ted by servo type motor devices ~~, 9a, ~oa° other suitable devices ~rhich a controlled °oa~ a. sui~~.ble ~~ tool e,lect~°~~uics device through short hop co ualica.~'~o~a~s9 or other l~aao~systex~s suitable ~~°or this ~ a of con~ol. As indicated by aaurner~.l ~2; in ~ iga~re ~ the servoanotor end the restc~ctioai array he coanbiaaed into ~, single pac~~.ge ~vhifdh is inserted into ?C~ e~is - g flow p~.ss~ge ~ a ~n ~ dell hit. Ag~.ia~, once the aaozzle oa~i~~.es ~.a-e ~djo.sted to the optinaa~a-~r value, die flcwr r~.te of t~.e sua~~ace and pump 2~ is adjusted to the pa~ope.~ v~.l~ae for th~.'t coa~°agua~~rtion. in this ~aaa~er, the opth~~'pa~essure aaad ~~~~r a~~.te for the drill bit ua~der ~ givea~ set of da'illing coaaditions araay be ~.d~usted.
o~eve~, once the ' 'i1 bit pa°essure end flow is ~d~a~~sted, y other ~ui~
.sing devices 26 in tl°~e drib string t6 rn~y also need ~to be adjusted ~'or optismal operation as well. 'pl~~s ~s don~° i~ refea-e~.c~e to i=i a ~.
higure G is ~ scbcstic ~.iagraa~ of ~Io~ ~r!-~.ngements possible in other ~I~id using devices 2G. The device itself is i~~c~c~tcd by nnn~c;al l~~ as a v~~~.ble fio~r resti-ictor. ire ose, it is desh-~ble to ad~ost the press~f~e drop and ~:he ~lo~
~vte ti~o~gh the device itsclf ~ ~Q~. ~ir~ce it is ~.lso ~ece;~sa~gr to set the _~o S rite at the exit &~~ of tic; .~~d ~~swng, de~~gce 2G, it ~r~~~~a b~:, necessa~~~ to eitlacr d~-~ert ~lo~r a~od tbc device itself ~~0 e~ith ~ variable fio~ restrictor 1~4, res~ict the ~1~~r into the, de~Tice itself ~ ~~t~ pith a va~~ble fio~r restrictor ~ OG, or rcstrict the flog ont of the device itself ~ ~~ with ~. variable flog restrictor i~~, or to divert flog into the borehole above the dev3~ce itself' ~~~ With a t ~ varyable flog restrictors 1. ~ and j 1 ~.
1~.~ practice only on.e or a.~ro oi° these ~r~~ri~bie fio~v restrictors ~~4, i~G, ~ 0~, i hand i I2 would ge~~c~all~r be ~.sed, depc~~ding iapu~:~ tl~e type of ~.evice ~.nd the desirable acc~.cy level.
tS
In a~~ case, in ordcr to properly set the va~~iable f~o~v restrictors ~~~, I~6, ~~~, ~ ~~3 it is neccss~~~ to isno~~~ one ~r yore of r~e tepc~°~!t~.re, i~oratc and p~°esse through ~~e ~'~uid n.sin~ device 2G. ~~rde~° to ~~e ese rea ~ gs, one or Snore keenso~~s s i~-, 1.16, ~ 1.~, i:~~.re used to provide the rcquired te~nperat~~res, flower rates df.cr pressures i~ tile opassages ~~~
of t~hc device required to optimise tl~e tool. tJnce tie optyrnurn pressure drop and o~ rate is calc$~a~,ted, and lCno~ng the t~lorate which ~nn.st be maintained by c fla~id eti~g the fh~id using device ~G, tl~e variable flog restrictors t, t ~G, t ~~, l. t ~ any 1. ~ 2 -- and if' r~ecessar~r the fio~
rite of the '<?S surface pump 2~ - ~.re ~~~en set ~s red~i~:-ed to pro~ra~ce tlne;se vales.
~~ch fh~zid using device ~G ~~ tl-~~s be ad~nsted tc, opt~r~auhydraulic operating values and still permit the drill bit 2~ to be operated at its opt~~mu l~ydraolic setting.
~l C7ra such quid using de:~ce 2~ is a positive dispiaceL~t do~ole motor ZO~. positive d~spiace~r~,r~t motors 2~~, as sore ~._~ cress sec~ior~ wick's in ~i~ es '~~ and '~ dominate ~il~~eld o,~eraor~s and over distinct o~er~~ion~.l d economic advantages over cot~ve~~.-io~al ro' ' drilling i~. ~riax~yr conditions. Do ole h4~~o9:ors ~~C o~~er tle option of~ drilling erg e~tber ~.
traditional rotary ~aodd or a sl=ding ~:node in ar~hici~ tbae hole follo~rs tl~e di~ect~ioa~ off' the gent ~Eor~sir~~ o~~ t;~ motor ~~~~. In directior~~.l drilling applications, do ole t~°~otor4 ~~a pewit contrc>l ~~ .~e ~rellbore direction 1G and tf~us, more e~'fecti~Te deviation cor~~rol tiara conventional rotary mends.
oea~ type positive displacement motors X02 ~~onsis~: o~° three major suh-assemblies, a power secr~ion, compr~fsi~~g ~. rotor ~:~~ ~~ a stator ~~~, ~rl~ich ~co~~rerts hydraulic er~e~~gy into mechanical rotary power, a tr~~asrmission IS section (not shop), ~rb~ich transmits rotar~r drive tom the powcr section to vhe bearing section and also i~corpor.tes the adj~.~s~~bl~: ~~ent lousing end a be g section knot sl~~.), A~lxich supports axi~.~ anc~ radial loads d g drilling and transmits ~: rs~tar~J~ d~°ive to the bit through <~ drive sl~a~~.
~0 'The poorer section the motor 2~2 converts h~rdr~.ulic power Trom the drilling Tluid into mecl~~cal po~~ev t~~ . tl~e b~~i~-:. 'his is accomplished by reverse application of z.e oine~,u pup p ~ ciple. ~rillir~g fluid i_s pimped into e'~eotor's 2Q2 poker section at a pressure that carases the rotor 2~~ to rotate wi the stator ~ ~C~. ~°l~is rot~.R:ion~.l force is den traJ~smit~ed ~bro~.gh a ~ansrnission sh~Tt and drive sl~~Tt to tl~e bit.
Typically, die rotor Z~~ is na~~~u~a,ct~r~;d o~'corro:9lo~~-resgstaa~t st~i~.less steel.
It ~zsuall~~ has a chro~_e pl~.tir~g applied to reduce ~.~ction and abrasion.
T"ungster~-cirbide coated rotors 7C~~= ~.~°e also ~.vail~~le for reduced ~b~-asion e~~ and corrosion d~ag~. 'i'~ st~~c~ ~~~ cons:ists c;~ ~ steel Vibe pith ~~
e~as~a~nae~- ding oid~d ~~tc the bore. T'he ei~stc~~ur in thge i~~~.~ ~s ~c~.iated specif~caii~ ~~ resist ~.b~~sicn ~~-~d i~yd~cca~be~a~~~~d~ccd deterioration.
The rotor ~0~- and stator ~J~ have si~.ilar helical p~c~~~les, b~.t the rotor Z~~.
has c~~e less spiral, or i~~be 2f~~, thin the stator 2~:~~. lrn an ~sse~cabied po~e~
section, the rotor 2a~- and the stator '~~ ~°o~ ~ co~~r~~~~s seal ~._~
their c.ont~.ct points al~n~ a sc~ai~~~t li~~e, ~rbych produces ~. robber of independent cages. l~s aid ~,ai~, ~~a~d or vva~er~~ is ~'orce~ ~o~s~h these pro~~essi~,re cages, it cases the ~~to~- ~~~ ~~s ~-at~:het around ~~sid~; the stator 20~.
'1'~~is ~o~rement o~the rotor :~~~~ inside die stator ~~S :is c~.ll~;d n~ta.tior~..
:~o~ e~eh ~.ut~~.on cycle, the rote 24 t~~s the distance of ~~~e s~ats~~° lobe ~
1 ~ width.
'~he ~°otor 204 .gist nuta:e for each ~o'os~ ~ ~~ in the stator 20~ to complete one revc~l~t~on of the bid b~~. ~ motor 26~ critic a '~:~ rotor/stator 1~be coal anon a~.d a sp~;ed o~ 1 ~ rp at the bit boy gill have a nutati~n speed of 703 circles per ate.
'the lobes 2~~, Gtr on the rotor ~~~ ~.nd stator ~.~~ ac~: Pie a gear bob. ~s .e~ nbers increase; fdr ~. ~iv~;n oto~° ~~~ see, the ~voto~°~s torque o~.tp~.t generally increases arid its ox~tp~t shift speed ~~,~~e~:all~~f decreases.
eca~se power is de~'~aed as spe~;d ~~°~~1~.~iied b:y the torque;,., ~ eater ~
ber o~ lobes ~0, 2(~ ~ in a motor ~.;~~ does ~~o'~ necessarily ~,~~°o~~~°
more hors~;ovr6er.
motors ~~2 ~th yore lobes ~~9 ~l~ are ac~all~~ Hess efficient because t~°~e :2~ seal ~.rea between the raptor ~~~ end s~:ator 2fl6 i~n~,reases with the nur~~be~° o~
lobes.
otcrs ~a2 are us~.ail~~ assembled vvh the rotor ~fl.~ sued larger tan the stator Zc~6. 'his produces a stroa~g positive i~ne'er~~nce seal, casing a posive tit. motors ~QG r~s pith ~, ~°~t~r Z4 e~~ di~etcr r~c~rc dm~~
~0.~~
greater th~.~ the stator ~f~& nor dia~etvr at do~nhol.e co~dit~orls a.re very strong (capable of prt~d~~cir<g ~~r~;e pressure, drops, but t~ae~ usa~~~~y~
have ~
reduced fife because :~°c~t~re uhn~~~~g o~ the ~~3~b-~er pouion o1° t~~e stator 2~~ oecurs.
~f increa.sed do~mho~e tepe~-a~~res -c anticipated, thc~ a,a~ount of positive fit is re~uccd d g ~~~ator ~~z asser:r.bly to alla;,Yw nor the s~el~ir~g of the eia.stoer ~' g in the; stator ~a~. ~avers~e staror ~0~ is usually rc~uircc~
to obtain the correct got o~° inter~'c~rence bet~ve~a t~:~e rotor ~(~~-~~d the stator 20~ f~r ten2per~t~i~res ~~c~ve 2fl~:~ deg~". ~~ thhe ~t~cipated circ~.dating teperat°~re of a ~reli is ~bovc ~.pp~o~~atei~r 22~ dcgg-0, the ia~ter~~,recc ~t must be ~. ash or ~~e~;avve ~i~, vahich thc. rotor 2~. :mew die~;er as ire see size as, or sa~~'er the ~~he stator 20c~ ~o~- di- star when a motor 2(~~ is assembled iti the shop.
Ch 'ng dcscribes ~. sda.tor :~0~ ~~hich tire r~~bcr across the top of the lobes 21.t~ his ~pparenti~,~ ripped a.~~.~. ~ha~g occu~°s whey the s~er~gth of the frictior! force between the ~°otor ~(~4 lobe ~fl~ ~:~d the stator 20E lobe 2 ~ (~
exceeds the strcngth of tshe rbher ~vhe st~.tor ~(~6. The a 't~d.e of the f~ct&on force bet'veer~ vhe rc~vor 2(~~ and the stavor ~(~~ is erected ~ tire lubricity of the mud, h~ter~erence t bet~.veen the rote>r ~(~~- d the stator 2~~, nu~~tior~ speed and pressure drop.
?S ~h:.ng prevention ~;~ a. s;o~~.bi~stion of tec roes ivol~~ing rotorfstator fit, botto~~hole tepesate, dr~ll~g r~.d select~_on, proper oper~.tyon, lost cinc~alat~on ax~ateri~I, ~o:~zled k otors 2(~4, dogleg severity d stator ~6 age t~-~ clsi~g.
'4 '~bc irdteri'erencc ~~t or'~ tic rotor 20~ a~ad stat~~r X06 is critic~i to ~i~e per~orr~aarlcc arid o~cr~xi iify o~~ ti°~c ci~.s~:orncr ire tho si~to206 tube. ~ motor 2D2 ~rith. too ~c~~ i~:~tc~~ererqce itbc ~wto~ 2t~4 ~~~ggcr tba~ the st~.tc~~-2t~6~
s ~itb a iaigb di~'fcro~t~a~ p~-css~.rc, i;9~z~ ~r~i.i gcn~ra~c c;i~~ing a~cr o~l~ a ~evv circ~iating boaxrs ~i.c,., 6-~ ~~s~. ib.~ ci~~ing .q~a~ ~c ~~ito~~, or ~oilo~
a spi~-~l patters tbro~g~ talc o4or 2~2.
,~ rotor/stator i~tcrf~rc~~cc fit that is thvo loose p~rodces ~. ~ca~ r:~otor ~~~
that stalls at io~r dif~e~c~~ti~3 prcssv. ~'~otor 202 stalizrig is ~c c~~~di~.io~ in t~3 ~rbicb the torq~ze req~ircd to c bit is gryater tlaar~ tbc ~ao'cor ~~L is capably o~ producing.
ya motor 2~~ stays, ti.y rotor Z~~- ~s p~.sbyd to o~y side o~d~y stator 2d6 at~d ~~.d is pumpyd acrswss a sy~.l lacy o~x vc op:~sosite side o~ y rotor 2~G~.
?5 '1'he lobs 210 profile o~ the stator 2()6 mist dyt'or~a :for the fluid to piss across the: sc~i f°~cc. "~~~i:~ ca~s~~~;s ~yr~ l~gh ~.id w~iocaty~
across tbc °~.y~'~ora~od top o~thy stator 206 loba~s ~i~g a~~d lc~c~s to clx ~ vg.
'i'he circulating typ~,raturc dictates the opt op i~tyr~~crer~cv in assyra~.blig the rotor ~t3~. and tb.c stator 206. "shy hrghcr tt~y a~~ticip~.tyd do olc tc~apera ~ e, vc less ~~opryssior~~. req~~~ry. ~c eyn the ~°otor 2~~
arid stator 2~6. "i'he ryd~ctic~_~ iu i~teyre~~cc d ~ g rotor 2~2 ~.ssybly co~perlsates for the s~~e 11 do~oly o:~~ tby elastor~aer because of tyr~perat~rc aid mud proper~.es. l~ there is too ~~cb iuterfere~.cy ~~et~rey~a fihy rotor aid tie stator 2~6 ~t op~ r~ti~~; co~.ditio~s, tbe~ th.o stator 206 ~rie~bpyr~te~ce high shearing stressys, rcs~.lt~.g ire fatigue da~~~ge. ~~ bis ~'~.tiguc lc~.ds to pre~~ature clog ~a~i~.tv. ~iaiir,~e to compensate f'or stator 206 selling res~.lting firo~ the ara~;ip~te~~ do hole øepyra y ~.s ~. lyadir~g case o~
~to~- 2~? faiiures.
t5 ~t is ~er~~~re desirable ~~ adjust ~ int~'er~~~,:~ <~'~ e~~ ~~~ rat~r :~~~ aid s~tat~r 20~ d~r~~~ dril~i~~~ ~~ ~~~.imrm v~l~~~s t~ a~~~t~~~dat~ cb~~~~es n~~
drillings conditions.
°rhe ~r~per it~ter~ere~~~~ ~~t a~~ die rya~t~r 2~2 ~~ b~ caic~lat~d ~sir~g i~c~ati~~r~~, press-up ser~s~rs aid t~p~r~~ s~gas~rs 11~-, ~lE~, 11, 1 ~.~ as described ~~~i.~sly, rid tu,~ v~ ir~~t~;r~~~~~r~~~ a~ b~ set b~
~ntr~iiir~~ the ~ress~.~r dr~~ ~~r~ss tb~ r~.~t~r 20~ bar ad~~sti~~~ ~~~ ~r ~b~
~~~ariabh ~1~~ ~-~stri~t~~rs 10~, 1~6, 111, 11~, as pry~vsl~ described.
'h~~-~as tt~~ g~r~s~nt ~;~t~~~r~ ~s b~~d~s~ribed. ~~ l~a~ti~~lar r~lati~r~g t~
~~~
dra~i.gs atta~b~d b~~-~rt~, ~t sl~~~d ~~ rd~rs~s~~that ~tber and ~r ~~di~~~a~.~~~s ~~art -~a~ t~~s~ s~c~~. ~r s~~~~st~d ~~r~., a~ b~ made dvith~~ the sc~pe and s~i~-it ~~° tb~ ~r~seat i~~~nti~~~.
Claims (17)
1. A method for optimizing drilling fluid hydraulics when drilling a well bore, the drilling fluid supplied by a surface pump through a drill string to a drill bit, comprising the step of adjusting the flow rate of a surface pump and a fluid pressure drop across the drill bit while drilling such that the drill bit drilling fluid hydraulics are optimized for a given drilling condition.
2. The method for optimizing drilling fluid hydraulics when drilling a well bore of claim 1 comprising the further step of controlling the fluid pressure drop and flow rate across at least one additional drilling fluid using device in the drill string intermediate the surface pump and the drill bit.
3. The method for optimizing drilling fluid hydraulics when drilling a well bore of claim 1 wherein the drill bit comprises a plurality of fluid orifices for discharging the drilling fluid, comprising the further step of controlling the fluid pressure drop across at least one of said orifices.
4. The method for optimizing drilling fluid hydraulics when drilling a well bore of claim 3 wherein the pressure drop across the orifice is controlled by changing a cross section area of the orifice.
5. The method for optimizing drilling fluid hydraulics when drilling a well bore of claim 1 wherein the drill bit comprises a drilling fluid pressure relief device, the method comprising the further step of controlling the fluid pressure drop across the fluid pressure relief device.
6. A method for optimizing drilling fluid hydraulics when drilling a well bore, the drilling fluid supplied by a surface pump through a drill string to at least one drilling fluid using device in the drill string, comprising the steps of monitoring the pressure of the drilling fluid at the device, adjusting a flow rate of the surface pump, and controlling a drilling fluid pressure drop through the device by selecting from the group consisting of restricting the fluid flow, bypassing the fluid flow and relieving the fluid flow, thereby setting the pressure drop and the fluid flow rate through the device.
7. The method for optimizing drilling fluid hydraulics when drilling a well bore of claim 6 wherein the device is selected from the group consisting of drill bits, drilling motors, drilling turbines, rotary directional drilling devices, mud driven electric generators, hole opening devices, measuring while drilling tools, and downhole communication devices.
8. The method for optimizing drilling fluid hydraulics when drilling a well bore of claim 7, wherein the device is a Moineau type positive displacement motor, and the method comprises the further step of adjusting the flow rate in response to a downhole temperature adjacent to the motor.
9. The method for optimizing drilling fluid hydraulics when drilling a well bore of claim 8, wherein the motor further comprises a rotor sized larger than a stator producing a strong positive interference seal and causing a positive interference fit.
10. The method for optimizing drilling fluid hydraulics when drilling a well bore of claim 9, comprising the further step of adjusting the amount of interference fit between the rotor and the stator by adjusting the pressure drop of the drilling fluid through the motor.
11. A drilling fluid using device for use in a drill string when drilling a well bore comprising a drilling fluid flow restricting device and a drilling fluid flow relief device, wherein in operation the drilling fluid flow restricting device and the drilling fluid flow relief device are remotely adjusted in operation to achieve optimum drilling fluid hydraulics through the device.
12. The drilling fluid using device of claim 11 wherein the device is selected from the group consisting of drill bits, drilling motors, drilling turbines, rotary directional drilling devices, mud driven electric generators, hole opening devices, measuring while drilling tools, and downhole communications devices.
13. A drill string for drilling a well bore comprising a drill bit, the drill bit comprising a drilling fluid flow restricting device and a drilling fluid flow relief device which are remotely adjusting in operation to achieve optimum drilling fluid hydraulics through the drill bit.
14. The drill string of claim 13 further comprising a drilling fluid using device comprising a drilling fluid flow restricting device and a drilling fluid flow relief device wherein the drilling fluid using device is selected from the group consisting of drilling motors, drilling turbines, rotary directional drilling devices, mud driven electric generators, hole opening devices, measuring while drilling tools, and downhole communication devices.
15. The drill string of claim 14 wherein the drilling fluid using device is a Moineau type positive displacement motor, and the drilling fluid flow restricting device is adjusted in response to a downhole temperature adjacent to the motor.
16. The drill string of claim 14 wherein the drilling fluid using device is a Moineau type positive displacement motor compring a rotor sized larger than a stator producing a strong positive interference seal and causing a positive interference fit.
17. The drill string of claim 16, wherein an amount of interference fit between the rotor and the stator is set by adjusting a pressure drop of the drilling fluid through the motor.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US31948102P | 2002-08-21 | 2002-08-21 | |
US60/319,481 | 2002-08-21 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA2437519A1 true CA2437519A1 (en) | 2004-02-21 |
Family
ID=31887996
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002437519A Abandoned CA2437519A1 (en) | 2002-08-21 | 2003-08-19 | Hydraulic optimization of drilling fluids in borehole drilling |
Country Status (3)
Country | Link |
---|---|
US (1) | US20040108138A1 (en) |
EP (1) | EP1398456A3 (en) |
CA (1) | CA2437519A1 (en) |
Cited By (1)
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US9347285B2 (en) | 2010-08-26 | 2016-05-24 | Atlas Copco Rock Drills Ab | Method and system for controlling a compressor at a rock drilling apparatus and a rock drilling apparatus |
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- 2003-08-18 EP EP03255100A patent/EP1398456A3/en not_active Withdrawn
- 2003-08-19 CA CA002437519A patent/CA2437519A1/en not_active Abandoned
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US9347285B2 (en) | 2010-08-26 | 2016-05-24 | Atlas Copco Rock Drills Ab | Method and system for controlling a compressor at a rock drilling apparatus and a rock drilling apparatus |
Also Published As
Publication number | Publication date |
---|---|
EP1398456A3 (en) | 2005-03-23 |
EP1398456A2 (en) | 2004-03-17 |
US20040108138A1 (en) | 2004-06-10 |
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