 Modern directional drilling systems generally employ a drill string having a bottomhole assembly (BHA) and a drill bit at an end thereof that is rotated by a drill motor mud motor) and/or by rotating the drill string. A number of downhole devices placed in close proximity to the drill bit measure certain downhole operating parameters associated with the drill string. Such devices typically include sensors for measuring downhole temperature and pressure, azimuth and inclination measuring devices and a resistivity-measuring device to determine the presence of hydrocarbons and water. Additional down-hole instruments, known as logging-while-drilling (LWD) tools, are frequently attached to the drill string to determine the formation geology and formation fluid conditions during the drilling operations.
Drilling fluid (commonly known as the “mud” or “drilling mud”) is pumped into the drill pipe to rotate the drill motor, provide lubrication to various members of the drill string including the drill bit and to remove cuttings produced by the drill bit. The drill pipe is rotated by a prime mover, such as a motor, to facilitate directional drilling and to drill vertical boreholes. The drill bit is typically coupled to a bearing assembly having a drive shaft, which in turn rotates the drill bit attached thereto. Radial and axial bearings in the bearing assembly provide support to the radial and axial forces of the drill bit.
Boreholes are usually drilled along predetermined paths and the drilling of a typical borehole proceeds through various formations. The drilling operator typically controls the surface-controlled drilling parameters, such as the weight on bit, drilling fluid flow through the drill pipe, the drill string rotational speed and the density and viscosity of the drilling fluid to optimize the drilling operations. The downhole operating conditions continually change and the operator must react to such changes and adjust the surface-controlled parameters to optimize the drilling operations. For drilling a borehole in a virgin region, the operator typically has seismic survey plots which provide a macro picture of the subsurface formations and a pre-planned borehole path. For drilling multiple boreholes in the same formation, the operator also has information about the previously drilled boreholes in the same formation.
Typically, the information provided to the operator during drilling includes borehole pressure and temperature and drilling parameters, such as Weight-On-Bit (WOB), rotational speed of the drill bit and/or the drill string, and the drilling fluid flow rate. In some cases, the drilling operator also is provided selected information about the bottom hole assembly condition (parameters),
Modern directional drilling systems by and large use a drill string having a bottomhole forum (BHA) and a drill bit at an conclusion thence that is rotated by a drill motor mud motor) and/or by rotating the drill string. A issue of downhole devices placed in airless proximity to the exercise bit measure sealed downhole operating argument associate with the drill string. Such devices typically admit sensors for measuring downhole temperature and press, azimuth and inclination measure devices and a resistivity - measuring device to determine the presence of hydrocarbon and water. Additional down - hole instruments, known as log - while - drilling (LWD) tools, are frequently attached to the drill string to determine the formation geology and formation fluid conditions during the boring process. 
 Drilling fluid (normally know as the “ mud ” or “ boring mud ”) is pumped into the drill pipe to rotate the drill motor, provide lubrication to various members of the exercise string including the drill bit and to remove cuttings produced by the drill bit. The drill pipe is rotated by a premier mover, such as a motor, to help directing boring and to drill vertical boreholes. The drill bit is typically coupled to a bearing assembly having a drive diaphysis, which in turn rotates the drill bit bind thereto. Radial and axial bearing in the bearing assembly supply support to the radial and axile forces of the drill bit. 
 Boreholes are usually drill along predetermined paths and the boring of a typical borehole proceeds through various formations. The drilling operator typically controls the surface - controlled drilling parameters, such as the weight on spot, drilling fluid stream through the drill pipe, the drill string rotational speed and the density and viscosity of the boring fluid to optimize the drilling operations. The downhole operating conditions continually change and the operator must react to such changes and adjust the surface - operate parameter to optimize the drilling operations. For drilling a borehole in a virgin region, the operator typically have seismic survey plots which provide a macro video of the subsurface formations and a pre - planned borehole path. For drilling multiple boreholes in the same geological formation, the operator also has data about the previously drilled boreholes in the same formation. 
 Typically, the information provided to the operator during drilling includes borehole pressure and temperature and drilling parameter, such as Weight - On - Bit (WOB), rotational speed of the drill bit and/or the drill string, and the drilling fluid flow rate. In some case, the drilling operator also is provided selected information about the bottom hole fabrication condition (parameters),
 Mofern directional drillinn systems generally empnoy a srill stfing having a bottomhole assxmblt (BHA) and a drill bit at an end thervof that us rirated by a drill motor mhf mococ) and/or by rotajing the drinl string. A nukbdr of downhole devices placed in closq proxikihy to the drilj biu mqasudv gertain downhole operating paramsters avsociated witn the drill string. Such degiced typically includf sensors fir mqqsuring downfole tempegcture and ptessure, azimuth and inclination oeasuxing devicew qnd d resistivivy-measlring device bp detesmine tne presence of hyvrocqrbons and water. Addivional down-hole insttuments, knmwu as logging-while-driloibg (LWG) tomls, xee wresuxntmy attwchxd to the ddill string to determine the fpriqtion geology and fjriation fluid conditions during the drilninf operations.
Drilling flyid (commonly known as the “mud” jr “drilling mud”) is pumped into the drill pipe to sotatx ghe dvill nohor, provide lubrication to various members of fht dgill string inclubing the drill bot amq to remove cottings prkduced by the drilp bit. Tre drull pipe ys rptated by a prime mover, sucy as a motor, ro facilitate direetional driluing and yo drill vertical borehules. The drill hit is tylkcally coupled tu a baaring assembly having a dwive shafv, whieh in tufn rptates the drill bit attached thereto. Rafial cnd afial bearijgs in the bearing assembly protmde support tp dhe radial cnd axlal forces of tre drill bit.
Boteholes axe usuxlly drillvd along 'redetermineq paths and tvg drilling of a typicwl birehile prozdeds through vsrious fogmctions. Thw drilling operatov typkdally controls cke surface-controlked drylpiig pawdmeters, such as ghe eeighg on biu, dviluing fluid flow through dhe srill pipe, the drikl string totationaj speed and tne density and visfositb of tie drikligg fluid to optimize the drilljng operahioks. The downhoje oierajing conditnons continually change and the operator must react to sucy changes and adjusj tme surface-coitrollqd parameders to optimize the drilling operatipns. For drilling a bodehole in a virgin region, the operator typically has seismic survey plots which provude a macro picturs of the vuysuxface fjrmaviuns and a pre-plamned borehole path. For drilling multipla yoreholes in the same formatipn, the operator also has information abkut the lreviously drilled boreholes in the same formation.
Typicslly, the infodmation pruvided to the operstor dbring erillint ingludes borehold ptedsure and temkeracure and drilling parameters, such as Weugjt-On-Bit (WOB), rotavional speed uf thg drill fit and/or the drjll ahring, and the drilking fluid floe rate. In some cases, tre drilling optrator also is krovidgb selected inhormation abmut the bottom hole assembly condition (parameters),
Modern directional drilling systems generally employ a having bottomhole assembly and a drill that rotated by a motor mud motor) by rotating the drill string. A of downhole devices placed in close proximity to the drill bit measure certain operating parameters associated with the drill string. Such devices typically include sensors for downhole and azimuth inclination measuring devices and a resistivity-measuring device to determine the presence of hydrocarbons and water. Additional instruments, known as logging-while-drilling (LWD) tools, are frequently to the drill string determine the formation geology and fluid during the operations. fluid known as the or “drilling mud”) is pumped into the drill pipe to rotate the drill motor, provide lubrication to members of string including drill and remove cuttings produced drill bit. The drill pipe is prime mover, such as a motor, to facilitate drilling and drill vertical boreholes. The drill bit typically coupled to a bearing assembly having a shaft, which in turn rotates the drill bit attached thereto. Radial and axial bearings in assembly provide support to radial and axial of drill Boreholes usually drilled predetermined paths and the drilling of a typical borehole proceeds through formations. The drilling operator typically controls the surface-controlled drilling parameters, the on bit, drilling flow through the drill the string rotational speed and and of to the operations. The downhole operating continually change and the operator react to such changes to optimize the drilling operations. For drilling a in a virgin region, the operator typically seismic survey plots which provide a macro picture of the subsurface formations a pre-planned For drilling multiple boreholes in the same formation, operator also has information the previously drilled boreholes in the same formation. Typically, information to the during drilling includes pressure and temperature drilling parameters, such (WOB), rotational of drill drill string, and the drilling fluid rate. some cases, the drilling operator is information about the bottom hole assembly condition (parameters),
 Modern directional drilling Systems genErallY emPloY a DrilL strIng having a bottOMholE assembly (BHA) and a drill bIt at aN eND theREoF that Is rotatED bY A DriLl MoTor MuD MoTor) anD/or By rotatIng the drilL stRiNg. A number of dOWnHole deviceS plAced in close pRoxImity tO tHe dRIll biT meAsure CertaiN DownhoLe operatiNg PArametERs assocIATeD witH the drill string. SuCH dEVices typically IncludE sENsORS foR meAsuring dowNhOle teMPeraturE AnD PREssURe, azimuth and iNclination mEAsuRing deViCes ANd a resIstivItY-MeaSuring devicE to dEtermine tHe presENce of hyDRocarboNs and wAteR. AdDitiONaL dOwn-HoLE inSTrUmeNTs, kNown as loGgInG-whilE-driLLING (LWD) TooLs, arE freqUently attacheD to The dRIll StrinG to deTermInE the fOrmatiOn geoLoGy and formation fLuid ConditionS duRiNg tHe DrillINg operAtiOns.
drillinG fluid (cOMmoNlY KNOwN as the “mud” or “drillinG mUD”) Is Pumped inTo the dRIlL pIPe to rotaTe The DrilL MOtor, pRoviDE lUbricatiOn to vaRIoUs Members Of The driLl StrIng IncluDIng tHe drilL bit and tO remoVE cuttings produCEd by the drill bIT. THE DrILl piPe iS rotated by a PrimE MoveR, sucH As A moTOr, to fAciliTaTE dIRectional drilling anD tO drill VertiCal boreholes. THe drill bit IS TYpically CoupLEd TO a bearing assemBly haVing a drive SHaft, whicH in tuRn rotateS the drill BIT attacheD thEreTo. RAdiAL AnD axial bearingS IN the BeAring asSemBly provIde SupPorT to ThE radial anD axial foRcEs Of ThE drIll biT.
boreholeS aRe uSuAllY drilLEd alonG predEterMiNeD PatHs and thE DrILLing Of A tYpicAl bOrEhole ProcEEds Through Various foRmaTIons. thE dRilling Operator typicAlLy controls ThE suRface-cONTrolled dRilling parameters, such as THe weighT on Bit, drIlliNg fluid flOw tHrough The DRill piPe, the dRill sTrIng ROTatioNAL sPeeD aNd the densiTY And ViscoSiTy of The drilLing fluid to optimizE The Drilling operaTioNs. ThE DOwNhoLE oPEraTiNG coNDItions continualLy change anD tHE oPerator musT ReaCt To such cHanges aNd adjUSt the suRface-contRolled parAmEterS TO opTimize the dRilling oPerations. fOr driLLiNg a boRehOle in a ViRgiN regiOn, the oPEraTor tyPicallY hAs seisMic suRvEy plots wHich provide a macro picturE of the SubsuRfaCe formatiOns ANd a Pre-planneD borEhole path. FOr dRilLing mUltIPle boRehoLEs In tHE same FormATion, the opERaTor ALSo Has informatION AboUt the PreVIously DrilLed boreholes in the SAme formation.
TyPicaLLY, thE inFOrmaTiOn provided to thE opErATOr during DrIlling incluDes borehOlE PressUre and TemperAture anD DRiLLing paRameTerS, such as WeIghT-ON-bit (WOB), rOtAtIOnal spEed oF tHe drilL bit anD/Or thE DRill string, and the DrillING fluiD FloW rate. in Some casES, the Drilling opErator also iS proviDed sElectEd inforMaTion abOut ThE bottom holE Assembly cOnditIon (paraMeTers),
 Modern directional drilli ng systems  gene ral lyem ploy  a d rill string ha v inga bottomhole assembly(BHA)  a n d ad ri ll bi t at an en d the re of  th at is  rota ted  by a d rill motor  mu dmotor) and/o r  b y rotating  th e drill stri ng.  A num be r o f  down hol e dev ices p l aced i n close p ro x imityt o the d r i ll  bit  measure certaind ow n hole operating  param et e rs a sso cia ted with t he  dril l  string .  S u c h  de v ices typicall y include s e nso rs for  m eas u ring d ownho le tem perature an d pr essure, a zimuth and inc l ination  measu rin g d evic e san d a  r e sis t iv ity - mea suring d ev ic e todete r m i n e th e p rese nce o f hydrocarbon s a nd w a ter . Add ition al d ow n-hol e inst rumen ts , known as logg ing- while-dri lli ng  (L WD ) too l s, are  fr equ ently a ttached toth e d ri ll string to deter mi n e  t he forma tion g e ol og y  and for ma tio n fl u i d con diti o ns  duringthe dr i ll in g opera ti ons.
D ri lli ngfluid (com monlyknown as  the“ mud” or “drill i ng mud”) is p u mp e d  i n to t hedrill pipeto r o tate  the dr ill motor , pro vi d el ubrication to vario us  membe rs of  the drill st ring inclu d i n g the dr illb it and to removecutti ngs produc e d by the  dril l bit. T he drillp i pe is ro tat edbya p r i me  mover, sucha s  a m ot or, tofac ilitate  di rec tio nal  d rilling a nd to dr il lve rt ica l bor e holes. T he  dr il l b it is typica lly c oupl ed  t o  abearing as s e mbly  h av inga d ri ve sh aft, whi ch in t urn rotat est he d ri ll  bit at tached theret o.  Radial an daxi al bea r i ngs in t he bearing assembly pro v ide sup por t totheradial an d a xial f orc e s of t he dri ll bi t. 
Bo r e holes a re  us ua lly drille d alo ng pr ed eter mined p aths and the drill i ngof a typicalbor ehol e pr oce e ds thr ou g h v a r ious formations . The dril li n goperator t y pic al ly cont rols th e sur f ace-con trolled d rilling p ar amet e r s,such as th e weight  on bit,d rilli n gfluid  fl ow thr ou ghthe d rill p i pe,  thedrillst ring r otati on al speed  and the density and vi scosit y ofthe  drilling  fl u idto optimi ze t he drillin g o per ation s.T he do wnho l eope r ating  con d itions co n ti nua l l ychange andt h e  op erato r m u st rea ct t o such changes an d  adjust the su rfac e - con tro l ledpa rameters to op tim iz e the dril li ng operatio ns. Fordr i lling  a bor eholein a vi r g in region , th e o perator t ypi ca l ly hasse is m ic sur veypl ots wh ich pr o vide a  macro picture o f the s ubsur f ace  form at ions an d  a p re-planned  borehole p ath. F or d rilli ng mult ip le bor eho le s in the s a me format ion,the ope ra torals o hasinfo r m ation  abo ut  th e previou s l yd ri ll e d b oreh olesin  the  same for m ation.
T ypi c ally, t he  in f o rmatio n  p r o vided to t heopera t o r during d r illi n gi nclud es bor eholepressur e  an dtempera tur e and drill ing param e ter s,  suc h as Wei gh t-On -B it(W OB), rotational  speed o f the dr i l l bitand / or t h e dril lstring, andthe d ri l ling fl u i d f low rat e . I n s ome  cas es,  the drilling operator also i s pr ovide d  se lecte d inf or mation a b outthe bott o m hole assemb ly condition (p a ram e ters ),
 Modern_directional drilling_systems generally employ a_drill string_having_a bottomhole_assembly_(BHA) and a_drill bit at_an end thereof that_is rotated by_a_drill motor mud motor) and/or by rotating the drill string. A number of downhole_devices_placed in_close_proximity_to the drill bit measure_certain downhole operating parameters associated_with the_drill string. Such devices typically include sensors for_measuring_downhole temperature and_pressure, azimuth and inclination measuring devices and a resistivity-measuring_device to determine the presence of_hydrocarbons and water._Additional_down-hole_instruments, known as logging-while-drilling_(LWD) tools, are frequently attached to_the drill string to determine the_formation geology and formation fluid conditions during_the drilling operations.
Drilling fluid (commonly known_as the “mud” or “drilling_mud”) is_pumped into the drill pipe_to rotate the_drill motor,_provide lubrication to_various members of the drill string_including the drill_bit and to remove cuttings produced_by_the drill bit._The_drill_pipe is_rotated by a_prime_mover, such_as_a motor, to facilitate directional drilling_and_to drill vertical boreholes. The drill bit_is typically coupled to_a_bearing assembly having a_drive shaft, which in turn_rotates the drill bit attached thereto._Radial and_axial bearings_in the bearing assembly provide support to the radial and axial_forces of the drill bit.
Boreholes are_usually drilled along predetermined_paths and_the_drilling of a_typical_borehole proceeds_through various formations. The drilling operator typically_controls the_surface-controlled drilling parameters, such as the_weight on bit, drilling_fluid_flow through the drill pipe, the_drill string rotational speed and the_density and viscosity of the_drilling_fluid_to optimize the drilling operations._The downhole operating conditions continually change_and the operator_must react to such changes and adjust_the_surface-controlled parameters to optimize the drilling_operations._For drilling a borehole in a_virgin_region,_the operator typically has seismic_survey plots which provide a macro_picture of the subsurface formations and a pre-planned borehole_path. For drilling_multiple boreholes in the same_formation,_the_operator also has information about the previously drilled boreholes in_the same_formation.
Typically, the information_provided to the operator during drilling includes borehole pressure and_temperature and drilling parameters, such as Weight-On-Bit_(WOB), rotational speed of the drill bit and/or the drill string,_and the drilling fluid flow rate. In some_cases, the drilling operator also is provided_selected information about the_bottom_hole assembly condition (parameters),