Teoria Sidetrack

Si det r acki ngGui del i nes Thef ol l o wi nggu i del i nesar eus edt oai di nu nd er s t a ndi ngan di nes t abl i s hi ngs omepr ot oc ol i nt hee v entof hav i ngt os i det r ac kwhi l edr i l l i ng.Al t hought hi sma maynotc ov eral l c i r c ums t anc es ,i tgi v esus ef ul i nf or mat i on f orb ot ht hede skan dfi el dengi neer .

Gener alPr i nci pl es

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Si d et r ac k i n gaHa r d erT ar g etFo r ma t i o n-adi a mon mo ds i d et r a ckbi ts ho ul db ee mp mp l o y ed .Ca ut i o n n ee dst ob ee x er c i s edwh enu si n gad i a mo mo nds i d et r ac kbi ta s,i tc anp r od uc ev e r yhi g hdo gl e gs . Mot ors et t i ngst y pi c al l yus edwi t hs i det r ac kbi t sshoul dbebet ween22. 5.Si det r ac kbi t sar eus edonl y t oes t abl i s ht he“ l edge” . Gener al l yonl y56m i scutwi t has i det r ac kbi t ,ast hi si st hedi s t anc et hatt hel edgewi l l bet he s amewi dt hast hebi tf ac e( t y pi c al l y —t —t heac t ual amountdr i l l edwi l l v ar y ) . Onc et heent i r ebi tf ac ei s off,andi sc ut t i ngnewhol e,t hebi twi l l gener al l ys t opdr i l l i ng,andt y pi c al l yani nc r e as ei nSPPwi l l be s een .Thes et wos i gnsi ndi c at et hatagoodl e dgei ss t ar t ed,andt hea ss embl ys houl dbep ul l e douti n f a vourofat r adi t i onal Di r ec t i onal Dr i l l i ngas sembl y . Si det r ac ki ngf r om aCementPl ug-ane w bi toft he s amet y peus edt odr i l l t heor i gi nal wel l bor es houl dbeus ed.Thei deal s i t uat i oni st hec ementpl ugi s har der( dr i l l ss l ower )t hant hef or mat i on,f ort henat ur al t endenc yi sdr i l l i ngi nt hepat hofl eas t r es i s t a nc e.Sho ul dt hef or ma t i onbeh ar d er ,t ha nt hec ementpl ug,ahi g hermo t ors et t i ng,andal es s aggr es si v e( s l ower )t i medr i l l i ngpr ogr am s houl dbecons i der ed. Th et y p eo fPDM i d ea l l yt ou s ei same di u ms p ee dc o nfi gu r at i o n,a sh i g he rb i ts pe ed st y pi c al l y r es ul ti ne as i ers i d et r ac k i n g.Bi tan df or mat i ont y pesne edt obec ons i der edwhenmak i ngt hi s dec i s i on. Si det r ac ki ngHor i z ont al s-i ti si mpor t antnott obegi ndr i l l i ngoutoft hebot t om oft hewel l bor e( 180 t ool f ac e) ,asi st henat ur al t endenc y .As et t i ngofappr ox i mat el y125ºe i t herl ef torr i ghtt ool f ac ewi l l wor k .Us i nggr av i t ysomewhatandas har pdi r ec t i onal c hangei nei t herdi r ec t i onwi l l ai di nt he pr oc es s.Thi ss cenar i oal l owsagr eat erabi l i t yt or et ur nt oei t herwel l bor e. Ex e r c i s ee x t r e mec me a ut i o nwhe ne x i t i n go uto fc as i n g.Si d et r a ck i n gs ho ul dn otb ec omme nc e dl e ss t h an1 52 0m o uto ft h eHzc as i ngs ho e.Thi sen su r e st he r ei snomag ne t i ci n t e r f e r en cea ndt o el i mi n at ean yda mag ma et ot h ec a si n g. Mai nt ai nadi s t anc eof152 0m s epar at i onbe t wee nmul t i l at er al KOP’ s ,Thi sdi s t anc eal l owsan eas i erdet er mi nat i onofwhi c hs i det r ac ky ouar er eent er i ng. Pr i ort obegi nni ngy ours i det r ac kandwhenr eent er i ng,al wa ysr es t r ap,andc hec kpi pet al l yt obe as s ur edofb i td ep t h.Doubl ec hec k i n gmeas ur emen t swi l l ens ur eco nfi denc et h att hes i d et r ac ki s bei ngi ni t i at edi nt hepr operpl ac e.

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Onc eas i det r ac kl edgei ses t abl i s hed,i ti sver yi mpor t antnott odr i l l aheadaggr es si v el y ,f ort he l e dg ema ybr e akoffan do newo ul dh av et or es t ar tt h een t i r epr o ce ssag ai n . Hi gh ert hannor mal dogl egsar et y pi c al l yex per i enc edwh ens i de t r ac k i ng,s oe x er c i s ec aut i on wh ens i d et r a ck i n g.

Si det r acki ngoffCementPl ugs

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Ami ni mum of100m ofcementshoul dbeused.Keepami ni mum of50m aboveand50m bel ow t hees t i mat eds i det r ac kpoi nt . T obegi ndr i l l i ng( pol i s hi ng)t hec ementpl ug,a“ s l i c k”as s embl ycanbeus edort obegi nf as t era PDM c anb eempl o y edt odr i l l u pt hec ement .I fus i ngas l i c kas s embl yt op ol i s ht hepl ug,f ol l o wt h e r u l eof5 ’ sf o rd r i l l i n gaha r dc eme ntp l u g–wi t h500 0d aNWOB,a ndr o t a r yt a bl eat5 0RPM,ROP s houl dbe+/ 5mi n/ met er .I fpol i s hi ngwi t haPDM,not i c eabl ewei ghtanddi ff er ent i al pr es sur eshoul d b eo bs e r v e d,a ndROPs h ou l db es o me wh atc l o s et of o r ma t i o nROPwh eno r i g i n al l ydr i l l e d. Dr i l l up1015m t opol i s ht hepl ugwhi l et h ec ementi ss omewha ts of tt obej us tab ov et he pr o po se ds i d et r ac kpo i n to rKi c kOffPo i n t( KOP) .I fp ol i s hi n gc e me ntwi t ha nMWDs y s t e mi nt h eh ol e b ea wa r et h att h i sma yda ma gea nd / o rp l u gu pt h eMWDt o ol .Ca r e f u l l ymo ni t o rs a mp l e st od et e r mi n e amountofc eme ntr et ur ns–o ns i t egeol ogysho ul dbec ons ul t e df ort hi si nf or mat i o n.An yt hi ngl es s t h an9 0% c e me ntr e t u r n sa ndt h ea s s emb l ys ho ul db ec h an ge do utf o rd i r e c t i o na le qu i p me nt . Wi t ht hedi r ec t i onal as sembl yi nt hehol ebegi ndr i l l i ngt hel as t1015m ofc ementi nas t aged a pp r o ac ht ot h eKOP .Fo rh i g hc omp r e ss i v es t r en gt hf o r ma t i o nsad i a mo nds i d et r a ckbi ts h ou l db e us ed.Pat i enc ei scr i t i c al i nt hi shol es ec t i onas ,onec aneas i l y , r us ht hepr oc es sandwas t et he c ementpl ug.Wi t ht hemot ors et t i ngs etbet ween1. 83ºand2. 8ºbegi nt i medr i l l i ng.Thei deal mot ori s ame di um s p ee do r4 : 5Lo bec o nfi gu r at i o n.Th emo t o rt y p ea ndmo t ors e t t i n gwi l l b ed i c t a t e db yt h e bi tt y p eb ei n g,u s ed ,f o r ma t i o nh ar d ne ss ,a gg r e ss i v e ne sst e nd en cyt oc omeofft h ec eme ntp l u ga nd bui l dr equi r ement .

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Ti meDr i l l i nas t ageda ppr oac h.

St agedAppr oacht oSi det r acki ngoffCementPl ugs

Stage 1

3-4 min/inch - First 2-3m

Visually 20-30% Formation observed in cuttings

Stage 2

2-3 min/inch - Next 2-3m

Visually 50% or > observed in cuttings

Stage 3

1-2 min/inch - Last 3m or more

Visually 80% or > observed in cuttings, reactive toue a!!arent and bit ta"ing on #eig$t

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Sur v e yf r equent l yandcl os el yobs er v et o ol f ac easWOBi si nc r e as ed .St eerac c or di ngl yt o es t abl i s hc or r ec taz i mut hf ors i det r ac k. Donoti nc r eas ewei ghtonbi tunt i l c ompl et el yoffpl ugt omi ni mi z et hebr eak i ngofes t abl i s hed l edge,andf al l i ngbac ki nt os of t erc ement . I fal owermot ors et t i ng,orabi tc hangei sneeded,t r i poutofhol eandc hangeBHAi nc l udi ngbi t . Adj us tmot ors et t i ngt oal owerr at ef ort henewbi t ,f or mat i onandwel l pl an.Us eamot orwi t ha7: 8 l o bec onfi gur at i o nandmo ni t orc ut t i ngsf orc ementper c ent age. I ti sgoodpr ac t i c et os t r appi peandc onduc tanaddi t i onal pi pet al l ywhent r i ppi ngoutoft hehol e af t erasi det r ac k.Chec kal l phy s i c al meas ur ement ss uc hast het ool f ac eoff set( OTF)asf r i c t i onal f o r c esal o ngwi t ht or qu ema yca us eac ha ng ei nt h ema k eu pt o r q ue so ft h eBHAa nddr i l l s t r i n g. Mo ni t ort ool f a ce,andaz i mut ho na nys ubs eque ntt r i pst oas s ur eo nei si nt hec or r ec twel l bor e.Onc e ag ai n,pa t i enc ei sr equi r e dwhenr et ur ni ngbac ki nt ot h es i de t r ac k edwel l bor ean dy ouma yha v et o or i entt heBHAt or eent ert hec or r ec tpat h.

Si de t r a ck i ngi nOpe nHol eWe l l bor e s

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Choos eanar eai nt hewel l bor ewi t hawel l es t abl i s heddogl egorpos i t i v ec hangei nangl e.I deal l y t hi sar eawoul dal s oha v eag oo dp en et r at i onr at et omak ef oraqui c k ers i de t r ac k . Begi nt oes t abl i s hat r ough.Thi swi l l bedi c t at edbyt het y peoff or mat i onandcompr es si v e s t r engt hoft her oc k.Nor mal l ya34m s l i deors t r ok ei spr ac t i c edf or0. 5t o1hourmai nt ai ni nga c ons t antt ool f ac e.St ar tt hes i det r ac ki nt hedes i r eddi r ec t i onandt i medr i l l @ 4mi n/ i nc hf or23m.A s t a ge da pp r o ac hs h ou l dbeus e da sb el o w. Cons c i ent i ous l yaddwei ghtc ons er v at i v el yt odet er mi nei ft hel edgehasbeenes t abl i s hed.I ft he s i det r ac ki sabl et ohandl eas l i ghti nc r eas ei nWOBc ont i nuet ot i medr i l l atar educ edwei ghtf or anot her34m,Onc et hel e dg ei sf ul l yes t abl i s hed,r es umedr i l l i ngwi t hnor mal WOB. Whendr i l l i ngaheadandmak i ngc onnec t i onsal wa ysor i entt hes t r i ngi nt hedi r ec t i onoft he s i de t r ac kt oa v oi de xi s t i ng.Fort hec onnec t i on,wheno nbo t t om,s hutoffp umps ,pul l upappr o xi mat el y 1m ands ets l i psonr i g.T or es umedr i l l i ngan da v oi dbr e ak i ngt hel edge,gobac kt obo t t om,k i c ki n pumpsandbegi ndr i l l i ng.Dono ta l l owt her ot at i onoft hedr i l l s t r i ngoutunt i l bac konbot t om andt hen t u r n i n go np ump s . T r i po uto fh ol et oc ha ng eBHAan db i t .Us eamo t o rwi t ha7 : 8L obec o nfi gu r a t i o ns .Ad j u s tmo t o r s et t i ngt oal owers et t i ngf orus ewi t ht henewbi t ,andappr opr i at ef ort hewel l pl an.

St agedAppr oacht oSi det r acki ngi nOpenHol eWel l bor es

Stage 1

3-4 min/inch - First 2-3m

&ercise caution and !atience using lig$t #eig$t

Stage 2

2-3 min/inch - Next 2-3m

'bserve any reactive torue and bit ta"ing on #eig$t

Stage 3

1-2 min/inch - Last 3m or more

(ontinue to control drill )urt$er to 5,0008,000da* +'

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I ti sgoodpr ac t i c et os t r appi peandc onduc tanaddi t i onal pi pet al l ywhent r i ppi ngoutoft hehol e af t erasi det r ac k.Chec kal l phy s i c al meas ur ement ss uc hast het ool f ac eoff set( OTF)asf r i c t i onal f o r c esal o ngwi t ht or qu ema yca us eac ha ng ei nt h ema k eu pt o r q ue so ft h eBHAa nddr i l l s t r i n g. Mo ni t ort ool f a ce,andaz i mut ho na nys ubs eque ntt r i pst oas s ur eo nei si nt hec or r ec twel l bor e.Onc e ag ai n,pa t i enc ei sr equi r e dwhenr et ur ni ngbac ki nt ot h es i de t r ac k edwel l bor ean dy ouma yha v et o or i entones el ft or eent ert hec or r ec tpat h.

Whi ps t oc ki ngi ns i deofCa si ng

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I ti sc ommo nt oco meo ffa“ On eT r i p ”wh i p st oc ks y s t e m.Wh end oi n gs o,i ti si d ea lt oha v ea di r ec t i onal dr i l l erpr es entwhent hewhi ps t oc ki sbei ngs eti nc as i ng.TheDi r ec t i onal Dr i l l erai dsi nt he or i ent at i onoft hewhi ps t oc kt oas s ur ei ti ss etatt her i ghtaz i mut h.Whi ps t oc k sc anbes etatupwar ds o f8 5º .Wh i p s t o c k ss ho ul dbes et2 ma bo v ec a s i n gc o l l a r s ,a sr e c omme nd edbyt h ewh i p s t o c k ma nu f a ct u r e r . Whi ps t oc ksar eor i ent edwi t hr ef er enc et ohi ghs i deoft hewel l bor eex ceptf ort r ul yver t i c al wel l s , whi c har es etb yaz i mu t h . Pr i ort os et t i ngt hewhi ps t oc ki ti sbes tt oc hoos eapoi nti nt hec as i ngwhi c hi snotatat ool j oi ntor ups eti nt hec as i ng.I ft her ei ssomeangl ei nt hehol ei ti sbes tt oc omeofft hel ows i deoft hehol et o al l owgr av i t at i onal f or c est ohel pi nc omi ngoff. ForVer t i c al wel l s( 04degr ees )agy r oi sus edt os ett hewhi ps t oc k.Ast hec as i ngi smet al ,t he us eoft hegy r oi sne ces s ar y , du et omagne t i ci nt er f er enc ewi t hMWDt el emet r y . I ti sal wa y sbes tt o s ett hewhi ps t oc k,mi l l ,anddr i l l outoft hewi ndowwi t ht hegy r opl ac eddi r ec t l yabov e,andor i ent edt o t hemot or .Thi senabl est hedi r ec t i onal dr i l l ert o‘ s ee’ ac t ual angl ebui l t ,andt her es ul t i ngdogl eg s ev er i t ysooner ,s ot hatabet t eri nf or meddec i s i onc anbemader egar di ngmot ors et t i ngf ordr i l l i ng ahead.I ns omei ns t anc esi tc anbenefi c i al t odr i l l wi t hanMWDwi t ht hegy r o“ pi g gybac k ed”ont op. On c et h ewi n d owi smi l l e da n dt h eMWDi s1 5 2 0 mo u ts i d ean da wa yf r o mt h ec a s i n gt h eMWD begi nst of u nc t i onnor mal l yan dt heGy r oc ant henbepul l eda ndnor mal dr i l l i ngoper at i onsc an

c ont i n ue.Caut i onmus tbeex er c i s edast heex t entoft h ev i br at i onandt h ehar s hen vi r o nmentma y c au seaMWDf ai l u r ewh enc on du ct i n gt h i sp r o c ed ur e.I ti sn ota l wa y sar ec omme nd edpr a ct i c e .

St agedAppr oacht oWhi pst ocki ngOut si deofCasi ng

Stage 1

5 min/inch - First 1m

&ercise caution and !atience, survey every 05m

Stage 2

4 min/inch - Next 2-3m

Survey every meter determine i) +$i!stoc" $as moved )rom original orientation

Stage 3

2.5 min/inch - Next 4-5m

Survey every meter as reuired

Stage .

1.5 min/inch - Next 2m

(ontinue to survey every meter

Stage 5

1 min/inch - Till 20m away

Survey to determine i) /+ !roviding good inclination surveys and 20m a#ay bottom o) +$i!stoc"

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Cont i nu edr i l l i ngahead,s t e er i nghi ghsi dewi t hMWDs ur v e ysands ep ar at i oni sev i dentf r om a l a ckofi n fl uen c ef r o mt h ec a si n g.Th eMWDwi l l b egi np r o du ci n gv a l i ds ur v e y sb ey o nd3 º . Th et o ol goesf r om gr a vi t yt ool f ac et omagnet i ct ool f ac e. Do gl e gspr o duc e db yWh i p s t o ck sc anbeashi g ha s14º / 3 0m ( o rmor e )f ort hefi r s t68 md r i l l e db y t hemi l l i ngas s embl y .