SPE-20150 Hor Well Plan-MS

8/19/2019 SPE-20150 Hor Well Plan-MS

1/15

SPE 20{50

Horizontal Well

Frank J . Schuh, Dri l l i ngechnol ogy,k.

NEWMEXI COTECH

CENTENNI ALSYMPOSi UM

Planning—Build Curve Design

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A 2m.x2

The goal of most hori zontal dri11ing proj ects i s

to pl ace a l ong hori zontal hol e i n a narrowverti-

cal target.

To accompl i sht hi s obj ecti ve i n the

most economcal manner, requi res a buiI d desi gn

that w l 1 hi t the target w thout numerous bottom

hol e assembl y changes and a ri g that can handl e

the torque and drag l oads produced by the dri 11-

str i ng i n the hori zontal hol e.

Thi s paper de-

scri bes several methods for designi ng the bui l d

curve that off er i mproved methods for hi tti ng a

smal1 hori zontal target whi l e usi ng a si ngl e bot-

tomhol e assembl y f or the angl e bui l di ng porti ons

of the hol e. The paper al so presents a novel

method for esti mati ng the torque and drag forces

for typi cal dri l l stri ng i n a hori zontal hol e.

J rt tr oducti on

The two character sti es that most cl earl y di f f eren-

ti ate hori zontal dri l l i ng f romconventi onal di rec-

ti onal dri l l i ng are the use of angl e- bui l dmotors

and speci al i zedbui l d curve desi gns.

A good bui l d

curve desi gn i s nearl y as i mportant as sel ecti ng

the best di recti onal dri l l i ngcontractor.

The opt imum l ength f or a hor i zont al hol e i s

reached when the i ncremental cost of addi ti onal

l ength i s greater than the val ue of the producti on

fromthe addi ti onal l ength. Si nce the producti ve

perf ormanceconti nues to i ncreasew th i ncreasi ng

l ength, the opti mumi s probabl y cl ose to the maxi -

muml ength that can be successful l ydri l l ed. The

mechani cal l i mts for hori zontal hol es are pri mari -

l y rel ated to torque and drag l i m ts f or the r i g

and dri l l str i ng equi pment.

To reach the maxi mutt i

possi bl e l ength, one needs to mni mze the torque

and drag forces.

Si nce buckl i ng and gravi ty

Referencesand i l l ustrat i onsat end of paper.

forces domnate the torque and drag eff ects i n the

hori zontal hol e, the opti mumdesi gn requi res the

sel ect ion of the l i ghtest possi bl e dr i l l st r in

components that w l l not be buckl ed duri ng dri l -

l i ngoperati ons.

Bui l d C

urve

QQQl

The %mpl est possi bl e bui l d curve desi gn i s a

si ngl euni formcurve that begi ns at the near vert i -

cal ki ckof f poi nt and r eaches 90” at t he end

of the curve i n a si ngl e conti nuous arc.

I f the

vari abi l i tyof the performanceof the angl e- bui l

motor provi des an error i n the verti cal depth at

the end of the cur~e that i s l ess than the al l o”

abl e tol erance of the hor i zontal target , .hl

bui l dcurvedesi gn i s i n fact the opti mumdesi gn.

Unfortunatel y, the vari abi l i ty and uncertai nty of

perf ormance of most angl e- bui l d motors greatl

exceeds the al l owabl e tol erance of the hori zonta

targets.

I t, therefore, becomes necessary to

desi gn adj ustment i nterval s i n the bui l d curve to

compensatefor these uncertai nti es.

Bui l d curve design begi ns w th a defi ni ti onof th

hori zontal target .

There are basi cal l y two type

of hori zontal targets:

o

A def i nedvert i cal depth target

o

A defi ned structural posi ti oni n a

reservoi r

For hori zon-i alwel l s i n gas and/ or ater coni n

appl i cati ons, i ? nay be most effecti ve to dri l l

t rul y hor i zont al hol e i n a TVD target t hat i

l ocated a f : . ~ddi stance fromt he gas/oi l and/ o

Wter /o l

~Oi,iaCts. For thi s type hori zontal wel

the target angl ew l l be 90°.

47


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2

HORI ZONTALWELL PLANNI NG B1’LOCURVE DESI GN

NMTECH

The most common type hori zontal target i s not

w l l use the maxi mumavai l abl e bui l d rate.

I f

necessari l yhori zontal but i s a l ateral path that

hor i zontal sert ion i s to be dr i l l ed w th su

t racks a speci f i c st ruct ur al posi t i on i n t he

rotati on, one shoul d l i mt the hol e curvatu

reservoi r.

For coni ng appl i cati ons, thi s may be

the curvature l imt of the dr i l l st ri ng co

ei t her t , e top o? bot tomof the reservoi r . I t

nentsm

Another i mportant consi derati on i

al so mght be a speci f i c posi t i on that has been

provi de a cur vat ur e t hat w l l not i nhi bi t

sel ected to assure ful l consrruni cat i on th the

sel ecti on of ordi nary conventi onal produ

reservoi r from hydraul i c fractures i ni ti ated at

tool s duri ng the compl eti on and future produ

that depth. ‘ Hori zontal ”tar~ets i n these cases operati ons.

w l l not be hor izontal but w l l at tempt to t rack

the sel ected st ructural posi t ion or be dr i l l ed

The f ol l owng sect i ons w l l cover t hr ee b

al ong a path that i s ex~zcted to track the

curve types whi chwe have i denti f i edas:

structural posi ti on.

The al l owabl e hei ght of thi s

path representsthe target tol erance.

1. The simpl e tangent bui l d curve;

2. The compl ex tangent bui l d curve;

The purpose of the bui l d curve desi gn i s to 3. The i deal bui l d curve.

provi de the operator w th an eff i ci ent method of

hi t t ing the hor izontal target w thi n the pre- The di mensi onsof these bui l d curves can be ca

scri bed tol erance w thout uti l i zi ng numerous BHA

l ated f romthe geometr i c rel ati onshi psof str

changes. The bui l d curve desi gn must provi de a

l i ; l esand ci rcul ar arcs.

FCC the si mpl e ta

bal ancebetweent he fol l ow ngconsi derati cms:

bui l d curve where we i ntend to keep the too

of the beri housi ng motor poi nted up and max

o

Avoi d probl emformati ons.

the angl e bui l di ng rate of the tool , the pat

be descri bed as a ci r cul ar arc i n a ver

o Mnimze t he di spl acemer i tof t he end of

pl ane.

See Fi gure 1. The key equati ons

the curve.

cal cul ati ngthe hei ght, di spl acement and l eng

a verti cal ci rcul ar arc are:

o Mnim ze the dri l l ed l ength of the bui l d

curve.

5730

0

Provi de an adj ustment i nterval for han-

R=—

. . (

dl i ng other than the i deal bui l d rate.

B“””””””””””

o

Al l ow the uti l i zati on of structural mark-

ers encountered i n the bui l d i nterval to

V= R* (si n I z- si n I l ) . . . . . (2)

adj ust the fi nal target depth.

o

Meet the target tol erancel i mts.

H= R” (COSI 1- COS 12) . . . . $(3)

o

Provi de a curve that w l l al l ow a f ul l

l ength hori zontal hol e to be dri l l ed.

100 0 (12 - 11)

L= (

Pr ovi de a compl et abl e hol e t hat w l l

.

0

. . , , . . . .

B

permt the use of al l necessary producti on

tool s and equi pment.

For the compl ex and i deal bui l d curves that

The opti mumbui l d rate for a speci fi c hori zontal

l i ze bui l d and turn segments, the path ca

hol e must both provi de the di rect i onal cor l t rol approxi mated by the geometry of ci rcul ar

needed to hi t the target as wel l as a bui l d curve

proj ected to the verti cal pl ane.

See Fi gu

hei ght that avoi ds i ncl udi ng troubl esome forma- The key equati ons for the geometry of the

t i ons i n the bui l d i nterval . If, f or exampl e, an

turn segmentsare:

especi al l yt roubl esomeformati on i s l ocated850 f t

above the hori zontal target, one woul d probabl y

sel ect a ki ckoff poi nt bel ow that formati on and

5730

use the remai ni ng hei ght to di ctate the requi red

Rvm—

. (

bui l d rate curvatures.

Be”””””””””””””

If

one onl y consi ders the requi rementsof dri l l i ng

t he bui l d curve, t he best desi gn w l l use t he

V=RV

“ ( si n 12 - si n I i ) . . . . . (6)

hi ghest curvature rate that can be obtai ned.

Si nce the bui l d curvature al so aff ects al l subse-

quent operati ons, one needs to bal ance the advan-

H=RV . ( COS11

-COSI Z) . . . . . (7)

tage of hi gh curvature w th the i mpact of that

curvatureon the future operati ons. Tabl e I l i sts

several of the curvature l i mts that shoul d be

100 ( I z - 11)

consi dered.

L=

. . . . . . . . .

(

Bv

I f one pl ans to steer the ent i re hor izontal sec-

ti on and no producti onequi pment or tool s w l l be

run through the curve, the opti mum bui l d curve

. -


3/15

.

SQE20150

NNTECtl

890008

FRANKJ . SCHUH

6T

DL=([z- I 1)*—

i nterval i s adj usted so that the second bui l

. * ( 9) . curve reaches the target i f i t bui l ds at the sam

BV ”*”*””

rateas the f i r st curve, Thi s l i mts the error i

hi tti ng the target to the di ff erence between th

‘ actual second bui l d and the adj usted pl anned se

cos DL -

cp~ 11 . Cos 12

ond bui l d.

I f the f i rst bui l d curvature on ou

Cos 4AZ ~

o .

(lo)

?xampl e were actual l y 8. 6°/100 ft the pl ann

si n 11 si n 12

second bui l d hei ght woul d be 1S5. 9 ft .

I f th

second bui l d actual l y bui l ds at 8.3”/100 f t

the actual second bui l d hei ght woul d be 161. 5 ft

Bv

whi ch i s 5. 6 ft l ower than pl anned. If a si ng

cos~=—

. , *. . . . . . . . .

(11) curvew thout a tangent had been used, an error o

8T

.3’ / 100 f t woul d have mssed the target by 2

feet.

Lastl y, the appropri ateequati ons for the strai ght

Sel e~$i ng the appropri ate tangent l epqth i s ve

adj ustment i nterval sare:

i mportant because few of the tan~ent dri l l i

assembl i es actual l y dri l l at constant angl e

Fortunatel y, i t i s not necessary to dr i l l a ta

V- L. COSI , , , , . , , . . ,

(12)

gent i nterval at a constant angl e provi dedone

a good j udgement of the f i nal angl e at the bi

The mni mum recommended l ength of the tange

H- L

si n I . , . . . . . . . . .

(13)

i nterval i s 120 f t . Thi s i s basedon the typi c

NUD survey spaci ngand the desi rabi l i tyofmni mz

i ng the tangent l ength.

Ui th a typi cal steerab

J he Swe Tanaent Bui l d Cur e MD package used for dri l l i ng the tanger, ti nte

The ol dest and most w del y used bui l d curvedesi gn

val , the HUD i ncli nati onsensor w l l be posit i or

about 60 f t above the bi t . Assumng one tak

i s the si mpl e tangent bui l d curve. Fi gure 3 i s a

surveys at 30 ft spaci ng, the survey . f the f i r

sket ch of a typi cal simple tangent bui l d curve. 30 f t of the tangent i nterval i s not avai l ab

The simpl e tangent bui l d curve di vi des the bui l d

unt i l 90 f t of t he t angent sect i on has be

arc i nto two segments that are separated by a

drt l l ed.

At thi s poi nt onl y one t hi r d of t

strai ght ‘ tangent” adj ustment i nterval .

I t

iS

tangent i nterval has been surveyed and that po

general l y assumed that both bui l d curve segments

t i on w l l al so i ncl ude any t ransi t i on af f ec

w l l be dri l l ed w th the same angl e-bui l dmotor

caused by pl aci ng the angl e-hol di ng steerab

assembl y and that the rate of bui l d i n the second

bui l d w l l al so equal the rate of bui l d exper i -

motor assembl y i n the bott omof the hi ghl y curv

angl e- bui l dport i on ‘ ~f the hol e.

After dri l l i

, encedwhi l e dri l l i ngt he f i rst bui l d segment.

120 f t of sect i on, %e deepest ND survey w

The concept for the si mpl e tangent bui l d curve

provi dedata on the fi rst hal f of the 120 ft i nte

val , Si nce we must predi ct the angl e at the b

comes fr om the observati ons’that an angl e- bui l d

i n order to correctl y J udge the depth at whi ch

motor w l l gi ve hi ghl y consi stent curvatureperf or-

start the second bui l d i nterval , we must extrap

mance on a gi ven wel l in a speci f i c area, even l ate the performancemeasured above the NW sens

though i ts performance may vary si gni fi cantl y

to the bi t.

between wel l s w th di f ferent target formati ons or

i n other areas, Ui th thi s desi gn, the operator

The fi nal sel ecti on i n. a si mpl e tangent bui l d

uti l i zes the observed bui l d curvature i n the fi rst

bui l d to cal cul ate the most l i kel y hei ght of the

curve desi gn i s the angl e for the tangent fnte

val .

One of the most consnanchoi ces i s 45

secondbui l d and f romthat the requi red l engthof Wth the tangent at 45”, the end of the cur

the tangent i nterval and depth of the secondki ck- fal l s at the same posi t i on regardl ess of t

of f poi nt . Thi s reduces the error i n hi tt ing the

curvatureof the angl e bui l d port i ons of the hol e

end of curve target to the rel ati vel ysmal l di ff er-

ence between the actual and predi cted hei ghts of I ncreasi ng the tangent angl e l owers both t

the second bui l d curve.

To be successful w th

hei ght and the magni tude of the potenti al error

thi s techni que, i t i s essent ial that the ki ckof f the secondbui ld.

The hei ght of the second bui

poi nt and the pl annedbui l d curve be desi gned ~5\ reases rapi dl y as YC. i ncreasethe angl e abo

usi ng the l owest possi bl e bui l d rate for the se-

For exampl e, t he hei ght of a secon

l ectedangl e- bui l dmotor assembl y. bui i d at 8“/ 100 f t decreases f rom209 f t for

45* tangent to 96 f t w th a 60” tangent

Tabl e 2 shows the step by step cal cul ati ons re- Pl aci ng the tangents at angl es greater th

qui red to cal cul ate the dimensi ons of the bui l d 45* i ncreases the l ength of the hol e and t

curve desi gn shm i n Fi gure 3. The key deci si ons

di spl acement of the end of the curve.

I t al

requi redof the desi gner are the curvature rates,

the angl e of the tangent i nterval and the l ength

makes the l ength and di spl acementsensi t i ve to t

actual curvatures i n the fi rst and second bui

of the tangent i nterval .

The desi gn bui l d rate

These consi derati ons make tangent angl es abo

must be no greater than the mni mumexpectedbui l d 60° unacceptabl e.

One other consi derati on

r at e f or t he angl e- bui l dmotor sel ect ed. choosi ng the posi t i on of t he t angent i nt er val

to provi de the abi l i ty to i ntersect any crtt i

I f the actual bui l d rate i n the f i el d exceeds the structural markers i n the tangent i nterval so t

pl anned (m ni mum rate, the l ength of the tangent

one can adj ust the second bui l d ki ckof f po

. -

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4

HORI ZONTALWELL PLANNI NG- BUI LDCURVEDESIGN

NMTECH890008

based on the actual observedposi ti on i n the stra-

remaini ng height,

The bui l d turn i nterval al so

ti graphi ccol umn.

has a greater total curvaturethan the bui l d of a

simpl e tangent desi gn, however, the i ncrease is

not l arge, For the exampl e case, the total dogl eg

A ComDl eLLanaent Bui l dCurve

i n the bui l d curve i s onl y 10%l arger than for a

compl eti ngsi mpl etangent desi gn.

The compl ex tangent bui l d curve provi des the next

l ogi cal step i n control l i ngthe accuracy of hi t- Thl s desi tn has i ts greatest appl i cati onfor hor~-

t i ng a smal l TVD t ar get .

A typi cal compl ex

tangent bui l d curve design i s shown i n Fi gure 4.

zontal hol es that are dr i l l ed to a st ructural

target . I t i s qui te useful when the f i nal target

The desi gn cal cul at ions for the exampl e are

posi ti on i s defi nedby the tops of formati onsthat

i ncl udedi n Tabl e 3.

For thi s bui l d curve desi gn,

ar e l ocat ed w thi n t he second bui l d cur ve.

one uti l i zes the fi rst bui l d i nterval to establ i sh

Al thoughone can cert ai nl y not make l arge correc-

the perf ormance l evel s of the angl e- bui l dmotor

ti ons, the si ze of the adj ustment can be si gni f i-

sel ect ed f or t he j ob j ust as i s done w t h t he

cant. For exampl e, i n our 6- 1/ 2’ / 100 f t

si mpl e tangent method.

However, i nsteadof usi ng

design bui l d case, we w l l r each 70’ when we

thi s same curvature i n sel ecti ngthe ki ckoff poi nt

are 53 ft above the hori zontal target.

At that

for the second bui l d curve, the concept i s to use

point , i t i s possi bl e to reach the hor i zontal

a l ower desi gn rate than was actual l y experi enced

target w th our maxi mum 8“/100 f t bui l d rate

i n the upper part of the hol e,

i n a vert ical hei ght of onl y 43 f t by turni ngthe

tool face strai ght up. Thi s woul d al l owa 10 ft

I n the exampl e case, he have desi gned the fi rst

upward verti cal adj ustment fr omonl y 53 ft above

bui l d at the expected mni mum rate of

the target. I t i s al so possi bl eto achi evedown-

8“/100 f t and desi gned the second bui l d w th a

ward target adj ustments byi ncreasi ng the tool f ace

bui l d rat e that i s 1. 5*/ l CO f t l ess than t he angl e.

f i r st bui l d rate or 6-1/2° / 100 f t .

One of the

key concepts of thi s techni que i s that the l ower

The compl ex bui l d curve provi des a trade- off be-

Wgn rate for the second bui l d can be obtai ned

tween target TVD accuracy and target posi ti onand

c

the same angl e-bui l d motor as the f i rst

di recti on,

Tabl e 4 summari zes the eff ect of the

bui l by or ient ing the tool f ace to the r ight or

tr ade- of f s.

To use thi s design most eff ecti vel y,

l ef t of vert i cal .

The 6-1/ 2’ / 100 ft vert i cal

the wel l desi gner needs to establ i sh a greater

bui l d rate can be obtai ned from the 8“/100 f t

l ati tude i n end of curve di spl acement and di rec-

angl e-bui l dtool used i n the f i rst bui l d by turn-

t i on t o maxim ze t he cont rol of t he ver ti cal

i ng the tool f ace of the angl e- bui l d motor to

target.

35” l eft or r i ght of vert i cal ,

The wel l could be desi gned to pl ace al l of t he I t LQdeal Bui l dCurve

t urn i n one di r ect i on i f t hat were desi r ed.

However, i n most si tuati ons i t i s better to turn

The i deal bui l dcurve i s shown i n Fi gure5. I t i s

t he wel l t o ei t her t he l ef t or r i ght f or about

si mpl y a compl ex bui l d curve w thout a tangent

hal f of the second bui l d and then i n the opposi te

i nterval ,

I t coul d therefore be dr i l l ed w th a

di rect i onf or the f i nal hal f .

In

our exampl e we si ngl eangl e- bui l dmotor run unl ess l i mt edby the

chose to turn the wel l l ef t for the f i rst hal f and

bi t l i f e.

Obvi ousl y thi s woul d provi de the l owest

ri ght for the second hal f. Thi s strategyproduces

cost method for dri l l i ng a bui l d curve.

I t woul d

a change i n azimut h of 16, 8’ t o t he l ef t f ol -

al so requi re that the expected range of perfor-

l owed by a turn to t he ri ght of 14. 7”.

The

mance of the angl e-bui l dtool woul d be l ess than

approxi matevert i cal secti on and other key di men-

coul d be absorbed by the adj ustment of tool face

sions of the second bui l d can be computed using

angl e whi l e dr i l l i ng the second bui l d and turn

thebui l d turn equati ons5 through11.

secti on, Al thoughwe can probabl ynot predi ct the

bui l d rate perf ormanceof angl e- bui l dmotors pre-

The compl exbui l d curve desi gn i s not i ntendedto

cisel y enough to use the I deal bui l d curve on the

produce a strai ght wel l bore path but to provi de

fi rst wel l i n an area, i t shoul dbe considered.for

the dr i l l er w th the abi l i ty to adj ust the curva-

the secondor thi rdwel l i n an area,

ture rate both upward and downward whi 1e dri 11i ng

the second bui l d curve, Compari ng thi s exampl e

w th the exampl eof the simpl e tangent bui l d curve

J Oaue and Drag

shows some of the advantagesand di sadvantagesof

thi s desi gn, The greatest di sadvantageof thi s

Af ter one has desi gnedthe opti mumbui l d curve f or

desi gn i s that the l ength, hei ght and di spl acement the wel l , one of the next questi ons i s howf ar CGFI

of the second bui l d are i ncreased The l ength of

you dri l l hori zontal l y, The probl emnow shi fts

the second bui l d i s i ncreased f r om 500 f t t o

fr omdi recti onal control to torqi i s~nd drag, I rIa

615 f t . The height i s i ncreased f r om168 f t t o

206 ft , and the di spl acement l ength i s i ncreased

gi ven hol e, the maxi mum hori zontal l ength i s

from460 ft to 567 ft , The pri ncipal advantageof

reachedor perhaps exceededwhenyou can no l onger

rotate the pi pe or suf f i ci ent ly l oad the bi t to

t hi s desi gn i s t hat t he act ual hei ght of t he

dr i l l .

Tabl e 5 1i sts the current record hori zon-

second bui l d curve can be adj usted both up and

tal l engths as a funct i onof hol e si ze and bui l d

down.

The maximumvert i cal adj ustment i s as much

curvature rates.

Al though we do not know how

as 38 f t upward i f t he change i s known at the

begi nni ngof the second bui l d curve. Thi s woul d

cl ose these record l engths were to the l i mts, i t

i s assur ingto real i ze that the l i mt i s not l ess

provi de a maximumhei ght adj ustment of 18%of the

than these l engths,

The wel 1 desi gner needs to

- .


5/15

.

t

SPE20150

NMTECH890008

FRANKJ . SCHUH

I

understandthe torque and drag consequencesof hl s

al ter~atedesi gnchoi ces.

One sol uti on adopted by many operators on thei r

f i rst attempt i s to pl an for a hor izontal l ength

on the l ow side of the spect rum

That concept

w l l pr obabl y gener at e 500 f t as super saf e,

1, 000 ft as reasonabl e, 2, 000 ft as aggressi ve,

and 4, 000 f t woul d equal the record.

If

one stays

under the 2,000 ft mark, i t i s unl i kel y that true

torque and drag l i mt s w l l be reached. Operati on-

al probl ems w th torque or drag i n thi s l ength

woul d i ndi cate some other probl emsuch as cutt i ngs

accumul ati onor wal l sti cki ng. However, to opti -

mze the cost of hori zontal hol es, one must come

t o gri ps w t h t he t rue l i m ts. Tabl e 6 l i st s t he

most i mportant factors aff ecti ng the torque and

drag l i mts.

I

To pl an for 2,000 ft hor i zontal wel l l ength, i t i s

probabl y necessary to consi der the torque and

drag.

The torque and drag anal ysi s must i ncl ude

predi cti onsof the torque and drag whi l e rotati ng

off bottom dri l l i ngw th surfacerotati on, dri l l -

i ng whi l e steeri nga down hol e motor, and the drag

forces whi l e tr i ppi ng.

It

ts al so i mportant to

know the stresses on the dri l l stri ng components

due to the curvatureof the hol e and these l oads.

There are a number of propri etary and commerci al

torque and drag computer model s that can be used

to prepare the best possi bl e estimates of torque

and drag for a hor i zontal hol e.

If

the wel l

course i s qui te compl ex or i f the wel l i s a combi -

nat ion di rect ional wel l w th a shal l ow ki ckcf f

poi nt and a l ong tangent secti on, these programs

of f er the onl y reasonabl emethod for anal yzi ngthe

probl em However, for a typi cal on- shore hori zon-

t al hol e t hat uses a deep ki ckof f poi nt and a

rel ati vel ycompact bui l d curve, i t i s possi bl e to

esti mate the torque and drag usi ng some rel ati vel y

si mpl eapproxi mati ons.

I f one assumes that:

I

o The bui l d cur ve can be r epr esent ed by a

si mpl e90° arc.

I

o The same si ze and wei ght of pi pe are used

throughout the bui l d curve.

o The hol e i s approxi matel yhori zontal .

o None of the pipe in the hor i zontal hol e i s

buckl ed. (See Appendi x 2) .

o The coef f i ci ent of f r i ct i on i s equal to .33.

I

The torque and drag rel ati onshi ps can be reason-

abl y approxi matedby the fol l ow ngrel ati onshi ps.

1

Torquef or the pi pe i n the hori zontal hol e i s:

1

I

OD* Um*L

Th. _

. . . . . . . .

(14)

72

The torque for rotat i ng pfpe in the 90” bui l d

depends on the magni tude of the axi al force ap-

pl i ed to the end of the curve. Mhi l e dr i l l i ng a

hori zontal hol e w th surface rotati on, the axi al

f orce at t he end of the curve i s equal t

wei ght on the bi t.

ForU08c . 33 . I i m R:

I

OD

Q

Wm

“

R

Tb =

. , . . * . . . . .

(

72

I

I

ForUOB> . 33 wUrn“ R:

oo.wm” R OD o UOB

Tb =

.—

+—

. . . . (

1+4 46

For exampl e, l ets consider a hori zontal hol

a bui l d curve radi us of 850 f t and a hor

l ength of 1,000 f t .

Uhat i s the torque

rotat ing of f bot tomw th 30,000 l b on th

Assumng that we are usi ng 9.2 l b/ gal mu

5 i n. Hevi wate dr i l l pi pe throughout the

curve and hori zontal i nterval , the buoyant

of t he pi pe i s Urn= . 86 50 l b/ f t .

The

i n the hori zontal part of the hol e woul d be:

6. 5 ( . 86 “ 50) “ 1000

Th =

72

I

Th = 3, 882 ft- l bf.

I

The torque i n the bui l d curve whi l e rotat

~gttomwhen UOB =

O i s cal cul ated frome

I

la

I

81

6.5 “ ( .86 “ 50)

850

Tb =

144

I

Tb = 1650 ft- l bf.

The total torque rotati ngoff bott omi s:

T=Th+Tb . . . . .. . o- . - . . . - . zo~

T =3882+ 1650= 5532 ft - l bf

Ui th 30, 000 l b on the bi t, the force at the

the curve exceeds . 33 . U R and the to

thebui l d curve i s cal cul a~edf romequati on

6. 5

(. 86 “ 50)

. 850 6. 5

30, 0

Tb =

+’

144

46

I

Tb= 5, 889 ft- l bf.


6/15

=20150

6

HORIZONTALWELL PLANNI NG- BUI LDCURVE DESIGN

MHTECH8

;~~ ~~otal torque rotati ng w th 30, 000 l b on the

:

T= Th+Tb

T- 3, 882+ 5, 889 = 9, 771 ft- l bf

The axi al drag whi l e l oweri ng the pi pe on a tri p

or whi l o steeri ng w th a downhol e motor can be

cal cul at~df romthe fol l ow ngapproxi mat i ons.

For

the pi pe i n the hori zontal hol e, the axi al drag i s

gi venby:

I

% = . 33* Mm”L . . . . . . . . . (18)

The drag f or t he pi pe i n the bui l d curve i s a

functi onof the axi al force on the pi pe at the end

of the curve as i t enter s the hor i zontal hol e.

Thi s force i s equal to the wei ght on the bi t pl us

the drag of the pi pe i n the hor i zontal .

I f the

bottomhol e assembl y i s expectedto provi de si gni f -

i cant st abi l i zer drag, t hi s f or ce shoul d be

i ncl udedin the end of curve force. Thi s force at

the end of the curve i s gi ven by:

Fo=Dh+U06+f3HA . . . . . . . . (19)

I

The drag for the pi pe i n the bui l d curve i s depen-

dent on the magni tude of the axi al force at the

end of the curve.

I f Fo. 25. Wm”R:

Db =

.25 .

Wm“

R+. 69. F0 . . . . (21)

The drag for the exampl e wel l descri bed above

whi l e dri l l i ng w t h 30, 000 l b bi t l oad i n the

steeri ngmode i s cal cul atedas fol l ows:

(. 86 50) . 1000

Dh =

3

oh= 14, 3331b

Fo= 14, 333+30, 000

F. = 44, 333 l b

.250WM0 R= .Z5

(. 86

50) +850

. 25 s Wm

R= 9, 1381b

Therefore: F. > . 25 “ Wm s R

(. 86 50) 850

Db =

+ . 69 +44, 333

4

Db=9, ]37 +30, 390

Db = 39, 727 l b

The total drag i s:

D=Dh+Db . . . . . . . . . . . . (22)

D= 14, 333+39, 727

D = 54, 960 l b

To dr i l l w t h 30, 000 l b, i t w l l be necessa

sl ack off the bi t l oad pl ’ {sthe drag or 84, 0

i n thi s exampl e.

To cal cul ate the hoi st ing drag, the steps

qui te si ml ar.

The drag i n the hori zontal po

of the hol e i s gi ven by:

Dh =

. 33” WM”L . . . . . . . . . . (18

The tensi l e drag i n the bui l d Interval i s a

ti on of the tensi l e l oad on the pi pe at the e

the curve.

Thi s force i s equal to the fr i ct

drag for the pi pe i n the hori zontal i nterval

any nongravi ty fri cti onal l oads such as mgh

caused by stabi l i zer hangi ng or other such

fects.

The drag around the bui l d curve i s c

l atedas fol l ows:

Fot=Dh+BHA . . . . . . . . . . . (23)

I f Fot. 85. Wm~R

Dbt=. 69* Fot- . 25. i fm*R . . . (25)

These rel ati onshi ps can be used to esti mat

magni tude of torque and drag for most hori z

wel l desi gns. When these eval uati ons are co

w th an anal ysi s of the cr i t i cal buckl i ng

i ncludedi n Appendi x B, i t i s possi bl eto eva

the aff ect on torque and drag by changi ng c

nents i n the hori zontal dri l l stri ng. Reducin

wei ght of the pi pe i n the hori zontal w l l dec

torque and compressi vedrag as l ong as the l i

pi pe does not buckl e. I f condi ti onsdi ctate

buckl i ng w l l occur , the anal ysi s need go

beyondthese si mpl e rel ati onshi ps.

52


7/15

.

NMTECH890008

FRANKJ . SCHUH

SPE 20150

v

I -1’’””

B

BT

Bv

BHA

o

Db

‘ b’

Dh

DL

F.

Fot

H

11

12

L

OD

R

Rv

T

Tb

Th

v

Um

UOB

Bui l d Rate (“/100f t) .

Total curvature for bui l d- turn segment,

(’/100 f’) .

Verti cal bui l d rate for bui l d-turn seg-

ment, (“/ 100f t) .

Nongravi ty i nduced axi al f ri cti onal force

i n the bott omhol e assembl y, (l bf ).

Total drag (l bf).

Compressi ve Drag i n the bui l d curve,

( l bf) .

Tensil edrag i n the bui l d, (l bf).

Axi al drag whi l e pul l i ng or l oweri ng the

pipe in the hor i zontal por ti on of the

hol e w thout rotati on, (1bf) .

Total dogl eg i n a bui l d-turn segment,

(deg) .

The axi al compressive force on the pi pe

at the end of the curve, ( l bf) .

Axi al tensi on at the end of the curve,

( l bf) .

Di spl acement, ( f t) .

I ni ti al i ncl i nati onangl e, (deg).

Fi nal i ncl i nati onangl e, (deg).

Length of hol e or pi pe segment, (f t) .

Outsi de di ameter of the tool j oi nt s,

(i n).

Bui l d radi us of a segment or the overal1

bui l d curve radi us for torque and drt ig

esti mate, (f t) .

Vert i cal bui l d radi us,

Total torque (f tOl bf ).

Rotat ing torque i n

(ft- l bf)

(ft).

the bui l d curve,

Rotati ng torque for pi pe i n a hori zontal

porti onof the hol e, (ft. l bf) .

Verti cal hei ght, (f t).

The averaoe buoyant wei ~ht of the Di ne

.

( i bmft).-

Wei ght on bi t,

Azi muthchange,

Tool faceangl e,

l bf) .

(deg) .

(deg) .

I ‘eferences

1.

Oawson, Rapi er; Exxon Producti on Research

and Pasl ay, P. P. ; Consul t ant : ‘ Dri l l

Buckl i ngi n I ncl i nedHol es, ” J PT, (Oct. 1984

2. Mori tes, Guntes:

Worl dw de Hori zontal Dri l

Surges,” Oi l & Gas J ournal , (Feb. 27, 1989).

AppENDI XA

J oraue and D aa ADorox

i mati ons for A Uni f ormB

Q &

Let: D=

F=

f .

1=

R=

T=

w

Fc =

F. =

OD =

AT=

Tnol j oi nt OD, ( i n. ) .

Axi al f or ce on the pipe at any poin

the curve.

Coeff i ci ent of fri cti on.

Angl e of hol e above hori zontal .

I =0 atend of curve, (hori zontal ) .

I =90” at KOP i n radi us.

Radi us of bui l d curve, (f t) .

Torque i n the bui l d curve.

Uni t buoyant wei ght of the pi pe i n

curve, (l b/ ft) .

Lateral contact f orce i n curve,

( l b/ f t ) .

Ax~~oompressi ve f orce on the pi pe at

.

Tool j oi nt OD i n bui l dcurve, (ft) .

Torque producedal ong_a A@1ength

el ement of pi pe, (ft l b).

For these deri vati ons i t i s more useful to de

the coordi nate systemfor angl e as begi nni ng

zero at the hori zontal end af curve Dosi ti on

90’ as the angl e for the

poi nt.

vert ical ki ck

The torque produced al ong an

pi pe i n a ci rcul ar bui l dcurve

el emental l engt

i s gi ven by:

[1

T=f~ABS;+wcos I A . . .

(A-

2

The force at any poi nt al ong the bui l d curv

gi venby:

F. Fa

-wsi nI . . . . , . . . .

(A-

Combi ni ngA- 1 and A-2:

5$


8/15

sPE20~50

8

HORI ZONTALUELL PLANNI NG- BUI LDCURVE DESIGN

NNTECH89

AT= f~ABS

[

F.

-wsin I+wcos IA4 “

2R

. .,.

.(A-3)

For a Ci rcul ar bui l d arc:

A4= R.

AI.......,..

. . (A- 4)

Substi tuti ngA- 4 i n A-3 and rearranging to a dimen-

si onl essform

AT

[

F.

=l ABS—

i n I + cos I AI

f , D. w~R 2 WOR

. . . . . (A- 5)

T

=

f*D.w R

I=x/2 1

[

F.

~-ABS—

in i + cos I AI

1=0 2 w . R

. . . . . (A-6)

Usi ng an i terati venumeri cal procedure, we sol ved

equati on A-6 i n terms of (F~wR) and pl otted the

resul ts i n Fi g. 5.

I n l i ght of the signi f i c ant uncer tai nt y in the

magni tude of the fri cti on factor and radi us, we

bel i eve that these resul t s can be adequatel y

approxi mated by the two strai ght dashed l i nes

shown on the f i gure.

The resul t i ngapproxi mati on

i n equati onf ormi s gi ven by:

ForFocw

R/ 3

T=(f . D”w*R) / 2 . . . . . . . (A- 7)

Fo>w*R/ 3

UOB>. 33” WM*R

OD.WOR OD*WOB

Tb =——

+—

. . (A-1O)

144 46””

Compressi veDrag, whi l e dri l l i ng i n the steer

mode or whi l e l oweri ngthe pi pe i n the hol e:

l et Ft = force at the top of the curve.

The change i n axi al force al ong the sl i di ng p

i n a ci rcul ar bui l d curve i s gi ven by:

F=f . ABS~

+wcos IAi -w( si n I ) *A@

R

. . . . .

(A-n)

The axi al force at any poi nt i n the bui l dcurve

al soaf fectedby the axi al drag bel owthat poi nt

Fi =Fi - l +AF . . . . . . . . . . (A- 129

At the bottomof the curve where I = O the axi al

forcei s:

Fi =o=Fo . . . . . . . . . . . . (A-13)

Substi tuti ngfor At and di vi di ng to make the for

di mensi onl essgi ves:

~“f

“ABs[:+csin

. . . . .

(A-14)

Ft

[

I=fi/2 Fi

—+= ~:.

WOR

w R

.

F.

T=(f . OD.w R)/ 4+ . . (A- 8)

4-w*R

f “ABs[A+cOsl l A1” (si nl ) “AII

. . . . .

(A- 15

In oi l f i el duni ts for f= .33and WOB = F. these

become:

I

The drag forceDf i n the bui l d curve i s gi ven by

woBc.33. wm”R

I

Of

t

- Fo+w

R.. . . . . . . . . . . . . . . . . . (A-16

OD* WM* I

Tb =

. . . (A- 9)

Di vi di ng by w o R to make the sol ut i

72- ’ ’ ”””’

di mensi onl ess:

54


9/15

.

b

SPE20~50

NMTECH890008

FRANKJ . SCHUH

.

Df Ft F. Pi Ft

F.

—=— .

—+1 . .

. (A-17) ,

—“—

— 1. . . .

(A- 26)

w*R

w-R WOR

w-R

wok w*R

Usi ng an i terati venumeri cal procedure, we pre

The numerical sol ut ion for the tensi l e drag

f ared the pl ot of (Df /wR) ver sus ( F~wR) f or

= . 33 shown i n Fi g, 7.

showni n Fi g 8 for f = .33.

The approxi mati onfor tensi l e drag i s shown by t

The approxi mat i on shown by the dashed l i nes i n dashedl i nes i n Fi b. 8 and i noi l f i el duni ts i s:

Fi g. 7 i s oi l f i el d uni t s f or f= . 33 i s:

for Fot < .85 “ Urn. R:

For Fot < .25 . Urn

R:

Df=, 4. Wm*R . . . . . . . . . (A- 18)

o~t = . 33. UmOR . . . . . . . . (A- 27)

ForFo>.85*w *R:

ForFo> . 25 “ Wm

R:

Dbt=.69. Fot- . 25” Wm”R

. . ( A- 28)

Df = .25 c Um

R+ . 69 “ F. . . . (A- 19)

To sol ve f or t he t ensi l e dr ag ( pul l i ng out of

hol e) :

l et F. = tensi l ef orce at end of curve.

[

Fi

AF=f*ABS- . - wcos I

1

.A@+w(si n I )”Ae

l R

. ..-

“=f“ABs[A-cOsll

~+@i~~AI

*K

.

. . . .

(A- 21)

tkwn

dix 4

Torque and drag force approxi mati onsf or the hor

zontal porti on of a hol e assume that none of t

pi pe i s buckl ed.

Cri t i cal buckl i ng force for a pi pe i n hori zon

hol ewas deri vedby Dawsoni .

[

1

“I ” Umsinel ’ 2

FC=2

. . . . .

(B-1)

12.r

Fc = cri ti cal buckl i ngforce, (l b).

Where:

Fi =Fi . l +AF . . . . . . . . . . ( ’ - 22)

E = 29.6

10s psi steel .

Fi =O=Fo . . . . . . . . . . . . . (A- 23)

I =momentof i nerti a, (i nt).

f ‘ABs[A-cOsllA’+si”r

A

. ...

(A- 24)

The tensi l edrag force Df

IS P;ien b’:

Df=Ft- Fo-w *I i . , . . . . . (A- 25~

I ndi mensi onl essf ormi t becomes:

urn=buoyant wei ght of pi pe, (l b/ f t] ,

[1

5. 5 - MU

Wm= Wa

65.5

. . . . . . .

(B-2)

Ua = averagewei ght of pi pe and tool j oi nts

i n ai r , ( l b/ f t ).

NW= Mud densi ty, ( l b/ gal ) .

r = radi al cl earancebetweenpipe and hol e,

(i n).

There has been consi derabl econcernover the app

pr iate radi al cl earance to use w th coupl ed

tool j oi nted pi pe.

If

the pi tch of the buck

pi pe i s I &rge compared to the di stance betw


10/15

sPE 20150

10

HORI ZONTALUELL PLANNI NG- BUI LDCURVE DESIGN

NNTECH

tool j oi nts the radj al cl earance i s ~sfi ned by the

t ool j oi nt 011 r at her t han t he OD of t he pi pe

body.

Si nc&thi s i s general l y the case for. hori -

zontal dri l l i ng appl i cati onswe defi ne the radi al

cl earanceas:

r= (Dh - Dt j ) / 2. . . . . . . . . . . . . . . . . . .+ . . . (B-3)

O = hol e angl e 90” for hori zontal hol e

Dh=di ameter of hol e, (i n).

Dtj =di ameter of tool j oi nt, ( i n. ).

I n oi l fi el duni ts for a hori zontal hol e:

[

1

(25.5 - Mu)1’2

Fc=550. l“ua

. . (8-4)

Dh - Dtj

Torque for rotati ng nonl wckl ed pi pe i n a strai ght

i ncl i nedhol e:

OD . Wm .

L+fsi nO

T=

. . . . .

(B- 5)

24

T = torque, (f t l bs) .

I n oi l f i el duni ts w th f= .33 and for a hor izontal

hol e:

OD wWm“ L

T.

. . . . . . . . . . (B- 6)

72

Axi al drag for pul l i ng or pushi ng nonbuckl edpi pe

i n a strai ght i ncl i nedhol e:

D=Hm L. f ”si n9 . . . . .

. (B-7)

Where:

D= drag force, (l b).

I n oi l f i el d uni ts f or a hori zontal hol e w t h

f = . 33:

Dh=. 33~ti m*L . . . . . . . . . (B- 8)

WVATUREJMIIS

o Rotate conventi onal steeri ngtool s 3- 4’ / 1

o Rotate nonmagdri l l col l ars

6- 7”/1

o Use conventi onal producti ontool s

10”/1

o Rotate 5“ Heviwate drill pi pe

12-15”/ 1

o Motor dri l l i ngw thout rotati on

30+”/ 1

PLF

TANGE~

Gi ven:

Expected angle bui l d per formance,

9. 5’ / 100f t.

M ni mumtangent l ength, 120 f t.

Tangent angl e, 50’ .

Target angl e 90” at 9000 f t TVD.

Sol uti on:

Use the mni mumexpected bui l d rate to pl

bui l dcurve.

Use the same bui l d r ate for f i r st bui

secondbui l d i nterval s.

5730 5730

Bui l dradi us: R=

—=—=716f t

B8

Hei ght f i rst bui l d:

V=R. (si n I z- s

V-716 “ (si n50-

Hei ght of tangent:

V=L” COSI

n 11)

si nO) = 549 f t

v= 120

Cos (50) = 77 ft

Hei ght of secondbui l d:

V= 716 . ( si n90 - si n 50)= 168f t

KOP= 9000 - 349 - 77 - 168 =8,206 ft

m


11/15

.

SPE20150

N?4TECH890008

FRANKJ . SCHUH

.

Di spl acement, f i rst bui l d:

I

Pl annedhei ght of bui l d curve:

ti =R

COS

It -

COS 12}

‘

549+ 77 + 168 = ?94 ft

H= 716

(eos O - cos 50) =256 f t

I

Requi redTangent Hei ght:

Di spl acementof tangent:

I

794- 603 = 191 ft

H= L. si n I

Lengthof Tangent:

H=120. si n50=92ft

Di spl acementof secondbui l d:

H- 716 .

COS so - COS

90) =460f t

v

191

L. —=

— = 297 f t

Cos 1

Cos 50

Lengthof fi rst bui l d:

I

LEXTANGM EXANPLEPROB~

100 (12 - rl )

L.

8

GI VEN:

10G (50 - O)

Expectedangl e bui l d perf ormance

L=

8 to 9. 5’ / 100ft.

= 625 ft

8

Mni mumtangent l ength - 120 f t.

Tangent angl e - 50”.

Lengthof secondbui l d:

Target angl e 90” at 9, 000 f t.

100 (90 - 50)

L=

Second bui l d 1. 5°/ 100 f t l ess than t

= 500 ft

8

f i rst bui l d

NeasuredDepths:

SOLUTI ON

Atend of f i r st bui l d: 8206 + 625 = 8831 f t

Use the 8° /100 f t mni mum expected bui

rate for the f i rst bui l d.

At end of t angent : 8831+ 120= 8951 f t

I

Use 8 - 1. 5 = 6. 5°/ 100f t for secondbui l d.

At end of secondbui l d: 8951 + 500 = 9451 ft

I f bui l d rate i s 9. 5”/ 100 f t, how l ong i s the

tangent secti on?

5730

Bui l d r adi us: R=— =603 f t

9. 5

Hei ght fi rst bui l d:

603 (sin50 -

si n O) = 462 f t

Hei ght secondbui l d:

603 (sin90 -

si n 50) =J m

Total 603 f t

Fi rst bui l d radi us:

5730 5730

R1 =

—=—=716f t

68

5730 5730

R2=— -

—=882ft

B

6.5

Hei ght fi rst bui l d:

V-R . (si n 12 - si n I i )

V =716 . ( si n 50 - si n O) = 549 f t

Hei ght of tangent:

VmL. coSI=120. coS51)= 77f t

97


12/15

SPE 20150

12

l i OR120NTALNELL PLANNI NG-

WI1O

CURVEOESI GN

MMTECH890008

Hei ght of secondbui I d:

V

882 s (si n90 - sl n 50)

206 f t “

KOPR 9,000 - 549 - 77 - 206 ~8,168 ft

Di spl acementf i rst bui l d:

H=R ~

COS Ii

COS Iz

H=

716 *

COS

O “

COS

50) = 256 ft

Di spl acementt angent:

H= Losl n In120. stn50=92f t

Di spl acementof second8ui l d:

H= 882 ~

COS

50- COS 90) =567 ft

Lengthof fi rst bui l d:

cos

DL -

Cos 11 * Cos 12

cosAAZ=

sl rr11si n 12

AA = arc ~os COS 49, 23 -

COS

50

X COS

90

z

si n 60 x stn90

= 31, 5*

Azi muth change i f f i rst hal f of second bui l d fs

turnedl ef t and

secondhal f i s turnedri ght.

Fi r st hal f : I I M50’ I I

70’

8,0

Total dogl eg: OL R

— (70 - 50)

24. 62’

6,5

COS 24, 62 -

COS

50

COS

70

Cos AAZ

m. 96

sl n50 s si n70

100 ‘

(12 11)

L.

B

AAZ ~rc cos (, 96)m16, 76”l ~f t

100 (50 - o)

L.

= 625 ft

8

Lengtht angent: L

120 f t

Lengthof seccmdbui l d:

100 (90 - 50)

L=

- 616 ft

6, 5

[1

, 6

Tool f acermgl @2ndbui l d~arc cos— 35, 7’

8*O

Azi muthchangei nsecondbutl d,

Total dogl q i nsecondbui l d{s:

Secondhal f : I t ~70” 12R90’

8.0

DLu — (90’ 70)=24, 62’

6, 5

AA2

m

[

COS24, 62

1

- C os

?0 8

Cos 90

arc cos

sin 70 ~

sl n90

= 14. 65”ri ght

Totaldi recti onchang~i rrsecondbui l d:

~z

“

=16, 76”(l ef t)+ 4, 6$’(ri ght)

~2, 11’ ( l ef t)

8,( . )

1, Target TVD VS, posi ti on

and dfrect l on of the

DLMuwmn

(90 = i O)~49023’

end of curve

6,5

i ?,EOC poslt l l onvs ‘ . ddi recti on,

I f al l

turn I s I n tho same di recti onthe azimuth

3, Target TVD, Qoc posi ti on

andd ractl onaccuracy

changets:

VS*

ost

I


13/15

.

H I ?TECH90008

=20150

FRAHKJ . SCHLJ H

1

~’

Type

Si ze

Radi us

Length

k++

Short

$3/ 4

; :

425

889

Mediurn

;- 1/ 2

300 1, 300

300

2,200

8- 1/ 2

400- 800 3, 350

Long 8- 1/ 2 l , 0~O~; b500

4,000

12- 1/ 4

s

1,000

NTAL TA I oETTRADE OFFS

.

1. Target TVD vs. posi ti on and di recti onof

the end of curve.

2. EOCposit on vs. EOCdirection.

3. Target TVD, EOC posi ti onand di recti on

accuracyvs. cost.

m

ORS ~TI NG TOROUEAND DRA~

o Lengthof Hori zontal Hol e

o Dr i l l str ingDesi gn

- Hevi wate

- Dri l l pi pe nhori zontalhol e

- Requi redbi t l oads

o Coef f i ci entof Fr i c ti on

- Mud type

o Rig Capaci t y

- Torque

- Axi al

- Top dr i ve

o Hori zontal Dri l l i ngTechni que

- Surfacerotati on

- Steeri ngmode


14/15

SpEz

O1~~CH 890

HORI ZONTALUELL PLANNI NG- BUI LDCURVE DESI GN

VERTICAL

SECTION

1

R

t+

PLAN

VIEW I

2

Fig.

i Basic build curve geometry.

PLAN

VIEW f

t-l=+

2

A/k

Fig. 2 Build and turn geometry.

549

77 ‘

8 deg/100 ft Build rate

50 deg Tangent angle

120 ft Tangent length

Fig. 3 Simple tangent build

716

EOC

w

7i6’

5U

549‘

77‘

206

PLAN

VIEW

8deg/ i OO ft motor

build rate

6.5deg1100’ 2ndbuild rate

120 ft

tmgont t 50 deg

ngle

Fig. 4 Complextangent build

curve.


15/15

, .

SPEU150

NMTECH890008

FRANKJ . SCHUH

15

549

206

567‘

l--f

.

a d8g/ l oo ft Total Curvatw e rate

a deg/ l oo ft Fi rst bui l d r8te

6. S dag/ 100 f t

d Euild

rate

Fig. 5 Ideal build rate.

F@. 6 Torque k

the build curve,

d

,

Fi g. 7-Compwsti e drag i n bui l dcurve.

3. 00

2. s0

-2. 00

$

~

y so

s

0

1 00

0. s0

O*OO

Ii

*O i

EOC FC

5

Fig. 8-Tensile drag in buiid curve.

Date post:	07-Jul-2018
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SPE-20150 Hor Well Plan-MS

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