8/19/2019 SPE-20150 Hor Well Plan-MS
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SPE 20{50
Horizontal Well
Frank J . Schuh, Dri l l i ngechnol ogy,k.
NEWMEXI COTECH
CENTENNI ALSYMPOSi UM
Planning—Build Curve Design
-ktht Iw% SOMY of PetroleumEngineer%Inc.
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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°.
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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
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8/19/2019 SPE-20150 Hor Well Plan-MS
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.
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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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
- .
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SPE20150
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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.
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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
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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$
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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
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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
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sPE 20150
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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
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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
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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
8/19/2019 SPE-20150 Hor Well Plan-MS
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.
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
8/19/2019 SPE-20150 Hor Well Plan-MS
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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.
8/19/2019 SPE-20150 Hor Well Plan-MS
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, .
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.