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*
,
SPE 19656
Reser~oir Description and Performance Analvsis of a Mature
S
=- tuorF% - unmmErms
Miscible Flood in Rainbow Field, Canada
D, E. Bi l ozi rnd P,M Frydl ,Mobi l Gi l Canada
r
A
Copyright1SS9,Societyof PetroleumEngineers, Inc.
Thispaper weapreparedfor preaentalionat theS4thAnnualTechnicalConferenceand Exhibitionofthe Societyof PetroleumEngineereheld In San Antonio,TX, Octcber S-1 1, 19S
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ae preearrtad,have notbean reviewedby theSocietyof Petroleum Engkrearaand aw subjectto correctionby the author(a).The material, aa preeented,doesnotneceeeerily retfe
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[email protected] restrictedtoen abetmcfofnot momthen 3Wwc@e. Iffuetratiomamaynotk copied.TheabetrectehoufdcontainconapkuoueaekmM@nenf
ot where end by whomthe paper la preeented. Write PubllcationaManager, SPE, PO. BoxSSSflSS,Richerdaon,TX 7S0SS-SS3S.Tetex, 72CIW9SPEDAL.
.4BsIlUI
producti onmethods (reve?seconi ng, gas cycl i ngan
hori zontal wel1 applicati on) .for di f ferent part s o
The Rai nbow Keg Ri ver AA pool i s a dol omt i zed
the pool ,
carbonatereservoi r i n a mature sta e of a verti cal
?
ydrocarbonmsci bl e f l ood. Tba ong hi story of
MUU &LM
enhancedrecovery, pl us the fact that the pool had
not produced accordi ng to i ni ti al ex pectatons,
Thi s study i l l ustratesthe newengi neeri ngparadi g
f ormed an i deal fr amework for an i nterdi sci pl i nary
and the appl i cat i onof
(~festi gati v geol ogi cal an
re- eval uati on ; : e theres~tl
and i t s depl et i on
engi neeri ng techl ~i ques .
Art i cl es documenti
mechani sms.
p~n; i ded
verti calw~tdrocarbonmsci e fl aods have typ a
i nterpretati on
of the pool
al l ow~d %
dqalt
$)
t i
i ni t i ati on )3),
devel opmentof an opti mzeddepl eti onstrategybased
perf ormance *7 ,
moni ; ori *~~$*~
expansi on(e) , si mul a i
on mni mzi ngconi ng and maxi mzi ngrecovery i n the termnati on (due to poor perf ormance)1 o~ th
remai ni ngoi l sandw ch.
f l oods. No speci f i cdocumentat i oncoul d be foundo
managi ng a mature vert i cal hydrocarbon msci bl
Acqui si ti onof 3- D sei smc data provi ded a better
f l ood where the remai ni ng oi l bank i s rel ati ve
def i ni t i onof the shape and si ze of the reservoi r
thi nand sandw chedbetweenthe sol vent bank and th
and l ed to the dr i l l i ngof four f l ank wel l s. The
ori gi nai oi l -water contact. Thi s paper di scuss
3-D sei smcdata, i nf ormati onf romthenewwel l s and
themanagementof thi s type of maturemsci bl ef l oo
r ei nt erpret at i on of ol d wel l s resul t ed i n a
i n the Rai nbowKeg Ri ver AA pool .
reassessmentof pool vol umetr i c. A newgeol ogi cal
model suggestedthe presenceof unswept oi l , whi ch
The Rai nbowKeg Ri ver AA pool i s l ocated i n th
was l ater substant i ated when one wel l
was
nort h-westerncorner of Al bert a, Canada, about 96
recompl eted above the sol vent/ oi l contact and
L l ometers (600 ml es) south of the Arcti c Ci rcl e
~ro:ced oi l whi ch had been bypassedby the soi vent
I t was di scovered i n Apr i l 1967 and pr imar
In combi nati on w th a revi sed materi al
bal an; e and a ravi ew of msci bi l i t y, t he new
producti onresul tedi n a pressuredecl i nebel owth
bubbl e poi nt pressure w thi n one year. I n Apri
reservoi r i nterpretat i onexpl ai nedpast erf ormance
B
1969, a gas i nj ecti on scheme was i mpl ementedan
and demonstratedthe successof themsci l e f l ood.
; : ; ; r i nj ecti oni nto the aqui fer commencedi n Apri
After the reservoi r descripti on ad performance
anal ysi swere compl eted, the maj or chal l engewas to
Si nce August 1972, the Keg Ri ver AA pool has bee
devel op a producti on strategywhi ch opti mzed the
under a verti cal hydrocarbonmsci bl e fl ood, Th
oi l recovery f romthe remai ni ng15-metr eoi l bank.
f l oodconsi sts of i nj ecti nga sol vent composedof
The mai n obj ecti veof the str i ttegywas to reducethe
m+ni mumof 45 mol e percent ethane-pl usi nto the ape
sandw ch l oss.
Usi ng xyl ene washes, si gni fi cant
i ncreases i n the producti vi ty i ndex were achi eved
of the reservoi rand forci ngthe sol vent downwardt
msci bl ydi spl acethe oi l bei ng prodccedf rombel o
w thout l arge i ncr eases i n gas product i on. A the sol vent - oi l cont act ( Fi gure 1) , The i ni t i a
simpl i fi ed coni ng
si mul ati on model provi ded a
total recovery factor usi ng thi s enhanced oi
qual i tati vevi ewof how the maj or reservoi r f aci es
af fectedcone devel opment, The model pl us reservoi r
recoverymethodWS esti matedto be 85 percent,
descri pti on l ed to recommendati ons of opti mum
In 1986, the Rai nbowKeg Ri ver AA msci bl e fl oo
appearedto be i n j eopardy,
The oi l producti onwa
Referencesand f i guresat end of paper,
decl i ni ngrapi dl yand the produci nggas-oi l rati o
289
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RESERVOI RDESCRI PTI ONANDPERFORMANCEANALYSI SOF
2
A NATUREMSCI BLEFLOODI NRAI NBOWFI ELD, CANADA
sp~1965
.
w?.: abnormal l yhi gh. I n addi ti on, the dctual oi l
producti onf romthe pool had typi cal1y bem about 70
f
the rate ori gi nal l y predi cted (Fi me
7
e f fn 2% Based on t he ori : , i naloi l - i n- paCe
2)~$
esti mateof i 5 9
$106 m3 and
an esti matedrecovery
of 12. 5x 10~ m ,
the pool had onl y produced
one-hal f of i ts expected recovery, and yet there
were i ndi cati ons that the remai ni ng ~11 bank was
qui te thi n.
The i ntegrati on of geol ogi cal and engi neeri ng
anal y;esprovi dedthe opportuni tyto:
.
Redefi ne the reservoi r, the associ ated
vol umetri c and i denti fy bypassedoi l i n
the sol vent- sweptzone.
2.
Anal yze the basi c dat a provi ded by
previ ousstudi es.
3.
Anal yze the current
msci bl e
f l ood
perf ormance.
4.
; ; ; odthe new reservoi r descri pti on and
per f ormance to
provi de
recommendati onson how to opti mze the
remai ni ng proti ucti onpotenti al I n the
pool.
Ful l understandi ngof the AA msci bl ef l ood and i ts
opti mzati on
has two i mportant ramf i cat i cms.
Fi rst. several mscl bl e fl oods i n the Rai nbowfi el d
are approachi ngmaturi ty and are devel opi nga thi n
oi l bankw th sol vent above the oi l and the ori gi nal
oi l -water
contact bel ow
The ef f i ci ency of
depl et ing thi s oi l sandw ch i n the AA pool may
serve as a standard for the other msci bl e fl oods.
Secondl y, i f the msci bl e fl ood mechani smand the
geol ogy i s ful l y understoodi n the AA pool , future
f l oods fn Rai nbowcan be desi gned and i mpl emented
w th l ess ri sk and greater conf i dence.
SEOLOGY
(a) Reservoi rDescri pti on
The
AA pool i s one of
more
than 80
hydrocarbon-beari ng carbonate bui l dups i n the
Rai nbowFi el d.
The bui l dupsdevel opedapproxi matel y
3P0 ml l i on years ago i n the nnrthwesterrfpart of
the Mddl e Devoni anEl k Poi nt Basi n. The El k Poi nt
Basi nwas occupi edby a shal l owtropi cal sea whi ch
coveredmost of the provi nceof Al bert aand extended
as far south as North Dakota. At the northwestern
edge of the sea,
an extensi ve barr ier reef
(Presqu i l e)devel oped,
The barr i er reef control l ed
the i nfl owof f reshmari newater i nto the basin and
periodi c restr ict ions l ead to devel opment of
evaporl ti c condi ti ons,
Cfowth of the numerous
smal l er carbonatebui l dups, whi ; ~edevel oped i n the
Rai nbow
sub-basi n behi nd
barr ier , was
:;MN4L
i nterrupted by these hi gh sal i ni ty
Tho AA pool i s a carbonatebui l dupcoveri ngan area
of approxi matel y one square ml e and reachi ng
el evatt , onf nearl y 165metres abovethe surr oundi ng
off - reef carbonate sed{ments (Fi gure 3).
The
bul l dup sedi ments are compl etel ydol omti seal . The
t~mngand dol omtl zati onof the AA pool as wel l as
the other Ratnbowreservoi rs ha
(
ot been cl earl y
establ i shed.
Schmdt et al 141 f v,r earl y
dol omti zati on,whi l e Ql ng and Mountj oy
h$
1ater dol omtl zatl on duri ng i ntermedlate ~~ ~?
Al though dol omtl zati on compl etel y destroyed the
ori gi nal sedi ment f abri c on the mcroscopi c l evel ,
f ai r preservatl o~h~f sedi mentary ; ~[i $ures a
bi ocl asts on
masoscopi c
al l ow
recogni ti m of numerous sedi mentaryfacl eq and. t
devel opment of a deposi ti onal model of, ,the
bui l dup.
The tr ansformati onof the deposi ti onal model i nto
reservgi r model i nv~l vedseveral steps.
Di f ferm
faci eswere characteri zedby a range of porosi tya
permeabi l i ty val ues,
types
of porosi t y,
a
var iat i ons i n cont i nui ty of pc?ous uni ts.
T
faci eswere then grouped i nto l arger uni ts based
the envi ronment of deposi ti on. . Because each
these l arger uni ts was domnated by one or t
sedi mentary f aci es,
i t was rel ated to a set
reservoi r propert i esand provi dedthe f i nal step
transl ate the deposi ti onal model i nto a reservo
model .
The deposi ti onal envi ronments i denti fi ed I n t
reservoi r descri pti on are
shown in Figure
Al thougheach deposi ti onal envi ronment has p?ovl d
an i mportant cl ue i n understandi ngthe msci b
f l oodperf ormance, the most i nf l uenti al faci eswe
ths exposuresurf aces.
There wa$ stwmg evi dencethat the growth of the A
bui l dup was 1nterruptedat 1east two ti mes duri
per i ods of l owered sea l evel and caused t
devel opment of exposure surf aces.
The exposu
sedi ments are characteri zed by extremel y l
porosi tyand permeabi l i ty. Becauseof thei r ori g
dur ing bui l dup exposure, they form thi n bu
l ateral l yextensi veuni ts whi chcan be correl atedi
cor es and on l ogs through a l arge par t of t
bui l dup.
(b) Vol umetri c
Sei smc i sochronmappi ng pl ayed a l eadi ng rol e i
expl orati onand earl y devel opment dri l l i ng i n th
Rai nbowFi el d. The methodrel i ed on detecti ngthe
anomal i esi n the i ntwval
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.
SF5 19656
DI ANEE. BI LOZI R, PAUL MFRfDL
3
I l l ustratedi n Fi gure 5 where unswept oi l exi sts
perchedon anhydri tehori zonsnear the peri hl eterof
the pool .
Uhen theAA pool was revi ewedusi ngthi s concept, i t
becam apparent that 3 exi sti ngwel l s penetratedthe
reservoi r i n a posit i onanal ogoust o the far ri ght
wel l i n Fi gure 5.
Re- eval uati onof the open hol e
l ogs of one of thesewel l s suggestedthe presenceof
unswept oi l near the topof the reservoi rhi gh above
the sol vent- oi l contact.
Comp: ;i sonof the densi ty
and neutronporosi ty l ogs (Fi gure5) shows that the
two curves overl ap fr om1618 to 1640 metres, are
separatef rom1650 to 1683metres, and overl apagai n
f rom168s to 1726 metr es.
The curves.separate i n
the sol vent- sweptzone becausethe neutronporosi ty
; ; ~ve~sponse i s su[; pressedi n the presence of
The wel l was i ni ti al l y perforatedbel ow
the sol ; ent- oi l ccntact at 1683 metr es and produced
cl ean oi l for two years unti l sol vent breakthrough.
However, i n 1988, the wel l was re-~erf oratedabove
t he anhydri t e i n t he upper zone where the
overl appi ng l ogs had suggested the absence of
sol vent. Thi s i nterpretati on was subsequentl y
confi rmedby the producti onof cl ean oi l fr omthi s
upper i ntervhl .
I EHOF PREVI OUSSTUOW
(a) Revi ewof Aqui fer Stze
The eval uati onof the aqui fer si ze i n 1969was very
si ml i sti c as there were onl y f i ve wel l s i n the AA
oo . Usi ng the cyl I ndr ical- type concept of the
reef, the aqui fer was assumed to exi st under the
oi l - beari ngKeg Ri ver AA reef onl y, w th the edges
: ;s:; ; . ~ff j fer
descri bedby the sl opes of the reef
. Thi s resl ted i n a very smal l aqutfer
of 14 x 106 m3 whi ch provi dedvery l i mtedpressure
support .
Addi ti onal dri l li ng i n the Rai nbowfi el d si nce 1969
has al l oweda much broader perspecti veon the si ze
of the aqui fer.
Several wel1s, whi ch were dri 11ed
and abandonednear the AA pool , were eval uated for
water- beari ngzones occurr i ngat the same depth as
the aqui f er i n theAA pool and provi dedan extensi on
of the AA pool aqui fer,
hs ew otenti a a~l i f r
si zewas vol umetri cal l yesti matedto be 59 x 10 m .
(b) Revi ewof Materi al Balante
The numerous materi al bal anc c c
[ l 2, 1\ J ti ~~~c$~a~~
thi s pool from1968 to 1972 11)
on the peri od of t i me f rom the start of oi l
producti on(May 1967) to the start of gas i nj ecti on
23 months ater,
The pressure responseduri ng thi s
ti me peri odwas stri ctl ydue to f l ui dproducti onand
water i nf l ux, thus simpl i f yi ngthe materi al bal ance
cal cul ati onto sol ve for the ori gi nal oi l - i n- l ace,
8 the
Gi ven a l i mtedaqui f er si ze of 14 x 106 m,
materi al bal ance cal cul ati onsconsi stent l yresul ted
i n ori gi nal
3
o l - i n- pl ace est imat e of
approxi matel y16 x 106m ,
Usi ng the new reservoi r vol umetri c and a l arger
aqui fer, the materi al bal ance cal cul ati onf or the
same peri od of ti me was revi ewed an provi ded an
$
ori gi nal oi l - i n- pl aceof
11 x 106 m .
A sampl e
cal cul ati onts provi ded+3 Appendi xA.
The water i nfl ux vol umes frcm the new materi al
bal ancecal cul ati onswere tested by two methods to
determnethei r val i di ty.
The graphof water i nf l ux
versus ti me (Fi gure 6) i ndi cated that no water
i nf l uxoccurredunti l f our months af ter producti on
The l ack of earl y water i nfl ux i s reasonabl egi ven
that a thresha~d pressure drop had to be reached
before the ~nf l uence of the aqui f er could be
measured.
The water i nfl ux i ncreased duri ng the
next tour months unti l the bubbl epoi nt pressurewas
rzachzd.
At that poi nt ,
the rate of the water
i nf l ux stabi l i zed, whi ch woul d be expscted b~cause
the expansi onof the gas cap then becomes the mai n
dri vi ngf orce.
The second test f or t he val i di t y of t he i nf l ux
vol umes was to use the stabi l i zed water i
~di $at c ~
vol ume to esti mate the potenti al aqui fer si ze .
The cal cul at i on, shown i n Appendi x B,
aqui fer si ze of approxi matel y60 x 10 m.
Thi s
matched the aqui fer si ze of 59 x 106m3 determned
vol umetri cal l y.
(c) Revi ewof Hi sci bi1i ty
The Rai nbowKeg Ri verAA pool was an i deal candi date
for a ver ti cal mscibl e f l ood.
By 1969 i t was
conceptual i zedthat the pool woul d i ni ti al l y be
fl oodedw th a sl ug of enri chedgas above the oi l ,
fol l owedby i nj ecti onof a l ean natural gas. The
oi l woul d be msci bl y di spl aced downward by the
enri ched gas (sol vent) , whi ch woul d be i n turn
msci bl y di spl aced downward by l ean gas.
oi l
producti onwoul d be taken f rombel owthe sol vent- oi l
contact.
Di spl acement woul d be I , l aximzedecause
the downwardmovement woul d perm t favorabl egravi ty
stabi l i zat i onef fects.
The AA pool msci bl ef l oodwas desi gned, there ,
to be a mul t i - contact co:::;;:ng gas dri ve
[ $
Reservoi r
oi l
woul d
enri ched
Wt;
i ntermedi ate-mol ecul ar- weightydrocarbonsf romthe
sol vent unti l the oi l woul d becomemsci bl ew th the
i nj ectedsol vent sl ug i n the swept zone. I n turn,
the l ean chase gas i nj ectedaft er the sol vent slug
woul d be condensed i nto the sol vent to form a
l i ghter reservoi r fl ui d whi ch woul d then become
msci bl ew th the l eanchasegas,
Tne S1i re- tubedi spl acement tests done i n 1969(17)
used
adaptedversi on of the method presentedby
Koch(f $) to determne msci bi l i ty condi ti ons,
oi l
recuvti ryat fl ood gas breakthrough was pl otted
agai nst di f f erent methane-ni tr ogencontents at a
constant
pressure greater than the sol vent
cri condenbarof 13, 100 kPag. Once a sharp decrease
i n oi l recoveryw th an i ncreasein methane- ni tr ogen
content was observed, the maxi mum content of
methane-ni trogenfor msci bi l i ty at that pressure
was
esti mated.
These experi mental
maxi mum
methane-ni trogencontents for msci bi l i ty,
y i f
h
correl ated cl osel y w th Benhams correl ati on
were then pl otted versu? the ethane-pl usmol ecul a;
wei ght of the gas (Fi gure7). Thi s f i gure showed
that msci bi l i tywas assuredi n the AA pool i f the
poi nt representi ngthe composi ti onof the i nj ected
sol vent was bel ow the l i nes representi ngthe two
experi mentalpressures,
The pseudoternarydi agramfor the AA pool msci bl e
fl ood was constructed fr omw ndow cel l PVT tests
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RESERVOI RDESCRIPTI ONANDPERFORMANCEANALYSI SOF
4
A MATUREMSCI BLEFLOODI NRAI NBOWFI ELD, CANADA
SPE 196S6
(Fi gure8) (20).
Fromthi s d?agram two requi rements
Df the f l oodwere sti pul ated:
1.
Th~ ethane- pl us content of the sol vent
coul dnot b~ l ess than45 mol e percent.
2.
The mni mumdatumpressurer@st be 15 500
kPag, wh: ch woul d al so be consi deredthe
mni mummsci bi l i typressure.
Af ter the msci bl ef l oodconsnencedn 1972, the POC1
di d not per formas wel l as i ni t i al l y expectad
(Fi gure 2).
M sci bi l i ty was questi oned but the
cur rent rat ional e i s that msci bi l i t y has been
achi eved
and mai ntai ned.
Thi s r easoni ng i s
supported by the i ni ti al sl i m tube di spl acement
resul ts, actual f l ood performance and recent
di scover i es i n mul t i - cont act
di spl acement
mechani sms.
Recent l i terature has
star ted to explore the
l i mtati onsof usi ng one pseudoternarydi a~t; ;
descri be
mul t i - contact
i ~~~ ~~ yExperi mental
condensi ng- gasdri vemechani sm
Observati onshave i ndi catedthat the condensi ng- gas
dri ve
mechani sm i s
actual l y conbi ned
condensi ngi vapori zi ~g- gasdr ve mech~ni sm The
generati onof msci bi l i ty occurs by the extracti on
of reservoi r f l ui dcomponents i nto the sol vent ( i . e.
msci bi l i tydevel ops i n the forwardcontacts) rather
than by the condensati onof sol vent i nto the crude
Dil (i e. msci bi l i tydevel ops i n the swept zone).
Characteri sti csof the AA pool whi ch i mpl y that the
combi ned condensi ng/ vapori zi ngmec
) l \
sm i s i n
z; ;tct , based on thi s l i terature , are as
fol l ows:
1.
The cr i t i cal poi nt i s t o t he l ef t of t he
systemcri condenbarof 13100 kPag on the
pressure-composi t i onP- x) di a~ram
2.
The reservoi r temperature i s 84 degrees
Cel si us whi ch i s a
rel at i vel y hi gh
reservoi r temperature.
3.
The sol vent i s ethane- r i ch (15 mol e
percent ethane).
There i s di sagreement as to whether or not thi s
condensi ng/ vapori zi ngmechani sm actual l y devel ops
t rue msci bi l i t y,
even
though
the generated
di spl acementsare ef f ecti vel ymsci bl e and di spl ace
nearl
{
00 percent of the oi 1 i n 1aboratory
tests 21
The most recen+.work by Novosad and
Costai n(2~) provi des strori , ,evi dence that true
msci bi l i ty i s obtai ned through the mul ti - contact
process. Th~nwar~ concl udes that pseudoternary
di agrams, constr~cted
usi ng the
mul ti pl e- contactpath, cannot be used to accuratel y
predi ct the di spl acementof oi l by sol vent,
(a) Waterf l oodPerf ormancel , nalsi s
The AA pool was never tr ul ywaterf l ooded, Water was
i nj ectedfrom1971 to 1973 to i ncreasethe pressure
above the mni mummsci bi l i ty pressure of 15, 500
kPag pri or to the commencement of the rr i ici bl e
f1ood.
Water was agai n i nj ected i nto the aqui fer
f rom1975 unti l 1981 as an emergencymeasure when
the avai l abl egas quanti ti eswere not suf f i ci ent to
repl acevoi dage,
The pressure f l uctuati onsi n the
reservoi r refl ect these peri ods of water i nj ecti on
(Fi gure9).
Accurate defi ni ti on of the hypotheti cal waterfl ood
recoveryf actor i s an i mportant consi derati onas i t
di rectl y aff ects the i ncremental reserves over
waterfl oodatt ri butabl eto the msci hi ef l ood. Thi s
M l ul ti matel ydefi nethe successor fai l ureof the
enhancedrecoveryprocess.
I n 1970, the i ni ti al waterf l oodreco
the AA pool was esti matedto be 67%
~ ~~ a;~h~
recovery
factor was j ust i f i ed
by as~uming nil
resi dual oi l saturati oni n the caverns. I n 1972,
the msci bl e f l ood recovery factor was esti matedto
be 78. 3% by
the Al ber ta
Energy Resources
Conservati onBoard. The i ncrementalrecoveryf actor
attri butedto the enhancedoi l recovery processwas
therefore11. 3%
The newreservoi rdescri pti on,whi chdi d not i ncl ~ d
caverns and i ndi cated a si gni fi cant reducti on i n
OOI P, requi redthe re-def i ni ti onof th~ hypotheti cal
waterf l ood
recovery factor.
The theoreti cal
cal cul at i on of thi s f acto
[Y
as based upon the
Dykstr a- Parsons corr el at i on23 .
By varyi ng the
maximumand mnimumpermeabi l i tyvari ati onsexpected
i n the AA pool , a range f rom40% to 52% for the
expectedwaterf l ood recovery factor was cal cul ated
for a water - oi l r at i o 1i mt of _25 (Apendi x C) .
+
hi s range corresponds cl osel y 10--t e recorded
waterfl ood recovery factors i n other Rai nbowKeg
Ri ver pool s.
Si ncetheAA pool had been produci ngfor over twenty
years, i t was al so possi bl e to esti mate
hypotheti calwaterf l oodrecoveryfactorbasedon the
actual vol umetr i c sweep ef f i ci ency. The vol umetr i c
sweep eff i ci ency was opti mstic however, as i t
representedthe ef f i ci encyof the msci bl ef l oodand
not of a waterfl oodi n the AA pool . The cal cul ati on
shown i n Appendi x D provi ded a hypothet i cal
waterfl oodrecovery factor of 49% whi ch i s i n the
rangespeci f i edby the Dykstra-ParsonsLi near model .
(b) Current Hi sci bl eFl oodPerf ormanceAnal ysi s
The current recovery for the swept zone of the
msci bl e f l ood i n the AA pool can be determned
usi ngt he newgeol ogi cal sl i cedmodel shown i n Tabl e
2, I n 1987, the sol vent- oi l contact was esti matedto
be at 1285metr es subsea, Thi s was 18 metr es above
the ori gi nal oi l -water contact. From th~ sl i ced
model , the cumul ati ve
OOIPf romthe t op of t h r e f
5
to thi s sol vent - oi l contact was 8,755 x 10 m
U~i ng the cumul ati veoi l producti onof 6, 550 x 105
m, the recovery in the swept zone was 75% In
addi t i on, usi ng
the m croscopi c di splac t
ef f i ci encyof 95%determnedfromcore studi es
the vol umetr i c sweep ef f i ci encywas esti mated a;
79%
These parameters
i ndi cate a successful
msci bl edi spl acement process i n the AA pool . The
detai l edcal cul at i onsare shown i n Appendi xE.
(c) FutureHi sci bl eFl oodPerf ormanceAnal ysi s
Predi cti ngthe futureperf ormanceof the AA pool i s
compl i catedby two mai n factors:
1.
Water was i nj ected i nto the aqu fer and
di d sweep upr: ardsi nto the o ? zone to
some extent,
2, The remai ni ng oi l
bank cannot be
compl etel yproduceddue to sandw ch10SS,
292
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7/24/2019 19656-Reservoir Description and Performance Analysis of a Ma
5/16
.
SPE 19656 DI ANEE. BI LOZI R, PAULM FRYOL
5
I i aterI ndecti onin the AA pool was usedmai nl y as a
marginalrates because the product i onemphasi s has
pressure- regul ati ngmechani sm The net amount of
J
shi fted to recoveri ng the val uabl e natural gas
&;oOi n ected ;nto the pool was appruxi m?tel y
s l vent
3
bank
(current
whi ch correspondedto a maxi mumwater
l $~i l i ~pl ac;n= . ; 106m) .
l ev~l ri se above the ori gi nal oi l -water contact of
4. 7 metres.
However, the l ast f our wel l s dri l l edi n
Achi evementof the predi ctedperf ormancerequi resan
earl y 1987 showed an average oi l -water contact of
1302. 1metres subseawhi ch i s oi i l y0. 9 metres above
ef fecti ve producti on opti mzati on strategy whi ch
uses i nnovati ve producti on practi ses,
the new
the ori gi nal oi l - watercontact. Thi s i ndi catedthat reservoi r descri pti onand the unders: , andi ngf the
the de-wateri ngprocess whi ch commenced i n March,
msci bl e
di spl acement
1982 had been successful i n l oweri ngthe oi l -water
process,
The
current
producti on opti mzati on strategy i as I nvesti gated
contact to al most i ts or igi nal posi t i on at 1303
the fol l ow ngi tzms:
metres subsea.
In
addi ti on,
oi l should have
Rate- Test i ngprogram(xyl enetreatments) .
resaturatedt he waterf l oodedzone successful l yas
; :
Coni ng control (gas cycl i ng and reverse
~~r~~~~i t~[f$~es ~. c~~~r~&e~~~~c ~~eb~~
3 coni ng)
Hori zoi l talwel l technol ogy,
demonstratedi n o~ber reefs .
.
.
(b) Rate- Testi ngProgram
The second maj or i nfl uenci ngfactor on predi cti ng
futureperf ormancei s the magni tudeof the sandw ch
The prese~ce of asphal tenes i n oi l fromthe Keg
l oss.
Sandw ch l oss i s the amount of oi l whi ch
Ri ver zone i n the Rai nbow fi el d i s consnon.
The
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7/24/2019 19656-Reservoir Description and Performance Analysis of a Ma
6/16
.
A MATUREMSCI BLEFLOOD
.
.
RESERVOI RDESCRIPTI ONANDPERFORMANCEANALYSI SOF
I
RAI NBOWFI ELD, CANADA
SPE 19656
The l ongevi ty of the xyl u; ; etr eatment i s unknown.
I n . heKeg Ri ver B pool , xyl enewashes ar conducted
b. Gi venn some WO1l S as often as once a month )
the encou~agi ngresul tsof the rate- testi ngprogram
some of the poorer producers of the AA pool shoul d
benefi t f roma routi nexyl ene-washprogram
There are two drawbacksto doi ng xyl ene treatments.
Fi rst, al though i t i s a comparati vel yi nexpensi ve
procedure($15, 000Cdn, ) , the xyl ene treatment must
have a short payout peri odto be economcal because
the benef i tsmay be short term Secondl y, repe
xyl enewashesw l l di ssol vethe downhol epackers
:
resul t i ngi n expensi veworkovers.
(c) Coni ngControl Program
A coni ng
si mul ati on model
was devel oped to
qual i tati vel yeval uatet he ef f ect of maj or reservoi r
faci es on vari ous producti on strategi es.
The
bl ack-oi l program si mul ated
f i rst- contact
msci bi l i ty between an i nj ected sol vent and the
i n- pl aceoi l usi ngut. . ~mxi ng parameter approach.
The
si mul ator
one- equat~on
sequenti al
formul ati onto sol ve i mpl i ci tl y for pressure and
then expl i ci tl yfor gas and water saturati ons. The
sol uti on techni que was based on di rect Gaussi an
El i mnati on.
The bui l di ngof the coni ngmodel was simpl i f i edi n
two maj or ways because the qual i tati veef f ects of
reservoi r heterogeni ti es,and not the quanti tati ve
effects,
were the
mai n goal .
The first
simpl i f i cati onwas to accept the model s abi l i ty to
simul ate onl y fi rst-contact msci bi l i ty, al though
the AA pool i s a mul ti -contactmsci bl ~fl ood. The
secondmaj or si mpl i f i cat i onwas si mul at i ngonl y f rom
the current oi l
sandw ch
condi t i on,
whi ch
consi derabl yreducedthe si ze of the model .
The coni ng model was bui l t as a two- di mensional
radi al system(Fi gure12) , cnmposedof 9 l ayers and
7 concentr i c ri ngs (r=7; THETA=360degrees; z-9) .
Sol vent was l ocated i n the top layer , ot l was
l ocatedi n the next f i ve l ayers (15-metreoi 1 bank)
and water was l ocated i n the bottomthree l ayers.
One three- phase oi l producer was l ocated i n the
ceotre of the model .
Two pseudo-wel l s, a sol vent
i nj ector and a water i nj ector, were pl aced i n the
outsi de radi al r i ng and coul d i nj ect i nto the top
and bottom l ayers, respecti vel y,
The concentr i c
r i ngs were i ncreasedi n w dth i n a l i near tashl on
(mul ti pl i edby the factor of 2) to avoi d materi al
bal ance errors resul ti ng f rom l arge area changes,
The i nner radi us of two metres provi dedreasonabl e
f l ui d saturat i on prof i l es at the wel l bore whi l e
maintai ni ng numeri cal
stabi l i ty w th reaso~l abl e
t~me.stepsi zes.
The outer radi us of 239 mdres
refl ectedthe averages aci ngof the 16wel l s i n the
R
otal pool area of 291 ectares.
The constrai nts i ntr oducedi nto the model refl ected
typi cal f i el dl l mts,
Theseconstrai ntswere:
1.
The dat um pressur e at t he or i gi nal
oi l -water contact was mai ntai nedat 16, 100
kPa absol ute,
2, Al l vo{dage was repl aced by sol vent or
water i nj ecti on.
3.
Water i nj ecti onwas used onl y to mai ntai n
a l evel orf gi nal oi l -water contact.
4.
~~ ~& nufl , l l owabl e sol vent- oi l rati o
,
- , .
5.
The maxi mumal l owabl e
percent.
6.
The l owest al l owabl eoi
The si mul ati on programwa~h;~~
homogeneous
reservoi r.
heterogenei ti es, whi ch were ev
sandw ch f rom core and l og S1
i ndi vi dual l yi ntegratedi nto the
Theselmaj or f aci es:
? exposuresurf aces;
uater cut was 95
rate was 2n / d.
i ni t i al l yw th
a
maj or
reservoi r
dent i n the oi l
udi es,
were then
homogeneousmodel .
cl usteredvuggy porosi ty; and
: :
l ayers of al tered verti cal to hori zonta
permeabi l i tyrati os.
In order to understandthe ef fect of thesereservoi r
f aci es on coni ng, two types of produci ngstrategi ~
were i ntroduced i nto the f r~del :
gas cycl i ng and
reverse coni ng.
The gas cycl i ng strategy al l owed
oi l to be produced fromthe oi l bank and handl ed
i ncreasi ng amounts of gas,
The reverse coni ng
strategyal l owedoi l to be producedf rombel owthe
ori gi nal oi l -water contact and handl ed i ncreasi n
amounts of uat
i n the pas>~l $2 verse c0ni n9 has been studi ed
synopsi s
of cur rent
:: ~;: ; l $)y
ns of rev~rse coni ng I s provi ded by
and i ndi catesthat favorabl eresul ts are
achi evabl eusfngthi s producti onstr ategy.
Pri or to runni ng the si mul ator, the theoreti ca
maximumconi ng rates and perf orati onl ocati ons for
the oi l bank andwater zonewere cal cul ated
[m
the
: ; f l i j
i ons and f i gurespubl i shedby Cott i n
, respecti vel y.
For the producti onof ~~
str i ct l yfromthe oi l bank, the cri t i cal c i ngrate
for monophasi c oi l producti on was 16
3
/ d @ a
perforati on i nterval l ocated 7 metres bel ow the
sol vent- oi l contact.
For the producti onof oi l fr om
the water zone by reverse coni ng, the cr i t i ca
coni ng r te for bi phasi c oi l and water producti on
9
was 20 md of oi l w t h a WOR of 2. 4 ( tot al f l ui d
rate = 68 m3/ d) perf oratedat an i nterval 4 metres
bel ow
the or iginal
oi l -water
contact.
The
si mul at i onruns used these perf orati oni nterval sand
60%of themaximumconi ngr ates for the b, . : - . nnt, r
cases i n eachof the two produci ngstrategi e;
The resul ts of the si mul ati onruns were comparedi n
terms of predi cted sol vent- oi l rati o SOR), water
\
ut, recoveryof OOI P i n oi l bank and reakthroug
ti me.
A characteri sti cGOR curve for a typtcal AA
wel l was al so used as a reference to compare the
shape of the SOR curves generated f r om the
si mul at i onruns (Fi gure13) ,
The effect of oi l rate on coni ng i s shown for the
gas cycl i ng control case : hof i i ugeneouseservoi r) I n
Fi gure 14.
Bel owthe cri ti cal coni ng rate, the SOR
curvegradual l yi ncreasedw th no water cut, As the
oi l rate i ncreasedabove the cri ti cal rate, the SOR
and water
cut i ncreased not iceabl y and the
di f f erence i n ul ti mate? f~f~erybecame smal l er as
the SOR i ncreased.
as cycl i ng
s t i l l
recovered a notabl e porti on o
the oi l bank even
when si gni f i cant sol vent coni ng had occurred,
pr ovi ded t hat t he economc l i m t on SOR was
suf f i ci entl yhi gh enough,
The resul ts of i ntegrat i ng the three reservoi r
faci es i nto the homogeneous contng model are
sunnnari zedI n Tabl e 3.
The I ntroducton of
cl usteredvuggy porosi tyand vari ati onsi n vert i cal
294
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7/24/2019 19656-Reservoir Description and Performance Analysis of a Ma
7/16
.
.
CPF lQtVWi
DI ANEE. BI LOZI R. PAULM FRYDL
7
; Ohor zo, alpermeabi l i tyrat i os causedonl y mnor
l uctuat l ons I n 011 recovery.
However,
the
i ntroducti onof a _ exposuresurfacearoundthe
~el l borehad the greatest rel ati ve eff ect on oi l
. ecoverywhen comparedto the homogeneousc~se.
~or the gas cycl i ng strategy, the i ntroducti onof a
:urved l ens between the sol vent bank and the
woduci ng perf orati ons i ncreased the recovery uf
)(IIP
signi fi cantl y(Fi gure15). I n addi ti on, there
~as an asymptoti c i nc~easei n SOR whi ch i s typi cal
] f the GOR responsei nAA pool wel l s (Fi gures14 and
15).
A re - -se curved l ens was al so i mpl ementedto
epresent an exposure surf ace on the edge of the
eef and the resul ts sti l l i ndi cateda noti ceabl e
l mpro~~ementver the control case (Fi gure15) .
: or the reverseconi ngstr ategy, the curvedexposure
surfacewas very unfavorabl e f l ocated at the
ti l -watercontact.
The wel l producedonl y water &s
theoi l coul dnot cone i nto the perf orati or~socated
belOW the oi l -watercontact.
Usi ng the resul ts of the s:: em; i vi tystu. u; :; srom
the coni ng
si mul ati on
a
of
recommendati onsdel i neati ng the opti mumareas for
reverse coni ng and gas cycl i ng were devel oped
(Fi gure16).
(d) Hw zontal Mel 1 Technol ogy
Hori zontal wel 1 technol ogy i s a produci ngstrategy
uhi chcan provi detwo mai n advantages:
1.
reduce gas and/ or water coni ng through
reduceddrawdown; and
2.
i ncrease
contacted
pay,
i ncreasi ngwel l producti vi ty.
potenti al l y
The appl i cati onof hori zontal wel l technol ogy i nto
the maturemsci bl ef l oodoft heAA pool i s l ogi cal .
Theoreti cal l y,a wel l dri l l edhori zontal l yi nto the
remai ni ngoi l bank shoul dmni mzeconi ngand reduce
sandw chl oss. I n practi se, dri l l i ng a hori zontal
wel l for such a thi n target woul d be operati onal l y
di ff i cul t.
Wo mai n areas of tho AA pool were i denti f i edas
excel l entpotenti al l ocati onsfor a hori zontalwel l .
Ver ti cal i nfi l 1 dr i11i ng i s not economcall Y
feasi bl e i n these areas because of the thtn pay.
The areas i denti f i edwere the northeast corner and
westernedge of the pool (Fi gure16) .
a)
ReserveEsti mates
1, The new~eservoi rdescri pti oni ndi catd a
%m
ori gi nal oi l - i n-pl aceof
11.0
x
10
vol umeti tcal l yt
Thi s was a si gni f i cant
de re se fromthe 1972estimateof 15. 9 x
1O$m~. The decreasewas supportedby the
i ncreasedwel l database and 3-D sei smc
data.
2,
The vol umetr i cOOI P of 11. 0 x 106 m3 was
conf i rmed by a
materi al
balante
cal cul ati on
after re-eval uati ng
the
i ni ti al esti mateof the aqui f er si ze.
b) Perf ormanceAnalysl s
10
The AA pool achi evedmsclbi1i ty througha
296
mul ti - contacti ngmechani sm The i nabi l i ty
of the pseudoternarydi agranrw represent
thi s mul ti - contact
/
ath expl a;ned the
previ ousconcepti ono i rm i sci bi l i ty.
2. The hypothet i cal
waterf l ood
recovery
factor was cal cul atedto be 49% whi ch i s
si gni f i cantl yl ower than the 1972esti mate
of 67%
The decrease was j ust i f i ed
theoreti cal l y and through actual fl ood
pc: f ormance.
3. The current recovery factor of the
msci bl ef l ood i s 75% whi ch i s l ower than
the 1972 esti mate of 78. 3% Nowever, due
to a four- metresandw chl oss, the overal l
recovery factor w l l be 70%
Remai ni ng
3
recoverabl e oi l i n t e oi l bank i s
approximatel y1, 105x 10 m3.
4.
Furt her refi nement
of the depl et i on
strategyi s requi redto ensuremaximumoi l
recovery.
c) ththodol ogyfor ReservotrHanagemwt
Thi s study demonstratedthe nevrengi neeri npparadi gm
and the appl i cati onof i
engi neeri ng
technl quest~~~i gat?e eo~i z~~~
i ncorf matedthe i ntegrat~onof geol ogi cal data w th
engi neer i ng data to re-devel op the raservoi r
descri pti on upon
whi ch t he AA pool vert i cal
hydrocarbonm{sci bl e f l ood had been desi gned. The
f ramework for arana~i ng maturs msci bl ~f f l oodwas
establ i shed.
i mpl ementati on
recent
technol ogi cal advances were di scussed as i ntegral
co, , ~onents i n the on-goi ng devel opment of an
opti w zedproducti onstrategy.
f ormati onvol ume factor
compressi bi l i ty
mcroscopi cdi spl acementeff i ci ency
vol ume factor for expansi or:of f l ui dand
rock abovePb
recoveryfactor
vol umetri cdi spl acementeff i ci ency
cumul ati ongas producti on
gas-oi l rati o
i ni t i al gas cap to oi l zone rati o
cumul ati veoi l producti on
md-poi nt perf orati ons
ori gi nal oi l - i n- pl ace
pressure
oi l r at e
recoveryf actor
producedgas-oi l rati o
sol uti ongas-oi l rati o
saturati on
sol vent- oi l rati o
vari ati onof permeabi l i ty
cumul ati vewater i nf l ux
water- oi l rati o
cumul ati vewater producti on
SUBSCRIPTS
b
= bubbl epoi nt
f
= gas
= i ni t ial
o = oi l
t = total
w
=water
-
7/24/2019 19656-Reservoir Description and Performance Analysis of a Ma
8/16
1.
2.
3.
4.
5.
6.
7,
8,
9.
Ml l hei m K. K. :
TheNewE i neeri ng Paradi gm
and the
Emergence I nvest i gati ve
Engi neeri ng,paper SPE 18103presentedat 63rd
Annual Techni cal Conferenceand Exh bi t i cnof
t$e Soci ety of Petr ol eumEngi neers, Houston,
Texas, October 2- 5 {1988) .
Wl l mon, G. J . :
Verti cal M sci bl e Fl ood to
Hi ke Recover; By 70 M l l i onBarrel s,w d Oi l
( J anuary, 1966) 75- 78.
Omoregi e, 2.S. and Jackson, G.R. : Ear ly
Perf ormance of a Large HydrocarbonM sci bl e
Fl ood at the M tsue Fi el d, Al berta, paper SPE
16718 presented at the 62nd Annual Techni cal
Conference and Exhi bi ti on of the Soci ety of
Petrol eumEngi neers, Dal l as, Texas, September
27- 30 (1987).
J onasson,
.
Reservoi r
Survei l l ance
Program J u~yp&eek Beaverhi l l Lake A Pool
Hydrocarbon$i i sci bl eFl ood, aper prepri ntNo.
6-37- 34presentedat the 37t Annual Techni cal
Meeti ng of the Pet rol eum Soci ety of the
Canadi an I nsti tute of M ni ng and Metal l urgy,
Cal gary, Al bert a, J une 8- 11 (1986) .
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Tracer Appl i cati on to Moni tori ng Sol vent
Spreadi ng i n the Rai nbow Keg Ri ver 8 Pool
Verti cal HydrocarbonMsci bl eFl ood, paper SPE
14440 presentedat the 60th Annual Techni cal
Conference and Exhi bi ti on of the Soci fJ ~ad; f
Petrol eum Engi neers, Las Vegas,
t
September22- 25 (1985) ,
Da Si c, W et al : Assessmentof a Vert i cal
HydrocarbonMsci bl eFl ood i n theWesternNi sku
D Reef, paper SPE/ DOE 17354 presentedat the
SPE/DOEEnhancedOi l RecoverySymposi umTul sa,
Okl ahoma, Apri l 17- 20 (1988) .
Mazzocchi , E. et al :
Tert i aryAppl i cati onof
a HydrocarbonMsci bl eFl ood, Rai nbowKeg Ri ver
8 pool , paper SPE 17355 presented at the
SPE/ DOE Symposi umon Erl hancedOi l Recovery,
Tul sa, Okl ahoma, Apri l 17- 20 (1988) .
Backmeyer, L,A, , Gui se, D,R. , KacDonel l , P.E, :
TheTert i ary Extensi onof the WzardLakeD- 3A
Pool M sci bl eFl ood, paper SPE ?3271presented
at the 59th Annual Techni cal Conference and
Exhi bi t i on of t he Soci ety of Pet rol eum
Engi neers, Houston, Texas, September 16- 19
(1984) ,
Benni on. D. W and Stewart . B. : Si mul ati onof
a Di rect l y Msci bl e Vert ical Di spl acement
Hydrocarbon Solvent
Fl ood ~
( J anuary-February,1987) 97- 103,
In.
11.
12.
13.
14.
15.
16.
17,
18,
19*
20,
21,
Rei 4zel , G. A. arsd Cal l ow G.O. :
Pool
t
Descri pti onand P formanceAnal ysi s Leads to
Understandi ngGol d
Spi k~ s M sci bl e Fl ood,
M sci bl eS~~f~w ~ses (SPERepri nt Seri al No. -
M
Petrol eum Engi neers
Ri chardson, Texas (1985) 580- 589.
Sl otboom R. A. and Ambl er, J , S. : Reservoi
Depl eti on Study -
Rai nbowKeg Ri ver AA Pool ,
Rai nbowFiel d, Al bert&aeNOCAN R69-47PEE- C)
appl i cati on Resources
Conservati onBo~~d, J une 9 (; =~~~
Sl otboom R. A. et al :
M sci bl eFl ood Study -
Rai nbow Keg Ri ver AA Pool , Al berta (NOCAN
R71-53PEE-C), appl i cat ion to the Ene y
7
esourcesConservati onBoard, October 1 (1971 .
Trach, MR.
and Matthews, MW: Econ6m
Eval uati on of Sol vent Fl oodi ng, Rai nbow Keg
Ri ver AA Pool , Al berta {MCCAN R?3-22PEE)
appl i cati onto the Government of the Provi nc
of Al berta -
Department of Energy and Natural
Resources,October 16 (1978).
Schmdt, V. et
al:
t4i ddl e Devoni an
Cementati on Peefs Encased i n Evaporates
Rai nbow Fi el d, Albwta, Roehl , P.O. and
Choquette, P. U. , eds. ,
m
Spri nger- Verl ag, Berl i n (1888
- ,
Qing, H. and Mount j oy, E.W:
y$~ti sta*
?
ol omti zati on i n Rai nbow Bui l dups, Hi dde
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~ (1989) 3 4, 114-126.
Craf t, B. C. and Hawki ns, M F. ,
v
t prenti ce-Hal
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Humphri es, C. L. andMcCarrol l , J . : Rai nbowM
Msci bl e Fl ui ds Study (RR691230- l FR),Nobi l
Research and Devel opment Corporati onResearch
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Koch, H. A.
and Hutchi nsorr,C. A. : M scibl
Di spl acementsof Reservoi rOi l Usi ng Fl ueGas,
~, AIM (1958) u, 7.
Benham A, L, , Dowden, WE, , and Kunzn an,WJ . :
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~~~ci btli ty, ~ (October,
1960
*
George, R. A. and Hol l abaugh, G.R. : Hi scl bl
Fl ui d Di spersi on, Rai nbowAA Reservoi r, Canada
(RR700505-1FR),Mobi l ResearchandDevel opmen
Corporati onResearchDepartment, Fi el dResearc
Laboratory,Dal l as, Texas, May 5 (1970) .
Z ck, A,A, :
A CombinedCondenslri g/ Vapori zi
Mechani sm i n the Di spl acement of 011 by
Enri chedGases, paper SPE 15493 presentedat
the 61st Annual Techni cal Conference and
Exhi bi ti on of t he Soci et y of Pet rol@u
Engi neers, NewOrl eans, Loui . :anna, October 5- 8
I 22,
(1986)0
Novosad, Z.
and Costai n, T. :
New
I nterpretati on
of Recovery Mechani sms i n
t?
A MATUREMSCI BLEFLOOD
~
The authorswoul d l i ke to thankMobi l Oi l Canadafor
perm ssi onto wri te, present and publ i shthi s paper.
The authors woul d al so 1ike to thank Ri chard C.
Sydor who greatl y assi sted ; n runni ng the coni ng
si nvl ati onmodel .
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7/24/2019 19656-Reservoir Description and Performance Analysis of a Ma
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.
., ,
SPE 19656
ti I ANEE. BI LOZI R. PAUL M FRYDL
a
Enr i ched Gas Dr i ves, J , Cdn, Pet . Tec~
(March-Apri l ,1988) 54- 60.
23. Crai g, F. F, :
The Reservoi r Engi neeri ng
Aspects of Waterf l oodi ng, Monograph Seri es,
Vol ume 3, Soci ety of Petr ol eumErgi neers, New
York (197ij 79-80,
24. McNi el , J . St : Bot tom Water i nj ect i on -
Rai nbow AA Puol - Fl ow Cel l Studi es ,
correspondence to I t, J .
Cl auser from ?i obi l
Rssearch and Development Corporati onResearch
Department, Fi el d ResearchLaboratory, Dzl l as, ,
Texas, August 15, (1972) .
J
25. Van Lookeren, J . : 0 1 Product i on f rom
Reservoi rsw th an Oi l Layer Between Gas and
BottomWater i n the Same Sand, J , Pet. l ech. .
(March, 1965) 37.
26. Si nnokrot, A.A. ,
Mobi1
Expl orati on and
Produci ng ~ervi ces, Dal l as, Texas, personal
communi ca, tl on,March (1989) .
27. Cott i n, R. H, andDmbret, R. L. : Appl i cati onof
a Mul ti - phase Coni ng model t o Opt im ze
Compl eti onand Producti onof Thi n Oi l Col umes
Lyi ng Betwen Gas Cap and Wate~aZone, paper
SPE 4632 presented at the 48th Annual Fal1
14eeti n of the Soci ety of Petrol eumEngi neers
if AI E, Las Vegas, Nevada, September 30 -
October 3 (1973) .
28. Odeh, A. S. : Fl ow Capaci t y of Wel l s w th
Li mted Entry to Fl ow, YEJ ~ (March, 1968)
43- 51.
APPENDIX. material Balance Wsulatfm
Cf= 4. 06x 10-7; Cw= 4. 35 x 10-7vol / vol / kPa;
Sw= 0. 082 (f r.); m = O; Pi = 16,090 kPag;
b -15$159 kpa; p -14 933 Pag
Boi = 1. 3046; B = 1. 3040rmm ;
Np = 126, 600m ; Gp = 13, 216x 103m3;
Rsi = 92, 73; h = 91.30; Rp
10 ,39 m3/ m3;
; : ; : ; :~: ;; ; : : &70 m3&
~ ~f . O rm3/ m3;
p=81m We=6~, 000m
N
Bt + I RDRsi l Bol We+~
= 11 x 106m3.
- Bti + i f + mBti ~Bg/ Bgi- 1]
1X B. l l gyi ferS~
~ = Ct*Del taP (Ref . 17)
Potenti al Aqui fer Si ze
Stabi l i zedI kte rI nfl ux= 63 x 103m3 (Fi g, S)
Ct = Cf + Cw= 8. 41 x 10-7 vol / vol / kPa
Del ta P - total pressuredropUnti l
stabi l i zati onof water i nfl ux
- 14, 834= 1, 256kPa
Thus, po~e~f{~faqui fersi ze = 60 x 106m3,
WOR-25; Mobi l i tyRati om 1; SW O. 082 (fr. );
V = 0. 48 (Lower Li mt) ; V -0. 1 (
yY l
r Li mt)
FromDykstra-ParsonsLi nearModei
LOWERLI MT: ,
EF(l - O. 52*SW= 9. 379; Er = , 40
UPPERLI MT:
1
r( l -O. 52*Sw=0, 50; Er = , 52
D. ~f l ood ~vorw =
Sw = 0. 082; Sor(WF)=0. 35;
Ev-
0, 79 (App, E)
Di spl a~~nt Ef f i ci ency=~yi - Sorl WF~= 0, 62
~)
1 - Sw
Water l oodRecovery= (Ed)(Ev) = 0. 49
~mw
OOI P=
l1,000x 103m3
Sol vent-Oi l Contact (1987) = 1, 285msubsea
Depth at Top ofRe, \ f = l , i 42, 9msubses
hLiCal
klOUllt sWC@ - -1,142,9+1,285142,1 M
Swept OOI P (usi ngTabl e 2)
=8,727+[(142.1-141.8)/ S. 1]*571=8,755103m3
Ed = (Soi - Sor) So = (0. 92- 0, 05)/ 0. 92s0. 95
$4
Np =6, 55OX1O m
Recover?of Swept Zone = (6, 550/ 8, 755)= 75%
Ev. (Rf / kd)m(0, 75/ 0, 95). 0, 79
Oi l 8ank Thi ckness (1987) 181s
Amount of Uater- Fl ushedOi l Bank =4, 7m
Sandw chLv:s = 41S
OOI P BelowS\ ~l vent-Oi lContact (Tabl e2)
= 571(5. 8/ 6. 1)+776(6. 1/ 6. 1)
+ 926[{(6. 1- 4. 7)+4. 7*0 51)~/ 611
= 543 + 776 + 576 = 1, 895X 10 n+
ExpectedRecoveryof Unswept Zone = 75%
Remai ni ngRecoverabl eOi l
= [((18- 4) / 18*1,895*0.75]= 1, 105x 103m3
i
otal Recovers l e Oi l =6550+1105=7655x 103m3
Ul ti mateRecovery= (7, 655/ 11, 000)= 70%
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7/24/2019 19656-Reservoir Description and Performance Analysis of a Ma
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----- .- . -.
1. AverageRock
Porosi ty,
AverageTh
AverageOl
Average01
ROCKCompr
~, Fl ui dOl strl b
ConnateWa
Orl gi n41O
Current 01
3. Reservoi r Pre
Datum mei
Ori gi nal P
Current (1
4. Fl ui dPropert
Saturatl oc
Fl ash011
at I n
at Sa
Fl ashSol u
Otl Oensl t
oi l Vi scos
Reservoi r
Oi l Compre
Mater C
Y
, Reservoi r o
Area, m
Otl Zone R
Ori gi nal a
Ori gi nal O
6. Aqui fer Data
RockVolum
AveragePa
Vol ume, 10
kopert l es
i ercent
I ckness,metres
Zone Hori zontal ?ermeabl l i ty,md
I
Zone Vert i cal Permeabi l i ty,md
msi bi l i ty, vol / vol / kPa(g)x 10-6
hi on
; erSaturati on,percent
11- l i aterontact?metres subsea
- datarContact (1987) , metres subsea
; sure
essubsea
essure,kPa(g) at datum
189)Pressure, kPa(g) at datum
1es
Pressure, kPa(g)
oluma Factc*, res m3/ st m3
ti al Pressure
; urati onPressure
; i onGa~-Oi l Rati o, m3/m3
t, g/ cm
l tyat I ni ti al Condi ti ons,mPa, s
e eratureC
Tsi i l i ty, vol / vol / kPa(g)x 10- 6
essi bi l i ty,vol / vol / kPa(g)x 10-6
IIMS
(1989)
tckVol ume, 1 3m3
l - i n- Pl ace, ?;~m~~l f i 3
i l Content,
;1989
i
) , 10m3
;0 i ty, percent
tm
8*6O
63. 11
4500
875
0,4S6
8, 20
- 1303, 0
- 1 302, 1
- 1~: 4: i :
16150
15 160
1,3046
1,3070
0. 8 ;
0.472
84. 4
1. 84
0.435
2910000
183687
0.060
11000
1 763
5;
Jablez. WmwuUIM f ort he~
234
112
453
750
908
:
; ; : : 4
6
1221
1201 :
571
776 1
926
11
\ TI VE
: P
J &
34
146
fgg
i 49
157
i 23
105
i 26
127
98
174
)00
THI CKNESS
CUMULAT VE
OF SLICE
DEPTHFROMTOP
- a ~
;;.;
12: 2
12*2
1202
24, 4
18, 3
12, 2
1:,;
6:1
6.1
25,9
38, 1
50. 3
; : , ;
99: 1
117, 4
129, 6
141, 8
147. 9
154*, O
160. 1
294
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7/24/2019 19656-Reservoir Description and Performance Analysis of a Ma
11/16
Tabl e 3. Rel ati veEf f ectsof Reservoi r Faci es on Produc
i ne $tr ateai es
RELATIVEEF)_ECT
RELATIVEEFFECT
RESERVOI RFACIES
EVERSEC
ONl &
Exposure Surface
Favorabl e i f above
Unfavorabl e i f
perf orati ons.
l ocatedat oi l -
Curvatl l m s i mmant .
water contact.
Reversecurvaturei s
not s f avearabl eas
noraal curvature.
ClusteredVuggy
Margi nal l y
Marginal l y
Porosi ty
unfavorabl e.
f avorabl e.
Anisotr opyFactor
Marginal l y
margi nal l y
Vari ati on
unfavorabl e.
favorabl e.
MOTE: Eff ects are relati veto homoge,wus reservoi r.
Fkl nBcuo Flood PmdMcum
1971
188: -
lsisl 2 1
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7/24/2019 19656-Reservoir Description and Performance Analysis of a Ma
12/16
I
*
t
I
H-t--i
I
I
IL
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7/24/2019 19656-Reservoir Description and Performance Analysis of a Ma
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II*
SPE 96 6
I
t-
sol
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7/24/2019 19656-Reservoir Description and Performance Analysis of a Ma
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SW 96 6
4\-=-\
0.,
I I
T
I
I
o
I 1 1
400
800
1200
1600
OI L RATE (mS/ day)
F19. 11- J un.
1988 and Oetobor 1988
IPR Curves for 12-13-11O-6W6M
0,093
0,025
0.0
0,018
0,0 0.0
Fig. 12-
~~-~1~. nsl onal
Radial Coning
Modol &ld System
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7/24/2019 19656-Reservoir Description and Performance Analysis of a Ma
15/16
~
,, ta
sPE 96 6
2,0
3
0.6
0
1
8MDCYIWED
3
,..=2
@
AOTUAL -
1
t
[RA
~)
1.2
1.4
1.6
1.8
2:0
CIMJLA TIVE &% %GTlON
(ma )
Fig. 13- QOR vs. Cumulatlvo 011ProductIon for
Typical AA WON(10-14-11O-6W6M)
e
0
0 10
20
60
40 60
60
70
PEROENT RsOovmv OF w ~
m
Fig. 14- SOR and Water Cut vs. Porcont
Rocowry of OOIP for Throo Rates
In Homogonoous Ro orvolr
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7/24/2019 19656-Reservoir Description and Performance Analysis of a Ma
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WE
96 6
6-
~Lms
e;
I
2
i
~
CIJnvEDlsm
0 ~
1
-~
o
10
20 so
40 so
60
70
ao
Pmm47nEcOveRY oFOow l
Fig. 15- SOR vs. Percent Rocovory of OOIP
for Curved Lens -
s
Cycllng Strategy
1
1
n
...,.,,
.:;.:
,,,.
KILOMETRE
1
GAS CYCLING
REVERSE CONINQ
HORIZONTAL W
Fig. 16- Rocommondod Aroau for lmplomontatlon
of Optimum Producing Stratoglos
S t