Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
F-~7as -1-
q'HQI:~ OF PRE~EATI~TZ A I~EAVY OIL ZON~:
THROUGR EXISTING BOTTC)~ TER A~
I)IVERTI~IG ~AM ~NTO q!HE OI~_Z~
This ~pplioation is relat~d to copenCllng
appllcation Serial No. 068,290 ~iled July l, ls~7. I~
., i~ Rl~o ralated to Serial No . 292, 7~ which W2~ filed
on ;l ~nua~y 3, ls~8s . It is further relat~d to Seri al
S No. 292, 799 whlch wa~ ~iled on J'anuary 3, l~a9 .
~his invention rel~t~s ~o the heating of a
relatively impermeable formation through ~team heating
of a bot~om water zorle and then divert1ng this ~team
into c~verlying oil zc:nel; through the ac~ion of a Colid
g~l in the bottom water zone.
In ~he recovery Or o~l Srom oil-containing
~ornlation~ is usu~l ly possibl~ tc~ reooYer only
minor por'clon~ of ~he origirJ~l oil-in-place by
~o-called primary rec~o~rery methods which utilize only
natural force~: . To increase the recovery of o~ l A
variety o~ 5upplement~ry recovery tec:hnique~ are
e~p~ yed~ ~hesx techniques include waterflooding,
ml~ci~le ~looding, ~he~mal recov0~y, ~nd ste~m
flood~ ng.
A problem tbat ari~e~ in variou~ flooding
pxoc~a~e~ i~ th~t dl~eren~ E;trata or ~ones ln the
reservo~r o~t~3n ~osse~s differ~nt permeabilities~
~hue, displaaing fluid~ enter high permeabillty or
"thie~" ~one~ ln pre~renc~a t~ zones of lowe~
pexmea~ility. signi~icant ~uantitles of oil may be
l~ft in zone~ o~ lowe~ pcnneability. T~ ¢ircnmvent
thi~ ~di~ficull:y th~ technique o~ pror'ile ::antrol l~
applie~ to plug the high permeability zone~ wi~h
polymerio glalG and thu~ div~r'c ~che dl~placing ~luid
into the low permeab~llty, ~ll rich zone~. Among the
pol~mers ~xamined ~r improving waterflood confor~nance
ar~ m~ l cro~-link~d polysac- charid~ etal
~0 d ~OO N Zl: 1 I~' S ~ 8-0~ :131 ~dO lIO ll~O~i
2 0
P--5726 -2-
oross-linked polya~ryl~ s, and organic ~ross-linke~
polyaarylamide~,
Another proble~ tha~ arise6 when ~team flooding a
~ormation having a non-aquifer bot~o~ water zone 1~
th~t on o~ca~ion ~te2m channel3 into khe ~ottom w~ter
zone~ Th~s botto~ water ~one has rela~iv~ly high
per~eabllity wnl~h allow~ high St¢~m and wate~ mobili~y
therethrou~h. It ~ difficult to re-dlrect the steam
lnto upper por~ion~ of ~he reservoi~ or formation since
1~ ~tc~m prefers th~ path oÆ lea~t resistance. The path
of least resistance ln t~ ituation happen~ to be the
bottom w~ter zone.
Therefore, wh~t i~ needed i~ ~ method ~or
prevonting ~te~m chann~llin~ in a bottom water zone
wh~c~ will allow steam to bo r~direCt~d into ~n upper
~on~ o~ ~ re~ervol~ 50 tha~ hydroaarbon~ceous ~luids
can be removed therefrom.
~hl~ invention i~ directed to a method for ha~ting
a form~t~on throu~h a non-aqui e~ botto~ wat~r z~ne and
th~ ~ubsequen~ diversion o~ ~t~am into a preh~at~d
formation viscou~ oil ~ontaining zon~.
Ste~m ls first injeo~:ed ln~o tha bottom water
2c>ne. W~tll comm~ln~cation ia e~tabli6hed with a
p~ducer or p~od~er~. The bottor~ water zone lg used
2s in 1 leu c~f injeatlns1 into the v;scous oil zone direotly
dUR to anticipated lnjec:tivity problems. Injec~ion of
steam at low ~uality i~ contlnued for a tim~ suf~ic~ent
to preheat ~ome o~ the l~wer and mlddle par'c~ of the
oil zone~ When the tempe~atu~a o~ the ove~lylng oi~
30 zone rQaches a de~ir~d t~mper~tu~e range, steam
in~ecti~n is t~mporar~ly ~e~m$nat~
8inc~.Gommunic~tion ha~ occurred betwoen the
injec:tox and produ~er well~ in the bottom w~ter zone,
di~icult to no~ redirQct steam intc~ the oil zone
35 to give th~ needed conv~c~ heating for oil
product~on. ~hi~ problem iEs eolved by in~ecting a
gQllabl~ compQ~i'cion cap~ble Or in-~1tl~ polynlerization
~O d ~OO N Zl:T 16'S ~d~ at~8-0~ :131 ~dO lIO lIaOW
3 ;.~ ~i 2 ~3
F-S72 6 -3 -
to ~orm polymer gel ~ into ~he bot'com water zone at th2
producing well ~ Polymer gel~ ~re of ~ type thA'c can
wath~tand hlgh temper~t~res. PenetXat$on of th~
composltton into the bottom waker zone ~houl~ be 1/3 to
1,J2 the dis~ ce to th~ lnjector, depending upvn
pro~ected econemic~:. The pr~du~er well i~ recompleted
abov~ the bottom water zone. Care must be taken not to
complete th~ produaer too ~lgh above the w~srmed oil
20n~ . Steam ln~ ~ction l"to the bottom water i~ now
r~sumed, However, the bottom water zone 16 now block~d
ofP. With t~ bloclcage o~ the bottom wat~r zone, steam
is ~ire~ted tlp~ardly into the warmed oil zone and oil
is produced fro~ ~he same ~one at the producer~
Gravity aids thi~ p~oces: sinc:e steam ~IB redi~c'ced
upwardly.
It i~ ~her~3~ore an ob~ e~t of thi~ invent i on ~:o
p~ovide for ~ gellable composition which aan be
delivered 1 nto a heated bottom wats~ zone h~ving el
t~mperatur~ su~ficient to a~ivate said composition and
~er}n a solid gel ther~ln.
~t ~ another ob~ect o~ thi~ in~ntion to p2ovi~l~
~or a composi~ion that will minimize g~31 dam~ge to ~n
~pper productive zone whil~ clo~ing pore3 in a haated
higher permeability bvtto~n water zone.
~IG. 1 is a diagrammatic plane view o~ a ~ormation
where S'C~a~ iE~ pa~6ing through a b~ttom water 70ne in'co
a produation w~ll.
FI~;. 2 i~ a diagranunatic plan~ vlew where th~
lowe~ bottom wa~er ~one ha~ b6~en parti~lly close~ ~ith
a g~llable compc3ition ~rhile ste~m 18 pas~ing through
an l~pper hydroc:arbonaceous flUid bear1n51 zone or area.
In the prActl~ o~ thls lnventiolJ, xe~errlng to
Fig. l~ ste~m i~ ctad by ~t~am ln~ector 8 lnto
in~eator w~ll lO. S~Qam exits injector W~ll lO via
perforations 2~ So as to c:reat~ a ~;team Zon~ 24 in
bot~om Watsr Zone 18. Steam aontinue~ i:'lowing~ through
bottom water zone ~8 ~here the perm~bility i3
~O'd ~00'N Zl:T T6~S 3d~ 9~8-0J :131 ~dO lIO lIaOW
.
.
lF--5726 ~4~ ~ ?s
su~tantiall~ greater th~n vl~cou~ oil bearing zone~ 14
an~ l6. Becausa ho~tom Wat~r zohe 18 ha~ A
p~rm~a~ility ~ubst~ntially yre~t~r than th~
perm~ability of ei~he~ zon~ 14 or 16, Zohe lB ~ecomsfi a
relat~vely hi~h s~am ~nd water mobllity zone~ Visco~s
oil contai~ed ln zonea 14 and 16 oan compri~ tar
~and~. Ste~m i5 cohtinually ln~ected into ~team zo~
24 and exi~ that zone ~ia per~or~tions 22 in~o
produ~er well 121
Stea~ i~ in~ected into bottom wate~ zone l~ ~o~ a
time sufflcient ~o hea~ zone 18 to ~ temperat~re in
~xees~ of about 2~0-F. In~ectio~ or steam into ~ottom
wa~er zone 18 ~lso ~ause~ a~ incr~ase ln the
temper~ture of upper ~ormatIonY 14 and 16. Steam
lS in~ction ~n~o bot~o~ water zone 18 lfi con~inu~d until
vi~co~s oil cont~ln~d in zones 14 and 16 ~ecome~
mobile. The tempera~ur~ obtained in 20ne8 14 and 16 or
botto~ wa~e~ zone 18 will of course dapend upon 'he
~team in~ection ra~e, temper~ure~ and pre~sUre of the
~te~ being injected lnto in~e~tor w~ 0. The longQr
~ea~ i~ in~ec~d lnto tne ~o~mation, the hotte~ the
temperature in zone~ 1~, 16 and 18.
After obtainlng the d~si~ed temp~ratUr~ in zone3
14 and 16 BU~i~iCient to mobil ~z~ viscou~ oiI cont~ined
25 thereln, s~eam injection into injector w~ll lO i~
aeased. Subse~ ntly, ~ gellal~le compositiotl is
prepare~ abo~e ground ~or injection into ~leated bottom
water zon~ 18. Th~ gellable composition i Iorrnulated
So a~ to ~llow penet~atihn into th~ bottom water zone
30 for ~ di:tan~e ~ about lJ3 to 1/2 t~e distan~e from
the in~ ac~or well . Initiator~ and r-atarder~ or
inhibi~oro ~an be incllld~d ln~o ~he compos ~ tion to
obtain ~h~ desired penetration. since pen3tration must
be cc~ntrolled, thi~ ~e~hod iæ intended ~r us~ in a
35 non-a~uif~r bottom water zonQ.
While bot:tom wat~r ~one 18 i~ o~ a te~nperaturo
gr~a~er th~n about ~10~, a g~ bl~ composition is
~Q-d ~00 N Z1:1~ 16'5 Id~ 9~8-0~ :131 ~0 lI0 lI~UW
y~
F-572 6 _5 _
in~ected into bottom water Zone 18. Th6~ ~el is allowed
to remain in 20nQ lB ~or h tlm~ u~ficie~l~ to ~orm a
solid gel ~8 ao ~ B ~hown in ~ig. 2 . Th~ solid g~l that
form~ l~ capable of wlth~tandlng ~empera~c~re~ grea~r
th~n about 210~.
Onae ~olid gel 28 ha~ formQd steam ~nject~on i~
again commenced int~ 'che formatlon by in~ tor well lO
as beforq~. ~s is l3hown ln Fig. 2, ~;'ceam exiting
in~ector well lO ~ia per~oratlon~ 22 en~ountar~ ~olld
l ~el 2~ And continues to heat oil con~cained in zone 16.
In or~er to re~ove vlscou~ oll from zone 16,
produ~e~r ~ell ~.2 i~ recompletes~ ~u~Ficiently above zone
1~ via additional perfora~lonsl 22 50 a~ to allow 1uid
commun ~ ~ation with zon~ 16 . Steam inj eoted into zone
16 ~vi~ inject~r well lo ~leat; up oiî ~n zone 16 and
cause~ it to flow into producar woll 12. Steam
injeC~i~rl lntD ~o~e 1~ continue~ until ~ufficient oil
ha~ been remo~r~d ~rom that zc~ne by produc~ well 12 Yla
pump 6.
There ar~ ~everal g~lla~le composition~ which can
~e usad to form ~ ~olid ge~ in zon~ 18. Th~Ss lnclude,
but are not limited to, an ln~ u gellable com~osltion
di~closed in U. s . Patent 3, 557, 562 w~lich contalns
~crylamide mono~ner, methylene bls-acrylamid~ a~ an
organlc cro~ l inker, and a free ~adiaal inltlator.
Thi~ p~tent ~s incoxpor~ted l~y referen~e herein. This
~stem undergoes polyDerization in the ~orm~tion to
give a polyacrylamide cross-linked wit~
m~hyl~ne-~is-ac~ylamid~. However, ~h~ co~i~y o~
~he ~ollltion ~hen ln~ected is llke that of water~
MechAnic~} 1 sala~lon is r~3~auired ein~e the~e solu~ion~
are ~uite capabl~ of penetratinq low permeflb~ y~ oil
bearing ~one6.
A p~ ymeric gel lable compo%ition i~ di~lo~d in
U. S~ Patent N~ ~, 658, ~98 wl~iah i~u~d ~o Paul Ana
Strom o~ April ~l, 1987. ~rhi~ patent disaloses an
agueous ~olution o~ hel~ropoly~charide S-130 combined
01 ' d POO N Zl: T 16' S Id~ 9~-0~ :131 ~dO lIO lIEOW
F-5726 -~- 2 ~ ~3 {~
with lnorganlc c~tions which rorm3 gels ~t elevated
t~mperature~. U.S. P~en~ No. 4,716,g66, i~su~d to ~hu
on January 5, 1~8~, dlaclose~ A g~l ~ormed by ~mino
resins ~uch a~ mela~nins~ ~ormaldehyd~ wh1ch modi~y
5 biopoly~n~r~ in combi3~ation with tran~itional met~l
ion~. ~he~e patent~ are hereby incorparatçd by ~ J
referenc~ herein.
Another ~ellable oompo~itlon which c~n be used
herel~ is dis~losed in U.S. Paten~ ~o. 4,834,180 ~hich
lssu~d to Shu. Thi~ pat~nt discl~ses a cros~-linkable
polymer whioh include~ xanthan blopolymer~,
h~e~opolysaccharld~ S-130,
poly(acrylamid~-co-acrylam~do-2-methylpropanesulfonate
)l a~d acryl~mide ~odi~ied pGlyvlnyl alcohol. ThR
l; cross linke~ i~ a par~ y methy~ated aminoplast r~sin
whioh cro~-link~ with the polymer therehy formlng a
yel in the Absence of a s~l~ whi ch 1~ acid generatin~
upon the applicatlon of heat. ~hi~ paten~ is hereby
lncorporatQd by re~erence herein.
~team~lo~d proce~se~ which can be ut;lized wh~n
em~loying the~e gels de~crik~d above are detailed in
U.S. Patent Nos. 4,4~,783 and 3,918,521 l~ued to Shu
and Snav~ly, re~pe~tivel.y. These patents are hereby X
incorporated by re~erence herein.
Although the present inventio~ ha~ h~en descrlbed
with preferred ~m~odimont~, it 1~ to b~ under~tood that
modi~lcations and va~iations may ~e res~rted to without
~epArting from th~ spirit and scope o~ this invention,
as thos~ sXilled in ~he art will readlly understand.
Such modifiaations and v~1ation~ ~re consi~ered to he
wi~hln the purvie~ and scope of the appen~ed claims.
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