pe troleum potentiel of tight sand in algeria basinmembers.igu.org/old/igu...
TRANSCRIPT
PE
zohra KAlgeria,
Keywor
Recoveprior to knowledunconvetechnololow matresultedcarbonastimulatinducinghas achconceptthese reand geothis papsolution Tight saas havpermeamatrix cannot rates nnatural a largeproduce Increascombinetechnolointervenlow-per
ETROLEU
Kerboub azib phone: 00
rds: Uncon
erable reser1970. Com
dge of the pentional Pogies effecttrix permead in porosityate, and pytion to increg new oneshieved excet and justifyesources reomechanicsper is to o
ns. The Ordo
INTROD
and reservoving less
ability and porosity (Fbe produ
nor recovergas unless
e hydrauliced by a hori
ing demaed with newogies dening years, meability re
UM POTE
bi, Sr. Petro213 21549
nventional
rves in Algemplex and spetroleum saleozoic rtively. Thesbility. Pore y reductionritic cemenease the ms, typically tellent resultsy ongoing i
equires a thos to determoptimize theovician rese
DUCTION
oirs are genethan 0.
less than Fig.1). Succed at ecr economicthe well is
c fracture izontal wellb
and for nw drilling aneveloped
pushed deesources.
ENTIEL O
ophysicist , 301, fax: 00
Tight Sand
A
eria fields asubtle playssystem, highreservoirs e reservoirsmorpholog by predomts. Some re
matrix permethrough hyds that confirnvestigationorough und
mine the bese well formervoirs, loca
erally define1mD matten perce
ch reservoconomic floc volumes stimulated treatment bore.
natural gand completio
during thevelopment
OF TIGHT
SONATRA0 213 21 54
d Reservo
ABSTRACT
are mainly s were not h costs andwhich cous are compy is domina
minantly silieservoirs aeability by cdraulic fractrm the hydrn efforts in erstanding st drilling a
mation evalated in Illizi
ed rix
ent irs ow of by or
as, on he of
T(Eev
T SAND
ACH DCGA47180, zohr
ir, Illizi bas
T
from convepursued a
d risks. Impould be acclex and ofteated by the ca cementare naturallyconnecting turing. Recerocarbon int
this domaiof the geolo
and completuation, redbasin repre
hese reseE&P) stratevaluation te
IN ALGE
AST, Djenara.kerboub@
sin
entional rest that time ortant resoucessed byen difficult toextensive d
ation but aly fractured b
existing naent intense terest assocn. Successogy, stratigrtion methoduce uncert
esent our ca
rvoir typesegies and aechniques.
Fig.1 Cross-Pl
ERIA BAS
ane El Malik@sonatrach
servoirs, disbecause o
urces still rey using ado produce wdiagenesis lso with sombut require atural fractu
explorationciated with sful developraphy, petrods. The putainties andase study.
s require adequate fo
lot PHI/K
SIN
k Hydra h.dz
scovered of limited emain in dvanced with very that has me clay, artificial
ures and n activity this new
pment of ophysics rpose of d advice
specific ormation
I The Illizbroad inis bouMessaoTihemb
Fig. 2: Illi
It is shato a coperiod othe estMesozo
LLIZI BAS
zi basin wntra-cratoniunded by
oud ridge oka arch fa
zi Basin on the P
allow marinontinental of intense tablishment
oic sedimen
Fig.3: Illizi Basi
IN CASE S
which correic Paleozoiy the Ato the W
arther to the
East South flanPlatform
ne deposit lmargin suerosion that of a Patary column
in Stratigraphic
TUDY
sponds to c depressio
Amguid-Hasest and thEast Fig.2.
nk of the Sahara
located closbjected to at resulted aleozoic ann Fig.3.
column
a on ssi he .
an
se a in
nd
TcoinTtositoisseTafbyimofTthTrepe
W
TarotEoba ba TchGanacco Devofin Tavta
he Ordoonstitutes a
n Illizi basin,he Hamra
o coarse igmoidal cro massive ss interpretequence whe upper ffected by y several s
mmersion prf the Ouarghe Hamra
he best prohe flow rate
elation to ermeability
WELL FORU
hree Wells re considerthers to illuach well reqbjectives ancomprehen
ased on log
he Hamrharacterized
GR less thand low pccuracy in ontact.
Despite of tvaluation of an importa
n three wells
he petrophyvailable lo
able1.
ovician Ha major Hyd, objective oQuartzite isquartzitic sross beddinsandstone ted as ith a lower part of Hearly diagetage of dissrior to the mla sandstonQuartzite
olific reserve from this r
the fractuless than 1
MATION EVUNCERTAI
A, B and Cred in this pustrate Tighquires a carnd local consive well egs, cores an
ra Quartzd by a veran 15 °APIporosity ca
all poros
he poor ref logs suggant hydrocas Fig.4, 5 &
ysical resulgs are su
Hamra Qdrocarbon rof our studys made of sandstone ng grading rich in Skoa progra
r erosive boHamra Quaenesis matsolution sug
major floodinne. represents
voirs in Illizreservoir is ure intensmD.
VALUATIOINTIES
C within a sapaper amonht Sand resreful analysnditions to evaluation nd testing.
zite reservry low radioI, a high reausing a sity logs a
eservoir qugests the parbon beari 6
lts derived fummarized
Quartzite reservoir y.
medium rich in upward
olithos. It adational oundary.
artzite is erialized ggesting ng event
one of zi basin. in close
ity with
ON AND
ame field ng many servoirs. sis of the develop program
voir is oactivity, esistivity lack of nd fluid
ality the presence ng zone
from the in the
Fig.4 ELAN Well A
Floprasmin
ormation eogging androblematic.ssociated
measuremennterpretation
Well Availa
A Drilled 1979
GR/CANPH
B
Drilled 2009
GR/cal-Densit -No formpressurmeasur -No borimages
C
Drilled 2010
-GR /H- GR/LD- HNGS- GR/C- Sonic-BorehoimagesUBI/OB
Table.1
Fig.5 ELAN W
evaluation interpretaUncertainwith p
nts, signaln methods.
able Logs
ALI/ILD/DT
I/RHOB
Sed&Frchastud
iper/sonic ty
mation re rement
rehole s
-LaRoctest-1Dgeostud
DIL DT/CNL S
CBL/VDL scanner ole
s BMI
-1Dgeostud-Prointesonbore
1
Well B
with convation methonties are gphysics ol processi
Studies
dimentological racture aracterization dy.
boratory ck mechanical ts
D MEM omecanical dy
D MEM omecanical dy. ocessing and
erpretation of nic scanner & ehole images
ventional ods are generally of tool ng and
Results
pay interval =26Phie=5% , Sw=1Barefoot tested mwith gas & oiL sh Pay interval= 34Phie=4% , Sw=1DST-1: 212m3/h gas 0.54m3/h oil Flowed postfrac 2572 m3/h of ga7.23m3/h of oilBSW= 5-10% Pay interval=37mPhie=4.5% , Sw= Flowed during 6h40’after barefoDST-1 738m3/h of gas3.2 m3/h of oil 3of water on BSW10%
m 10% mud hows
4m 15%
test. as
m=25%
oot
350l/h
W=
EffectiveRw pardetermibecausedeflectiowater-bplot cawater sa The cedecreaswater sa The poto matrand clay Shale myield co Archie eporositie
To bepropertiin the e
ely, the forrameter is dned from Pe there is on. Often earing leven tend to aturation Sw
ementation sing porositaturation.
rosity deterrix changey presence.
models areorrect answe
equation bres.
Fig.6
etter defines and to r
estimation o
rmation wadifficult to ePS is not
no develothere is a
el for calibroverestim
w.
factor decy and leads
rmination ises, incompl.
e complex aers.
reaks down
ELAN Well C
ne the reduce the of hydrocar
ater resistivestimate. Reven reliabopment of bsence of ation. Pickeate Rw an
creases ws to lower th
s difficult dulete invasio
and may n
n at very lo
petrophysicuncertaintie
rbon in plac
vity Rw ble
a a
ett nd
ith he
ue on
not
ow
cal es ce
anexpa Sre-sahi-been-dipoun-boev-manstsh
Tthsulitinmde
Tmhoqu
nd fluid coxtensive laarameters i
ome advaneliable form
In low andstones igh requires Acceleratoetter signanvironmentMagnetic
irect measorosity wncertainty.Wellbore imoth depositivaluation stThe Sonic
measuremennd aids in etress distribhears wave
SEDIM
he sedimehe log to ubdivision thofacies ancluding a middle shore
eposit.
he Hamra qmarker Fig.
omogeneouuartz sand
Fig.7
ontact in tiaboratory as needed.
nced wireliation evalua
porosity the resistiv
s resistivity or neutron pal-to-noise al effects resonance
sure of ewith no
maging logional envirotudies. c Scanner nts of fast fevaluating
butions from anisotropy
ENTOLOG
ntological ccore calibrof the Ordand genetvariety of
eface and g
quartzite co7 and is
us facies dcemented t
Seismic sectio
ight reservanalysis for
ine loggingation as folland perm
vity contrastmodeling.
porosity logratio and
e logging oeffective an
matrix re
gs are esseonment and
tool offerformation vopen fractu
m both Stoney analysis.
GICAL STUD
core analysration leaddovician in tic paraseq
progradingglacio-fluvia
onstitutes a character
dominated bto quartzite.
n NE-SW/W-E
voirs, an r Archie
g allows low: meability t is very
s offer a smaller
offers a nd total esponse
ential for fracture
s better velocities ures and eley and
DY
ses and d to the
several quences g lower-al/marine
regional ized by by clean .
The coallowed
- QS
- w
The uppdominatsandstograins sorted a
The Ordseveral transforcomposmain sigaffect thpervasivand Illitquartz quartz o
The seqQuartzit
-Dissolu-Quartz-Growth-Dissolu-Growthpore-fillChlorite-Fractursedimencementa
ore descrip identifying
Quartzitic Sigmoidal cMassive with Skolitoper part of ted by
one rich inare mediu
and frequen
dovician resdiagenetic
rmation osition and thgnificant diahe petrophyve precipitate as wellat grain
overgrowths
quence of dte is as follo
ution of feldovergrowth
h of auution of h of pore-bing Illite;-I
e and ring occunt had beation and g
Fig.8 Th
ption of stwo distinc
Sandstcross beddi
Quartziticos bedding
the Hamramassive
n Skolitos. um to finently cemente
servoirs wec events leof both he interstitiaagenetic altysical propeation of qu as the dcontacts fas Fig.8.
diagenesis ows:
dspar and ro; uthigenic
authigenibridging annsignificant
Kaolinter after
een lithifiedrain-contac
in section well A
several wet facies:
one wng
c Sandston
a Quartzite quartzi
The quar, moderateed by silica.
ere subjecteading to thmineralogical space. Theration whicerties are thartz cemen
dissolution avourable
in the Ham
ock fragmen feldspa
c feldspand pervasivt carbonat
e cementhe Ham
d by quarct dissolution
A
ells
ith
ne
is tic rtz ely .
to he cal he ch he nts of to
mra
nt; ar; ar; ve te, nt;
mra rtz n.
It octerepepo
DQdideisprasPupatsura
Perm
ability
(mD)
seems likccurred
emperatureseservoir ermeability orosity aver
Despite its pQuartzite wa
issolution evelopment
s some evidreservation ssociated orosity tenpper layersttribute of tubaerially eainfall condi
0,01
0,1
1
10
0
Perm
ability (mD)
kely that dto burieds up to degradationmainly less
raging 5%
Fig.9 Cross-Pl
poor reservoas subjected
event t of seconddence for th
of sewith fel
nds to be s of this rethis reservoexposed undtions.Fig.10
Fig.10 Thin sec
5 10
Porosit
diagenetic cd reserv
100°C n resultis than 1mD Fig.9.
lot PHI/K
oir quality thd to an earlyleading
dary porosithe developecondary ldspar dibetter tow
eservoir. A oir is that tder warm a0, 11.
ction well A
0 15
ty (%)
changes voir at
causing ng in and low
he Hamra y and late to the
ty. There ment and
porosity ssolution.
wards the common
they were and heavy
20
ELAS
TABA
ELA‐
BCA
S‐
A
1
Tight rfracturinexploratFrom frhigher N20°) aSW fauopened cement the prefracturehydroca
Two fadistinguThe fracementeor silica
The unumerosystem mainly maximuSE.
The peris extrefrom ldevelopsystem productthe cha20°, obopen orwith smreservoreservo
FRACTURCHARAC
reservoirs ng with a stion & produracture studfracture de
are observeults. Most and/or partFig.10. It h
esence of es seem arbon produ
amilies of uished: the acture maed or comp
a cement.
upper Haous stylolite
of low intenNS and N4
um horizont
rmeability omely low anlow to mpment of
this restive. Howevaracterizatiobserved in r partially ce
mall spacingir propertieir flow beha
RE NETWOCTERIZATI
are pronetrong impauction activdy of abouensity (N45ed in the pr
of these tially filled bhas been es
numerous to be
uction.
natural fraN°45 & N
y be opepletely cem
amra resees and a nnsity. These45° implyintal stress is
of the Hamnd the poromoderate.
open fracservoir wover, the inteon of the Ncores suggemented
g have a grs and they
aviour. Fig1
Fig.11
ORK ON
e to intensct on drillinities. t 122m cor5° & N10°roximity of N
fractures by silica or cstablished t
tensile Nsufficient
acture can N°10 fracturened, partimented by c
ervoir shoatural fracte fractures
ng that currs oriented N
mra rock maosity can ran
Without cture netwould be nerpretation aN45°, N10°gest that oN45° fractureat impact
will affect 1.
se ng,
res, ° to NE-are
clay that
N45° for
be res. ially clay
ows ture are
rent NW-
atrix nge the
work non and ° to only ures t on the
Minhycocothabpa
Awan
BstP
GEO
Most tight ren our case ydraulically ommercial gompletion ihe mechanibove, withinay intervals
F
A 1D mechworkflow wa
nd C. Fig.13
F
asic rock ptress fieldoisson’s rat
OMECANICA
servoirs arestudy (Figfracture tre
gas-flow ratt is necesscal propertin, and belo of Hamra q
Fig.12 Cross Se
hanical eas establish3
Fig.13 1D MEM
properties sd, Young’stio, were de
AL STUDY
e thick, up g.12) that meated to protes. To optisary to undies of all th
ow the hydrquartzites.
ection E-W
arth model hed in both
WorkFlow
such as ths moduluetermined to
Y
to 200m must be oduce at mize the derstand he layers rocarbon
(MEM) wells B
e in-situ s, and o design
a fractuand wel
The shatheir hoin Hamstress im
The mrecommwell C excessitechnicafishing) to a con
This inOrdovicbasin evporoper
ure treatmell test data F
Fig.14
aly zones reomogeneity.mra quartzit
mbalance.
Fig.15 Rock
mechanical mended rais
to mitigateve back real constrainwere regis
nsiderable w
CON
ntegrated cian target iven thoughrm property
ent by usingFig.14 &15.
4 Stress Profil
emain stabl The breakes section
Properties Cali
earth msing the me breakout
eaming, sincnts (jammingstered in wewaste of tim
NCLUSIONS
study imps a promisi
h it has an ey.
g logs, core
e because kout observe
is due to
bration
model studud weight ts and avoce numerog, break, anell B, leadin
me.
S
lies that ng play in
extremely p
res
of ed
a
dy in
oid us nd ng
the Illizi
poor
Tasremsiaswalpa
Tladisethprlacrpr
Gdececofr
ThiprrereBoiQ
Wbeaqdicosuanbatrun Inwgathen
he Hamra s a potentiaemarkable
medium-graiilica cemenspect. The
was subjelterations parameters.
he reservoiargely coniagenetic equence ihat partiallyrimary poro
ate dissolureating a ferecipitation
Generally thensity of faemented Nore, whilst actures are
he Hamra igh resisitivresence oeservoir is eservoir qua and C welil bearing
Quartzite.
Well C evearing intequifer preseifferent zonomprising uccessful and water fad candideatment acncertainty.
n Well B thwas success
as and oil his reservonhanced pe
Quartzite wal reservoir thicknesned sandsttation givingupper part cted to presents t
r quality of ntrolled by
alteration. ncludes q
y and/or totosity but inution of tew vuggy pof clay cem
e Hamra Qulting and f45° fracture
mud loss conductive
Quartzite ivity related
of residualvery tight. ality, the evl logs sugge
in entire
valuated aerval with ence was tnes. Only
the entind a small lowed. It wdate to ccording to
e hydraulicsful and imthirteen tim
oir is relaermeability.
which is conis characte
ss of cleantones with g to the rocof Hamra Q
many dthe best r
Hamra Quay fracturin
The diauartz overtally destronhibits comthe silica porosity andments.
Quartzite hafractures; oes are obsses suggese.
is characted probablyl oil and Despite h
valuation ofest the pres
zone of
as a hydrno indica
tested four the first w
ire intervaamount of
was considhydraulic o the fluid
c fracture trmproved themes. The flated to
nsidered erized by n fine to a strong
ck a tight Quartzite digenetic reservoir
artzite is ng and agenetic rgrowths oyed the mpaction,
cement d finally,
as a low pen and erved in st some
rized by y to the d/or the his poor f well A, sence of
Hamra
rocarbon ation of times in
well test al was f gas, oil dered as
fracture contact
reatment e flow of ow from fracture-
Well A drilled in 1979 has similar hydrocarbon potential to well B and C but just shows of gas and oil were observed in the well test. The well was abandoned definitively that time. The well formation evaluation of tight sand remains complex and full of uncertainties that can be reduced by using appropriate parameters, interpretation methodology and logging tools.
Production of such reservoirs involves in several cases horizontal drilling and/or induced fracture program which is strongly dependant on correct characterization of the natural fracture systems and in situ stress conditions.
Considerable efforts are undertaken to develop and produce tight gas reservoirs in different basins of Algeria. An intensified program is conducted to optimize completion and fracture treatment at economic rates.
Table 2 presents the largest successful tight gas fields in Algeria where appropriate process has been implemented.
Field & location
Reservoir Formation type
Reservoir Properties
Phi% KmD
Applied Technology
Tiguentour S-W of Algeria
Lower Devonian
Sandstone 20 <1 - Underbalance drilling. -Horizontal drilling & Fracturing. -Multi hydraulic frac stages.
Krechba S-W of Algeria
Lower Devonian
Sandstone 8.5 <1 -Horizontal drilling. -Geosteering. -Multi hydraulic frac stages.
InSalah S-W of Algeria
Lower Devonian
Sandstone 10 -3D multi-azimuth seismic survey. -Nuclear Magnetic Resonance. -Directional drilling. - Hydraulic fracturing. -Improved proppant
Table.2
REFERENCES
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2. B. Kennedy (2011) Shale and Tight Gas Reservoirs Global Overview, Baker Hughes.
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5. J. YiMing (2010), Sonic Scanner in Geomechanics Applications, Schlumberger.
6. R. Paramatikul, New application of Sonic Scanner in Gas reservoir evaluation, Schlumberger
7. F. Sekour, K. Kartobi (2011) Geomecanical study of well C, Sonatrach.
8. A. Bensari, S. Grelaud, J. YiMing, 1D MEM Geomecanical study of well B, Schlumberger.
9. S.Bentaalla, S. Meriem, M. Terki (2010) End of well report: well C Sonatrach.
10. D. Bahmed (2010) End of well B report
11. Algeria Well Evaluation Conference (2007), Sonatrach-Schlumberger.
12. Algeria Tight Gas Book (2009), Halliburton.
13. Sedimentological Study of the Ordovician Reservoirs (2006), Sonatrach-Numhyd
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15. A. Ali (2010), Tight Sand Formation Testing, Schlumberger.
16. George E. (2009), Fracturing Basics, King Engineering.
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