Enhancing carbonatE rEsErvoir charactErization 9 0 0 2 9 e u s s I
38 w e i v e R r i o v r e s e R a i s A & t s a E e l d d i M
DEInIng A IElD stRAtEgy Oe o he ke haee i a oi ad a reeroir i o eabih ho hdroarbo id i moe hroh he rre dri prodio. Oe he eieer hae eabihed he roe ha id i ake hroh he rok ad ideifed here hdroarbo mih be e behid, he a deeop raeie o maiai prodio ee ad boo oa reoer. I arboae reeroir, he aeme o o pah i ompiaed b eare h a ara rare, erai oer he oeii beee he ario par o he reeroir, ad ariaio i eabii ha i iee he eeiee o reoer mehod h a aer ijeio. I hi arie, Berard Moaro, Mihae sder, ad geor Za examie mehod ha haraerize rare paha, eabih he deree o id exhae beee reeroir omparme, ad eabe perophii o defe eabii ariaio aro he fed.
04 9 0 0 2 9 e u s s I
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Crbt xprts r dvlpg wys t pply bth ld d w tchlgy t bttr ct rsrvr chrctrzt. R&D prgrms cdctd by Schlmbrgr hv hlpd th dstry t hc th chrctrzt rctrd rsrvrs, t stblsh th cctvty btw th cmprtmts cmplx rsrvrs, d t dtrm hw wttblty vrts c rcvry ctrs. 9 0 0 2 9 e u s s I
40 w e i v e R r i o v r e s e R a i s A & t s a E e l d d i M
Reeroir haraerizaio i he a o bidi a mode o a reeroir baed o i haraerii ih repe o id o. to to ahiee a arae pire o a reeroir ad ho i i behae dri i prodie ie, reeroir eieer m be abe o idei he mai o paha ad defe he oeio beee he ario par o he reeroir. Oe he eieer hae eabihed he roe ha he id ake hroh he rok ad ideifed here hdroarbo mih be e behid, he a deeop raeie o maiai prodio ee ad boo oa reoer.
Fgr 4.2 Fue ree mpme
RActuREs, cOnnEctIvIty, AnD wEttABIlIty the ara rare eork od i arboae rok oe hae a oroi iee o id moeme. rare a be repoibe or aer breakhroh, a oi, ad drii probem h a md oe ad k pipe (i. 4.1). Mo arboae reeroir oai rare ha a rae rom ioaed miroopi fre o kiomeerkiomeer-o o rre oaii ma idiida rare. I oi ad a reeroir, he ara rare ma ere a odi ha eabe or ehae he o o hdroarbo, or he ma a a barrier preei or oi he moeme o iqid ad ae ad diidi he reeroir io omparme ih diere prere reime ad oi/aer oa (Owc). I ome fed, a e o rare ma perorm boh roe a diere ime or a diere prere. Fgr 4.1
A
B
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Oil saturation
4.1: Fracture corridors can control the movement o injected water and sweep eciency. A central injector well is sweeping oil to our producers located in the corners o a homogeneou s reservoir block (A) and a reservoir with large racture corridors (B). Recovery is reduced in the ractured reservoir.
4.2: A detailed understanding o the interactions between reservoir compartments will guide eld development planning and may help to locate bypassed hydrocarbon zones.
where rare pi he reeroir io dii hdroarbo ome, eooi ad eieer eed o eabih he ome ad he exe o eah omparme i a rae o eohemia ad prodio e. Ideii he idiida reeroir omparme ad he deree o id oeii oeii be ee hem i a ke ape o reeroir eieeri i arboae reeroir. thi beome pariar impora dri he aer ae o prodio he bpaed omparme ma oai are ad apped hdroarbo ome (i. 4.2). weabii ha aa bee reoized a a impora parameer o be oidered i oi reeroir. Hoeer, aoi or he diribio o eabii i arboae reeroir i a oep ha ha emered o ree i he idr. weabii ha a ro iee o reeroir perormae ad o he proporio o oi ha a be reoered. aire o haraerize he eabii reime a ead eieer o impeme deeopme pa ha a damae he reeroir. ne oi ehiqe ombii meareme rom mipe lwD ad ireie oo a o be ed o hep haraerize eabii i ope hoe. Ke meareme ide nMR, reiii, ad a oher meareme eiie o araio, idi dieeri, ima ero apre ro eio ad arbo/oxe.
unDERstAnDIng unDERst AnDIng tHE RActuRE nEtwORK a ad rare deeop hroh a rae o eooia mehaim (i. 4.3). aed ih hi ompexi, eieer m ork o idei rare pe, orii, ae, ad oeii, ad he phia oro o heir behaior. rare do o aa pree hih-permeabii paha or id. I ma fed, ome or a o he rare ma be emeed, hih eeie omparmeaize he reeroir ad make prodio more dif. O he earh iei ad eieer ahiee a horoh deradi o he a ad rare eork, a he deide heher he rare i he reeroir i hep or hider hdroarbo prodio ad he ee he mo eeie pa or fed deeopme. the oi ad a idr ha derood he poeia imporae o rare or deade. Hoeer, ear deradi o he rae ad dieri o rare rre ad he roe he pa i deermii reeroir orae apai ad prodii ha o bee ahieed i ree ear. the oa poroi oribio rom rare i pia 0.1% or e, ee i heai rared reeroir. I reeroir ompoed o poro rok, ha i a reeroir oher ha rared baeme, he rare poroi i a er ma raio o oa poroi. Mo o he hdroarbo reere are i he marix, b he hdroarbo i he rare are mh more mobie ad ea o prode.
rared reeroir oe deier hih iiia o rae rom dioer ad ear deeopme e. thi ma ead eieer o oerei mae a reeroir’ poeia prodio beae prodibe hdroarbo a qik be depeed oe he oi oi oaied i he rare eork ha bee proded. rared reeroir oe appear o hae hik reeroir zoe, b he Owc a be hard o defe ad, he hi i he ae, eieer ma hae dif i arae eimai reere. Ideed, ihi he ame zoe o a prodi reeroir, he Owc i he rare ma be er diere o he Owc i he marix. marix. thi dieree i de o he are permeabii ora beee he o reeroir eeme.
RActuRE DIstRIButIOns AnD REsERvOIR lOw I arboae reeroir, he ome o oi ad he rae a hih i a be proded are a ieed b a rare eork ha exed hroho he fed. Hoeer, he aaia oo deeoped o examie rare i ai reeroir a o meare rare properie i he reeroir oe o he e. thi eae he eoiei aempi o predi he reeroir-ide diribio o rare i idire oberaio or ampio. I ara rared arboae reeroir, hee mehod proide ifie daa o defe he reeroir rameork. Reoizi he eed or a more deaied pire o rare diribio ad reeroir o rre, shmberer ha a broad, ro-diipie ommime o oio improi rare modei i arboae.
Fgr 4.3 Fracture types
Joint Mode 1 (opening)
Stylolite compaction band Antimode 1 (volume loss)
4.3: The main development mechanisms or natural ractures.
Fault Mode 2 (sliding)
Mode 3 (tearing)
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JaCqueS Pion Jacques Pion is currently geosciences manager at the Total representative oce in Abu Dhabi. He has held various positions with Total worldwide, including head o geophysical R&D until 1996, geosciences manager on several Iranian buy-back contracts until 2001, and geosciences manager or Total Angola until 2004.
q: Wht s spcfc/ bt chrctrzg glgcl strctrs crbts? carboae rok pree a peia haee i erm o rok phi: he Poio’ raio i arboae i 0.28 or aie, 0.2 or doomie (ompared ih 0.1 or ai rok) ad hi make reeroir haraerizaio mh more dif a ea hroh a aia aoi ierio. whe hdroarbo i pree i a arboae i i oe preere he rok’ perophia properie; b here he rok marix i expoed o aer, diaeei ee i reae diere rok properie. id biio aorihm eed o ake diaeei io ao. I ai rok, aera ea oideraio are er impora ad a rre are a aeed o deermie oeii beee adjae reeroir. I ora, eria ommiaio i domia i arboae rok ad aked arboae reeroir are oe od o ommiae hroh eria “hae” reaed b poro aie ad/or rare. a ao pa a impora roe defi id o i arboae, b be a ih er ma hro are oe iored ee hoh he ma hae aie emeaio ha reae a eeie barrier. q: Hw r y ddrssg ths chllgs Ttl? we’e bee pioeer i AvO-AZ (azimha ariaio o he AvO repoe) ie he ear 1990. or exampe, i 1991 e pbihed a d abo poiie AvO-AZ ee i a arboae reeroir i he Pari bai. Hoeer, e reoize ha AvO mehod, ad AvO-AZ i pariar, are er dif o app i arboae. thereore, or emphai i o i he ierpreaio oare sIsMAgE or be a raki ih a ombiaio o aribe ad he perpoiio o eria eio o ha i raked o ie. I toa e ieiae he rok phi mode ad he preeda re fed a hee are ke or haraerizi pariar direio or eai or oeai ee. we ao hae a
preie aibraio or eimi ear he e: e a hek or be a i ore ierpreaio, imae o, ireie o, prere daa, ad e e ierpreaio. we ake hi approah beae rra aribe drie he diribio o rare properie i he mode. q: Wht r th mst cmm chllgs y s th Mddl est rg wth rgrds t crbts? there are o mai haee. the fr i o defe he ae o heeroeeiie ha i meai or reeroir deeopme ad he eod i o eabih hih a are eai ad hih oeai. A addiioa haee i o fd ad d reea eooia aao, ad e are er orae o hae i he soh o rae e-died rok orop ha proide a aid aao o he arboae reeroir i he Midde Ea. q: Hw mprtt s ccrt strctrl glgy dfg fld dvlpmt pl r crbt rsrvrs? Arae rra eoo i eeia or he o-erm ie o he reeroir. A ear deradi o heeroeeiie hep ih deiio o aer maaeme ad o he pe o ijeio reqired; ad ide or pa or eriar reoer. wih o permeabii arboae oi reeroir e hae o dea ih a paradox: he iher he rok are, he more proe o rari he i be, ad ha reae a major haee! toda e’re orki ih he Ab Dhabi operai ompaie ADcO ad ADMA i order o deeop more ompex ad hier arboae reeroir or hih improed oi reoer mehod (h a arifia i, ompex e) i be reqired o ar mh ooer. toa ha a peia roe o pa i hi beae he Ab A Bkhooh fed operaed b toa i Ab Dhabi i mh more mare ha he operai ompaie’ arer fed ad ha aread bee he bje o mero experimea improed oi reoer (IOR) ehiqe deied o ph he reoer aor beod iiia expeaio. O he Ab A Bkhooh fed, rra eoo die hae proed er impora or idi IOR aio, ad he experiee aied o hi fed a be oidered a a pio or rher improed reoer proje.
Frctr crrdrs
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Fgr 4.4
Die rare are pread hroh he reeroir reeroir,, ad heir dei ad orieaio a be meared ih hih-defiio eimi re ha iorm ampe he oe–azimh oim. Hoeer, ome arboae reeroir oai are-ae heeroeeiie ko a rare orridor. thee rre oi o mero rare ha hare he ame orieaio ad are oaied i a reaie ma ome ihi he reeroir, pia a e meer ide, a e e o meer hih, ad eera hdred meer o (i. 4.4). A major rare orridor mih oai 100,000 idiida rare ad proide a permeabii o more ha 50 D. the hih permeabiiie od i rare orridor mea ha he proide dire odi or ijeed or proded aer. thi a re i hih aer , ear aer breakhroh, ad reded oa oi reoer (i. 4.5). Hoeer, rare orridor ao proide opporiie. I he reeroir eieer ha iormaio abo he preee ad poiio o rare orridor beore prodio bei, i hod be poibe o iorporae hem io he fed deeopme pa ad o dri ijeor ad proder ha ompeme he reeroir’ ara o paer ad o imae hdroarbo prodio. rare orridor a oro prodio ad reoer. ied deeopme pa are oe deied ad impemeed iho prior koede o he rare orridor i he reeroir (i. 4.6A). Ear aer breakhroh mih re i ma e bei aered o ihi a e ear o prodio (i. 4.6B), hie ha he oa oi prodio or he fed ome rom a e e, i hi exampe o hree e are prodi oi (i. 4.6c). aed ih hi kid o iaio, he o a ha fed operaor a be re ha he i improe fed ad e perormae i b haraerizi he rare eork o ha a remediaio proram ad addiioa e a ahiee heir oa.
43 w e i v e R r i o v r e s e R a i s A & t s a E e l d d i M
4.4: High-permeability racture corridors consist o numerous ractures that share the same orientation and are contained in a relatively small volume within the reservoir.
Fgr 4.5
Phase resistivity R m = 0.024 ohm.m 100
whe reeroir eieer ko he oaio o rare orridor beore he deeop a fed, he a opimize prodio b pai horer horizoa ijeio e ad prodio e i he be oaio (i. 4.6D ad 4.6E). the ae eimi ehoo ad adaed proei mehod eabe he preee ad oaio o rare orridor ihi reeroir o be deermied. thi iormaio i ia or eeie e paeme ad reeroir imaio.
m . m h o , s p
R
10 1 X590
X 6 10
X 630
X 650
X 67 0
Depth, m
4.5: In this Abu Dhabi well, all the produced water (160 m 3 /d) came rom a single, 9-m wide racture corridor.
bele m e ued le d dee ue ee well, u e e wde ue ewk eque dee pp. sem uey, w e d el ee d mpeme me elu, e del deled de ee-le eeeee. 9 0 0 2 9 e u s s I
Fgr 4.6
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B
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44 w e i v e R r i o v r e s e R a i s A & t s a E e l d d i M
Water
Oil
Gas
4.6: A typical eld development plan might involve vertical producers and horizontal injector wells around the edge o the eld (A). Ater 5 years, 10 o the wells might have watered out (B and C) and hal o the oil production could be coming rom just three wells. Through knowing the location o racture corridors (D), the development team could have optimized the eld by drilling shorter horizontal injectors and positioning them away rom the racture corridors. Deviated producers could have been used to intersect the racture corridors and to drain compartments (E).
MAPPIng RActuREs
Frctr clstr mppg Kwt
Borehoe imai a be ed o oae ad deribe rare ha iere a e, b haraerizi he ider rare eork reqire a diere approah. seimi re, ih heir broad area oerae ad ooi improeme i imae reoio, are idea or deaied defiio o reeroir-ae heeroeeiie.
the cM orko, hih shmberer ahed i 2007, i baed o he ampio ha he ara rare orm are er (ih exe o 10–30 m or more) he hod be iibe i 3D eimi daa. the cM orko ierae borehoe daa ih he 3D eimi daa o opimize he exraio proe ahieed hroh dioii exraio oare (DEs) proei.
Daa rom Q-tehoo* ie-eor eimi hardare ad oare ombied ih e eimi proei mehod eabe earh iei o dee ad eaae rare properie beee e. the aai o azimha aiorop parameer (he ariaio i he eoi ad ampide o eimi ae raei i diere direio) a reea he iei ad orieaio o beimi rare beee e. seimi aribe proei reea be rra deai i he reeroir, ad ierpreer a e rare aribe o ier re reime ha orrepod o rare dei.
Lctg rctr crrdrs the cM* rare er mappi orko, deeoped b eoiei i he Daa & coi serie (Dcs) ih he ppor o he shmberer saaer Reearh (ssR) eam i nora, ombie hih-reoio eimi daa ih o daa ad e he aomaed rra ierpreaio apabiiie i he Pere* eimi-o-imaio oare o oae rare orridor ihi he reeroir reeroir..
seimi aribe ha are eiie o rare er are ideifed ad ip o he DEs. the 3D eimi daa m hae opima paia/empora badidh ad ia-o-oie raio o ere ha he aribe ip o he DEs proei oai meai iormaio or rare er mappi. thi ma reqire peia aqiiio dei ad daa proei orko i ie-eor daa. the dei o he direioa (azimha) ad iiaio (dip) fer ed i he DEs proei are baed o he aai o ore, borehoe imae, oi o, vsP re ad oher iormaio o he eoo or eomehai o he fed.
Fgr 4.7
D
Model 1 A
Model 2 B
F
C
A
Time sliced from a 3D cube showing fracture clusters output by DES using azimuth filter opened to all directions
B
Fracture sensitive seismic attribute
C
Azimuth filter 330–030 and 150–210
D
Time sliced from a 3D cube showing fracture clusters output by DES using azimuth filter opened to 030–090 and 210–270 210–270
E
Time sliced from a 3D cube showing fracture clusters output by DES using azimuth filter opened to 090–150 and 270–330 270–330
F
Time sliced from 3D cube obtained by merging the 3D volumes of fracture clusters output by three runs of DES using three different ranges of azimuth filters
E
4.7: FCM workfow and ant tracking.
Fine-tuning or cluster detection the rra ad eoi hior o he d area i ao ed o opimize parameer ad ae re. t he eera DEs proei oe oerook ome rare er he he direioa fer i kep ope o a 360˚ o azimh ih a fxed rae o eare iiaio. I hi iaio, he DEs proei ed o oo he roe aera dioiiie i he er ia pae, hoe aed b arer rare er, ad o mi he eaker iare o maer rare er. to apre h dioiiie, he direioa fer a be diided io ido or rae ad he iiaio fer a be e a eera dip iiaio rae.
DEs proei i r eparae or eah e o direioa ad iiaio fer. Eah r o DEs proide a 3D ome be o rare er ieame. thee be are he mered io a ie 3D ome be ha ie a mh more reaii pire o he rare er ha are pree (i. 4.7) .
Fgr 4.8a
X-3
Strike rosettes of open fractures from borehole images
X-2
X-3
X-5 X-1
X-4
X-4
Filters: Search azimuth:
All 360° Dip Angle: Dip >70°
4.8A: North-northeast–south-southwest trending racture clusters at a horizon within the Middle Marrat carbonate reservoir, extracted rom the seismic volume using the DES.
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Fgr 4.8B
Largely north-northeast– south-southwest striking fracture clusters detected by ant tracking when the azimuth filter was opened to 315–045 and 225–135
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X-2
X-3
X-3 X-5
Filters: Search azimuth:
X-1
315–045 and 135–225 Dip angle: >70°
X-4
Fold-related longitudinal fracture clusters following the north-northeast–south-southwest north-northeast–south-southwest trending fold axis of Sabriyah anticline
X-5
Northeast–southwest; east-northeast– west-southwest; northwest–southeast; and west-northwest– east-southeast striking fracture clusters detected when the azimuth filter was opened to 315–045 and 225–135
4.8B: The FCM workfow enables operators to create 3D maps or all the major racture corridors in a carbonate eld.
Filters: Search azimuth: 045–135 and 225–315 Dip angle: >70°
X-1
X-4
Riedel shears caused by north-northeast– south-southwest south-southwest striking right-lateral. Strike–slip faults bounding the Sabriyah anticline Fold-related longitudinal fracture clusters following the fold axis of Sabriyah anticline
FCM Kwt the cM orko a appied o he eqee o Jrai arboae i fe fed (orhe Radhaai, Radhaai, umm niqqa, sabriah, ad Bahra) i he orher par o Kai. the sabriah fed a eeed a he ke area or he d beae or e ere bei dried here a he ime ad i oered a haei rra ei (a pop-p rre aed b rapreio ao he ea ad e bodi rike–ip a). rare eidee a he exii e ad daa rom he e dried e ere ed o aidae he rare er oaed i he DEs o he eimi ome. ire 4.8A ho mai orh-orhea–oh-ohe redi rare er a a horizo ihi he Midde Marra arboae reeroir exraed rom he eimi ome i he DEs. rare er o exa he ame orieaio ad iiaio ere obered i he 3D be hroho he Marra eio.
Hoeer, borehoe daa rom oe o he exii e hoed a domiae o ea-orhea–e-ohe riki rare (more ha 400 ope rare) ihi Marra. whe he DEs proe a appied o he ame eimi aribe ome, b ih o diere azimha fer (315–045 ad 135–225; ad 045–135 ad 225–315), rare er ih orh-orhea–ohorh-orhea–ohohe, ea-orhea–e ea-orhea–e-ohe, -ohe, orhea–ohe, orhe–ohea, ad e-orhe–ea-ohea rike ere hihihed (i. 4.8B). the orh-orhea–oh-ohe riki rare er are probab od-reaed, a he are parae o he axi o he sabriah aiie, ad he ea-orhea– e-ohe ad e-orhe–ea-ohea riki rare er, hih are more oeraed ihi he sabriah aiie, are poib Riede hear. the re ere aidaed a he oaio o exii e ad a he e e.
the cM orko eabe operaor o reae 3D map or a he major rare orridor i a arboae fed, a demoraed b i e appiaio a fe fed i Kai. Experiee ho ha he be re ere obaied he i hihreoio eimi ehoo.
Fgr 4.9
47
the preee o rare orridor ha oe bee propoed a a expaaio or ear aer breakhroh. wih 3D map o rare orridor beomi aaiabe, hee impora rra eare a o be ieraed io reeroir mode o deermie opimm e oaio b i more reaii imaio. thi mehodoo i hep operaor o aoid aer breakhroh rprie ad ai heir eor o ireae hdroarbo reoer aor i arboae reeroir ad oher ara rared ormaio.
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A unIIED MODEl O tHE RActuRE nEtwORK I he pa, arboae reeroir ere deeoped ih ie or o iormaio abo he rare eork beee e. toda, hoeer, reeroir eieer a examie a eire reeroir o obai a ear deradi o he rare orridor eork, i impa o id o, ad ho he dami re reime (he eore) ihi he reeroir ae permeabii. thi i ahieed i a ieraed approah ha ombie adaed eimi proei ad diree rare eork (Dn) modei.
4.9: Reservoir engineers can establish the controls on reservoir- and well-scale noncontinuous fow behavior using the DFN workfow and then model the racture networks and perorm dual-porosity and dual-permeability simulations using ECLIPSE* reservoir simulation sotware.
expltg rctr cctvty Adaed eimi proei a reea rare diribio, b doe o proide iormaio abo he eomehaia ad hdrai properie o a rare eork. thee are he properie ha defe he dami behaior o he rare eork ad iee reeroir perormae. Reeroir eieer a reae a reaii mode or he dami behaior o rare ad eabih he oro o reeroir- ad e-ae dioio o behaior i he Dn orko (i. 4.9). wihi he orko, eah rare i deribed b i phia properie, h a rae area ad hape, ad eah ha defed id o properie or permeabii, ompreibii, ad aperre.
9 0 0 2 9 e u s s I
“ree eee ee el mdel e dym e ue d el e l ee- d well-le duu fw e u e DFn wkfw.”
9 0 0 2 9 e u s s I
Fgr 4.10 Petrel software
ECLIPSE software
48 w e i v e R r i o v r e s e R a i s A & t s a E e l d d i M
Combination of input sources
Well tests Interference tests
4.10: The key to accurate characterization o ractured reservoirs involves integrating measurements rom dierent disciplines; building accurate geological models that incorporate ractures; and perorming simulations using dual-porosity, dual-permeability simulators that correctly predict production history.
ui Pere eimi-o-imaio oare, eieer a ierae iormaio rom mero ore, idi 2D ad 3D eimi re, map, orop, reeroir eomehaia die, e o ad e, o o, ad rra or depoiioa oepa mode, o reae a ifed repreeaio o he reeroir.
the ombiaio o he cM orko ad Dn modei i he had o experieed eoiei proide he mo eeie mehod or modei rared reeroir ad opimizi he ia prodio deiio ha are ake a he ar o he fed deeopme proe.
A Dn mode pia ombie deermiii ad ohai diree rare. the deermiii rare are hoe ee o MI* bore ormaio miroimaer borehoe imae o ad he rare orridor ha are dire imaed hroh hih-reoio eimi aqiiio i Q-tehoo erie. Oher, a maer-ae, rare ha orm die rare eork are eeraed ohaia o mah heir oeie properie (dei ad orieaio), a obered i he eimi daa. the reeroir mode ombie he Dn orko ad he rare orridor ha are dire imaed hroh eimi imai i a raki.
EstABlIsHIng REsERvOIR cOnnEctIvIty
A pia Dn mode ma oai eera miio rare, ad hi iormaio i ed io he EclIPsE reeroir imaio oare hroh a pai proe. Eieer he eerae a 3D imaio rid ha oai he rare poroi, he permeabii permeabii,, ad he ima aor reqired or a da-poroi or da-permeabii imaio (i. 4.10). thi mode a he be r i he EclIPsE oare o proide a arae pire o id o i he reeroir ad eabe he eieer o ompare he eeiee o ario prodio raeie.
A reeroir omparme i a prodie eme o a oi or a fed ha i o i dire id ommiaio ih he remaider o he fed. Prodie omparme ma be ioaed a he ime o edime amaio b depoiioa proee or ma beome ioaed aer depoiio ad bria a a re o diaeei or rra hae i he rok eqee. Reeroir ha hae beome omparmeaized reqire diere approahe o ierpreaio ad prodio ha oio reeroir, ad eieer m be aare ha he deree o omparmeaizaio ma hae a a re o hdroarbo prodio. comparmeaized fed ma be ompex, ih diere Owc or a/aer oa i eah omparme. A he reeroir i depeed, ome o he rare beee he omparme ma op ai a ompee aera ea ad eabe ome ommiaio, hih rher ompiae id diribio ad moeme.
Fgr 4.11
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Fgr 4.12 Negative
Current
Positive
Measured
Reservoir 1
30 a P M , e r u s s e r P
49 Reservoir 9
25
Reservoir 5
Reservoir 6
20 No interference
Reservoir 3
15 1970
1980
Reservoir 2
Reservoir 7
Reservoir 4
Reservoir 8
1990
Time
4.11: A pressure match using several years o production data enables engineers to establish the extent o intererence between various reservoir compartments. In this example, the data indicates that there is a n exchange o fuids between two compartments.
Thickness of connection indicates interference strength Res. 1 Res. 2 Res. 3 Res. 4 Res. 5 Res. 6 Res. 7 Res. 8 Res. 9
Msrg d prdctg th cts rsrvr cctvty Eeie reeroir deiio reqire ae o hioria ad rea ime prodio daa. Reeroir ad prodio eieer a e he DEcIDE!* daa mii baed prodio opimizaio oare o eerae readi abe iormaio rom are ome o fed daa. the em’ aaia daa mii apabiiie make i poibe o diaoe reeroir odiio ad o od prediie modei. thi a ide reeroir maaeme deiio, reea prodio opporiie, ad prioriize operaioa deiio, idi ak h a opimizi he fed ijeio/prodio raio (IPR), ehai arifia i perormae, ad mar e oro. ui he maeria baae ih iereree (MBI) mehod ihi he DEcIDE! oare, eieer a aaze prodio daa o eabih he deree o oeii beee reeroir omparme. A are arboae reeroir ma oai doze o omparme ih ari deree o oeii oeii.. Eieer a prere mah he ario reeroir omparme oer a period o prodio (i. 4.11) ad reae a iereree marix (i. 4.12) ha defe he oeii. the MBI approah i more eeie ha impe maeria baae mode, i eaier o app ha meria imaio mode, ad eabe prodio eam o maae heir reeroir ieraie. ieraie.
Res. 1
0
0
0
7.73
7.04
0
0
6.22
0
0
–3.15
0. 0.62
0
0
0
0.01
0
0
0
0
–2.75
–1.51
0.40
0
0
0
0
0
0
0.03
–0.74
–0.11
0
0
0
Res. 2
0
Res. 3
0
0
Res. 4
0
0
–0.01
Res. 5 –7.73
3.15
0
1.51
Res. 6 –7.04
–0.62
0
–0.40
0
Res. 7
0
0
0
0
0
0. 0.74
Res. 8
0
0
0
0
0
0. 0.11
0
0
2.75
0
–0.03
0
0
Res. 9 –6.22
4.12: The extent o the intererence between nine dierent reservoir compartments.
0 0
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50 w e i v e R r i o v r e s e R a i s A & t s a E e l d d i M
applyg MBi th Mddl est I a major Midde Ea fed, he MBI mehod a ed o ieiae prodio aiabii; o ae heher here had bee oerijeio o aer; o predi re aer prodio or eabihi he eear aer hadi apai; ad o aerai he mo eeie ijeio aoaio o opimize fed perormae. the MBI approah a ao ed o opimize he IPR, o eaae e orko or ijeio maaeme, ad o ee a e ijeio heme ha od maiai prodio. ui he MBI mehod ad arifia ieiee oo (era eork prox mode), shmberer orked ih he fed operaor o idei he oi ad aer iereree beee he reeroir eme ad o opimize he ijeio profe aordi o he prodio eed. the proje had hree phae: daa preparaio ad aai; modei; ad oreai ad opimizaio. the MBI mode ieraed a rae o daa pe, idi proded ome o oi, aer, ad a; ijeed aer ome; ehead prere; e daa or oi, aer, ad ro prodio rae; aer ; gOR; ad Pvt. Baed o he mahed MBI mode, he eam eabihed he opimm ijeio profe or hree diere prodio eario ad poed he perormae or eah opio o 2030. the proje opimized he IPR rom 1.18 o 1.06; refed he emeaio mode or he mai par o he fed; ad ideifed he oi ad aer xe beee he periphera eme ad he era area o he reeroir.
wEttABIlIty, PRODuctIvIty, AnD OIl REcOvERy I ma oifed appiaio, rok are deribed a bei eiher aer-e or oi-e. thi i a exreme impifaio ha mak he ompexi o ei phi i reeroir rok. I a homoeeo, poro maeria araed ih oi ad aer, here are ma deree o ei beee ro aer-e ad ro oi-e. soid ha do o dipa a marked preeree or oe id oer he oher are iermediae- or era-e. Deaied haraerizaio o ormaio eabii are ria or prodio eam eeki o opimize oi reoer. the ei preeree o reeroir rok iee ma ape o fed perormae, pariar he operai ompaie app aeroodi or ehaed oi reoer ehiqe. treai a reeroir a hoh i ere aer-e he i i oi-e or ha mixed eabii ma ae irreeribe damae.
Dri primar reoer, eabii iee prodii ad oi reoer. the oriia eabii o a ormaio ad he aered eabii dri ad aer hdroarbo miraio iee he profe o he iiia aer araio, S i, ad he prodio haraerii o he ormaio. weabii ae he amo o oi ha a be proded a he pore ee, a meared aer aeroodi b he reida oi araio, S or. I a aer-e ormaio, or exampe, oi a be i he arer pore dioeed rom he oio bod o oi ad hereore remai rapped. I a oi- or mixed-e ormaio, oi adhere o he rok, hereb ireai he probabii o a oio pah o a prodi e ad rei i a oer S or.
Msrg wttblty weabii a hae dri ad a a re o oi prodio. or exampe, aphaee preipiaio i depei arboae reeroir ma hae heir eabii eabii.. to appreiae he pore-ee hae ha oro oi prodio, eieer m derad pa ad pree eabii diribio. Reeroir eabii i oe o ma parameer ha a be deried rom aai o arboae ore ampe (i. 4.13). Hoeer, ore eabii a be modifed i eera a beore he ampe reahe he aboraor. Ee he eor are made o preere he ore ampe’ oriia ei ae, drii md rom he e ma oamiae i. A he ore i broh o rae, emperare ad prere hae ma hae he ompoiio o he id i oai, omeime ai aphaee ad axe o preipiae ad oer he pore rae. Oe he ore ha reahed he rae, expore o oxe ma aer he hemia ompoiio o he rde oi i oai ad eerae raa ha ae i properie. the haee o preeri ore ampe i priie odiio hae ed o a mehod or reori he oriia reeroir odiio o he ore. the fr ep o reori ore i a eai proe ha make he ampe aer-e. the ore i he araed ara ed i imaed ormaio brie ad aed. ia, i i ooded ih rde oi ad aed or eera eek a reeroir emperare ad prere. the aim o hi proedre i o rereae he ei ae o he ormaio rok. Hoeer, ariaio i brie or oi ompoiio beee he ormaio ad he aboraor a ae he rea ei ae.
Fgr 4.13
Carbonate Core Data
5-in whole core
9 0 0 2 9 e u s s I
5-in whole core Slabbed core description Texture Fauna, flora Sedimentology Sequence stratigraphy Structures (fractures, etc.) Mini permeameter measurements Biostratigraphic dating Mineralogy X-ray diffraction, fluorescence Scanning electron microscopy analyses Microprobe elemental analyses Isotopic analyses
Geomechanical analyses Compressive properties Elastic moduli Acoustic properties Electrical properties Fracture/stress field analyses
51
1-in core plug
Special core analyses Relative permeability Capillary pressure Whole core porosity, permeability Saturations CT scan Restored state
Seismic/logs Calibration of log data Calibration of seismic response
Thin section
1-in whole core Core plugs Porosity, permeability Grain density Fluid saturations Mercury injection for pore size, capillary pressure Thin section Thin-section petrography Porosity types Micro fauna, flora Diagenesis Cathodoluminescence Grain size, sorting, etc. Cement analyses 4.13: Core samples present geologists and reservoir engineers with a wealth o inormation about the reservoir in the immediate vicinity o the well, including wettability.
“ree wely e my pmee e deed m ly e e mple. hwee, e wely e mded eel wy ee e mple ee e ly.”
w e i v e R r i o v r e s e R a i s A & t s a E e l d d i M
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52 w e i v e R r i o v r e s e R a i s A & t s a E e l d d i M
weabii a be ierred rom oher meareme. or exampe, ro aer-e ad ro oi-e maeria dipa haraerii reaie-permeabii re, b he iermediae ad mixed ei ae are o a impe exrapoaio beee he eabii exreme.
Fgr 4.14
A pree, here i o mehod or meari eabii ha a deier a arae re. the ak o a defiie e or hi ia reeroir haraerii i he drii ore behid ma ooi reearh proje.
Wtrdg Wtrd g d hcd l rcvry Oi- ad aer-e zoe a be od ihi he ame reeroir. the haee or eoiei ad eieer are o defe he diribio o hee aer ad rak he hae ha or hroho prodio. weabii ae he perormae o aeroodi, hih a ioe iifa p-ro pedi. Imbibiio ore, he ede o a ormaio o dra i he ei phae, deermie ho eai aer a be ijeed ad ho i moe hroh a aer-e ormaio. waer breakhroh or aer dri aeroodi, ad more oi i proded beore he aer break hroh i a aer-e aer-e reeroir ha i a oi-e reeroir. waeroodi i reeroir ha oai boh aer-e ad oie aer a be dif o oro. simaio oded a he Ab Dhabi reioa ehoo eer hae ho ha o imied amo o oi a be reoered rom oi-e aer beae, ahoh ijeed aer a dipae oi rom aer-e aer, i dipae er ie rom oi-e aer (i. 4.14). the reoer aor or aered reeroir a be e ha 10%. Beae he impa o eabii exed rom pore hroh o reeroir ae, eabii a ae proje eoomi. weabii iee oi reoer, hih i oe o he mo impora qaiie i he E&P bie, hroh he parameer S i ad S or. I addiio, he reaie permeabiiie o oi ad aer ar ih ormaio eabii. I proje ih he p-ro apia expedire or aiiie, h a hoe i deepaer area, aire o derad eabii ad i ramifaio a be o. uderadi eabii dri ehaed oi reoer, he ma diere id are pree ad moi hroh he reeroir, i be ria o eri he e o ehaed oi reoer operaio.
Gravity-dominated flow in water-wet reservoir
Gravity-dominated flow in a reservoir with layered wettability
4.14: Waterfooding recovers only a small proportion o the oil in the oil-wet layers o a mixed wettability reservoir.
Sstd rts rsrvr chrctrzt chrctrzt nara rared reeroir pree ma haee. the eraiie reai o he phia rre ad he id oe o he reeroir make id o appear prediabe. shmberer ha reearhed ad deeoped a iqe ombiaio ombi aio o modei ad iaizaio ehiqe o imae rare properie ad proide a more ompee deradi o reeroir oeii ie ad id o mehaim. thi reearh eor i oie aro a broad perm o ehia diipie ad eoraphia oaio.
HiSHaM KHaLiL ZuBaRi Hisham Khalil Zubari is petroleum engineering manager or the Bahrain Petroleum Company (Bapco). In 1998, he received the Distinguished Engineer award rom the Bahrain Ministry o Labour and Social Aairs. Hisham’s technical interests ocus on the management o mature elds, and he is chairman o the Well Testing Committee and the Sponsor o the Corporate Geographical Inormation System Implementation Project in Bapco.
oodi, eam oodi, ad mirobia reame. the haee i o raae he ehia ee e hae ejoed i aboraor die o or fed-ae operaio i a o-eeie ad eoomia eaibe a. thi i reqire are-ae ieme ad ommime b he oerme. we pa o e a eamoodi mehod o he reida oi i he Maddd reeroir, ad e hope hi i proide aabe re o bid o.
q: Th Bhr fld cts my stckd rsrvrs, mst whch r crbt rcks bt ll t drt. Hw hv fld dvlpmt pls chgd vr tm d wht c th xprc tll s bt thr Mddl est rsrvrs? the Bahrai fed a dioered i 1932 ad i oidered he ode i he area. Oer he ear he fed’ prodio ha bee maiaied a a reaoabe ee ih he hep o a ijeio ad adaed ii mehaim. Expori diere ad more adaed ehiqe i be ria or prooi he ie o he reeroir. to ear ao, he Bahrai goerme, hroh he naioa Oi ad ga Ahori, iied ieraioa oi ompaie (IOc) o pariipae i he deeopme o he fed. seera IOc hae died he fed ad ho ofdee i reiaizi he mari ae. we hae oded deaied aeme ad eaaio o eera poibe deeopme proram o ee he oe ha a mo oe aied ih or objeie i arei dif reeroir. thi ear e are hopi o orm a joi ere ih a IOc ha i addre ad reoe he haee.
q: is thr sgfct pttl r hvy l prdct Bhr, d wht tchlgs d y thk shld b vltd r ths pplct? the Bahrai fed oai more ha 1 biio barre o hea oi ad ar i arboae reeroir. uorae, he idr ha o e mared he i ome o exrai hea oi rom heeroeeo ad ih hea-oi reeroir. Bapo, i oaboraio ih a ieraioa oi ompa, i i he proe o ei a areie pa o ake hi haee. we are ofde ha e i fd a eeie ombiaio o ehooie o hep prade hee reore io he proe aeor, ad hi i reqire oaboraio ih IOc, erie ompaie, ad reearh iie.
the mari arboae reeroir i he Bahrai fed proide a aabe oppori or he idr o expore ehooie ha a ireae reere ad prodio. the Bahrai fed i a arhepe or fed i he area. idi appropriae oio or he ompex arboae reeroir i he Bahrai fed i hep proide a earer iih o ho o pa eodar ad eriar ae operaio or rrodi ia fed. I ha ee he Bahrai fed i aabe or he peroem idr i he Midde Ea arboae. q: Th m l prdcg hrz Bhr, th Bhr grp, s l-wt. Wht tchcl chllgs d pprtts ds ths crt? the oi-e Maddd arboae reeroir i he mai reeroir i he Bahrai rop. I heor i reida oi oe, hih i eimaed a 50–60% 50–60% o OOIP, od be ripped b hemia
q: Hw mprtt s rsrch crbts r Bpc, d wht rsrch drcts wld y rcmmd s prrts? Reearh i he ke ha i ok he poeia o arboae reeroir. the hihe priori i m ie i o reoe he ie o eabii i arboae. Idea h a eamoodi, ad mirobia ad hemia oodi are orh ieiaio, b he mai haee i o deie a o-eeie mehod or rippi reida oi rom he rok rae, ad ih hiher oi prie hi i be ahieabe. Aoher haee i o deeop a meria imaio o arboae reeroir o ha fed operaor a rak bpaed oi e i poke dri he eodar ad eriar phae o deeopm e. thi i reqire ieie reearh io he haraerii o arboae rok. M hird priori or arboae reearh od be o opimize he prodio o hea oi o ha e aai he hih ee o reoer ha a be ahieed i ai rok.
9 0 0 2 9 e u s s I
53 w e i v e R r i o v r e s e R a i s A & t s a E e l d d i M
