Presenta(on*at*CCOP*training*course,*August*20522,*2013**Fridtjof*Riis*and*coworkers***

A"ributes*of*a*CO2*storage*complex.**

*

CO2*in*the*subsurface,*injec<vity,*capacity,*trapping*

mechanisms*and*types*of*traps!*!!**

6/3/15*2* CO2CRC*Statoil*

CO2*in*the*subsurface:*physics,*

chemistry,*geology*

Injec<on*of*large*volumes*

of*CO2*requires*a*be"er*

understanding*of*regional*

aquifer*behavior*

*

P*and*T*

Density*at*1*bar*and*0*degC*is*1.977*

Part*2*

6/3/15*3* CO2CRC*Statoil*

CO2*in*the*subsurface:*physics,*

chemistry,*geology*

Injec<on*of*large*volumes*

of*CO2*requires*a*be"er*

understanding*of*regional*

aquifer*behavior*

*

P*and*T*

Density*at*1*bar*and*0*degC*is*1.977*

Solubility*of*CO2*in*water*(Eclipse*300*package)*

Density*of*water*increases*when*CO2*is*dissolved*

Solubility*1.45*g/l*at*standard*condi(ons*

CO2*and*water*

Water*and*CO2*

*Water*saturated*with*CO2*at*100*bar*contains*approximately*25*Sm3*CO2,*corresponding**to*about*50*g*CO2/l.*This*represents*a*density*increase*of*about*0.005*g/cm3.*Solubility*is*less*in*brines*with*high*salinity*(Yan*et*al.*2011)**Denser,*CO2*saturated*water*tends*to*flow*downwards,*which*is*an*advantage*for*long*term*storage*of*CO2.*The*tendency*is*less*in*high*salinity*brines.**CO2*solubility*depends*on*temperature*and*water*salinity.**If*pure*CO2*is*injected*in*rocks*with*a*high*salinity*pore*water,*water*will*move*from*the*brine*into*the*CO2*plume*and*may*cause*salt*precipita(on*near*the*injec(on*well.*Salt*precipita(on*in*pore*throats*can*reduce*permeability*and*create*problems*for*injec(vity.**CO2*dissolves*in*water*to*create*a*weak*acid.*Carbonic*acid*will*react*and*reach*equilibrium*with*minerals*in*the*subsurface*and*cement*in*wellbores.*The*mineral*dissolu(on*effect*has*been*shown*to*be*negligible*for*storage*capacity*in*a*1000*year*scale.*Effects*on*injec(vity*and*sealing*proper(es*are*possible*in*e.g.*carbonate*rocks*and/or*in*fractured*reservoirs.**

CO2*and*water*

CO2*hydrate*stability*diagram*Hydrate*is*stable*to*the*le[*of*the*curved*line*

Black*boxes*show*experimental*data*(Sloan*1998).*Source:*Wikipedia*

CO2*and*water*

In*order*to*contain*the*CO2*in*the*subsurface,*pressure*build5up*must*not*exceed*the*fracture*pressure*of*the*sealing*rock.***Pressure*build5up*is*commonly*the*limi(ng*factor*for*the*capacity*of*the*reservoir*of*the*storage*site**To*quan(fy*pressure*build5up,*the*pore*volume*and*permeability*of*the*aquifer*system*must*be*es(mated**Pressure*build5up*can*be*mi(gated*by*produc(on*of*pore*water.****

Pressure*limita<on*

CO2,*water*and*rock*

How*to*es(mate*fracture*pressure*in*an*area*with*scarce*or*no*data?**NPD*storage*atlas:*use*of*regional*pressure*data*base*

Pore pressure Fluid pressure in a permeable rock, measured by producing a small sample of fluid by RFT, MDT,.. Or by drill stem test DST P = ρgz Gas density 0,15-0,3 g/cm3 increasing with z (density in reservoir) Oil density 0,6 – 0,85 increasing with GOR Water density 1,00 – 1,10 increasing with salinity Overburden density 2,1 – 2,5 increasing with depth g = 9,81 m/s2 10 m water is approximately equivalent to 1 bar Lithostatic stress The stress on the mineral grains caused by the weight of the overburden. Can be calculated from density logs. Fracturing pressure The amount of pore pressure necessary to create leakage. Calculated from LOT (leak-off tests).

z

p= ρf*gz*

Hydrosta(c*pressure*

CO2,*water*and*rock*

Reservoir*permeability*

q= k/µ* p , k = permeability, µ = viscosity of fluid q = volume of fluid flux

The*permeability*of*a*layered*reservoir*is*different*in*the*x,*y*and*z*direc(ons.*It*can*be*measured*on*core*plugs,*test*data*and*es(mated*from*well*logs.**Permeability*(or*permeability*thickness)*is*the*key*parameter*for*evalua(on*of*the*injec(vity.****Norwegian*Atlas*check*list:*Poor*quality**<10*mD,*good*quality**>*500*mD.**Connec(vity:*In*a*large,*well*connected*aquifer*with*high*permeability,*fluid*is*free*to*flow*in*large*volumes,*and*the*pressure*build5up*caused*by*injec(on*will*be*small.*With*poor*connec(vity,*pressures*can*build*up*near*the*injec(on*well*

Darcy’s*law*

In*a*fully*open*reservoir*volume,*water*can*escape*and*the*pressure*build5up*from*the**injec(on*well*can*be*calculated*in*a*reservoir*simula(on*model*with*open*boundaries.*

kh*

kv*

CO2,*water*and*rock*

In*the*Norwegian*atlas,*an*aquifer*is*defined*as*a*body*of*porous*and*permeable*reservoir*rocks*which*are*well*connected,*and*with*pressure*communica(on*throughout.*It*is*separated*from*other*aquifers*by*barriers*or*baffles.*

Aquifer*

Storage*complex*

Storage*complex*means*the*storage*site*and*surrounding*geological*domain*which*can*have*an*effect*on*overall*storage*integrity*and*security;*that*is,*secondary*containment*forma(ons.*

Pressure*buildIup**Water*compressibility,*PVTImodule*in*Eclipse*300*

Because*water*compressibility*is*very*low,*injec(on*of*CO2*into*a*fully*closed*water*volume*will*create*a*pressure*increase*according*to*the*equa(on**dV/V*=*5cwdP*

CO2,*water*and*rock*

Pressure*buildIup**Pore*compressibility*

In*the*Frigg*study,*the*reservoir*is*poorly*consolidated.*Compac(on*was*calculated*as*reversible*compac(on*in*the*reservoir*model*

******

******ROCKTAB**Pressure***PV5mul(plier**Trans5mult*

****************************50*************0.945*************1.00*****

**************************200*************1.00***************1.00******

**************************300*************1.0072**********1.00**/**Frigg*aquifer**

*

When*a*fluid*is*injected*into*a*closed*aquifer,*the*pore*pressure*increases,*consequently*the*effec(ve*ver(cal*and*horizontal*rock*stresses*will*decrease,*and*the*reservoir*will*expand.*(Compare*with*a*sponge*in*water).*So[*rocks*and*sediments*will*expand*more*than*consolidated*rocks.**

CO2,*water*and*rock*

The*pressure*build5up*caused**by*injec(on*of*CO2*into*a*closed*aquifer*depends*on*the*water*and*rock*compressibili(es*according*to*the*formula**Vinj*/V*=*(cr+cw)dP*****or*Vinj*=*(cr+cw)*Pinc*Vpore**

*Here,*cr*corresponds*to*the*pore5volume*mul(plier.**Vinj*can*also*be*expressed*by*the*injected*mass*of*CO2*and*the*CO2*density*at*reservoir*condi(ons**minj*=*(cr+cw)*Pinc*Vpore*ρco2res*

*Example*calcula(on:*If*a*volume*of*CO2*corresponding*to*1*%*of*the*total*pore*volume*is*injected*into*the*Frigg*aquifer,*the*rock*pore*volume*increases*with*0.7*%,*and*the*water*volume*in*the*pores*decreases*with*approximately*0.3*%,**crea(ng*a*pore*pressure*increase*of*approximately*100*bar.**

The*frac(on*minj/Vpore**is*the*storage*efficiency*for*the*aquifer.*

Pressure*increase*by*injec<on*into*a*closed*aquifer*

Regional*fracture*pressure*Based*on*a*good*match*between*maximum*observed*pore*pressures*and**minimum*leak5off*pressures,*a*regional*fracture*gradient*is*drawn*as*a*black*line.*At*an*injec(on*site,*the*upper*limit*for*pressure*build5up*must*be*below*the*fracture*gradient*

Hydrosta<c*

Lithosta<c*

NPD!data!

CO2,*water*and*rock*

Pore*pressure*and*leak5off*pressure*from*600*North*Sea*wells***

Capillary*forces**

Capillary*forces*occur*between*the*grain*surfaces*and*the*fluids*in*the*reservoir.*In*a*hydrocarbon*field,*the*capillary*forces*determine*the*height*of*the*transi(on*zone.*Because*of*surface*effects,*two*fluids*will*not*flow*simultaneously*at*the*same*rate*through*a*reservoir*or*a*baffle.*

Free*water*level*Transi(onal*zone*Oil*or*gas*reservoir*

CO2,*water*and*rock*

CO2 in the sedimentary formation

6/3/15* 16*

Formation water

Residual trapping

In*a*storage*complex,*the*rela<ve*amount*of*CO2*trapped*by*

these*mechanisms*will*vary*through*<me.***

CO2,*water*and*rock*

17*

0.0000*

0.1000*

0.2000*

0.3000*

0.4000*

0.5000*

0.6000*

0.7000*

0.8000*

0.9000*

1.0000*

0.00* 0.10* 0.20* 0.30* 0.40* 0.50* 0.60* 0.70* 0.80* 0.90* 1.00*

Kr*

SgCo2*

Frigg*case*drainage*and*imbibi<on*

krg(drain)*

krw(drain)*

krg(imb)*

krw(imb)*

Residual*trapping*–*rela<ve*permeability*between*CO2*and*water*

Rela(ve*permeability*curves*are*different*in*different*reservoir*rocks.*Mainly*water*will*flow*at*high*water*satura(on,*leaving*an*immobile*CO2*behind.**No*water*flow**above*70*%*gas*satura(on.*In*imbibi(on,*CO2*will*not*move*below*35*%*CO2*satura(on*Injected*CO2*is*partly*trapped*as*a*plume*of*high*satura(on,*partly*as*residual*CO2,*partly*as*dissolved*CO2.*Rela(ve*permeability*curves*are*input*into*the*reservoir*simula(on*model*to*quan(fy*the*trapping*mechanisms*

Displacing**pure*water*with*CO2:*use*drainage*curve.*At*a*water*satura(on*of*30*%,*water*will*cease*to*flow*due*to*capillary*forces.**Reverse*experiment*by*displacing*the*two*phases,*CO2*and*residual*water,*with*water:*Use*imbibi(on*curve.*Residual*satura(on*of*CO2*is*35*%.**

–  Regridding*horizontally*only*•  Cells*51*x*51*x*17*

•  The*outer*cells**for*”fully*open”*scenario*

•  Other*cells*

–  12.5*km*x*12.5*km*x*100*m*

–  Poro=0.2*–  PV=3125*Rm3**

–  Inj.*Rate*6MSm3/d*

–  Max*delta*BHP=100bar*

–  2*runs;*Kv/Kh=0.1*and*0.001*

–  Only*1*well,*injector*in*the*middle***

Model*overview*

From*above*CO2*plume*theore<cal*model*

12.5*km*12.5*km*

100*m*

Porosity*0.2*Injec(on*rate*6MSm3/day*Open*boundaries*

•  After 25 years reaching the outer boundary of the 12.5 km x 12.5 km. Then CO2 ”disappears” into to the infinite aquifer

•  CO2 injected = 4.4% of PV

Summary5kv/kh=0.1*

A[er*5yr* A[er*25*yr*(BT)* A[er*50*yr*

High*degree*of*segrega(on*

•  After 55 years reaching the outer boundary of the 12.5 km x 12.5 km •  CO2 injected = 8.1% of PV

Summary5kv/kh=0.001*

Ini(ally* A[er*100*years*A[er*150*years;*

BT*

A[er*5yr* A[er*25*yr* A[er*55*yr*(BT)*

Limited*segrega(on*Will*theore(cally*store*more*CO2,*but*with*real*geology*will*need*more*injec(on*

wells*to*contact*all*the*reservoir*volume*

Case*studies*with*real*geology**

The*significance*of*geological*understanding*I*and*coopera<on*between*

geologists*and*engineers*

*

The*capacity*and*injec(vity*of*a*CO2*storage*prospect*is*es(mated*from*a*reservoir*simula(on*model,*and*this*model*depends*strongly*on*the*geological*input.*The*sta(c*model*is*typically*a*3D*grid*with*rectangular*cells*a*few*hundred*meters*across*and*a*few*meters*thick.*Each*cell*is*given*values*for*porosity,*permeabili(es,*water*satura(on*and*net*gross,*based*on*geological*data.*The*reservoir*engineers*convert*the*model*to*a*dynamic*model*where*different*well*loca(ons*can*be*tested*and*fluids*can*be*injected*and*produced.**

Different*sedimentary*environments*create*large*differences*in*how*permeable*layers**are*distributed**and*connected.**Low*permeable*baffles*and*impermeable*barriers*can*control*the*distribu(on*and*migra(on*of*the*CO2*plume.*(Example:*Snøhvit*injec(on*in*Tubåen*Forma(on)**Geologists*and*reservoir*engineers*must*work*in*one*common*team*and*cooperate*closely*throughout*the*evalua(on*project*

15/657*Skagerrak*Fm*Mainly*alluvial*fans*

6508/551*Ile*fm*deltaic,*(dal*

6407/153*Garn*fm*Prograding*delta*

Cores*from*different*forma(ons**Kv,*Kh,*connec(vity?*

Snøhvit*and*Sleipner*CO2*plume*monitoring***

Sleipner:*Large*aquifer,*permeable*sands,*plume*is*controlled*by*surface*topography,*very*small*pressure*build5up**

Snøhvit:*Plume*and*pressure*build5up*is*controlled*by*permeable*channel*which*is*poorly*connected*to*other*high*permeable*sandstones*

Source:*Statoil,*printed*in*North*Sea*Storage*Atlas*

Sleipner*4D*seismic*amplitudes*rela(ve*to*1994*baseline*Plume*is*controlled*by*structure*and*pressure*build5up*

Snøhvit*4D*seismic*measured*2009*a[er*pressure*build5up.*The*4D*anomalies*are*interpreted*to*correspond*to*the*plume*and*to*increased*pressure.*Note*the*shape*of*the*main*anomaly,*which*reflects*a*high5permeability*channel*in*(ghter*rocks.*

Kmol*CO2*

130*Mt*

Rela(ve*distribu(on*of*CO2*in*plume*(green),*residual*CO2*(black)*and*CO2*in*solu(on*(blue)*from*year2000*to*year10000*in*the*Utsira5Skade*aquifer*model.*Note*the*increasing*propor(on*of*dissolved*CO2*and*large*uncertainty*in*the*amount*of*residual*trapping.**

From*plume*to*dissolu<on:*

Change*of*CO2*trapping*mechanisms*through*<me,*SkadeIUtsira*model*

Pham*et*al.,*2013*

Bennion*et*al*

Singh*et*al*

Geocapacity*project*methodology*

Storage*capacity*

=*RV*x*NG*x**

RV****Rock*volume*NG****Net*to*gross*ra(o*

*1.*If*you*burn*1*kg*of*methane,*how*much*CO2*will*be*produced?***2.*How*much*pore*space*will*it*occupy*at*1000*m*depth*compared*with*the*methane?***2b.*Which*numbers*do*you*expect*for*combus(on*of*petroleum*?**3.*How*much*does*the*pressure*increase*in*a*closed*aquifer**a[er*injec(ng*CO2*

corresponding*to*0.5*%*of*the*pore*water*volume?****1.  Approximately**3*kg**(atomic*weights*of*O,*C*and*H)*

2.  Approximately*40*%**(density*0,7*compared*to*0,1).*Combus(on*of*oil*creates*more*CO2*volume*than*the*pore*volume*of*oil*

3.**Approximately*50*bars*(water,*rock*and*gas*compressibility)*

Classifica<on*and*capacity*of*storage*sites*

Open/half*open*aquifers****** * * * *Large*volumes,*Gt,*climate*purposes*

Closed*structures*(prospects)*in*open*aquifers * *Moderate*volumes,*Mt,*and*pilots*

Abandoned*(gas)*fields * * * *Moderate*volumes,*Mt*up*to*Gt,*and*pilots**

EOR*projects*combined*with*aquifer*storage * *Large*to*moderate*volumes,*Mt*to*Gt*

Pilots * * * * * *Small*volumes,*up*to*a*few*Mt*

*

Theore(cal*storage*efficiency*calculated*from*pore*volume*in*an*aquifer*is*typically**0.5*to*1*%*because*of*pressure*build5up.*Higher*values*for*depleted*aquifers*or*if*forma(on*water*is*produced.*Theore(cal*storage*efficiency*in*a*closed*structure*(prospect*or*abandoned*field)*can*be*much*higher,*but*is*limited*by*capacity*of*the*communica(ng*aquifer***

Neogene*aquifer*(Utsira*–*Skade*Forma<ons)*

Half5open*aquifer*with*several*structural*traps*

Storage*in*abandoned*gas*field*(Frigg*field)**

Saline*aquifer*without*closure,*storage*as*residual*and*dissolved*CO2*(Froan*Basin)*

A[er*10*000*years*

CCS*Workshop*TCM*6th*May*2013*

Storage*of*CO2*combined*with*EOR*Techno5economical*infrastructure*model*

•  SINTEF*has*developed*a*technoIeconomical*infrastructure*model**for*large*scale*deposi(on*of*CO2*in*oil*reservoirs*and*aquifers*(Holt*&Lindeberg,*2007).*In*the*model,*70*Mt*of*CO2*was*injected*in*the*North*Sea*annually*in*40*years.*Part*of*it*was*used*for*EOR*in*waterflooded*oil*fields,*the*remaining*was*stored*in*a*saline*aquifer.**

*

**

CO2*for*EOR*in*Norwegian*Hydrocarbon*Fields*140812*

CO2*from*industrial*sources.*Compressed*and*fed*into*main*pipeline.**

***

Branch*pipelines**

Main*pipeline*infrastructure*

Oil*reservoirs.**Oil*producers*buy*CO2*according*to*needs.*

Aquifers*Excess*CO2*is*deposited*in*aquifers.*

31*

*Export*terminal*******(Emden)*

Ongoing*study*

Bennion*DB*&**Bachu*S.,*2008:*Drainage*and*imbibi(on*rela(ve*permeability*rela(onships*for*supercri(cal*CO2/brine*and*H2S/brine*systems*in*intergranular*sandstone,*carbonate,*shale,*and*anhydrite*rocks.*SPE*Reservoir*Evalua(on*&*Engineering*2008;11:pp.4875496.**Holt,*T.*and*Lindeberg,E.,*2007:*EOR*and*CO2*disposal*–*economic*and*capacity*poten(al*in*the*North*Sea.***Presenta(on*given*in*the*4th*Trondheim*Conference*on*CO2*Capture,*Transport*and*Storage.*October*16*5*17*2007,*Trondheim*Norway**North*Sea*Atlas*(2011):*hxp://www.npd.no/Global/Norsk/35Publikasjoner/Rapporter/PDF/CO25ATLAS5lav.pdf**Norwegian*Sea*Atlas*(2012):**hxp://www.npd.no/Global/Norsk/35Publikasjoner/Rapporter/CO25ATLAS5Norwegian5sea52012.pdf**Pham*VTH,*et*al.,*2013:*Assessment*of*CO2*injec(on*into*the*south*Utsira5Skade*aquifer,*the*North*Sea,*Norway,*Energy*(2013),*hxp://dx.doi.org/10.1016/j.energy.2013.03.026**Singh*V,*Cavanagh*A,*Hansen*H,*Nazarian*B,*Iding*M,*Ringrose*P.,*2010:*Reservoir*modeling*of*CO2*plume*behavior*calibrated*against*monitoring*data*from*Sleipner.*Norway:*Society*of*Petroleum*Engineers;*2010.**Yan,W.*,*Huang,*S*and**Stenby,*E.H.*2011:**Measurement*and*modeling*of*CO2*solubility*in*NaCl*brine*and*CO2–saturated*NaCl*brine*density.**Interna(onal*Journal*of*Greenhouse*Gas*Control,*Volume*5,*Issue*6,*November*2011,*Pages*1460–1477******

References*

Presenta(on*at*CCOP*training*course,*August*20522,*2013**

Fridtjof*Riis*and*coworkers*!

*

Maturing*poten<al*storage*capacity*to*opera<onal*

capacity.*Norwegian*case*studies**Site*screening,*selec(on*and*characteriza(on***Examples:**The*Frigg*field,*an*abandoned*gas*field*Utsira5Skade*and*Johansen*aquifers*****

Norwegian*experience:*CCS*projects*and*status*Statoil:*Offshore*CO2*injec(on*in*Sleipner*and*Snøhvit.*Based*on*petroleum*legisla(on**Mongstad*gas*plant.*CO2*capture*pilot*and*lab,*0.1*Mt/a.*No*storage*yet.*A*CCS*pilot*project*for*the*cement*industry*was*recently*approved.**Extensive*research*ac(vity*on*CO2*storage,including*LYB*pilot**Norwegian*regula(ons*for*CO2*storage*are*now*developed.*New*dra[*CCS*legisla(on*planned*on*public*consulta(on*2013/2014.*Risk*acceptance*criteria*are*based*on*the*storage*direc(ve*and*the*London*Protocol.*The*new*legisla(on*is*based*on*an*implementa(on*of*the*EU*storage*direc(ve,*and*on*the*Norwegian*petroleum*legisla(on.**It*is*a*poli(cal*decision*to*capture*and*store*CO2*from*Mongstad*gas*plant,*in*the*order*of*1*Mt/a.*Decision*on*investment*to*be*taken*2016,*and*an(cipated*start5up*in*2020.*This*will*probably*be*the*first*project*where*the*regula(ons*are*applied.**5*areas*considered*to*have*a*storage*poten(al*have*been*nominated*by*the*industry*and*are*currently*evaluated*by*the*Ministry*of*Petroleum*and*Energy.*Will*be*based*on*the*new*CO2*storage*regula(ons.**In*the*future,*Norway*may*offer*storage*capacity*in*the*North*Sea*for*CO2*captured**from*European*industry*

Characteriza(on*of*aquifers*–*at*least*5*criteria*

Volumetrics*

Risk:*Quality*of*storage*volume*and*seal*

Uncertainty:*Data*quality*and*interpreta(on*

Matura(on:***How*far*from*development*

Economy*of*storage*project*

Classifica<on*of*CO2*storage*volumes*–*the*pyramid*

Es(mated*volumes*in*the*Norwegian*North*Sea*storage*atlas*classified*by*maturity*

Limited*data,**some*seismic*lines,*a*few*wells,*geological*concepts.*Volumes*based*on*area*–*thickness*considera(ons*

Typical*geological*data*and*knowledge*related*to*the*pyramid*levels*

*

Rela(vely*good*2D*data*coverage,*possibly*some*3D*cubes.*Explora(on*wells.*Good*understanding*of*regional*geology.*Structural*maps*of*the*relevant*aquifers**

Good*data*coverage*of*the*injec(on*site.*3D*seismic*data*and*(plans*for)*a*dedicated*well*if*this*is*a*large*injec(on*project.*Good*knowledge*of*the*corresponding*aquifer.*Reservoir*simula(on*model.*

Good*data*coverage*and*simula(on*model.*Monitoring*of*injec(on*and*upda(ng*of*models*

Selec<on,*matura<on*and*development*of*storage*sites***

Matura<on*pyramid*corresponds*to*the*decision*gates*in*the*regula<ons*

Reconnaisance*studies*

*

Explora<on*permits***

*

Storage*permits**(”PDO”)**

Opera<on,*monitoring,*mi<ga<on*

*

Closure*and*postIclosure*

*

Transfer*of*responsibility/liability*

*

*A geological formation shall only be selected as a storage site, if under the proposed conditions of use there is no significant risk of leakage, and if no significant environmental or health risks exist.**(Ar(cle*4,*EU*Direc(ve*2009/31)**Direc(ve*requires*highly*competent*industry*and*authori(es*

Economy*of*project*

How*large*injec(on*volumes*are*planned*for?*****Present*needs*and*future*strategy?***What*is*the*present*and*future*price*of*storage*of*CO2*volumes?***Investments*and*opera(onal*costs******

Mongstad*case,*site*selec<on*

6/3/15* 41*

North*Sea*Atlas,*the*three*most*likely*aquifers*for*injec(on*in*the*near*future.*Frigg*Field*also*regarded*as*a*possible*candidate*

Mongstad*

Frigg*Field*

Sleipner*injec<on*

Bryne*

Joh*

Mongstad*

Loca<on*of*Mongstad*site*and*aquifers*considered*for*storage*of*captured*CO2*

Joh*******Johansen*Forma(on*Bryne**Sandnes5Bryne*aquifer*

100*km*100*km*

The*Utsira*and*Skade*Forma(ons*are*shown*with*yellow*and*gray*shades.*Arrows*point*at*areas*which*are*presently*matured*to*the*yellow*level*

Case*:*Matura<on*of*Johansen*site*

December*2006:*MPE*request*to*the*NPD*to*suggest*and*evaluate*storage*sites*for*CO2*from*Mongstad,*up*to*3*Mt*annually.*The*costs*of*capture*and*storage*to*be*covered*by*the*state.**NPD*decided*to*evaluate*the*Johansen*Forma(on*and*compare*with*a*site*close*to*the*exis(ng*Sleipner*site,*which*was*considered*to*have*a*proven*capacity.**The*proposed*injec(on*area*was*located*south*of*Troll,*at*250053000*m*depth,*600*m*below*the*Troll*aquifer*and*separated*by*several*shale*layers.**

The*Johansen*Forma(on*was*considered*to*be*water*bearing,*and*the*knowledge*of*the*forma(on*was*limited.*2D*seismic*coverage*and*no*wells*in*the*proposed*injec(on*area*south*of*the*Troll*field,*but*3D*and*several*well*penetra(ons*in*the*Troll*Field.*Petrophysical*proper(es*were*es(mated*from*logs.**

J*

T*

Case*:*Matura<on*of*Johansen*site*

Reasons*to*ini(ate*the*Johansen*study:*Why*not*just*go*for*the*simpler*Utsira*case?**•  Shorter*distance*to*the*CO2*supply*(70*vs*300*km),*lower*transport*costs*

•  Good*seal,*virtually*no*risk*of*leakage*to*the*sea*floor*

•  Strategic:*Possibly*a*large*storage*capacity*for*the*future*

•  Proximity*to*fields*which*might*use*CO2*for*EOR*in*the*future*

•  There*were*some*concerns*about*the*sealing*capacity*of*the*Utsira*Forma(on,*and*a*parallel*study*was*ini(ated*to*map*the*Utsira*Forma(on*for*alterna(ve*injec(on*sites*closer*to*Mongstad.*

Case*:*Matura<on*of*Johansen*site*

Based*on*geological*models*of*the*injec(on*area*and*the*regional*aquifers,*SINTEF*Petroleum*Research*constructed*a*reservoir*simula(on**model*in*ECLIPSE*and*ran*several*cases.**The*geo5model*was*also*made*available*to*the*universi(es,*and*several*studies*were*performed.*

* * * *Main*conclusion*and*uncertain<es*

* Capacity:*Sufficient*for*the*high*case*of*CO2*supply.*Uncertainty*related*to*the*size*of*the*connec(ng*aquifer.*In*the*low*case,*pressure*build5up*could*become*a*problem.**Injec<vity:*Uncertain(es*related*to*burial*depth*and*possible*shaling*out*of*the*forma(on*towards*the*south**Seal:*Uncertain(es*related*to*possible*leakage*through*faults*and*up*into*the*forma(ons*above,*which*form*the*water*zone*of*the*Troll*Field.*Possible*conflict*of*interest*with*the*Troll*Field*owners.**

Profile!across!main!fault:!!Red!–!Troll!field!reservoirs,!yellow!–!JohansenACook!aquifer!

6/3/15* 46*

Results*from*simula<ons*2007* •  Annual*injec(on*3Mt*

•  Injec(on*period*110*y,*330*MT*

1 year 50 years 110 years 310 years 510 years

Case*:*Matura<on*of*Johansen*site*

*FollowIup*studies*by*consultants*and*industry*

*

Fault*seal*analysis:*Mapping*of*fault*geometries,*development*of*fault*rocks*and*their*possible*sealing*capacity***Detailed*reservoir*study*of*Johansen*and*Cook*Forma(ons*Core*analyses,*petrophysics,*correla(ons**Seal*rock*lab*study.**Wexability*of*shales**Reservoir*modelling*(based*on*the*same*geological*model)*cataclas<c*def’m*bands*

shale*

smear*

breccia*

gouge*

Main*conclusions:*Johansen*and*Cook*forma(ons*appear*to*be*connected,*should*be*treated*as*one*aquifer.*Migra(on*of*CO2*ver(cally*along*faults*is*not*likely.*Fault*geometries*may*allow*migra(on*of*CO2*into*the*overlying*forma(ons,*but*only*a[er*a*long*way*of*plume*migra(on.*Based*on*2D*data.**

Case*:*Matura<on*of*Johansen*site*

*New*data*acquisi<on*

In*2010,*the*state*agency*Gassnova*acquired*and*interpreted*3D*seismic*data*in*the*southern*part*of*the*Johansen*area*in*order*to*reduce*uncertain(es*related*to*reservoir*capacity*and*fault*seal.*The*whole*injec(on*site*and*large*parts*of*the*aquifer*are*now*covered*with*3D*data*of*high*quality.***Main%conclusions:%Interpreta(on*of*the*new*data*results*in*a*detailed*map*of*the*fault*paxern*in*the*south,*and*makes*it*possible*to*suggest*an*injec(on*site*to*the*south,*almost*30*km*away*from*the*Troll*Field.*This*reduces*significantly*the*risk*of*conflict*with*the*petroleum*industry.*Simula(ons*indicate*no*plume*migra(on*into*sensi(ve*areas*the*first*500*years.**The*3D*data*interpreta(on*supports*a*sedimentological*model*where*reservoir*rocks*were*developed*with*a*high*sand5shale*ra(o*in*the*south.*Because*the*suggested*injec(on*site*is*at*3000*m*depth,*there*is*an*uncertainty*that*injec(vity*could*be*low.*The*capaci(es*es(mated*in*the*previous*studies*were*confirmed.**A*well*is*needed*to*test*the*injec(vity*and*reservoir*proper(es*before*the*Johansen5Cook*aquifer*can*be*qualified.*Drilling*of*a*well*must*be*performed*by*an*oil*company*which*is*qualified*for*this*opera(on.**

RMS*axribute*on*top*of*Johansen*seismic*reflector**

Porosity* Permeability*Depth*

RMS*Seismic*axribute*and*outline*of*Johansen*Forma(on*

Parameter*maps,*input*to*sta(c*modelling.*Based*on*well*calibra(on,*seismic*axributes*and*func(onal*rela(ons**

Examples*from*the*new*study*by*Ross*and*Gassnova*

Dynamic*modelling*of*the*Johansen5Cook*reservoir*based*on*new*data*and*detailed**interpreta(on*

Case:*Matura<on*of*the*Utsira*–*Skade*aquifer*

Since*2007,*the*NPD*has*inves(gated*the*Utsira*–*Skade*aquifer*by*regional*mapping*of*3D*seismic*data,*biostra(graphical*and*geological*studies.**

Pham*et*al.*(2013)*Reservoir*modelling*of*the*southern*part*of*the*Utsira5Skade*aquifer.*Central*part*is*not*suited*due*to*shallow*burial*

Modelling*aquifer*capacity,*southern*part*of*Utsira5Skade*aquifer*Large*half5open*aquifer*with*structural*culmina(ons*

Pham,*V.T.H.,*Riis,*F.,Gjeldvik,*I.T.,*Halland,*E.K.,*Tappel,*I.M.,*Aagaard,*P.*2013.*Assessment*of*CO2*injec(on*into*the*south*Utsira5Skade*aquifer,*the*North*Sea,*Norway.*Energy*(2013),*hxp://dx.doi.org/10.1016/j.energy.2013.03.026*

How*much*CO2*can*be*stored*in*the*southern*part*adjacent*to*the*Sleipner*injec(on*site*

Top*surface*of*model*a[er*injec(on*of*approximately*130*Mt*CO2,*a[er*8000*years,*3*cases*with*different*ver(cal*permeability*

Utsira5Skade*aquifer*model*

Matura(on*of*storage*capacity*in*a*large,*half5open*aquifer*with*closed*structures*

Conclusions*UtsiraISkade*aquifer*study*

*The*Utsira*and*Skade*aquifers*have*excellent*reservoir*condi(ons*and*high*injec(vi(es.*The*model*is*based*on*3D*seismic*mapping*where*several*structural*culmina(ons*are*iden(fied.*Structural*trapping*prevents*CO2*to*migrate*further*into*the*area*where*CO2*may*con(nue*to*leak*to*shallower*levels*where*there*will*be*a*change*to*gas*phase.**In*the*model,*170*Mt*were*injected*in*50*years*with*10*bar*pressure*increase.*The*segment*only*represents*a*frac(on*of*the*total*possible*injec(on*area*of*the*aquifer,*but*even*so*the*calculated*volume*is*small*rela(ve*to*the*total*theore(cal*capacity*of*the*aquifer*calculated*in*the*Storage*Atlas.***The*main*uncertain(es*related*to*CO25injec(on*in*the*Utsira5Skade*aquifer*are*considered*to*be*the*sealing*capacity*of*the*caprock*and*to*the*integrity*of*old*explora(on*wells*drilled*through*the*forma(on.*There*is*no*leakage*from*the*Sleipner*site.***For*the*opera(onal*storage*capacity*it*is*important*to*understand*the*degree*of*communica(on*between*the*different*sandy*forma(ons*within*the*aquifer.*Regional*horizontal*barriers*at*shale*layers*within*the*aquifer*will*help*to*increase*the*opera(onal*storage*capacity.**

Frigg*Fm*outline*

Heimdal*Fm*outline*

Colors:*******Mid*Jurassic*depth***UH*************Utsira*High*

UH*

100*km*

Aquifer*includes*Frigg*Forma(on*Balder*Forma(on*Hermod*Forma(on*Heimdal*Forma(on*Ty*Forma(on*

*

Case:*Simula<on*of*CO2*injec<on*in*the*abandoned*Frigg*Field*

Top*of*reservoir*sand,*Frigg*Field*

Deple(on*caused*by*gas*produc(on*in*the*Frigg5Heimdal*area*

Ini(al*pressure*gradient*before*Frigg*produc(on*1974*

Pore*pressure*in*several*explora<on*wells*show*that*the*en<re*aquifer*is*depleted*by*the*gas*produc<on*

Model*built*by*AGR*for*the*NPD.*Field*model*provided*by*the*previous*operator,*Total*Very*coarse*grid*covering*the*Frigg5Heimdal*aquifer,*finer*grid*in*the*Frigg*Field*

East*Frigg*

NE*Frigg*

Frigg*

Heimdal*

Odin*

Model*overview*

Rock*compac<on*regions*

Case:*Simula<on*of*CO2*injec<on*in*the*abandoned*Frigg*Field*

Composi(onal*model*in*colors**

Blackoil*in*black*

Frigg*

Field*

Produced*approximately*220*Sm3*gas,*max*pressure*drop*in*Frigg*50*bar,*in*aquifer*10*bar?*

NPD*–*AGR*study*of*pressure*development*in*the*Frigg*area*and*average*aquifer*History*matching*the*pressure*development*in*the*aquifer*

Case:*Simula<on*of*CO2*injec<on*in*the*abandoned*Frigg*Field*

Frigg*abandoned*gas*field:**A*CO2*injec(on*study*was*performed*by*AGR*for*NPD**

Is*it*possible*to*produce*remaining*gas*at*the*same*(me*as*injec(on*starts*up?*

Ver(cal*scale*x*25*

Final*gas*cap*size*case*H1,*2015*

•  “Base*case*(H1)”*trapped*gas*satura(on*(about*28%)*!*Small*gas*cap*

•  Sensi(vi(es*run*for*lower*trapped*gas*satura(ons*

Case:*Simula<on*of*CO2*injec<on*in*the*abandoned*Frigg*Field*

Injec(on*at*3*different*loca(ons*5*overview*

Frigg*

East*Frigg* Aquifer*

Injector*loca(on*cases**

Case:*Simula<on*of*CO2*injec<on*in*the*abandoned*Frigg*Field*

Gas*satura(on*

CO2*molar*frac(on.*in*gas*

Gas*satura(on*

2015* 2030* 2070* 2100*

LGR*

Produc(on*of*remaining*gas*with*CO2*injec(on*in*the*aquifer*5*gas*distribu(on*–*injec(on*and*produc(on*start*simultaneously*

Pressure*response*with*limited*and*half*open*aquifer*

Field*pressure*

Frigg*pressure* CO2*injec<on*

*******Limited*aquifer********Leaking*aquifer*

*

•  Confined*aquifer*:*55*years*of*injec(on*(3xMongstad)*before*the*field*(aquifer)*pressure*reaches*its*ini(al*value**

•  For*a*leaking*(half*open)*aquifer*it*takes*85*years*for*the*same*point**

440*Mt*injected*CO2*–*17*bar*pressure*increase*Corresponds*to*210*109*Sm3*CO2,*1/Bg*approximately*350*

Case:*Simula<on*of*CO2*injec<on*in*the*abandoned*Frigg*Field*

Long term effects, convection and diffusion

2015* 2025* 2040* 2200* 2600* 3070*

Long*term*effects*of*CO2*injec(on*–*without*diffusion*

Gas*satura<on*

Mol*frac<on*CO2*in*water*

Water*density*

•  Clear*convec(on*paxern*but*a[er*very*long*(me

Case:*Simula<on*of*CO2*injec<on*in*the*abandoned*Frigg*Field*

Conclusions**The*abandoned*Frigg*field*reservoir*has*a*large*capacity*and*good*injec(vity.**Possibly*remaining*methane*gas*could*be*produced*before*injected*CO2*reaches*the*remaining*gas*cap**The*risk*of*leakage*through*the*cap*rock*of*the*field*is*considered*to*be*low*as*long*as*the*pressure*is*not*exceeding*hydrosta(c.**One*natural*seepage*area*has*been*observed*east*of*the*field,*but*the*plume*will*not*migrate*into*that*area.**The*main*risk*of*leakage/seepage*is*considered*to*be*the*integrity*of*the*explora(on*and*produc(on*wells*of*the*field.**

CO2*injec<on*vs*petroleum*explora<on:**

*What*is*new*from*a*geoscien<st’s*point*of*view?****1.*The*proper(es*of*CO2*in*the*subsurface*and*its*interac(on*with*rock**and*fluids.**2.*In*CO2*evalua(on,*a*large*effort*must*be*put*on*the*quality*of*the*seal,*including*the*faults*and*fractures*in*the*caprock.*Leakage*and*seepage*mechanisms.**

3.*The*development*plan*must*contain*a*plan*for*monitoring*the*CO2*plume,*and*how*to*mi(gate*devia(ons*from*the*model.*Monitoring*plan*and*possibility*for*base*line*surveys*should*be*considered*at*an*early*stage*in*the*inves(ga(on.*Measuring*of*CO2*lost*to*the*surface*may*become*necessary.***4.*The*effect*of*the*injected*CO2*plume*has*a*poten(al*to*affect*the*areas*and*aquifer*volumes*out*of*licenced*areas.*This*can*happen*by*pressure*build5up*and*by*migra(on*of*the*plume.*Regional*studies*and*mapping*of*possible*areas*of*conflic(ng*interests*are*essen(al.**5.*A*CO2*storage*is*supposed*to*last*for*thousands*of*years,*hence*long*term*reservoir*simula(on*is*necessary.*

*1.*If*you*burn*1*kg*of*methane,*how*much*CO2*will*be*produced?***2.*How*much*pore*space*will*it*occupy*at*1000*m*depth*compared*with*the*methane?***2b.*Which*numbers*do*you*expect*for*combus(on*of*petroleum*?**3.*How*much*does*the*pressure*increase*in*a*closed*aquifer**a[er*injec(ng*CO2*

corresponding*to*0.5*%*of*the*pore*water*volume?****1.  Approximately**3*kg**(atomic*weights*of*O,*C*and*H)*

2.  Approximately*40*%**(density*0,7*compared*to*0,1).*Combus(on*of*oil*creates*more*CO2*volume*than*the*pore*volume*of*oil*

3.**Approximately*50*bars*(water,*rock*and*gas*compressibility)*

Bennion*DB*&**Bachu*S.,*2008:*Drainage*and*imbibi(on*rela(ve*permeability*rela(onships*for*supercri(cal*CO2/brine*and*H2S/brine*systems*in*intergranular*sandstone,*carbonate,*shale,*and*anhydrite*rocks.*SPE*Reservoir*Evalua(on*&*Engineering*2008;11:pp.4875496.**Holt,*T.*and*Lindeberg,E.,*2007:*EOR*and*CO2*disposal*–*economic*and*capacity*poten(al*in*the*North*Sea.***Presenta(on*given*in*the*4th*Trondheim*Conference*on*CO2*Capture,*Transport*and*Storage.*October*16*5*17*2007,*Trondheim*Norway**North*Sea*Atlas*(2011):*hxp://www.npd.no/Global/Norsk/35Publikasjoner/Rapporter/PDF/CO25ATLAS5lav.pdf**Norwegian*Sea*Atlas*(2012):**hxp://www.npd.no/Global/Norsk/35Publikasjoner/Rapporter/CO25ATLAS5Norwegian5sea52012.pdf**Pham*VTH,*et*al.,*2013:*Assessment*of*CO2*injec(on*into*the*south*Utsira5Skade*aquifer,*the*North*Sea,*Norway,*Energy*(2013),*hxp://dx.doi.org/10.1016/j.energy.2013.03.026**Singh*V,*Cavangh*A,*Hansen*H,*Nazarian*B,*Iding*M,*Ringrose*P.,*2010:*Reservoir*modeling*of*CO2*plume*behavior*calibrated*against*monitoring*data*from*Sleipner.*Norway:*Society*of*Petroleum*Engineers;*2010.**Yan,W.*,*Huang,*S*and**Stenby,*E.H.*2011:**Measurement*and*modeling*of*CO2*solubility*in*NaCl*brine*and*CO2–saturated*NaCl*brine*density.**Interna(onal*Journal*of*Greenhouse*Gas*Control,*Volume*5,*Issue*6,*November*2011,*Pages*1460–1477******

References*

Backup*slides*

Selec(on*of*field*candidates**

•  40*oil*fields*on*produc(on*in*the*Norwegian*North*Sea*selected*for*screening*

•  23*fields*chosen*for*EOR*calcula(on*•  Fields*screened*out*due*to:*

–  Size*(too*small)*

–  Gas*cap*–  Earlier*gas*flooding*–  Earlier*WAG*

•  In*some*of*the*chosen*fields*only*part*of*the*field*with*water*injec(on*chosen*

CO2*for*EOR*in*Norwegian*Hydrocarbon*Fields*140812*

70*

Example*of*produc(on*profile*calculated**by*the*SINTEF*module*

CO2*for*EOR*in*Norwegian*Hydrocarbon*Fields*140812*

Brage

0

1

2

3

4

5

6

7

8

9

0 10 20 30 40

Years of production

Pro

duct

ion

rate

s

Oil (mill. Sm3/year)EOR oil (mill. Sm3/year)Water (mill. Sm3/year)Gas (bill. Sm3/year)field data

The*predicted*oil*recovery*profile*is*matched*to*historic*values*by*use*of**the*two*geological*fit*parameters*(heterogeneity*exponent,*ver(cal*permeability*mul(plicator)***

71*

Addi(onal*CO2*storage*in*saline*aquifers*

•  Use*saline*aquifers*as*buffer*storage*capacity**to*maintain*stable*CO2*deliveries*from*Europe*(*~70*mill*tonnes*CO2/year)*

•  Will*use*aquifers*around**Sleipner*(Utsira)*and*Frigg(Frigg*and*Heimdal*sand)*

•  Johansen*Fm*south*of*Troll*also**considered*but*uncertain*due*to*storage*place*for*Mongstad*CO2*

•  Bryne/Sandnes**aquifers*east*of*Ekofisk*also*considered*but*too*far*away*

•  Es(mate*approx.*1*mill*tonnes*CO2*/year*per*well*in*CO2*in*saline*aquifers**

72*CO2*for*EOR*in*Norwegian*Hydrocarbon*Fields*140812*

Conclusions*•  Screening*of*oil*fields*for*CO2*EOR*in*the*Norwegian*North*Sea*has*

shown*23*possible*candidates*with*a*total*poten(al*of*250*–*340*mill*Sm3*of*extra*oil*from*2020,*corresponding*to*5.4*–*7.4*%*of*OOIP.*

•  Total*investment*42*bill.*USD*•  70*mill*tonnes*CO2*injected*per*year*

•  Main*pipeline*transporta(on*cost**8.5*USD/tonne*CO2*

•  Net*present*value*(NPV)*40*bill*USD*at*7%*interest*(oil*prize*90*USD/bbl,*CO2*cost*25*USD/tonne)*

•  IRR*20.6%**with*320*mill*Sm3*extra*oil*corresponding*to*6.9%*recovery*

•  Doubling*of*well*cost*gives*a*nega(ve*NPV*at*base*case*oil*prize*and*CO2*cost*

•  Using*WAG*(1:1)*instead*of*con(nuous*CO2*flooding*can*increase*the*NPV*by*40%.*Reducing*CO2*cost.*Less*CO2*is*stored*

73*CO2*for*EOR*in*Norwegian*Hydrocarbon*Fields*140812*

EU*Storage*Direc(ve*requirements*to*sta(c*and*dynamic*modelling*