Capabilities of TOUGH Codes for Modeling Geologic Sequestration and Leakage of CO 2

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1 Capabilities of TOUGH Codes for Modeling Geologic Sequestration and Leakage of CO 2 Karsten Pruess Earth Sciences Division Lawrence Berkeley National Laboratory Presented at Workshop on Leakage Modeling Princeton University, 13 November 25

2 TOUGH2 General model for nonisothermal multiphase flow of multicomponent fluids Space discretization by integral finite differences (IFD) Applicable to 1D, 2D, 3D regular or irregular grid geometries; single porosity or multicontinua Fully implicit time weighting Simultaneous, iterative solution of all mass and energybalances Phase (dis)appearance handled by switching primary variables Preconditioned conjugate gradients, direct solvers Fluid property modules for geothermal reservoir studies, nuclear waste isolation, environmental contamination problems, geologic storage of CO 2 Inverse model itough2 TOUGHREACT: reactive chemistry TOUGHFLAC: rock mechanics K. Pruess, Vadose Zone J., Vol. 3, pp , 24

3 TOUGH2/ECO2N TOUGH2/EOSM 3 Components: watersaltco 2 3 Phases: aqueous gas solid CO 2 properties after Altunin et al. Phase partitioning according to Spycher and Pruess (25) 5 C T 11 C; P 6 bar Coupled fluid and heat flow Applications to generic studies of CO 2 storage, design and analysis of Frio pilot test Available to the public ( 3 Components: watersaltco 2 4 Phases: aqueousliquid CO 2 gaseous CO 2 solid Phase change between liquid and gaseous CO 2 Fluid property model similar to ECO2N Applications to leakage studies, design of experiments Code development ongoing

4 3D Grid Design for Frio Pilot 46,5 grid blocks in 3D

5 Sticky vs. Slippery Plume Slippery plume Sticky plume

6 Leakage Scenarios Highpermeability conduit Fault or fracture zones land surface land surface highk conduit "parasitic" CO2 reservoir highk fault g liquid CO2 + immob. water highk fault aquifer "parasitic" CO2 reservoir CO2 reservoir CO2 upflow from storage reservoir

7 Idealized Fault (Fracture) Zone land surface Fracture 71 m CO 2 h = 1 m Matrix w = 2 m homogeneous medium embedded in impermeable country rock start from natural watersaturated, geothermal/hydrostatic conditions apply CO 2 overpressure (8 71 m depth, compared with hydrostatic pressure of 7.5 bar)

8 TemperaturePressure Profiles (1 m thick fracture zone) liquid CO2 saturation line hydrostatic profile T ls = 15 ÞC deep 2 gas yr 6.38 yr 9.16 yr 3 4 shallow Temperature (ÞC)

9 Leakage Flux and 3phase Volume 2x x = 1 m flux for fixed temperature Time (years) 4 5 CO2 flux x = 1 m x = 175 m x x = 1 m x = 175 m land surface m threephase volume x1 6 CO 2 h = 1 m Time (s) w = 2 m At early time, 3phase volume is inphase with flux at x = 175 m outofphase with flux at x = 1 m K. Pruess, Geophys. Res. Lett., Vol. 32, No. 14, July 25

10 Wellbore Flow: Water w/ Dissolved CO 2 atmospheric conditions Water and CO 2 discharge 4x1 2 15x1 3 Depth (m) 3 2 liquid CO water with 3.5 wt.% CO Time (s) 4 5x1 3

11 TOUGHREACT transport flow chemistry chemical reactions Processes advection hydrodynamic diffusion { dispersion heat transfer TOUGH2 homogeneous heterogeneous { gas advection conduction { phase change acidbase redox { aqueous complexation ion exchange adsorption mineral dissol./precip. dissolution/exsol. Introduce reactive chemistry into TOUGH2 Reactions between gas aqueous solid phases, equilibrium or kinetics General database for minerals, aqueous and gaseous species Porosity and permeability change Sequential iteration, implicit timed weighting, automatic time stepping, QSS

12 Gulf Coast Frio Formation Injection well Mineral phases Aqueous species H 2 O H + Ca +2 Mg +2 Na + K + Fe +2 SiO 2 (aq) HCO 3 SO 4 2 AlO 2 Cl O2(aq) 1 m 1 m OH Al +3 HAlO 2 (aq) NaAlO 2 (aq) AlOH +2 Al(OH) 2 + Al(OH) 3 (aq) CaCl + CaCl 2 (aq) CaSO 4 (aq) NaCl(aq) FeCl + FeHCO 3 + φ =.1 k = 1 18 m 2 φ =.3 k = 1 13 m 2 r FeCO 3 (aq) FeCl 4 2 NaHCO 3 (aq) CaHCO 3 + MgHCO 3 + CO 2 (aq) CO3 2 CaCO3(aq) KCl(aq) MgCl + MgSO 4 (aq) NaSO 4 KSO 4 Shale x Sandstone NaHSiO 3 (aq) CaOH + NaOH(aq) NaCO 3 H 3 SiO 4 Fe +3 HS H 2 S(aq) CH 4 (aq) H 2 (aq) acetic~acid(aq) SO 2 (aq) HSO 3 z Mineral Primary: quartz kaolinite calcite illite kerogenos oligoclase Kfeldspar Nasmectite chlorite hematite porosity Secondary: anhydrite magnesite lowalbite dolomite siderite Casmectite pyrite ankerite dawsonite alunite Chemical composition CaCO 3 CaSO 4 MgCO 3 CaMg(CO 3 ) 2 FeCO 3 CaMg.3 Fe.7 (CO 3 ) 2 NaAlCO 3 (OH) 2 KAl 3 (OH) 6(SO 4 ) 2 Vol.% of medium Sand Shale

13 CO 2 Geological Sequestration CO 2 is sequestered as ankerite and dawsonite, with minor siderite. The simulated mineral alteration is consistent with field observations (Moore et al., 23; Watson et al., 22). The mineral trapping capacity can reach 8 kg/m 3 medium. CO2 sequestered (kg/m**3 medium) Ankerite [CaMg.3Fe.7(CO3)2] + Dawsonite [NaAlCO3(OH)2] 1, yr 1, 1 1 CO2 sequestered (kg/m**3 medium) Ankerite + Dawsonite Ankerite: CaMg.3Fe.7(CO3)2 Dawsonite: NaAlCO3 (OH) 2 1, yr 1, Radial distance (m) (a) CO 2 only Radial distance (m) (b) CO 2 + SO 2