Dissolution/Precipitation with time

[Nitin]

Hello fellow members,
   I want to simulate the data for CO2-Brine-Rock interaction. Assuming brine in reservoir is at some depth at 55C temp and 81atm pressure. I am adding CO2 in that reservoir at same P-T conditions and simulating the mineral precipitation and dissolution with time. So please check if the program is working as described conditions or not.
Thank you

Code: [Select]

PHASES
END
SOLUTION 1
-temp 55
redox pe
pH   7.5
Na   2.91
Ca   0.521
K    0.039
F    0.017
Cl   2.6
S    0.78  as   SO4-2
C    4.74  as   HCO3-1
Si   0.67  as   SiO2

EQUILIBRIUM_PHASES 1
Dawsonite     0        0
Kaolinite     0        0
Calcite       0        0
Ankerite      0        0
Dolomite      0        0
Mordenite-Ca  0        0
Magnesite     0        0
Siderite      0        0
Magnetite     0        0.030057824
Huntite       0        0
CO2(g)        1.908    0.3
RATES

K-feldspar
-start
10 REM PARM(1) = MSA (Molar surface area) [m^2/mol]
    20 si_kfeld = SI("K-Feldspar")
    30 if (M <= 0 and si_kfeld < 0) then goto 200             
    40 SA = PARM(1) * M             
    50 if (M = 0 and si_kfeld > 0) then SA = 1e-05  #nucleation
    60 k_acid = 10^(-10.06)*EXP(-51.70e+03/8.314*(1.0/TK-1.0/298.15))*ACT("H+")^(0.500)                 
    70 k_neut = 10^(-12.41)*EXP(-38.00e+03/8.314*(1.0/TK-1.0/298.15))
    80 k_base = 10^(-21.20)*EXP(-94.10e+03/8.314*(1.0/TK-1.0/298.15))*ACT("OH-")^(-0.823)
    90 k_rateconst = k_acid + k_neut + k_base
    100 r = k_rateconst * SA * (1-(10^si_kfeld))
    190 moles = r * TIME
    200 SAVE moles
-end

Albite
-start
 10 REM PARM(1) = MSA (Molar surface area) [m^2/mol]
    20 si_alb = SI("Albite")
    30 if (M <= 0 and si_alb < 0) then goto 200             
    40 SA = PARM(1) * M             
    50 if (M = 0 and si_alb > 0) then SA = 1e-05  #nucleation
    60 k_acid = 10^(-10.16)*EXP(-65.00e+03/8.314*(1.0/TK-1.0/298.15))*(ACT("H+")^(0.457))                 
    70 k_neut = 10^(-12.56)*EXP(-69.80e+03/8.314*(1.0/TK-1.0/298.15))
    80 k_base = 10^(-15.60)*EXP(-71.00e+03/8.314*(1.0/TK-1.0/298.15))*(ACT("OH-")^(-0.572))
    90 k_rateconst = k_acid + k_neut + k_base
    100 r = k_rateconst * SA * (1-(10^si_alb))
    190 moles = r * TIME
    200 SAVE moles
-end

anorthite
-start
   10 REM PARM(1) = MSA (Molar surface area) [m^2/mol]
   20 si_anort = SI("Anorthite")
   30 if (M <= 0 and si_anort < 0) then goto 200             
   40 SA = PARM(1) * M             
   50 if (M = 0 and si_anort > 0) then SA = 1e-05  #nucleation
   60 k_acid = 10^(-3.5)*EXP(-16.60e+03/8.314*(1.0/TK-1.0/298.15))*ACT("H+")^(1.411)                 
   70 k_neut = 10^(-9.82)*EXP(-31.50e+03/8.314*(1.0/TK-1.0/298.15))
   80 k_base = 0
   90 k_rateconst = k_acid + k_neut + k_base
   100 r = k_rateconst * SA * (1-(10^si_anort))
   190 moles = r * TIME
   200 SAVE moles
-end

diopside
-start
10 REM PARM(1) = MSA (Molar surface area) [m^2/mol]
    20 si_diopsi = SI("Diopside")
    30 if (M <= 0 and si_diopsi < 0) then goto 200             
    40 SA = PARM(1) * M             
    50 if (M = 0 and si_diopsi > 0) then SA = 1e-05  #nucleation
    60 k_acid = 10^(-6.36)*EXP(-96.10e+03/8.314*(1.0/TK-1.0/298.15))*ACT("H+")^(0.710)                 
    70 k_neut = 10^(-11.11)*EXP(-40.60e+03/8.314*(1.0/TK-1.0/298.15))
    80 k_base = 0
    90 k_rateconst = k_acid + k_neut + k_base
    100 r = k_rateconst * SA * (1-(10^si_diopsi))
    190 moles = r * TIME
    200 SAVE moles
-end
Ilmenite
    -start
10 REM PARM(1) = MSA (Molar surface area) [m^2/mol]
20 si_ilmen = SI("Ilmenite")
30 if (M <= 0 and si_ilmen < 0) then goto 200
40 SA = PARM(1) * M
50 if (M = 0 and si_ilmen > 0) then SA = 1e-05 #nucleation
60 k_acid = 10^(-8.35)*EXP(-37.90e+03/8.314*(1.0/TK-1.0/298.15))*ACT("H+")^(0.421)
70 k_neut = 10^(-11.16)*EXP(-37.90e+03/8.314*(1.0/TK-1.0/298.15))
80 k_base = 0
90 k_rateconst = k_acid + k_neut + k_base
100 r = k_rateconst * SA * (1-(10^si_ilmen))
190 moles = r * TIME
200 SAVE moles
   -end

KINETICS
K-feldspar
-M0 0.007112829
-parms 6.523

albite
-M0 0.028235416
-parms 6.02

anorthite
-M0    0.05566668
-parms    6.03

diopside
-M0 0.136120968
-parms 2.97

Ilmenite
-M0 0.024906507
-parms 1.916


 -steps 3.154e+9 seconds in 50 steps
 -cvode true
 #-tol  1e-6
End


[dlparkhurst]

Sorry, I have a rule that I don't "check" programs. You know what you want to do better than I, and you will have to look at the output to see if the results are consistent with your objectives.