Question about PHAST

[Angus Calderhead <acalderhead@xxxxxxxxxx>]

Hello,

 

I would be grateful if you could answer a question about my PHAST input file.

 

I am setting up a dedolomitization problem with a 5-spot well pattern. I am comparing the PHAST output with the output of another model. 

 

I have attached two pictures to show you the discrepancies in results.

 

The 'Cl-' concentrations match up, indicating that this is most likely a chemistry problem.

 

I have double checked input and background concentrations,  amount of moles of the phase in the phase assemblage, I'm not sure what else to look for. Possibly the link between the .chem and .trans file?.  I have a feeling that the problem is possibly my notation in the CHEMISTRY_IC part or maybe the .chem file (?).  I have put a significant amount of time in trying to determine the problem, to no avail.

 

I have attached the PHAST input files. If you could have a look at the input files maybe you will notice something wrong or out of place.

 

I have also attached the equivalent (except 1-D instead of 5-spot well pattern) PHREEQC input file where the output matches up well with the other model.  

 

I hope you can help me with this problem.

 

Regards,

 

 

Angus Calderhead

 

Attachment: dedo.chem.dat
Description: Binary data

Attachment: dedo.trans.dat
Description: Binary data

Attachment: cl-noprob.wmf
Description: Binary data

Attachment: mg-prob.wmf
Description: Binary data

SOLUTION 0
    temp       25
    pe         4
    redox      pe
    units      mol/kgw
    density    1
    H(0)       1.1e-7
    Ca         0.0042
    Cl         0.00024
    Na         9.9e-005
    Mg         7.12e-005
    C(4)       5.5e-005
    S(6)       0.00415
    water      100

EQUILIBRIUM_PHASES 0
    Calcite   0 
SOLUTION 1-100
    temp       25
    pe         4
    redox      pe
    units      mol/kgw
    density    1
    H(0)       1.1e-008
    Ca         0.0011
    Mg         0.00082
    Na         0.0001
    S(6)       0.000845
    C(4)       0.00095 
    Cl         0.0013
    water      100 

EQUILIBRIUM_PHASES 1-100
    Calcite    0 
    Dolomite   0 13.91

TRANSPORT
    -cells                 100
    -shifts                12000
    -length			   1
    -time_step		   133627
    -initial_time          0
    -flow_direction        forward
    -boundary_conditions   flux flux
    -diffc			   1.0e-9
    -dispersivity          0.005
    -correct_disp		   true
    -punch			   100 
    -punch_frequency	   10
    -print			   50    
    -print_cells           100
    -print_frequency       1000