Permeability not evolving during the simulation

[Tong Guo]

Hi Glenn and Peter,

I met the problem that the permeability doesn't change over the mineral precipitation and dissolution, I have added UPDATE_PERMEABILITY in the chemistry block and it is still not changing, the porosity evolves over the time. The script is attached below, can you help to check out the reason why permeability doesn't change? 

Thanks in advance.

Best,

Tong

[Hammond, Glenn E]

Tong,

 

I apologize for the delayed response.

 

This functionality has not been exercised extensively. There is an internal variable that truncates the minimum scaling factor for permeability (due to change in porosity).

https://bitbucket.org/pflotran/pflotran/src/5bd1672c06c71724cf09959d291da9d35e9468b3/src/pflotran/realization_subsurface.F90#lines-2010

 

The default value of this variable is “1.d0”, which is an issue.

https://bitbucket.org/pflotran/pflotran/src/5bd1672c06c71724cf09959d291da9d35e9468b3/src/pflotran/material.F90#lines-195

 

Please add the following card to your MATERIAL_PROPERTY blocks

https://bitbucket.org/pflotran/pflotran/src/5bd1672c06c71724cf09959d291da9d35e9468b3/src/pflotran/material.F90#lines-789

 

PERMEABILITY_MIN_SCALING_FACTOR 0.d0

 

This should allow the scaling factor to drop below 1 and the permeability to drop below its original value. Unfortunately, this card is not documented.

 

Glenn

 

From: pflotra...@googlegroups.com <pflotra...@googlegroups.com> On Behalf Of Tong Guo
Sent: Wednesday, August 28, 2024 11:34 AM
To: pflotra...@googlegroups.com
Subject: [pflotran-users: 7945] Permeability not evolving during the simulation

 

Check twice before you click! This email originated from outside PNNL.

 

--
You received this message because you are subscribed to the Google Groups "pflotran-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to pflotran-user...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/pflotran-users/CAC3dJwjuY5JNz3ULYcyvN3kkmrnPMS2tnSaUn6uHcLgsxpm_xQ%40mail.gmail.com.

[Tong Guo]

Hi Glenn,

Thanks for your reply, that works. But here I have another question about the database in the code:

In PHREEQC, I add the CO2(g) and CH4(g) in the water solution and the hematite is included in the minerals, the minerals get equilibrium with the soluiton, the result showed using llnl.dat the hematite can be dissolved completely to get the high iron concentration. But in PFLOTRAN, when I did the same simulation using handord database, hematite only dissolved a little and the iron concentration is pretty low in the new solution.

I looked up the logk in these two database, seems the logk values are similar under different temperature. So I am wondering what can I change in hanford database or what reason caused the different results?

Thanks.

Tong

[Hammond, Glenn E]

Tong,

 

Mineral precipitation-dissolution in PFLOTRAN is entirely “kinetic”. If you specify an initial volume fraction of Hematite, it must dissolve through kinetically formulated mass transfer. To mimic PHREEQC’s “equilibrium” dissolution, you will need to assign a very large RATE_CONSTANT to the mineral precipitation-dissolution reaction, prescribe a small maximum time step, and allow time for dissolution.

 

Glenn

 

To view this discussion on the web visit https://groups.google.com/d/msgid/pflotran-users/bc2154b5-6fd1-444c-9f98-000ee7b1cf5dn%40googlegroups.com.

[Gérard Lods]

Hi,

I have an ERROR with varying permeability :

     CHEMISTERY
            ...
            UPDATE_PERMEABLITY   ! ERROR: Keyword "UPDATE_PERMEABLITY" not recognized in CHEMISTRY
      END

although : https://documentation.pflotran.org/user_guide/cards/subsurface/chemistry_card.html#chemistry-card  .

Best,

Gerard