Hello guys . Does anybody know how to simulate the deformation of the soil caused by fluidflow in both TOUGH and FLAC3D? Thanks

Floriane Youzan I didn't try the FLACTOUGH (FLAC calling TOUGH) implementation myself. I am suggesting it since the current implementation of TOUGHFLAC (TOUGH calling FLAC) alters TOUGH source code a lot which requires a really good knowledge of the Fortran language. It's even more complicated with TOUGH3 since you should now also consider that arrays are distributed in parallel. However, the TOUGHFLAC implementation is more optimized as it does not require to read and write TOUGH input/output files at each time step.

Assuming that you have already setup your problem for TOUGH and FLAC3D independently, a quick algorithm would look like as below:

1. Solve the mechanical state in FLAC3D to a time step Dt,

2. Calculate stress-induced changes in porosity and/or permeability and update TOUGH input files (MESH and/or INCON) with these new values,

3. Solve fluid and heat flow in TOUGH to time step Dt,

4. Import pressure and temperature from SAVE file and update zone pore pressure and temperature in FLAC3D,

5. Loop back to step 1 until end of simulation.

FLAC3D has a Python interface which should make this a bit easier to implement compared to using FISH. For instance, you can call an external program in Python as follow:

import subprocess

subprocess.call(["tough3-eco2n", "INFILE"], shell=True)

To update a zone pore pressure and temperature, I don't remember if there is a zone array for these properties, but you can loop over each zone and update the parameters as follow:

import itasca as it

for zone in it.zone.list():
    # Interpolate my_pp and my_temp from SAVE file
    zone.set_pp(my_pp)
    zone.set_temp(my_temp)

Reading TOUGH input and output files can be done using toughio. You can install toughio in FLAC3D by running this command in a Windows console:

cmd /C ""C:/Program Files/Itasca/FLAC3D700/exe64/python36/Scripts/pip.exe"" install toughio --user

Floriane Youzan Not sure about what you are asking. Assuming that your mesh is generated (with all zone groups assigned if necessary), you simply have to assign constitutive models and properties to your zones, initialize the initial and boundary stress conditions (e.g. roller at the bottom) and then solve the mechanical state to equilibrium.

Floriane Youzan I've attached a sample FLAC3D script. It shows the main commands to set up your model in FLAC3D.

Floriane Youzan It's a 2D model (extruded to 3D):

xlim = [-350000.0, 350000.0]

zlim = [-3000.1, 0.0]

Floriane Youzan Sorry for the late reply.

I never encountered this issue. Could you send me your script?

Floriane Youzan I am not sure what Line 4 is... is it the command

model configure fluid

that does not work?

Floriane Youzan You have to call

model configure fluid

before using

zone fluid something

Same for thermal, you have to call

model configure thermal

before using

zone thermal something

See my original script.

Floriane Youzan Put it at the beginning of the script. In my original sample script, it starts with

model configure fluid
model configure thermal

Floriane Youzan Of course.

In my sample problem, I applied roller boundary conditions everywhere except at the surface. To do so, I prevent lateral grid points from moving horizontally:

zone gridpoint fix velocity-x range position-x -350000.0
zone gridpoint fix velocity-x range position-x 350000.0

And grid points at the bottom of the mesh from moving vertically:

zone gridpoint fix velocity-z range position-z -3000.1

Since the sample problem is invariant in y, I fixed the velocity along the Y axis:

zone gridpoint fix velocity-y

but you shouldn't do that if your mesh is 3D.

Note that the mesh is 2D (XZ plane) with x in the range [-350000.0, 350000.0] and z in the range [-3000.1, 0.0].

Floriane Youzan You can read your SAVE file in FLAC3D using toughio.

save = toughio.read_output("SAVE")

This returns a namedtuple with a data dictionary that contains the primary variables X1, X2 ... up to X4. The number of primary variables and their meanings depend on the EOS you are using. For instance, for EOS3, X1 corresponds to pressure (or gas pressure if two-phase) and X3 to temperature. You can then update FLAC3D zones' pressures and temperatures using the instruction:

for i, zone in enumerate(it.zone.list()):
    zone.set_pp(save.data["X1"][i])
    zone.set_temp(save.data["X3"][i])