MINC to simulate dual-porosity reservoir, with some fractures are open, some are closed.
I'm using MINC to simulate dual-porosity reservoir, since I assume some fractures are open, some are closed, could I assign different permeability or porosity to fracture elements based on coordinate?
Right now, I found fractures are subgriddings of matrix, it will change both permeability if I add permeability modification factor to some cells.
7 replies
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Jing,
After you MINCed a primary mesh, you get a secondary mesh (on file MINC) that contains (at least) two elements at each coordinate location: one for the fractures, one for the matrix (each being treated as a continuum). Nothing prevents you from assigning individual permeability modifiers to all (or some) fracture elements, leaving the matrix permeabilities unchanged. Of course your pre-processor cannot just identify elements by their coordinates, but has to also check either for the material number (or name), the element name (which for all fracture elements starts with a blank), or simply the order (the fracture element always comes first, followed by the matrix element(s) at the same coordinates). In case you are using iTOUGH2 and geostatistics, you can simply identify the material names to be included in the mapping, easily leaving out the matrix elements.
Let me know if I misunderstood what you intend to do.
Stefan
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Thank you very much Stefan!
I saw the MINC file contains both fracture and matrix, do you mean to change fracture permeability in MINC file, and how? I read several manual, and knew that the first value after FRAC/MATX is volume, and the last three values are x,y,z. But what is the 0.0000E+00 after volume?
eg. part of MINC file:
0 1 FRAC10.1482E+020.0000E+00 0.3333E+010.3333E+01-.1967E+03
2 0 1 MATX10.8889E+020.0000E+00 0.3333E+010.3333E+01-.1967E+03
3 0 1 MATX10.1926E+030.0000E+00 0.3333E+010.3333E+01-.1967E+03 -
Jing,
Just read about the ELEME block in the TOUGH2 manual. The value after volume is the surface area for semianalytical heat exchange (you probably won't need it), but then comes the permeability modifier in Columns 41-50 - that's teh variable you need to provide.
Stefan
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Thank you very much!
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I'm trying to run a simulation with such a modified MINC file. But the modified file is overwritten with a new MINC file. How can I prevent this?
One suspicion was that the MESHMAKER block in the input file just starts repeating the pre-processing for the secondary mesh:
MESHM----1----*----2----*----3----*----4----*----5----*----6----*----7----*----8 MINC PART THRED MMALL 2 1OUT 10.0 10.0 10.0 0.05But without this block TOUGH2 would not recognize that it is set to MINC mode, would it? Even though I provide MESH and MINC file.
Any hints appreciated.
Thanks,
Julia -
Julie,
(1) Create the MINC mesh using a primary mesh (either provided in the input file or as external file MESH) and the MESHM block you showed.
(2) Edit the resulting MINC file as needed.
(3) Remove the MESHM block; remove the primary mesh.
(4) Copy the MINC file into the TOUGH2 input file, or provide it as an external file MESH.
Stefan
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That did the trick. Thanks, Stefan.