 |
| Titel |
Conceptual issues in upscaling of permeability of heterogeneous porous formations |
| VerfasserIn |
Gedeon Dagan, Aldo Fiori |
| Konferenz |
EGU General Assembly 2013
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250072787
|
|
|
|
|
|
| Zusammenfassung |
| We consider heterogeneous aquifers whose hydraulic conductivity K may change by orders
of magnitude in the same formation. The random variation is characterized by the
logpermeability variance and the correlation length scale I. Upscaling of conductivity over
blocks of size larger than I in models of aquifer flow is needed in order to reduce the
numerical burden, especially when modeling flow in heterogeneous aquifers of 3D random
structure. Also, in many applications the interest is in average values of the dependent
variables over scales larger or comparable to the conductivity length scales I. Assigning
values of the conductivity Kb to averaging domains, or computational blocks, is the topic of a
large body of literature, the problem being of wide interest in various branches of
geophysics and engineering. It is clear that upscaling causes loss of information and at
best it can render a good approximation of the fine scale solution after averaging
it over the blocks.The presentation focuses on upscaling approaches for random
media. We show that upscaling can be usually achieved only approximately, and the
result may depend on the particular upscaling scheme adopted. The typically scarce
information on the statistical structure of the fine-scale conductivity imposes a strong
limitation to the upscaling problem. The conceptual issues encountered in upscaling are
illustrated for the case of flow under a slopping soil surface for a layered medium. |
|
|
|
|
|
|