Pumping Test in fractured aquifer (double porosity)

Dear all,


I would like to simulate a pumping test that I have made in a fractured aquifer. The real data has been interpreted as a double porosity aquifer, [i]i.e.[/i] a medium where the fractures play a transmissive role, and the matrix a capacitive role. Hence, the flow comes first from the fractures, and then gradually from the matrix.

I am a little familiar with Feflow, and from what I have read, I have to use discrete elements to simulate fractures. Anyway, will it be possible to have both flows (fracture AND matrix) in Feflow with different hydraulic properties in the same layer ? Or will I have to superpose thin layers (one for fractures and one for matrix) ?

Any advice would be great !!!

Thanks, and all the best,

Johan  :)

Using discrete elements, the fractures will be 'between' the layers (if you think about horizontal fractures). They will be reduced in the model to 2D. FEFLOW does not handle a double porosity approach, where the same layer has different properties for the fracture and matrix parts.

Thanks for your answer Mr. Schätzel,

If I understand correctly, a horizontal (2D) fracture inserted as a discrete element will be located along the faces of finite elements. Does that mean that this fracture will behave as an individual layer located between the upper and lower layers ? or will it be located inside (in the middle of) one layer ?

I guess I may be able to simulate matrix-fracture exchanges by inserting a horizontal fracture between two layers having the same flow properties? This would be a sort of double porosity approach, which could work. I will try.

Thanks

Johan

[quote author=Peter Schätzl link=topic=539.msg1289#msg1289 date=1231748717]
Using discrete elements, the fractures will be 'between' the layers (if you think about horizontal fractures). They will be reduced in the model to 2D. FEFLOW does not handle a double porosity approach, where the same layer has different properties for the fracture and matrix parts.
[/quote]

Dear Peter,

I try to model karstic area with FEFLOW. You allready wrote down that FEFLOW does not handle double porosity. I just wonder that if I enter the tabular data  for unsaturated media to represent double porosity, would't the results represent double porosed media. If I enter data in the attachment and use the spline model for unsaturated flow, does the results represent double porosed media ? Or do I have to define discrete elements for the karstic media everytime ?