How to define a well in a multilayered aquifer in model muse....?

[Joaquin]

Well

Now, I'm trying to work with ModelMuse (MM) instead of VisualModflow
(VMF).

I don't have problems to assign hydraulic properties. It's easy and
useful the method in MM. But, the problem for me is to indicate the
program the characteristics of a well, principally the location of the
screen.

The way wich actually I use to define a well is:
1. I draw point in the well where the well locates.
2. Right click to edit the properties of the selected object.
3. In the object properties for the "Higher Z-Coordinate" I assign the
depth/elevation where begins the screen and for the "Lower Z-
Coordinate" the depth/elevation where the screen finishes.
4. In the object properties, in the Modflow Features I select the Well
Package and I set the total pumping rate.

Or may be I must use the MNW package, because the model is a
multilayered aquifer with wells that cross different layers?

Thank you everybody.

[Richard B. Winston]

The total pumping rate in ModelMuse would be more correctly labeled as
the total rate per layer. You would need to divide the rate by the
number of layers intersected to get the rate right.

If you want to simulate flow through the well from one layer to another
or to have MODFLOW calculate how to divide up the pumping between
layers, you should use the MNW package.

[Joaquin]

Well, let me show how I imagine the way to do that.

You say: Would be more correctly labeled as the total rate per layer.

Me: Sometime i worked with the PMWIN, and in that program the flow
assignation is by layer. It means, I needed to calculate the flow with
this formula

Q_i = [{L_i * K_xi}/{Sum (L_i*K_xi)}] * Q_T

Q_i is the discharge from layer i to a particular well in a given
stress period,

Q_T is the well discharge in that stress period,

L_i is the screen length in layer i,

K_x is the hydraulic conductivity in the x-direction in layer i, and

It's the same way in model muse to assignate the flow for a
multilayered system with the well package?

I'm so sorry. I really a newborn with this (Visual Modflow damaged my
mind)...

What's the difference for the pumping rate if I choose:

- Total (for me it means the total flow extrated/injected with a well)
- Direct
- Calculated

Can I read about it in some place?

On 14 dic, 05:46, "Richard B. Winston" <rbwins...@mindspring.com>
wrote:

[Richard B. Winston]

Go to where you define the wells and click the Help button.

[Richard B. Winston]

Here is what it says there:In many cases, if a polyline or polygon is
used to specify a group of wells, it may be advantageous to specify the
pumping rate as a rate per unit length or rate per unit area and then
multiply by ObjectIntersectLength <objectintersectlength.htm> or
ObjectIntersectArea <objectintersectarea.htm>. Doing so makes it
possible to modify the grid without reentering information. If the
Pumping rate interpretation is set to Calculated, those functions will
be included automatically.

Sometimes it may be desirable to specify the total well flux for an
object. One way to do this would be to use a formula of the form (Total
Rate)/ObjectArea <objectarea.htm>*ObjectIntersectArea
<objectintersectarea.htm> or (Total Rate)/ObjectLength
<objectlength.htm>*ObjectIntersectLength <objectintersectlength.htm>. If
the Pumping rate interpretation is set to Total, those functions will be
included automatically.

[Joaquin]

Thanx for the text about the definition of wells in model muse.

Also, I read the wells and pumping rates in the "Model Muse Class
Notes Extended", received from you.

It says in the page 18:
You may have noticed that on the pane for the wells in the Object
Properties dialog box, that there was a combo box labeled “Pumping
rate interpretation”. For point objects, it doesn’t matter what you
choose; the pumping rates are unaffected by the Pumping rate
interpretation for point objects.

And I define the wells as a point.

So... for testing purposes I made a model with

- 3 layers (the thicknes for each is 10 meters)
- 10 rows and 10 cols (with a side of 10 meters)
- Kx=Ky= 10 m/d and Kv= 1 m/d
- Ss = 1 e-5
- Sy = 0.2
- Initial Head = 25 meters

And I defined a well with a point with:
- Higher Z-coordinate=10 m
- Lower Z-coordinate = 5 m
- Activated with the well package in Modflow Features and a pumping
rate of 86.4 (m3/d) from day 1 to day 5.

The time steps in days

0 -1
1 - 5
5 - 10

I've tested this option with the pumping rate interpretation as total,
calculated and direct. It's true that for points doesn't matter the
pumping rate interpretation. As a result, in the .lst file I have
this:

WELL NO. LAYER ROW COL STRESS RATE IFACE

---------------------------------------------------------------------------------------------
1 3 5 5
-86.40 0.000

But, I need wells that cross two or more layers. In this case, the K
is the same for all layers. I changed the Higher Z-coordinate, and i
established 15 meters. With the same pumping rate, the results are the
same, but now, the model takes in account two wells, I saw it in
the .lst file:

WELL NO. LAYER ROW COL STRESS RATE IFACE

---------------------------------------------------------------------------------------------
1 2 5 5
-86.40 0.000
2 3 5 5
-86.40 0.000

for a total extration rate: 172.8 (m3/day).

Is this what you talked about in the answer of the 14th december?

Thanks

On 19 dic, 05:38, "Richard B. Winston" <rbwins...@mindspring.com>

[Richard B. Winston]

Yes. Each layer intersected by the point object defines a well with the
pumping rate you specified. The total pumping rate is the pumping rate
you specified times the number of layers intersected by the object.

Joaquin wrote:
> Thanx for the text about the definition of wells in model muse.
>
> Also, I read the wells and pumping rates in the "Model Muse Class
> Notes Extended", received from you.
>
> It says in the page 18:
> You may have noticed that on the pane for the wells in the Object

> Properties dialog box, that there was a combo box labeled �Pumping
> rate interpretation�. For point objects, it doesn�t matter what you