# HydroGeoSphere/Wells

Well domains, can be set up using the following instructions, as outlined in Section 2.3.2.2 and in Equation 2.55. The variable radius corresponds to ${\displaystyle r_{s}}$, while the pumping rates ${\displaystyle Q_{w}}$, use the new boundary condition format as described in Section 5.7.

## Default Well Properties

Unless the user modifies the default values, all well zones in the domain will be assigned the default properties. The default values, Table 5.8, can be and are recommended to be modified to fit the model application.

Table 5.8: Default Values for Well Properties
Parameter Value Unit
Screen Radius 1 × 10−5 m
Coupled Conductivity 7.438 × 10−5 m s−1
Coupled Length 1 × 10−4 m
Well Type Hagen-Poiseuille -
Manning’s Friction Coefficient 0.0548 m−1/3 s
Hazen Williams Coefficient 130 m0.37 s−1
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## Example Well Instructions

As an example, the following set of instructions, with prefix.wprops file Figure 5.12, could be inserted into the prefix.grok file to produce a pumping well:

```use domain type
well

properties file
prefix.wprops

clear chosen segments
choose segments polyline               !Screen interval
2
100. 100. 0.
100. 100. 20.

new zone
1

clear chosen zones
choose zone number
1

well one

clear chosen nodes
choose node                            !Bottom of pump intake
100. 100. 0.

create node set
well

boundary condition
type
flux nodal

name
well

node set
well

time value table
0.0 -80.0e-3                        !Pumping duration and rate
end
end
```

The well domain example opens the property file prefix.wprops, shown in Figure 5.12, and creates a 20 m long screen located at x = 100 and y = 100 with a pump intake located at z = 0. The well one properties are read into grok and a steady pumping rate is set at -80 × 10−3 m3 s−1. If the flowrate is set to zero, the well is passive but can still transmit water vertically through its screen.

```!------------------------------------------
well one

0.05d0

coupling length
1.0e-4

coupling conductivity
.0023

end
```
Figure 5.12: Sample well domain property file prefix.wprops

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Scope: .grok .wprops

The radius of the screen interval of the well.

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## Infilled

Scope: .grok .wprops

1. WellPropsInfilled Infilled well properties name from .mprops file.

This command should be included in the input file for an infilled well. The default values are a sand as described in Table 5.7.

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## Hagen Poiseuille

Scope: .grok .wprops

This command should be included in the input for the Hagen Poiseuille flow option.

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## Hazen Williams

Scope: .grok .wprops

This command should be included in the input file for the Hazen Williams flow option.

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## Manning

Scope: .grok .wprops

This command should be included in the input file for the Manning flow option.

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## Friction

Scope: .grok .wprops

1. well_friction Manning’s Well Friction.
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## Hazen Williams coefficient

Scope: .grok .wprops

1. well_hw_coeffient Hazen-Williams well coefficient.
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## Saturated wells

Scope: .grok .wprops

This instruction causes wells to remain fully saturated.

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## Dual nodes for wells

Scope: .grok .wprops

This instruction causes well flow scheme to use dual node approach.

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## Coupling conductivity

Scope: .grok .wprops

1. WellPropsCplCond Coupling conductivity for well [L T−1].

Coupling conductivity parameter only required for the dual node approach for wells.

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## Coupling length

Scope: .grok .wprops

1. WellPropsCplLngth Coupling length for well [L].

Coupling length parameter only required for the dual node approach for wells.

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