Merge branch 'update_doc' into 'main'

- cophp

- pressure 

- flow rate [m³/hr]

- well depth [m]

- reservoir depth [m]

For details on how these parameters are calculated we refer users to the [Thermogis calculation webpage](https://www.thermogis.nl/en/calculation-model)

For details on how these parameters are calculated we refer users to the [Thermogis calculation webpage](https://www.thermogis.nl/en/calculation-model) and documentation page of pythermogis

The simulations are conducted in Java, and this package uses [JPype](https://jpype.readthedocs.io/en/latest/userguide.html) to create a Python-Java binding.

The code will simulate a Geothermal doublet, utilizing ThermoGIS with DoubletCalc1D as the engine to produce values of:

- power [Mega Watt Hour]

- heat pump power [Mega Watt Hour]

- power [MW]

- heat pump power [MW]

- capex (Capital expenditure) [Million €]

- opex (Operational expenditure) [€/kW]

- utc (Unit Technical Cost [€cent/kWH])

- npv (Net-present-value)

- hprod (Discounted Heat Produced)

- cop 

- cophp

- pressure 

- opex (Operational expenditure) in first year [Million €]

- utc (Unit Technical Cost [cts/kWH])

- npv (Net-present-value) [Million €]

- hprod (Discounted Heat Produced) [MWh]

- cop (coefficient of performance of system) [-]

- cophp (coefficient of performance of heat pump) [-]

- pressure for driving the thermal loop (wells+reservoir) [bar]

- flow rate [m³/hr]

- well depth [m]

- reservoir depth [m]

For details on how these parameters are calculated we refer users to the [Thermogis calculation webpage](https://www.thermogis.nl/en/calculation-model)

The (geothermal) power and hprod, and utc only take into account geothermal heat, and do not include the heat pump contribution.

Therefore the estimated power and hprod are lower than the actual power and hprod of the system, which includes heat from electricity consumption in the ESP and heatpump.

The reason to do so is to avoid attributing produced energy which is not renewable, as renewable energy, such that utc for the goeothermal heat can be used as reference for feed-in tariffs and subsidies.

For details on how these parameters are calculated we refer users to the theory section as well as [Thermogis calculation webpage](https://www.thermogis.nl/en/calculation-model).

For energy conversion to electricity, and chill the power concerns net electricty production and net chill respectively

The simulations are conducted in Java, and this package uses [JPype](https://jpype.readthedocs.io/en/latest/userguide.html) to create a Python-Java binding.

# Modelling Geothermal Doublets

A geothermal doublet consist of a production and injection well, 

which at reservoir level are spaced around  is a software tool developed by TNO which calculates 

how much water can be pumped at a given pump power, given a doublet system and subsurface conditions. 

It is based on a simple subsurface model and standardised well design (Figure 1). 

The DoubletCalc1D calculation method is the basis of the ThermoGIS calculation model described here. 

The software and manual can be downloaded from [Doubletcalc1D](https://www.nlog.nl/tools).

The premises for the calculation of the geothermal energy, given the aquifer, wells 

and heat exchanger characteristics are:

- Mass balance: the mass flow (kg/s) is constant in the doublet system from the 

      intake in the production well until the injection in the aquifer.

- Impulse balance (pressure balance): this is valid for the entire doublet system 

    and for all of the elements within the system. The sum of the pressure differences over all element in the system is zero. The pressure balance determines 

   the mass flow at a given pump pressure.

- Energy balance: this is valid for all elements within the system. Release of heat

  to the immediate surroundings of the well and temperature drop in the heat exchanger are taken into account. 

Figure 1 is a schematic representation of the doublet system. The numbered 

nodes,  are used to describe the components of the 

pressure and energy balances. Further details of the model can be found in the [manual of DoubletCalc1D](https://www.nlog.nl/sites/default/files/6ab98fc3-1ca1-4bbe-b0a2-c5a9658a3597_doubletcalc%20v143%20manual.pdf)

![Figure description](../images/DC1D_cartoondoublet.png)

*Figure 1: Figure of a doublet system, showing the production well and injection well, with the reservoir in between. 

The production well extracts hot water from the reservoir, which is then used to produce energy, 

while the injection well returns cooled water back into the reservoir.*

The following parameter values are proposed for the doublet model, which can be adjusted in the ThermoGIS configuration file.

The Skin factor of -1 corresponds to having a 45° slanted well in the reservoir and the -3 

corresponds to the situation after well stimulation  (hydraulic or acidication) or drilling horizontal or multilateral sections 

in the reservoir.

The well distance is optimized in such a way that the maximum cooling of the production water is 1% of ΔT after 50 years. 

This means that the difference between production water and return (injection) temperature after 50 years,

is at least 99% of the original temperature difference.

| Technical parameter                                   | symbol     | value      | unit       |

|-------------------------------------------------------|------------|------------|------------|

| use Kestin visicosty                                  | kestin_use | True       | bool       |

| distance between the two wells  at reservoir          | L          | optimized  | m          |

| pump system efficiency                                | ESPn       | 0.6        | -          |

| production pump depth                                 | ESPz       | 500        | m          |

| pump pressure, limited to 30% of hydrostatic pressure | ΔPtotal    | optimized  | bar        |

| well trajectory curvature factor                      | scurve     | 1.1        | -          |

| calculation segment length                            | Δz         | 50         | m          |

| inner diameter (casing)                               | dw         | 8.5        | inch       |

| casing roughness                                      | m          | 1.38       | milli-inch |

| injector well skin (with stimulation)                 | Sinj       | -1 (-3)    | -          |

| production well skin (with stimulation)               | Sprod      | -1 (-3)    | -          |

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