implement NVOE calculation to avoid sand production by octavianor · Pull Request #329 · Project-OMOTES/simulator-core

octavianor · 2025-11-20T14:42:22Z

No description provided.

Copilot

Pull request overview

This PR implements NVOE (Net Volume Over Extraction) calculations to prevent sand production in ATES (Aquifer Thermal Energy Storage) systems by dynamically limiting charge and discharge flow rates based on physical constraints.

Key Changes:

Added methods to calculate maximum safe flow rates for injection and extraction based on aquifer properties, temperature, and pressure
Implemented dynamic calculation of saline density and viscosity to improve accuracy
Added state management to propagate calculated power limits to the controller

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
`controller_storage.py`	Added `set_state` method to update maximum charge/discharge power limits from ATES calculations
`ates_cluster.py`	Implemented NVOE calculations with helper methods for saline properties, maximum flow rates, and state propagation

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Copilot · 2025-11-25T10:09:45Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

-        rosim_input__flow = [volume_flow, -1 * volume_flow]  # first elemnt is for producer well
-        # and second element is for injection well, positive flow is going upward and negative flow
-        # is downward
+        rosim_input_flow = [volume_flow, -1 * volume_flow]  # the first-element is for hot well


Corrected 'first-element' to 'first element' (remove hyphen).

Suggested change

rosim_input_flow = [volume_flow, -1 * volume_flow] # the first-element is for hot well

rosim_input_flow = [volume_flow, -1 * volume_flow] # the first element is for hot well

Copilot · 2025-11-25T10:09:45Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

+        rosim_input_flow = [volume_flow, -1 * volume_flow]  # the first-element is for hot well
+        # and the second-element is for cold well. positive flow is charge and negative flow


Corrected 'second-element' to 'second element' (remove hyphen).

Suggested change

rosim_input_flow = [volume_flow, -1 * volume_flow] # the first-element is for hot well

# and the second-element is for cold well. positive flow is charge and negative flow

rosim_input_flow = [volume_flow, -1 * volume_flow] # the first element is for hot well

# and the second element is for cold well. positive flow is charge and negative flow

Copilot · 2025-11-25T10:09:46Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

+
+    def get_state(self) -> dict[str, float]:
+        """Function to calculate the maximum charge and discharge rate based on NVOE."""
+        P = self.aquifer_depth * 0.1  # bar assume pressure increase 1 bar per 10 m depth


The comment is missing punctuation and proper capitalization. Consider: '# Bar - assume pressure increases 1 bar per 10 m depth'.

Suggested change

P = self.aquifer_depth * 0.1 # bar assume pressure increase 1 bar per 10 m depth

P = self.aquifer_depth * 0.1 # Bar - assume pressure increases 1 bar per 10 m depth

Copilot · 2025-11-25T10:09:46Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

+        max_flowrate = max_flowrate * self.aquifer_depth * 0.01  # using depth factor because ATES
+        # is deeper than WKO


The magic number 0.01 lacks explanation. Consider defining it as a named constant (e.g., DEPTH_CORRECTION_FACTOR = 0.01) with a comment explaining its physical meaning and why it's specific to ATES vs WKO.

samvanderzwan

See the comments.
In general avoid magic numbers and ensure the documentation of methods is up to date explaining what a method does.

samvanderzwan · 2025-11-25T10:14:31Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

        self.salinity = salinity  # ppm
        self.well_casing_size = well_casing_size  # inch
        self.well_distance = well_distance  # meters
+        self.wellbore_diameter = 31.0  # inch


These are magic numbers, and need to be either defined in the asset defaults and better yet have them is input argument and set them in the mapper.
Next to this you have nicely added the unit, but you are now using in the same assets inch and m, this will lead to errors in future, please only use SI. When you need to pass non SI units to for example Rossim do the conversion at the latest possible moment

i will add in asset default since this value is not defined in ESDL

change to SI

src/omotes_simulator_core/entities/assets/ates_cluster.py

samvanderzwan · 2025-11-25T10:15:19Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

        SALINITY = self.salinity
        WELL2_X = self.well_distance + 300
-        CASING_SIZE = self.well_casing_size
+        CASING_SIZE = self.wellbore_diameter


This does not seem logical, you would expect here the casing size

yes now change to wellbore diameter

change back to casing size

samvanderzwan · 2025-11-25T10:16:06Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

        """Function to calculate storage temperature after injection and production."""
-        volume_flow = self.mass_flowrate * 3600 / 1027  # convert to second and hardcoded saline
-        # density needs to change with PVT calculation
+        saline_density = self._get_saline_density(


What is the 20?

forgot to replace the pressure here based on depth

Oke, but the comment is now incorrect, since it states per 10 m. Next to this it also assumes density of 1000 and g of 10, better to use actual values, since you have them.

implement the actual downhole pressure

samvanderzwan · 2025-11-25T10:32:51Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

        self.cold_well_temperature = celcius_to_kelvin(ates_temperature[1])  # convert to K
+
+    def get_state(self) -> dict[str, float]:
+        """Function to calculate the maximum charge and discharge rate based on NVOE."""


This is the get state method, to get the state of the object at a certain time step.

i am using this get state method to calculate the new maximum flowrate, do you have any other method?

samvanderzwan · 2025-11-25T10:41:46Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

+        # diameter
+        well_radius = 0.5 * self.wellbore_diameter * 0.0254  # m
+
+        cloggingVel = 0.3


It is not clear where this number come from, and it is not good practice to have this kind of numbers somewhere in a method.

i put reference parameters value

samvanderzwan · 2025-11-25T10:42:29Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

+
+        max_flowrate = (
+            2 * math.pi * well_radius * self.aquifer_thickness * max_infiltrate_flow_velocity
+        )  # m/h


should be m3/h

samvanderzwan · 2025-11-25T10:43:41Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

+        return max_flowrate
+
+    def _get_saline_density(self, P: float, T: float) -> float:
+        """Function to calculate the saline density."""


what are the inputs, what is the return value
What approach do you use?
This method needs more explanation, since there are some formulas in but it is not clear where they come from. It can also be added to the rst.

i have attach the reference and will add to rst

samvanderzwan · 2025-11-25T10:48:04Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

+
+    def _get_saline_density(self, P: float, T: float) -> float:
+        """Function to calculate the saline density."""
+        P = P * 1e5 * 1e-6  # Bar to MPa


This works, since P is a float and P outside of the method is not changed. but better to give it a different name.

i will change

samvanderzwan · 2025-11-25T10:48:17Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

+        return density
+
+    def _get_saline_viscosity(self, P: float, T: float) -> float:
+        """Function to calculate the saline viscosity."""


See comments previous method

is its using Batzle-Wang correlation

…formula-for-ates

samvanderzwan

There are still some comments open from previous review.
Other changes are ok

samvanderzwan · 2026-01-16T10:42:53Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

        """Function to calculate storage temperature after injection and production."""
-        volume_flow = self.mass_flowrate * 3600 / 1027  # convert to second and hardcoded saline
-        # density needs to change with PVT calculation
+        saline_density = self._get_saline_density(


Oke, but the comment is now incorrect, since it states per 10 m. Next to this it also assumes density of 1000 and g of 10, better to use actual values, since you have them.

samvanderzwan · 2026-01-16T10:43:18Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

+        water_density = fluid_props.get_density(average_temperature)
+        water_heat_capacity = fluid_props.get_heat_capacity(average_temperature)
+
+        max_extraction_flow_cold_well = self._get_max_flowrate_extraction_norm(


samvanderzwan · 2026-01-16T10:43:27Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

+
+    def _get_max_flowrate_extraction_norm(self, P: float, T: float) -> float:
+        """Function to calculate the maximum flowrate of production in norm."""
+        grav_accel = 9.81  # m/s2


samvanderzwan · 2026-01-16T10:43:34Z

src/omotes_simulator_core/entities/assets/ates_cluster.py

+        grav_accel = 9.81  # m/s2
+        saline_density = self._get_saline_density(P, T)
+        saline_viscosity = self._get_saline_viscosity(P, T)
+        aquifer_permeability = self.aquifer_permeability * 9.8692326671601e-16  # mD to m2


…um flowrate

octavianor · 2026-02-06T15:29:25Z

There are still some comments open from previous review. Other changes are ok

it is chicken-egg problem:

in order to get saline density downhole. I need to have downhole pressure

if I need to calculate downhole pressure using actual value: rho * g * h, I need rho

…formula-for-ates

implement NVOE calculation to avoid sand production

ef38c63

octavianor linked an issue Nov 20, 2025 that may be closed by this pull request

add NVOE formula for ATES #311

Open

octavianor marked this pull request as draft November 20, 2025 14:42

fix typecheck and linting

f4fc582

octavianor marked this pull request as ready for review November 20, 2025 14:58

octavianor requested review from MichielTukker, samvanderzwan and vanmeerkerk November 20, 2025 14:58

samvanderzwan requested a review from Copilot November 25, 2025 10:08

Copilot AI reviewed Nov 25, 2025

View reviewed changes

samvanderzwan requested changes Nov 25, 2025

View reviewed changes

octavianor added 5 commits November 28, 2025 09:26

implement feedback for review

9dd0339

create new function to calculate maximum charge and discharge rate

9979f4b

Merge remote-tracking branch 'remotes/origin/main' into 311-add-nvoe-…

805a7ce

…formula-for-ates

reformat text

1e8e15e

remove casing size

e269fc6

octavianor requested a review from samvanderzwan December 1, 2025 21:18

octavianor added 2 commits December 17, 2025 10:09

Merge remote-tracking branch 'remotes/origin/main' into 311-add-nvoe-…

03a0f0d

…formula-for-ates

fix linting

7c3df2c

samvanderzwan requested changes Jan 16, 2026

View reviewed changes

octavianor added 2 commits February 6, 2026 15:30

change back to well_casing_size and using new esdl ver 26.2 for maxim…

0a8f478

…um flowrate

fix lint, test, typecheck

7b94b5a

put gravity acceleration in default

ca2b8f4

octavianor requested a review from samvanderzwan February 6, 2026 15:32

Merge remote-tracking branch 'remotes/origin/main' into 311-add-nvoe-…

c5e27b4

…formula-for-ates

	rosim_input_flow = [volume_flow, -1 * volume_flow] # the first-element is for hot well
	rosim_input_flow = [volume_flow, -1 * volume_flow] # the first element is for hot well

		rosim_input_flow = [volume_flow, -1 * volume_flow] # the first-element is for hot well
		# and the second-element is for cold well. positive flow is charge and negative flow

	P = self.aquifer_depth * 0.1 # bar assume pressure increase 1 bar per 10 m depth
	P = self.aquifer_depth * 0.1 # Bar - assume pressure increases 1 bar per 10 m depth

		max_flowrate = max_flowrate * self.aquifer_depth * 0.01 # using depth factor because ATES
		# is deeper than WKO

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octavianor commented Nov 20, 2025

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Pull request overview

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