Joris Popineau and his team have created a geothermal numerical model of the Paris Basin to define and monitor the invaluable energy resource surrounding the iconic city.
Paris may conjure images of the Eiffel tower, the Louvre’s Mona Lisa, or sipping champagne on a Seine River cruise across the French capital.
But for Joris Popineau, it’s the geothermal significance of the 140,000 km² basin encircling this world-famous city that piques his interest.
“The Paris Basin is important to Europe for culture and wine, absolutely,” says Popineau, Geothermal Reservoir Engineer and researcher.
“What is less well-known is the critical role it has played below ground for over forty years, supplying geothermal heat to over 250,000 homes.”
In a first for Leapfrog Energy, Popineau and his academic colleagues have created a subsurface model of the Paris Basin and used it to build a numeric model connected regionally.
“We have used historical data to try to replicate past reservoir behaviour,” says Popineau.
“With the aim to more clearly define and better monitor this essential renewable energy resource.”
Location of the modelled sedimentary Paris Basin showing the reservoir layers at 1600 mRL
Warming the Paris region from below
The roughly oval-shaped plateaus and broad valleys of the Paris Basin were created in the Triassic and Jurassic periods.
Sedimentary layers of carbonate rocks not only support rich agricultural productivity and a thriving economy, but also low enthalpy geothermal energy for direct-use district heating systems.
The varying natures of clays, limestones and chalk give rise to the distinct characteristics of regional produce, such as Champagne.
“While below ground, geothermal production wells up to two kilometres deep, exploit the subsurface soil layers of the Dogger aquifer for heat,”
says Popineau.
Since harnessing this renewable energy source began in the early 1970s, the area has hosted more than 50 geothermal district heating network systems.
Over the winter, hot brine up to 75°C is extracted and re-injected back below ground at around 40°C, a production process known as the “doublet” concept.
“Modelling such a large-scale geothermal reservoir is valuable for understanding the pressure and temperature response in the productive areas,” says Popineau.
“And helps better support crucial, more sustainable decision-making for its future.”
Temperature and pressure distribution at the top of the geothermal reservoir in the sedimentary basin
Complex geothermal concepts made easy
Geothermal heat is clean, renewable and (with a much lower environmental impact than conventional sources) is an integral part of the energy transition towards net zero.
While global political and economic turmoil has sparked fresh urgency for Europe to be looking at and investing in sources of energy other than oil and gas.
“It’s about educating people as well as changing mindsets, which is something that as researchers we can do,”
says Popineau.
“We want to make geothermal energy easy to understand but what we’re essentially mining is an intangible product – heat – that is not always easy to show.”
Popineau’s model of the Dogger aquifer in the South-East of the Paris Basin calibrates initial field data with historical data.
“Leapfrog Energy’s robust and flexible modelling workflow allowed me to set up a sophisticated reservoir model that can be calibrated to the production history data,”
he says.
“It’s a great visualisation tool, tying all our data together beautifully and in a way that you can easily share with other people – even those who are not experts in the field.”
See the rocks and reservoir wells beneath
Leapfrog Energy is widely established in the industry for high-temperature geothermal applications but there are emerging opportunities to now map low enthalpy geothermal fluids.
“Our understanding of the Paris Basin reservoir has evolved with every new idea and data set that we integrate and visualise in our model,” says Popineau.
“With more production wells and more interaction between the wells we have lots of fresh, accurate data available to help give us realistic simulations of both past and future conditions.”
“Leapfrog Energy allowed a better understanding of the temperature and pressure inside the reservoir at the different locations and how they interact with each other.”
“We could easily integrate our geological map into our reservoir model to show the unique sedimentary layers of the region’s subsurface.”
This was not with the intention to reflect the proper lithologies but to represent the different productive layers needed for the numerical model.
“The numerical model was then imported back into Leapfrog for visualisation,” he says.
Representation of the geothermal wells and the sedimentary reservoir rock types underneath the South Paris area.
Working together towards the energy transition
Popineau understands that helping to unlock the future of clean, geothermal energy is not a silver bullet solution.
“It’s a sustainable option yes, but not necessarily the only answer, rather a piece of the puzzle. And we can all play our part in building a fuller picture,”
he says.
“I’ve been working in geothermal for six years now and what strikes me most is the tight-knit feel of the industry globally.
“There’s a real sense of collaboration and cooperation between people,” he says. “Our project to model the Paris Basin is a great example of that.”
Popineau trained to be a Geoscientist in France and after travelling in New Zealand, worked at the University of Auckland for four years.
He is now based on the island of New Caledonia, in the southwest Pacific Ocean, as a consultant on commercial projects advising clients on how to best manage their geothermal fields.
“My time in New Zealand taught me so many key things about working in geothermal,” says Popineau.
“I’ve always wanted to apply this knowledge to Europe – especially in France – because that’s where I studied and that’s where I’m from.”
Connecting with friends in the geothermal field
Popineau kicked off the project together with Theo Renaud and other university friends in 2020.
“Because we’re creating this project in our own time, one of the biggest challenges was trying to find space to work together across different time zones,” he says.
Being able to collaborate in the cloud to continuously integrate and update data with Leapfrog Energy would quickly put all the team on the same page, at the same time.
“Meaning we gained maximum value from our sessions when we could connect,” says Popineau.
“We hope people in the industry can gain good insights from our Paris Basin models for a better understanding of this famous district heating region.”