REFLECT – European research project on fluids and the optimization of geothermal energy extraction

REFLECT project sampling sites (source: REFLECT website)
Alexander Richter 25 Mar 2020

The efficiency of geothermal utilisation depends on the behaviour of fluids that transfer heat between the geosphere and the engineered components of a power plant, which is part of an European research project called REFLECT.

The EU-funded REFLECT project, is focused on “Redefining geothermal fluid properties at extreme conditions to optimize future geothermal energy extraction.”

The efficiency of geothermal utilisation depends on the behaviour of fluids that transfer heat between the geosphere and the engineered components of a power plant. REFLECT aims to avoid problems related to fluid chemistry rather than treat them. The physical and chemical fluid properties are often poorly defined, as in situ sampling and measurements at extreme conditions are difficult to date. Therefore, large uncertainties in current model predictions prevail, which will be tackled in REFLECT by collecting new, high-quality data in critical areas. These data will be implemented in a European geothermal fluid atlas and in predictive models allowing to provide recommendations on how to best operate geothermal systems for sustainable use.

From react to REFLECT: the project aims at preventing problems instead of treating them. Based on known operational problems and observations, REFLECT will determine the effect of relevant fluid properties and reactions in order to enhance predictive geochemical modelling and thus the energy exploitation and life-time of geothermal power plants. By moving from reacting to occurring problems, to reflecting in advance (and acting proactively), the project outcomes can fundamentally change the problem-solving strategies of geothermal operators.

Seven specific goals have been identified.

  1. Extend databases (solubility, activity, reaction kinetics) to higher temperatures and higher salinities through lab experiments and modelling approaches.
  2. Determine the extent and location of the degasification front of geothermal fluids during production (field, lab, and modelling approach) 
  3. Determine types of organic matter and microorganisms in various geothermal fluids and their effecton scaling and biofilm formation via laboratory studies
  4. Determine heat capacity, density, electrical and thermal conductivity, sonic velocity, and viscosityat various p, T, X through lab experiments and modelling approaches
  5. Develop a downhole sampling technique suitable to collect fluid at chosen depth in hot and superhot systems (proof of principle prototype)
  6.  Verification and implementation of the improved dataset by application in reactive transport modelling 
  7. Set up a geothermal Fluid Atlas that collates information on geothermal fluid properties across Europe together with their geological setting

A first meeting of the REFLECT Advisory Board was held at the geothermal site of Pfalzwerke Geofuture GmbH in Insheim (Germany) on 4 March 2020.

At this occasion, several operators expressed their interest in determining the bubbling point for CO2 at their site. Discussions also proved that lead deposits represent a challenge for operators due to the high cleaning and disposal costs.

It is foreseen that several sampling campaigns will be performed during the project life-time at the 13 sites, in order to collect samples of high temperature fluids and high-salinity types.

The REFLECT project consortium consists of the following partners:

Source: project website