The areas of Paris and Munich are early users in utilizing geothermal energy, esp. for providing it to their heating networks. Together, they have 70 years of practical experience consistently improved by means of applied research. Both pursue an extension of geothermal projects in a challenging urban context. The French-German tandem presentation will highlight the role of geothermal energy in both metropolitan areas: their success story, the further geothermal strategy, urban challenges as well as lighthouse and synergy effects.

In the last two decades, it has become obvious in hydrocarbon exploration that a standardization of project evaluation was needed. On the one hand, to evaluate projects in relation to each other, but also to ensure a standardized risk assessment of the projects. In order to accelerate project assessment, projects were divided into different phases, with a project description going from the rough to the detailed reservoir identification and quantification. The concept of dividing the phases into a play, lead and prospect phase is widely used internationally in hydrocarbon exploration. This approach makes it possible to make a quick decision, especially in the play phase, whether to proceed with the project or not. The decisive factor here is the correct identification of the reservoir and assessment of the associated risks. In the following lead phase, generally areas with similar deposit-specific properties are grouped together. In the prospect phase, the main focus is to identify a drilling candidate in each of the preselect leads. The risk assessment is therefore already defined with regard to the drilling location. This approach of evaluation for finding new hydrocarbon deposits has been adopted and adapted for geothermal project assessment. This paper will illustrate this implementation with an example of a geothermal project development near Vienna. In detail, the tasks that were carried out in the individual phases as well as the technical disciplines that were necessary will be highlighted.

The research project Eva-M 2.0 investigates two methods for the mitigation of calcium carbonate scaling at geothermal facilities in the Bavarian Molasse basin. The first is based on the injection of a liquid polymer inhibitor, and the second relies on the injection of CO2. In this paper the results of the economic efficiency of both applied are presented. The key performance indicators (saving of costly acidification jobs, lifetime of electric submersible pump (ESP), yield increase, increased yield losses through heat transfer degradation, costs for scaling prevention measures) are thoroughly analysed and evaluated. The results show that both methods have the potential to improve the economic efficiency of medium enthalpy hydrogeothermal projects in the South German Molasse Basin.

Geothermal energy is a highly reliable, eco-friendly, sustainable, and clean energy source that has proven to be a game-changer in the residential and industrial sectors. It can be developed from hot rocks saturated in geologically favorable reservoirs, in which water is produced at temperatures greater than 120 °C from a depth of up to 4 km utilizing an Electric Submersible Pump (ESP). Once its heat is converted to electricity in the power plant, the water is cooled and reinjected into the reservoir.

Due to the flow rates required, high-enthalpy fluids, and harsh downhole conditions of geothermal wells, a real-time well manager system was implemented to improve the ESP design, operation, reliability, and well performance. This paper details the operating conditions of a high-efficiency geothermal ESP system in Germany with in-house developed machine learning models. Our geothermal ESP well manager system has advanced to obtain virtual measurements, visual operating indices, vibrations tracking, real-time pump and well performance evaluation, electrical unbalance tracking, and scale detection.

The machine learning models predicted pump intake pressure, motor temperature, fluid temperature, flow rate, and overall operating parameters with less than 3% error. Additionally, the virtual parameters and real-time total dynamic head were analyzed together to indicate potential scale buildup within the flow meter, organic deposition on the motor housing, and changes in fluid composition.

A thorough assessment was made by continuously monitoring (24/7) the physical and digital aspects of the system, enabling recommendations to be made for improving efficiency and increasing the lifespan of the ESP.

Drilling costs hinder access to deep geothermal reservoirs, demanding innovative technologies for improved Rate of Penetration (ROP). The H2020 ORCHYD project focuses on developing hybrid high-pressure water jet (HPWJ) – percussive rotary hammering drilling technology, offering great potential for revolutionising drilling and advancing deep geothermal exploration. The project integrates experimental and numerical approaches to achieve its goals.

From a numerical perspective, ORCHYD takes advantage of novel multiphysics modelling techniques, utilising our powerful in-house software, Solidity and Fluidity, which combine advanced contact detection and analysis, multibody impact simulations, rock dynamic fracture based on the Finite-Discrete Element Method, and non-Newtonian high velocity water jet using adaptive mesh optimisation techniques. These integrated modelling components effectively address the extraordinarily complex interactions between the rock, bit, and jet, providing invaluable insights into the drilling process.

We strive to optimise the design of a new hard rock cutting system by collaborating with experimental drilling researchers and extend validated simulations to model conditions at 5 km depth, surpassing the limitations of laboratory settings that can only replicate depths up to 2 km. The proposed system significantly enhances ROP, a critical parameter for drilling efficiency. Our work overcomes computational challenges, showcasing dynamic rock destruction caused by bit hammering while the HPWJ simultaneously cuts a groove. Through precise simulation and analysis of the rock-bit-jet interaction, our modelling technology identifies optimal drilling system configurations and operating parameters.

This abstract underscores the immense potential of our modelling technology in driving breakthroughs in deep geothermal drilling.