Rock salt is abundant onshore Northern Germany deposited and this rock salt has mobilized and resulted in a range of features like salt pillows, salt walls and salt diapirs. Rock salt has a high thermal conductivity and with a closed loop geothermal well solution, with no fluid interaction with the subsurface, it is possible to efficiently utilize this high thermal conductivity for geothermal energy production.

A new closed loop geothermal well solution with a horizontal section can efficiently achieve utilizing this high rock salt thermal conductivity. The well is drilled to a vertical depth of 2-5 km depth with a 3-5 km horizontal section in rock salt. It can be a single well or a group of wells depending on the energy demand. Each well will be completed with the patent-pending dual vacuum tubing technology. The circulation fluid will be heated by flowing down the well outside the tubing along the geological formation in the horizontal section of the well. When the circulation fluid arrives at the toe of the well, it is returned to the surface through the inner channel of the dual vacuum tubing with a minimal heat loss as it acts as a thermoflask.

The proposed solution mitigates the issues with a conventional 2-well hydrothermal solution and can also be implemented where a conventional 2-well hydrothermal solution will not work. By taking advantage of the high rock salt thermal conductivity and the high speed of drilling in rock salt it becomes an efficient and commercially attractive solution.

Geothermal fields often require pumping systems to achieve commercial production rates and pressures. In lower-enthalpy fields, line-shaft pumps (LSPs) have traditionally been used to supply brine to binary plants, while self-flowing production wells have been relied on in higher-enthalpy fields to power flash plants. Despite their historical use, the use of LSPs poses significant challenges in geothermal applications. To address these challenges and enhance geothermal production, a new, innovative technology in the form of Electrical Submergible Pumps (ESPs) has emerged. This breakthrough in ESP technology provides a reliable and efficient solution for geothermal operators, unlocking new opportunities for reservoir optimization and energy extraction. provides a comprehensive overview of the key components of the ESP system, including the motor, protector, pump, power cable, motor lead extension, and downhole sensors. The new ESP system demonstrates improved reliability, power density, and operational efficiency by using high-efficiency permanent magnet motors, innovative encapsulation technologies, and optimized pump designs. The lecture also highlights the successful field trial of the newly developed geothermal ESP in Kizildere Field that showcased its enhanced reliability and increased production in a high-temperature environment. The key findings from this study demonstrate the remarkable success of the newly developed ESP in high-enthalpy geothermal wells in Türkiye and also it will summarize important lessons learned during the journey of designing, installing and operating ESP’s in geothermal wells.The introduction of this technology has initially boosted the production by 56% in the geothermal field subject of study.

High-temperature aquifer thermal energy storage (HT-ATES), with its high storage capacity and energy efficiency and its compatibilities with renewable energy sources, has generated widespread interest. One main criterion for a feasible HT-ATES is the thermal recovery efficiency, i.e., how much of the invested heat can be recovered. The heat lost during the HT-ATES is mainly due to the heat conduction and the density-driven buoyancy flow, which are more significant with HT-ATES compared to the conventional low-temperature ATES. Thus, understanding the fluid displacement and thermal transport processes during HT-ATES is essential for assessing the performance of HT-ATES. A group of key parameters regarding the thermal recovery efficiency for HT-ATES are identified in this study. The numerical model is set for a typical HT-ATES based on the geological in the Burgwedel region and the designed operational parameters. Over one thousand cases are simulated for a sweep of the key parameters for multiple cycles and storage volumes, and the resulting recovery efficiency for each case is obtained. The hot water injection and displacement processes and the correlation between the recovery efficiency and the key parameters are investigated. The correlation functions are built to estimate the thermal recovery efficiency, which can be used for a quick assessment of potential HT-ATES sites when the properties of the aquifer are known. Additionally, the possibility of several measures to improve the thermal recovery efficiency is investigated.

High-temperature heat storage deep underground can create a balance between the heat supply and the heat demand, subject to seasonal fluctuations. Proven depleted oil reservoirs can be used for heat storage. In the Upper Rhine Graben, the Tertiary hydrocarbon fields are ideal for this purpose.

The reservoir rocks of these hydrocarbon fields are characterized by the sandtones of Oligocene Meletta and Niederrödern Formation. Both are realtively thin sandstone layer of up to few tens of meters thickness, interlayered with about > 200m of marls.

Existing borehole measurements and core data from the hydrocarbon fields make it possible to reproduce the reservoir models. In addition, new studies on existing core material and cuttings can describe further properties. The resulting model describes the distribution of the petrophysical properties of the sandstone horizons and forms the basis for delineating the regional heat storage potential.

In this study, we present the results of a log analysis comprising 1200 logs from 35 boreholes north of Karlsruhe, Germany. The self-potential and resistivity logs are crucial for the precise localization of sandstones and the investigation of their spatial distribution and interlayering with the marls. By comparing these results with core data analyses from the Stutensee 1 well near the Leopoldshafen oil field, we establish a link between geophysical measurements and core material.

To visualize the rock texture and pore network, we perform micro-CT investigations on the core material of the Stutensee 1 well. These are intended to provide insight into possible cementation processes to characterize inhomogeneities in porosity and permeability.

Shallow geothermal energy is one of the energy resources with great potential to meet the heating energy demand in Norway and to release electricity for the transformation of heavy industry and transport systems. Norway's geology, which is characterised by crystalline rock, is well- suited for shallow geothermal systems. However, these systems face sustainability challenges in cold regions due to unbalanced heat extraction and injection. GENESS is a unique pilot set-up that addresses this challenge by integrating semi-deep geothermal wells and excess heat storage through borehole heat exchangers (BHEs) to balance subsurface temperatures. The innovative setup of GENESS with a variety of BHEs in 119 wells, photovoltaic-thermal (PV-T) panels, semi-deep wells, observation wells and a digital twin provides a comprehensive platform for real-time testing, data acquisition and analysis to evaluate and optimise geothermal energy extraction and storage technologies. This article introduces this unique facility at the University of Stavanger and the data collected so far. It also explains how the GENESS platform can foster interdisciplinary collaboration, increase knowledge in the fields of geology, engineering, and environmental sciences, and contribute to the development of more efficient and cost-effective geothermal systems.