GeoTHERM Journal

Editorial

2024-12-30T14:11:51+00:00

Editorial Notes

Der Beitrag oberflächennaher Geothermie zur emissionsfreien Energieversorgung in Industrie und Gewerbe

2024-09-23T08:47:16+00:00

Im Forschungsvorhaben „geo_base“ wird die Eignung der geothermischen Energienutzung für die Beheizung und Kühlung von Produktionsgebäuden und -prozessen untersucht. Die Integration von thermischen Speichern in Abwärme oder regenerative Energien nutzende thermische Energieversorgungssysteme für Industrie- und Gewerbeanwendungen ist nach den Ergebnissen aus den begleiteten Projekten innerhalb dieses Vorhabens in jedem Fall sinnvoll. Von herausragender Bedeutung sind hierbei als Zielvorgaben für die sinnvolle Planung und Auslegung der Geothermienutzung ein langzeitliches stabiles Temperaturprofil im Erdreich – welches durch eine bereits während der Planungsphase durchgeführte simulative Bewertung erreicht werden kann – sowie die angepasste ergänzende Einbindung von flinken Speichersystemen, um einen effizienten und funktionsgerechten Betrieb zu ermöglichen.

Zu beachten ist, dass Änderungen an der Anlagentechnik und der Regelungsstrategie im Betrieb und Produktionsänderungen (Lastveränderungen), die nicht auf das Geothermiesystem abgestimmt werden, zu signifikanten Betriebsproblemen führen können. Über die Integration eines betriebsbegleitenden Monitorings können jedoch bestehende Probleme effektiv identifiziert und Optimierungsstrategien erarbeitet werden. Die Überwachung und Bilanzierung des Systemverhaltens in der frühen Betriebsphase können dabei helfen, Probleme, Fehlfunktionen und unausgewogenen Betrieb frühzeitig zu erkennen und Gegenmaßnahmen zu ergreifen.

Digital Twin of Geothermal Assets Assisting the Production and Operational Decisions

2024-10-25T09:35:39+00:00

Efficient production and operation of geothermal systems, aimed at minimizing total costs, emissions, and environmental footprints, are crucial for the global adoption of geothermal energy. Operational challenges like scaling, corrosion, and equipment degradation significantly impact operational expenditures (OPEX). Mitigation measures often negatively affect the environmental footprint. Therefore, proactive monitoring and mitigation considering multiple objectives are vital for sustainable geothermal asset performance. Digital twin technology, proven in industries like chemical, manufacturing and petroleum, offers a solution for optimizing operations and reducing emissions. This paper demonstrates the development and application of digital twin technologies for real-time monitoring, performance optimization, and multi-objective process control in geothermal systems. The developed framework deploys open-source tools to create an open-source digital twin framework for the sector. The proposed architecture, real-time data integration, and functionalities such as process monitoring, event detection, forecasting, and optimization are further discussed in this publication.

Das am häufigsten unterschätzte Schlüsselelement für erfolgreiche Geothermieprojekte

2024-12-11T14:21:48+00:00

Der Weg zur Gewinnung geothermischer Ressourcen ist kompliziert und kostenintensiv. Erwartungen für den Wärmebedarf werden oft nicht erfüllt. Da der Untergrund selbst in benachbarten Gebieten nicht einheitlich ist, muss die Planung und Ausführung von Bohrungen stets individuell angepasst werden. Es können unerwartete Probleme beim Abteufen auftreten, die zu hohen Kosten und eingeschränkter Wirtschaftlichkeit führen. Einige wenige Projekte müssen aufgrund der Wasserzusammensetzung, ungeeigneter Grundwasserleiter oder unerwarteter Temperaturen sogar aufgegeben werden. Ein Geothermieprojekt ist ein dynamisches System, das während seiner gesamten Lebensdauer betreut werden muss – von Anfang an. Steht das erforderliche Wissen schon in der frühen Projektphase zur Verfügung, können Bohrungen mit hoher Leistung und langfristiger Integrität konzipiert werden. Warum scheitern Projekte dennoch? Ein ganzheitlicher und strukturierter Ansatz bei der Bewertung der verschiedenen Bausteine eines geothermischen Entwicklungsprojekts ist ein Schlüsselelement, mit dem sich die meisten Projektunsicherheiten verringern lassen. Dieses Element wird jedoch häufig übersehen. Ziel ist es, Datenlücken zu vermeiden. und die Integration technischer Kompetenzen mit Wissenstransfer zusammen zu bringen. Im Beitrag wird dargestellt, wie eine geeignete geothermische Play-Analysis in Kombination mit einem gründlichen und präzisen Well Delivery Process sowohl kleinen als auch großen Tiefengeothermieprojekten zu einer soliden Grundlage für eine reibungslose Projektentwicklung verhelfen kann und die Erfolgschancen des Projekts erheblich erhöht.

Modelling of seasonal borehole thermal energy storages and integration into a power plant simulation environment

2024-10-21T13:35:07+00:00

This paper presents an analytical method for calculating the thermal behaviour of borehole heat exchangers and borehole thermal energy storages under the boundary condition of a constant inlet temperature. An analytical model based on the use of g-functions is set up for this purpose. Due to the small difference in g-functions for different boundary conditions within short observation times, the analytical model can be verified with a simple numerical model. In addition, the numerical model is used to evaluate the thermal capacity of a borehole thermal energy storage with 80 boreholes. The analytical model is coupled to the EBSILON® Professional power plant simulation environment. In future, this connection should make it possible to simulate borehole thermal energy storages with high-temperature heat pumps.

Real-time Electric Submersible Pump Machine Learning Diagnostics Enable Scale Detection and Power Optimization in Geothermal Applications

2024-08-23T07:01:20+00:00

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).

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 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, and flow rate, with less than 5% error compared to actual measurements. Additionally, the virtual parameters and real-time total dynamic head were analyzed together to indicate potential scale buildup within the flow meter or downhole components.

A thorough assessment was made by continuously monitoring (24/7/365) the physical and digital aspects of the system,

enabling recommendations to improve power consumption and increase the ESP's runlife.

Monitoring geothermal wells: from HT directional, pressure and temperature while drilling to advanced casing integrity services.

2024-09-11T15:08:51+00:00

Nowadays the energy sector is undergoing a milestone turn into more environmentally responsible green industry to comply with ‘’net zero by 2050’’ regulations. The clear goal is to reduce the footprint of the global greenhouse gases to alleviate the ongoing climate change. Through this transformation, the geothermal energy plays an essential part by emitting significantly less harmful carbon dioxide, being more environmentally friendly than fossil fuel energy sector. Apart from the differences in the design and overall approach from the geothermal wells with respect to the oil and gas wells, safety and integrity is invariably the uppermost common denominator. With this view, the monitoring of a well throughout its entire life is the most powerful instrument: from the early stage of drilling operations, to optimize trajectory and acquire formation evaluation data in real time to be able of taking immediate informed decisions, until the later stages of casing and cement operations, to evaluate the shear bond quality and inspect the casing integrity condition even after years.

This article describes a new set of high-temperature Logging-While-Drilling (LWD) and Pressure-While-Drilling (PWD) technologies for operating up to 210°C and will continue with defining the conventional methods as well as the state-of-the-art modern E-Line technologies for a comprehensive overview of the casing/cement integrity.

New Advances in High Temperature Electronics and Sensors for Geothermal Drilling

2024-09-11T15:09:18+00:00

Enhanced and Advanced Geothermal Systems (EGS and AGS) are new methods of creating geothermal installations that have already been demonstrated to potentially increase electric power production by a factor of greater than 10 when compared with more conventional methods. Some involve fracturing the rock between injector and producer wells, and some rely on drilling wells to convey closed loop fluid systems to take heat from the rock.

Compared with conventional hydrothermal wells, they are technically challenging to drill. In particular, very accurate well positioning, generally including horizontal wells, will be required. The oil and gas industry can already drill accurate directional wells and this capability to position the well is directly transferable to some of the first EGS and AGS wells because they are likely to be drilled at temperatures familiar to oil and gas drillers. But to make EGS and AGS wells more economically interesting, they will need to be drilled at higher temperatures which are currently beyond the capabilities of oil and gas drilling equipment.

Even the claimed 175°C operating capability of oil and gas technologies is challenging for the economics of geothermal drilling because equipment operated at this maximum temperature limit exhibits low mean time between failure and/or service. Therefore, the industry needs a step change in its approach to the temperature capabilities of downhole equipment.