Resource exploration and characterization (Task 1.1)

The goal of the project is the characterization of the thermo-hydro-mechanical behavior of possible host and cap rocks for geologic carbon dioxide storage in contact with brine and supercritical CO₂. Changes in parameters governing the poromechanical and retention properties of sandstones, limestones, and shales due to CO₂ injection are measured in triaxial and oedometric compression tests and with microimaging techniques

In November 2013, the four year project IMAGE (Integrated Methods for Advanced Geothermal Exploration) has been launched, harnessing research power of key research institutes in Europe and industrial players to develop novel exploration techniques for geothermal power.
The objective is to develop new methods to scrutinize and appraise geothermal systems in such a way that exploration wells can be sited with greater accuracy than before, thereby maximizing the success rate and reducing the cost of drilling associated with geothermal projects. In addition, such precision wells would reduce any potential environmental impact.
New research methods will be tested in well-known geothermal systems, both in continental sedimentary systems in Europe and in high-temperature systems related to volcanism where one might expect supercritical fluids, as in magmatic areas, such as in Iceland and Italy.
The IMAGE project will develop a reliable science based exploration and assessment method to “IMAGE” geothermal reservoirs using an interdisciplinary approach based on three general pillars:

1) Understanding the processes and properties that control the spatial distribution of critical exploration parameters at European to local scales. The focus will be on the prediction of temperatures, in-situ stresses, fracture permeability and hazards which can be deduced from field analogues, public datasets, predictive models and remote constraints. It provides rock property catalogues for 2. and 3.

2) Radically improving well established exploration techniques for imaging, detection and testing of novel geological, geophysical and geochemical methods to provide reliable information on critical subsurface exploration parameters. Methods include: a. Geophysical techniques such as ambient seismic noise correlation and magnetotellurics with improved noise filtering, b. Fibre-optic down-hole logging tools to assess subsurface structure, temperature and physical rock properties, c. The development of new tracers and geothermometers.

3) Demonstration of the added value of an integrated and multidisciplinary approach for site characterization and well-siting, based on conceptual advances, improved models/parameters and exploration techniques developed in 1. and 2. Further, it provides recommendations for a standardized European protocol for resource assessment and supporting models.

The IMAGE consortium comprises eleven leading European geothermal research institutes and eight geothermal industry partners, who will perform testing and validation of the new methods at existing geothermal sites owned by the industry partners, both in high temperature magmatic, including supercritical, and in basement/deep sedimentary systems. Application of the methods as part of exploration in newly developed fields will provide direct transfer from the research to the demonstration stage The 19 participants are from the Netherlands, Germany, Iceland, Italy, France, Switzerland, Norway, the Czech Republic and Spain. The European Union provides € 10 million to the project.

The Swiss Federal Energy Strategy 2050 calls for scientific research to support industry's endeavours to generate electricity from geothermal energy and to develop deep geological sites for permanent, safe storage of CO₂, such that gas-fired power stations may be operated in an environmentally sustainable way. At present, there are no proven sites for these technologies in Switzerland. This project will therefore support industry's first steps towards these aims, namely the assessment of geothermal and gas-storage resources, the exploration for promising drilling sites and the characterization of potential heat- and gas-storage reservoirs. The project will elaborate exploration guidelines and methodologies to lower the risk of failure of exploration drilling. The research is organized into four subprojects, with overlapping participation of 17 scientists from the disciplines of geology, geochemistry, structural geology, geophysics and petrophysics.

The Geothermal Energy & Geofluids group is endowed by the Werner Siemens Foundation and investigates reactive fluid (water, CO₂, C_xH_y, N₂) and (geothermal) energy (heat, pressure) transfer in the Earth’s crust employing computer simulations, laboratory experiments and field analyses to gain fundamental insights and to address a wide range of societal goals and concerns.

The objective of this project is to provide better understanding of the various couplings between hydraulic and mechanical interactions in enhanced geothermal systems. In particular, this project provides a detailed study of how the friction properties control the transport properties of reactivated fractures for low porosity rocks. Previous experiments were conducted far from in-situ reservoir conditions, mostly at room temperature and low confining pressure. Here, we will experimentally study the evolution of both the fluid transport properties and seismic properties during deformation (seismic and aseismic) at pressure up to 200 MPa and temperature up to 400°C. These data will provide new constraints on the permeability evolution during the creation of geothermal reservoirs. Importantly, our results will shed new light on the physics of induced earthquake mechanisms by combining deformation experiments with the registration of the micro seismicity at high temperature and confining pressure, simulating geological conditions in the reservoirs.

This project aims at developing techniques to optimize deep geothermal well drilling with regard to borehole wall stability and intersection with potential feedzones.

This experiment aims at better understanding the hydromechanical processes related to fluid injection in a fault zone in clay rocks.

This experiment is part of the larger flagship stimulation experiment (demo-1 in work package 5) developed by the SCCER-SoE at the Grimsel test site and aims at evaluating the processes related with hydraulic fracture propagation in crystalline rocks and their potential for permeability enhancement.

This project aims at better understanding fault anatomy in carbonate rocks, their impact on the local stress field and their criticality.

We will develop a highly flexible, versatile and efficient joint inversion methodology for analyzing multi-method geophysical data acquired over complex geologies. The novel joint inversion framework based on unstructured grids will be capable of handling rough topography, complex acquisition geometries and arbitrarily shaped geological features. The linking of the different geophysical property models will be based on rock physics (petrophysical) coupling functions and structural coupling operators. Time-lapse functionality will enable analysis of monitoring data and allow characterization of dynamic changes.

Knowledge of the distribution of the hydraulic properties is essential for a wide range of important applications in the Earth, environmental, and engineering sciences, such as, for example, the sustainable use of groundwater, the optimized production of hydrocarbons and geothermal energy, and the safe storage of nuclear waste. The overall objective of this project is to explore links between seismic observations and the permeability of porous and fractured media through the quantitative interpretation of seismic measurements in a poroelastic context. Our research initially focused on obtaining permeability estimates for alluvial aquifers based on the joint inversion of the velocity dispersion and attenuation of multi-frequency sonic log data before proceeding to fractured rocks and layered sedimentary sequences. Currently, we are concentrating on the seismic reflection response of individual fractures and of the effects on intrinsic anisotropy on the attenuation and velocity dispersion of seismic waves. To date, this project has directly or indirectly resulted in more than 10 peer-reviewed publications.

The study of continental sedimentary succession in Argentina, provides new insights on the facies distribution and vertical architecture of clastic fluvial succession accumulated during dry climatic conditions similarly to Permian reservoirs which may be present in the deep graben structures occurring throughout the Swiss Plateau. The understanding of their nature and reservoir distribution can help understanding the geothermal reservoir potential of similar rocks present in the Swiss subsurface.

The study of carbonate sedimentary succession in Sicily provides excellent examples of carbonate rock lateral and vertical heterogeneity which are key reservoir parameters to characterize and quantify fluid flow properties and flow behavior in these rocks. This project will provide relevant analogue for part of the Mesozoic carbonate rich succession resent in the Swiss Plateau subsurface.

The greater Geneva basin area is being actively explored for geothermal resources within a coordinated effort between the State of Geneva, Service Industriel de Genève (SIG) and the University of Geneva. In this context, several aspects have been addressed spanning from the collection and examination of vintage and new subsurface data, characterization of structural framework at regional scale based on dense 2D seismic lines and passive seismic network and characterization and modelling of reservoir rocks from meter to nano scale. These data are being evaluated to drive a step-wise approach looking first at hydrothermal opportunities moving toward deeper targets (EGS) in the years to come.

The Carboniferous projects aims to understand the anatomy of a coal bearing sedimentary succession using the spectacular outcrops and subsurface data from eastern Kentucky. Carboniferous's continental deposits are in fact thought to reprint a considerable part of the graben structures existing in the deep subsurface of the Swiss Plateau. The understanding of these sedimentary successions, their architecture their organic material content and distribution will be of great assistance to predict the reservoir potential of the Swiss Carboniferous for holding deep fluids, including hydrocarbons which could possibly endanger the successful development of geothermal projects (St Gallen)

The deeply buried sedimentary succession in the Swiss Plateau can be source of hydrocarbons has it has been recently proved by the Saint Gallen geothermal well. Understanding the nature and distribution of deep reservoirs and occurrence of source rock at depth is deemed necessary to predict the presence of hydrocarbon generation and migration and thus ensure the success of future geothermal exploration wells.