S4CE Articles

Acoustic Emission and Guided Wave condition monitoring techniques promising candidates for casing integrity assessment

Geothermal wells capture energy from the earth and could be an extremely efficient way to address climate change.  Adequate inspection of the well casings is a key part of well management. S4CE partner TWI is under the process of identifying the most appropriate techniques for monitoring geothermal well casings, with the objective of the identification of failure and consequently avoiding it at lower maintenance costs. Acoustic emission and guided wave techniques have been tested in typical casing from a geothermal field site in Cornwall.  The results have shown a promising attenuation rate for a certain range across the casing. A potential combination of the two techniques could be a promising solution for condition monitoring of geothermal well casings. Read the full article here

Laser Gas Sensing for Clean Energy Science

With the rising threat of the consequences of climate change and the negative impact of air pollutants on human’s, and more widely the biosphere’s well-being, it has become ever more important to establish accurate and reliable monitoring systems of gaseous emissions released in the atmosphere. Whenever gaseous emissions occur, such systems are crucial to help answer important questions and support targeted action. What are the gasses being emitted? Where are the emission sources located? How much gas flux is being emitted? What are the processes leading to these releases? How can these emissions be reduced? Have targeted actions succeeded in reducing emissions? Field gas monitoring technologies provides quantitative information for site characterisation, legislation enforcing, decision making, mitigation assessment and transparency that supports a wiser use of natural resources. Read the full article here

Harnessing the potential of geothermal energy: are we ready for a geothermal revolution?

On the 10th of October, a geothermal workshop was organised at TWI regarding the opportunities and challenges related to geothermal energy. The workshop’s targets were to identify challenges with geothermal exploitation and demonstrate the techno-economic solutions through contributions of H2020 funded projects S4CE and Geo-Coat. Building on its expertise and knowledge in coatings, material properties and performance, plant management, composites and joining technologies, TWI pioneers geothermal energy research by providing solutions to help improve flexibility and efficiency of geothermal systems, while reducing plant operational costs, including provision of holistic approaches for cheap and efficient drilling solutions.

St Gallen Deep Geothermal Well: Implications for Gas Monitoring in the Shallow Subsurface

Figure 3. Predicted dissolved methane plume over time (5, 10, 15, and 20 years). Scenario ST-2. Background images taken from Geoportal St. Gallen (https://www.geoportal.ch/st_gallen).

The exploitation of unconventional reservoirs for natural gas production has rapidly increased in the last decades, and policy makers are planning and implementing its development worldwide. Public concerns regarding its potential environmental impacts have also risen, with a specific attention to surface and subsurface water resources contamination. Major risks of contamination of shallow aquifers are associated with: i) infiltration of flowback water from spills at the ground surface, and ii) leakage and upward migration of stray gases and formation brine through preferential pathways connected to deep geological formations.

Environmental impact of DNA-based tracer technology

In the framework of S4CE, ETH Zürich is developing a DNA-based tracer technology for surface and underground tracing. The DNA is adsorbed onto sub-micron silica particles and coated with a shell to increase the DNAs stability and applicability for tracing. Barcodes, as created with unique DNA sequences allow for multitracing applications in various tracing scenarios. ETH Zürich’s role within S4CE is to assess the environmental impact of large-scale tracer use by establishing an ecotoxicological profile through acute and chronic ecotoxicity assays.

What micro earthquakes tell us about geothermal reservoirs?

The key parameter for the efficiency of a geothermal system is the hydraulic conductivity in the subsurface. Fluid circulated between injection and production wells follows natural pathways, which cannot directly be mapped by geophysical measurements. Q-con GmbH have developed a new methodology where they use tiny earthquakes for measuring the hokydraulic pressure along these pathways. Measurements are used to calibrate computer models of the subsurface reservoir.

A software tool to trap CO2 in the subsurface

In order to better trap CO2 in the subsurface, it is important to understand how the CO2 molecules interact with different substrates in diverse geological situations. SCM, a Dutch computational chemistry software company, is developing software tools that will allow researchers to simulate those interactions in a computer. With the aid of those simulations, scientists will be able to build models pointing to the best ways to trap CO2 underground, for example within basalt rocks.

Decoding the Secret Lives of Subsurface Microbes Inhabiting Gas Storage Sites

Over 400 meters below the surface, in absolute darkness and squeezed by the pressure of the Earth, there is an invisible city of microscopic life inhabiting the geothermal aquifers of Iceland. The team at the University of Brittany (UBO) is using metagenomics, a microbial ecology technique which interrogates patterns in population gene content, to decipher the community dynamics of microorganisms who inhabit the groundwater at Carbfix1 and Nesjavellir.

Understanding the functioning of the subsurface biosphere in Icelandic aquifers used for gas storage

Fig. 1: Schematic of the BIOREP device used to run the reactive percolation experiments in the presence of an enriched, deep surface, microbial consortia. The reactor was filled with a sequence of basalt plugs (grey rectangles).S4CE partners IPGP, LGL, UCBL and UBO are working in close collaboration to decipher the functioning of deep biota in Icelandic aquifers used for gas storage. With the recognition that the vast majority of microorganisms on Earth lives in the subsurface, where they rely mainly on water-rock reactions for their energy and carbon supply, this raises questions regarding underground storage and any geoengineering operation targeting the subsurface such as carbon capture and storage, underground energy storage or geothermal exploitation. One aspect of the S4CE project is to understand the role of subsurface microorganisms in such operations.