Within the SHINE consortium, three specific research packages and corresponding training objectives are currently being pursued through three work packages involving 10 PhD students (Fig. 1):
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1) Work Package 1 – Fluid, Rock, and Microbial Interactions
This work package investigates how hydrogen injection into porous rock formations disrupts the chemical equilibrium between pore water, dissolved gases, and the rock matrix.
Researchers (R2 and R7) are examining the consequences of this chemical disequilibrium, focusing on geochemical and biochemical reactions that may result in mineral dissolution and precipitation, biofilm formation, hydrogen souring, and microbial hydrogen consumption.
Within this framework, R2 from the UNINA group is working to identify key microbial players involved in hydrogen consumption at existing underground hydrogen storage (UHS) sites using shotgun metagenomic techniques. The group is also isolating new microorganisms from UHS sites to serve as model organisms for controlled laboratory experiments, ultimately supporting future in situ applications.
In addition, the UNINA team is developing an R package for geochemistry data visualization and has established bioinformatics pipelines to analyse the metabolic potential and nutrient requirements of subsurface microbial communities.
At UGA, researchers are quantifying hydrogen adsorption at high pressures and temperatures (25–80°C), aiming to understand both microbial and abiotic reactivity in reservoir and caprock core samples. Their research includes modeling H2 migration and fluid–rock interactions in reservoir rocks and fracture networks within caprocks. The UGA team has designed a high-precision apparatus for measuring hydrogen adsorption under UHS-relevant conditions and has conducted initial experiments, observing significant hydrogen uptake in organic-rich samples (0.5–0.1 wt.% at 120 bar and 20°C).
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2) Work Package 2 – Reservoir and Caprock Integrity
This work package investigates key parameters affecting the integrity of reservoirs and caprocks during hydrogen injection, across multiple spatial and temporal scales.
Researchers (R1, R3, R6) are studying cyclic stress fluctuations near wellbores and testing workflows that incorporate multiparameter datasets describing the reservoir, caprock, overburden, and nearby faults, with the goal of understanding the risks and drivers of reservoir compaction.
Major research activities include:
a) UNINA: Subsurface data characterization from a depleted reservoir (ENI), creation of a key-parameter database, and development of a decision-making framework integrating safety, efficiency, and cost for UHS site selection and risk-informed operations.
b) EDIN: Experimental analysis of hydrogen–rock interactions and their effects on the mechanical properties of reservoir rocks.
c) TU Delft: Development of robust modeling frameworks for comparative analysis of CO2 and H2 plume migration in geological formations, along with modeling of injection-induced seismicity linked to hydrogen migration.
d) CSIC: Investigation of pressure buildup resulting from hydrogen injection and its influence on effective stress reduction, fault slip, and fluid pressure-induced seismicity. Their findings suggest that faults close to injection zones may reactivate during injection, while more distant faults may reactivate during resting phases.
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3) Work Package 3 – Safety and Monitoring of Subsurface Porous Storage
This work package, involving researchers R4, R5, R7, and R10, focuses on safety concerns associated with hydrogen storage—critical for building public trust and ensuring environmental protection.
Key research activities include:
a) Investigation of the impact of hydrogen injection/production cycles on composite cement–rock samples, in collaboration with TNO.
b) Experimental analysis with SLB on the effects of hydrogen exposure on industrial cement samples, covering geochemical, geomechanical, and petrophysical properties.
c) TU Delft: Study of dislocation creep and pressure solution creep in salt formations used for hydrogen storage, with implications for the structural integrity and long-term performance of salt caverns.
d) UGA: Use of geophysical magnetotelluric (MT) methods to characterize hydrogen accumulation in Bulqizë, Albania—an exemplary case study for assessing UHS-related safety.
e) CSIC: Development of a theoretical framework for modeling coupled Thermal-Hydraulic-Mechanical-Chemical (THMC) processes in hydrogen storage, employing numerical simulation, analytical solutions, and Physics-Informed Neural Networks (PINNs).
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Training Activities
SHINE has conducted a series of workshops and schools focused on:
a) Modeling of fluid–rock interactions
b) Hydrogen in microbial metabolism
c) Science communication, dissemination, entrepreneurship, and project management (co-organized training sessions)
