Helium Soil-Gas Surveying in Central Europe – Field Experience and Early Indicators
Helium Soil-Gas Surveying in Central Europe – Field Experience and Early Indicators
Introduction
The search for natural helium requires extremely early-stage, subtle, near-surface indicators. Unlike hydrocarbons, helium does not accumulate in conventional traps unless structural and geochemical conditions are exceptional. For this reason, soil-gas helium measurements have become one of the most promising and cost-effective exploration tools for identifying migration pathways, deep-seated faults and potentially permeable basement zones.
In 2024–2025, Mhyner Geoconsulting initiated a regional soil-gas helium screening programme across several sedimentary basins in Central Europe. Our goal is simple:
to detect anomalous helium concentrations that point toward active deep migration systems.
Methodology
Our sampling system builds on three pillars:
- Direct-push hollow steel probe – driven 60–120 cm into the soil, allowing isolated sampling of the sub-surface air column.
- Tedlar® gas bags – chemically inert, ideal for transporting small-volume samples without adsorption effects.
- Laboratory GC analysis (He, H₂, CO₂, CH₄, O₂, N₂) – performed in collaboration with an analytical lab using a helium-optimized GC system.
To minimise atmospheric contamination, each sample is collected using a gentle suction syringe and a three-way valve, allowing controlled flushing of the internal volume before filling the bag.
Preliminary Observations
From several hundred measurements, the following patterns are emerging:
- Background soil-gas helium ranges between 4.8–5.3 ppm, as expected from atmospheric equilibrium.
- Anomalous zones show 6–12 ppm or even higher, correlating strongly with mapped fault traces and basement-related structural trends.
- In some localities, helium anomalies coincide with weak hydrogen enrichments, suggesting deeper redox processes or serpentinization-related pathways.
- Sites above thick clay layers or compacted loess typically show suppressed helium values due to low permeability.
These early results confirm that soil-gas anomalies can reliably map migration corridors, even before deploying higher-cost geophysical methods.
Why It Matters for Investors
Helium exploration is still in a discovery phase across Europe. Projects that can rapidly identify promising structural domains have a significant competitive advantage. Soil-gas surveying:
- Reduces exploration risk at minimal cost
- Prioritises where to drill stratigraphic or structural test wells
- Helps design seismic lines in a cost-optimized manner
- Supports proof-of-concept for early-stage funding rounds
Next Steps
Mhyner is expanding its soil-gas grid into new target areas while integrating:
- airborne spectral data (red-edge vegetation stress),
- basement structural modelling,
- and deep geothermal gradient maps.
