HOW MINIRUEDI SNIFFS THE WORLD - REAL TIME ON-SITE ANALYSIS OF (NOBLE) GASES IN THE CONTEXT OF FRACKING, SEISMICITY AND TREES

Water and other terrestrial fluids constrain processes in deep earth and in the environment. Some of these processes are of large social significance: geological CO₂ sequestration, gas emanation in response to active tectonics, fracking, nuclear waste disposal, and the evolution of natural gas in continental basins and shallow ground waters. However, our understanding of (geological) fluid dynamics is still rather vague and incomplete as the conventional techniques for gas analysis are based on the laborious analysis of a few individual samples in specialized laboratories which do not allow to track fluid dynamics under field conditions in real time.

To overcome these technical limitations which impede the use of (noble) gases as tracer in hydrology and in geological and environmental systems new analytical methods were developed to quantify (noble) gas concentrations in terrestrial fluids under real world conditions [1]. Our new, self-contained and portable mass spectrometer miniRUEDI [2] can be operated in the field and allows the quasi-continuous quantification of He, Ne, Ar, Kr, N₂, O₂, CH₄, CO₂ and H₂ with a time resolution of seconds in gaseous fluids or a few minutes in liquids. Most recent tailored technical adjustments allow the technology even to be applied at high temperatures and at large water vapor pressures and enables the selective sampling of rare species for later laboratory analysis.

Our contribution presents some applications of our instrument e.g., in experiments using (noble) gases to systematically analyse the relation between fluids and seismicity, to determine groundwater recharge and to study gas transport along faults and trees. We aim to give a perspective on how (noble) gases can also be applied to assess gas evolution in (deep) sedimentary basin.

[1] ES&T 2012, 46, 8288-8296; ES&T 2016, 50, 13455-13463; ES&T 2017, 51, 846-854 [2] www.gasometrix.com