Gas monitoring systems, SurfMog®, ShallowMoG®, SysMoG®, GH₂ASBUSTERS®

Solexperts manufactures monitoring systems for soil gas and dissolved gases as well as in-situ gas sampling systems for boreholes up to 1500 metres deep. The product family sets new standards in terms of detectability and allocation of dissolved gases to the source formation and thus opens up new possibilities in the prospection of hydrogen, helium and natural gas as well as the monitoring of geological CO₂deposits or underground hydrogen storage facilities.

The diagram opposite shows possible applications of the various systems for measuring dissolved gases in groundwater down to a depth of 1500 metres. The probes are the result of many years of very successful collaboration with the GeoRessources laboratory at the University of Lorraine and the CNRS.

Application overview of Solexperts gas monitoring and sampling systems using the example of Follschviller Lorraine

SurfMoG®: unsaturated zone, soil gas up to 1 m depth

is an IoT tool for gas monitoring in the unsaturated zone down to a depth of approximately 1 metre with the following features:

Easy to use: stand-alone logger with battery and data transmission, IOT visualisation
Gas specific sensors for:
- Hydrogen: SurfMoG-H₂ in cooperation with the company 45-8 Energy
- Methane: SurfMoG-CH₄
- CO₂: SurfMoG-CO₂
- Helium: SurfMoG-He
- in combination with temperature and optional humidity

Specifications of the specific gas sensors

Procedure for installing a SurfMoG® probe

ShallowMoG®: unsaturated and saturated zone, down to approx. 50 m depth

is an IoT tool for gas monitoring in the unsaturated and saturated zone down to a depth of approximately 50 metres and has the following features:

Stand-alone logger at the surface with battery, data transmission and IOT visualisation
Probe diameter: 76 mm
Gas specific sensors for:
- Hydrogen: ShallowMoG-H₂
- Methane: ShallowMoG-CH₄
- CO₂: ShallowMoG-CO₂
- Helium: ShallowMoG-He
- in combination with temperature

Schematic representation of the borehole probe with the gas sensor and the data logger on the surface

Function test: Concentration curve in test well after two short hydrogen injections

SysMoG®: Detection of dissolved gases in boreholes up to 1500 m, 3000 m in development

SysMoG® is a system for detecting dissolved gases in aquifers in boreholes up to a depth of 1500 metres. The probe is available in two configurations, depending on the application:

Continuous measurement:

The measuring system consists of a borehole probe with a chamber into which the dissolved gases from the surrounding groundwater diffuse. The probe is connected to the measuring module on the surface via two pipes and a circulation module. Various analysers, such as Raman or FTIR spectrometers, are used to detect the gases. The measuring module integrated into the circuit continuously detects the components of the gas mixture and records the concentration development of the individual gases over time. The borehole probe can be installed in an open borehole, e.g. with a logging winch. Alternatively, it can also be integrated into a measuring interval of a multi-packer system. The adjacent figure schematically shows the SysMoG® system for continuous measurements.

Flight photo of the Follschviller test site

Philippe de Donato explains the surprising results of the gas analysis

Sampling of dissolved gases with SysMoG®GH₂ASBUSTERS:

With SysMoG®GH₂ASBUSTERS, depth-specific gas sampling is carried out with a SysMoG® probe and a winch (to a depth of 1500 m, 3000 m is under development). The system consists of a borehole probe with a chamber into which the gases (dissolved in the groundwater) diffuse. When the gas pressure in the probe has stabilised, the gas concentrations inside and outside the probe chamber are in equilibrium. A valve in the probe is then opened and two 75 ml ampoules are filled. After closing the valve, the probe is removed and the gas samples are analysed either on-site or in a laboratory.