Description

The ECCSEL Svelvik CO2 Field Lab is a small-scale laboratory for rapid and cost-efficient development and testing of technologies for quantitative geophysical monitoring. It is situated in an easily accessible geological environment and fills the gap between bench laboratory experiments and pilots. Due to its size, the controlled environment, and the potential of repeatable experiments, the field laboratory provides excellent possibilities to perform a wide range of studies of geophysical monitoring methods and equipment.

During the field trip, participants will be split into groups and guided to several different posts:

1) The water/gas/tracer injection facilities.
2) The control and instrument cabin (including the fibre-optic panel and interrogator system).
3) The monitoring wells and cross-well monitoring system.
4) The injection well and leakage monitoring setup.
5) Geology stop.
6) TBD.

Examples of areas of research at the field lab include:

1) Development and testing of seismic and non-seismic (e.g. ERT) techniques.
2) Quantitative CO2 monitoring including pressure and saturation determination.
3) Fibre-optic-based monitoring including testing of new cables, interpretation of recorded signals, and comparison with conventional methods.
4) Well integrity/leakage monitoring.
5) Surface detection methods for gas leakage.
6) Testing tracers for gas storage and leakage detection.
7) Drone-based leakage detection or orphaned wells detection.
8) Muon tomography.

Details on the field lab and geophysical installations:

The laboratory is established in the glaciofluvial-glaciomarine Holocene deposits of the Svelvik ridge and occupies a non-active part of a sand and gravel quarry in the outer part of Drammensfjorden, about 50 km southwest of Oslo in Norway. Down to approximately 30 m, the test site consists of unconsolidated to weakly consolidated sand.

Below, rather heterogeneous, and interlayered sand, silt and clay layers in varying proportions exist, displaying a large span of porosity and permeability.

The field laboratory consists of an injection well and four monitoring wells. The injection well is designed for injecting water/brine and/or CO2/gas at 64-65 meters depth. Tracers may be added to the CO2 stream. The four monitoring wells are 100 m deep and positioned at the corners of a rhombus with the injection well (#2) in the centre. The monitoring wells are located 9.9 m (M3 and M4) and 16.5 m (M1 and M2) from the injection well.

The monitoring wells are completed with PVC casing and instrumented behind the casing with:

– Capillaries for pore pressure measurements at three different depths, including the injection depth.
– Capillaries for water sampling at the depth of injection.
– Sensors measuring pressure and temperature at the depth of injection.
– Electrodes for electrical resistivity tomography (ERT).
– Commercial fibre optic cables from SOLIFOS: Straight DTS (Distributed Temperature Sensing), DSS (Distributed Strain Sensing) and DAS (Distributed Acoustic Sensing).
– Fibre optic cables provided by Lawrence Berkley National Laboratory (LBNL): Straight (DSS and DAS) and helical (DSS and DAS).