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Shear-wave reflection seismic test

Shear-wave reflection Seismic tests were implemented to improve the velocity model within in the upper 100m, to 
assess wave velocities through direct measurement. This shear-wave reflection seismic pilot study at the UNIS CO2 

lab site was the first experiment where this specific type of data acquisition technique was applied in an arctic envi-
ronment. The achieved results demonstrated that the technique can be well applied and opens new feasibilities for 
shallow subsurface exploration in high-resolution on Svalbard.

Seismics

The seismic work has given three key outcomes:

1) A 3D map of the reservoir and cap rocks, The succession is seen to climb gently to the NE.

2) Detailed subsurface information of the area around the well park.

3) Character and location of micro-earthquakes triggered during water injection in wells.

Microseismic monitoring 

Microseismic monitoring is a powerful and cost effective method for CO2 storage monitoring.   Microseismics could 
reveal the occurrence of micro-earthquakes during fracturing of the reservoir (and caprock) as the CO2 plume is 
growing and flowing in the reservoir and pressure is increasing. In the Longyearbyen case, few micro-earthquakes 
have been recorded (Oye et al. 2013).
In order to locate microseismic events, detailed insight of the local P and S waves’ velocities constrain the subsurface 
velocity model. The first model  was constructed using the information acquired through the seismic campaign in 
2008-2009, but has latter been significantly modified from the S-wave seismic - and new VSP campaigns, as outlined 
below (Oye et al. 2013).

Vertical Seismic Profiling 

Vertical Seismic Profiling (VSP) towards Dh4 in 50 m and 500 m distance
VSP acquisition and near-well baseline seismic study, both aimed on establishing a velocity model that would allow 
better seismic resolution of the subsurface around the well park.

Microseismic monitoring network at the UNIS CO2 Lab; red triangles: yellow borehole stations; green tri-

angles: heads of wells equipped with geophone strings. From Kuhn et al. (2014), substantiating Oye et al. 

(2013) 

Seismc section showing th subsurface of Adventdalen, with Dh4 as a line. The refelections at 1200 ms, 

comming up towards the Dh4 could be an intrusion similar to the one in the photograph (from Edgeøya), 

which has a domal shape.