Page 76

Page 77

Scientific missions 

– what will we learn that is truly new?

There is significant need for hard facts rather than modelling 
approaches into CO2 storage. This is in many ways trivial - no 
numeric model will be better than the dataset forming the base 
for the model. Longyearbyen CO2 lab can offer datasets and 
thereby scientific advances on several levels, as three differ-
ent storage units (reservoirs) can be targeted; 

• CO2/fluid injection in tight, unconventional sandstone reser-

voir(s) dominated by fractures is guided by directional, linear 
flow systems. Forecasting flow in such systems represents a 
major challenge in all subsurface fluid operations. However, for 
CO2 storage operations expectations around predictions of 
this behavior is high, as unknown flow systems influence con-
fidence around confinement.

Figure b

y: K

ei Ogata 2013.

• CO2 injection in carbonate-evaporate reservoirs is an optional choice, as permanent trapping in mineral phases 

will be fast. However, fast feedbacks may jeopardize the near-well region by enhanced dissolution (karstifica-
tion), or precipitation of clogging minerals.

• CO2 injection into organic shales is used in EOR, and shales in the subsurface of Longyearbyen could be a source 

to methane gas. However, testing these shales with CO2 injection also allows analyses of top-seal/caprock 
response to CO2 exposure. The Jurassic Agardfjellet Formation shales of Longyearbyen show nearly instant 
self-healing in Leak-Off-Tests – will a self-healing behavior also be the case for CO2 filled fractures?

Fracture configurations are dependent on lithology and will act differen-
tial on fluid flow. 

• The installation of a temporary surface broadband seismic network during CO2 injection (including several weeks 

of measurement before and after the injection)  assists in recording potential microseismic events and enables 
to analyze changes in material properties caused by injection of gas or fluids by inspecting ambient seismic noise 
records. It further allows for assessing aseismic/slow-slip events that are most probably occurring during injec-
tion, especially in shale layers. The application of these methods is transferrable to offshore CO2 storages as 

well as onshore and offshore oil and gas exploration in order to assess processes occurring in the reservoir and 

• The long-term monitoring of the reservoir by permanent borehole microseismic stations allows assessing back-

ground seismicity as well as seismicity induced or triggered by injections. The placement of geophones in bore-
holes will add to the steep learning curve on installation of (microseismic) instrumentation in Arctic environment, 
which is still a non-standard operation.

• The acquisition of repeated shear wave reflection seismic profiles employing a vibrating shear wave source will 

resolve the problem of unknown shear wave velocities within the uppermost few hundred meters (the accompa-
nying problem of unknown P-wave velocities will have to be tackled by conventional active seismic profiling). The 
knowledge of these velocities is critical to a number of the above mentioned data analysis methods for passively 
recorded data. A repetition of the survey is necessary due to the suspected large changes in seismic wave veloci-
ties close to the surface due to thawing and freezing of the active layer and temperature changes up to the depth 
of zero annual temperature am plitude. A pilot study showed the possibility to recover shear wave velocities 
down to depths of approximately 400 m.

Outcroppinghighly fractured chert and dolomites form the Upper Permian Kapp Starostin moderate po-

rosity, but low matrix permeability

Photo b

y:  Snorre

 Olaussen -. UNIS