Geophysical Monitoring of CO2 Injection in Saline Aquifers
Doctoral thesis
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http://hdl.handle.net/11250/280193Utgivelsesdato
2014Metadata
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Sammendrag
Carbon capture and storage (CCS) is a prerequisite to meet the internationally agreed
upon target of limiting the emissions of CO2. The international energy agency has a goal
that CCS should cover 14% of the CO2 emission reduction within 2050. Saline aquifers
and depleted oil- and gas reservoirs are of particular interest as storage sites. The
capacity and injectivity of the saline aquifers are crucial success factors for CO2 storage.
Fluid saturation, pore pressure and geomechanical changes are the most frequent
observed variations in reservoir parameters caused by CO2 injection. Monitoring is
essential to ensure safe storage and detect possible leakage of injected CO2. Time-lapse
seismic data is an important monitoring tool. Pore pressure variation is expected to
interfere with the CO2 fluid substitution on the time-lapse seismic for semi-closed
reservoirs.
The aim of this thesis is to study time-lapse seismic monitoring of pressure and
saturation changes caused by CO2 injection in a saline aquifer. Field data from the
Tubåen Fm. at the Snøhvit field is used in the analysis. Time-lapse seismic data is
combined with laboratory measurements, reservoir flow analysis, rock physics analysis,
synthetic seismograms and well-log analysis to estimate the changes in pressure and
fluid saturation caused by CO2 injection. This thesis consists of four main papers in
addition to two papers in appendixes.