One of the possible post-production utilization of abandoned hydrocarbon fields in the North Sea fields is to use them as reservoirs for CO2 storage. There are several advantages in doing so: the reservoirs are already discovered and the wells needed to access them are in place.
CO2 storage requires a careful risk assessment, based on integrated data analysis where all uncertainties are correctly balanced. In an ideal approach, the analysis must evaluate risks related to capture, transport and storage, the associated CO2 migration mechanisms and pathways, as well as effects on atmosphere, soil, groundwater, and surface water.
Current methods have severe limitations in the analysis of reservoir properties. Probabilistic analysis of geoscientific data and production data is not based on physically correct error propagation methods.
Instead, statistical predictions about the reservoir are only based on (1) large geological data bases, or (2) subjective expert assessments of geophysical and geological data.
Prediction models about the overburden are nearly non-existing. These limitations may have significant consequences for the appraisal of possible caprock failures, releases through induced or existing faults, displacement into non-target formations, or well leakage.
Furthermore, a miscalculation of these factors may have a dramatic consequence on the evaluation of migration scenarios and their short and long-term consequences.
The aim of this pilot project is to investigate and describe how a risk analysis system based on a consistent, probabilistic approach to geophysical/geostatistical inversion and flow data analysis can be developed.
Project coordinator,
Prof. Klaus Mosegaard, KU