Оценка на възможностите за провеждане на подземна газификация и съхранение на CO2 в ДВН
( Assessment of the opportunities of underground gasification and storage of CO2 for DCD )
Within the explored conceptual model uncertainty ranges, the structure of the groundwater flow in the Malm-Valanginian aquifer throughout the model domain is practically independent from the structure of the groundwater flow in the deeper hydrostratigraphic
units. Even in the worst-case scenario the groundwater flux (~0.019 m3/s) from the deeper units into the Malm-Valanginian aquifer is less than 3% of the total groundwater flux through the aquifer (~0.7 m3/s).
The effect of the faults and tectonic structures on the regional groundwater flow appears to be predominantly observed in the relatively low permeable Carboniferous aquifer complex.
The performance of UCG and CGS activities at a distance of 100 m from a vertical fault zone with high vertical permeability does not cause unacceptable environmental impacts in the Upper Jurassic- Lower Cretaceous aquifer.
In the local-scale numerical model analyses, the CO2 flow due to CGS injection is not expected to facilitate the migration of contaminants that are dissolved only in the aqueous phase.
Due to relatively small CO2 injection rate, the model predicts that injected mass does not form separate supercritical or gases phases, but it is dissolved in the aqueous phase.
Based on the performed analyses it is concluded that from a hydrogeologic standpoint, the UCG and CSS activities at the study site have limited impact on the groundwater quality.
The analyses identified a set of important parameters characterizing subsurface fluid flow and storage conditions. Future investigations should focus on better understanding of these parameters. This will require additional laboratory studies, field data collection, field testing (pumping and multi-tracer testing) and model interpretations.
These studies will effectively reduce existing uncertainties associated with model parameters and model predictions.
Last update: 15 April 2013