SP1. Impact of subsurface activities: Hydraulic fracturing, induced seismicity and well integrity
The main issues related to the impact of shale gas exploration and exploitation in the subsurface are targeted in this subprogram. The research focusses on activities at the depth of the shale formation. Impact on formations below the shale target up to groundwater levels is assessed. Key issues include analysis of
(1) the subsurface impact of hydraulic fracturing and risks of leakage to shallow aquifers along fractures: what processes control how fractures initiate and how
far will hydraulic fractures propagate in different shales, (2) risks of reactivating natural faults and inducing damaging seismicity, (3) seismic monitoring of
hydraulic fracturing and gas production, (4) risks of leakage along wellbores, and (4) drilling hazards and well integrity. Impact analysis will be based on data collection from experimental work and case studies as well as predictive modelling to extend knowledge from US and Canada and apply it to Europe.
Best practices for monitoring strategies and design of early warning systems will be established that can be used to mitigate risks. Crosslinks between work packages will be analysed, for example between analysis of the Fractured Disturbed Zone and risks of fault reactivation, seismic monitoring, well leakage and
well integrity. All research activities will provide scientific recommendations for best practices on minimising the footprint of shale gas exploration and
exploitation. The recommendations will be integrated in an inventory that can be used to classify subsurface risks for different European geological and environmental settings as well as to identify exploitation techniques that are suitable for Europe. The inventory will be used together with reviews of existing
data to provide scientific recommendations for best practices on minimising the footprint in the subsurface that will be input to the integrated European
knowledge base including all risks, impacts and scientific recommendations.