Assessing fault and fracture stratigraphy of carbonate reservoir rocks in the Irish Carboniferous and its impact on deep geothermal potential

Project Description

Geothermal energy will play an important role in achieving CO2 emission reduction targets by 2030. Carboniferous carbonate rock reservoirs in Ireland provide both shallow and deep geothermal targets. The porosity-permeability system in these carbonates is dominated by secondary porosity such as faults, fractures and karst. Despite their importance, the fracture and mechanical stratigraphy is not well understood. 

Therefore, this study will analyse fault and fracture stratigraphy of potential onshore carbonate reservoir rocks. It will provide upscaling by integrating regional-, outcrop- and bed-scale observations, comparing surface with subsurface observations. Field reservoir analogue studies will be conducted in quarries and key outcrops. This includes mapping of lithofacies, bed-scale parameters including thickness and variability, and fracture intensity and patterns. 

Field mapping will be upscaled through digital outcrop mapping using automated feature extraction on structure-from-motion drone photogrammetry. Present-day mechanical strength and elastic properties will be determined on representative lithologies using rock deformation experiments, to constrain mechanical stratigraphy.