Title: Syn-rift basin-fill architecture – constraints from forward stratigraphic modelling
Researchers: Eoin O'Donnell, Prof. Peter Haughton, Dr Lawrence Amy, Dr Conrad Childs
Triassic and Upper Jurassic rift-basin plays in the Irish offshore are relatively poorly imaged by seismic datasets and reflector geometry and seismic attributes provide only limited constraints on depositional architecture and potential reservoir distribution. In addition, some basins are only partly preserved due to subsequent uplift and erosion. Fault systems that were active during or immediately prior to deposition are better imaged and better preserved. An important question is to what extent knowledge of the fault geometries and the inferred fault system evolution can be used to predict aspects of the stratigraphic geometry and reservoir development that are otherwise poorly resolved? These insights could be key to identifying and risking prospects at syn-rift level in the Irish basins. In actively extending areas there is a strong coupling between tectonic deformation and factors that control sediment transport and accumulation. Testing and more effectively linking these relationships remains an issue. Further complicating the issue is the influencing factors of drivers other than tectonics inclusive of variable sediment input, water balance and base level. Forward stratigraphic modelling is an approach that can be used to explore competing controls on deposition and to address the implications for stratigraphy.
The main objectives are to:
• Better characterise the relationship between fault-system evolution, stratigraphic development and reservoir presence in syn-rift, hanging-wall depocentres.
• Investigate the insights stratigraphic forward modelling can provide in syn-rift basin settings.
• Test the extent to which the preserved fault geometries can help guide reservoir prediction in the context of the Irish offshore basins.