Project title: Temporal and spatial variability in Lower Jurassic hydrocarbon source-rock quality in Irish off-shore marine basins
Researcher: Dr. Ricardo Silva
Some of the most prolific hydrocarbon source-rocks globally, formed during so-called Oceanic Anoxic Events (OAEs), time periods in Earth history often marked by Large Igneous Province induced major greenhouse-gas release. Associated climatic, environmental and oceanographic change at these times let to the widespread development of anoxic/euxinic water-column conditions, strongly elevated bioproductivity and sedimentary organic matter preservation, and the associated formation of organic-rich black shales (Jenkyns et al., 2010). The temporal and spatial extent and quality of hydrocarbon source-rocks formed at these times, however, differ significantly at inter- and intrabasinal scales, largely due to differing local climatic and environmental conditions, sediment supply, bioproductivity, and the subsequent preservation and diagenesis. The Early Jurassic particularly, is marked by hydrocarbon source-rock formation in the rift basins across the proto-North Atlantic conjugate margins and across the European epicontinental seaway. The quality and temporal and spatial extent of source-rocks formed at this time, however, varies significantly. The Early Toarcian Posidoniashale, for example, varies significantly across Europe, both in quality and thickness (and stratigraphic occurrence). The proposed study aims to underpin the mechanistic processes that governed the formation and the temporal and spatial variability in the quality of Lower Jurassic hydrocarbon source-rocks in the Irish Atlantic and Irish Sea off-shore basins.
(1) To study Lower Jurassic sedimentary succession from wells (cores & cuttings) across the Irish offshore (from both the Irish Atlantic conjugate margin and the Irish Sea).
(2) To provide high-resolution chemostratigraphic (δ13C) constraints on the age and duration of formation of Early Jurassic Irish offshore hydrocarbon source-rocks.
(3) To constrain the temporal and spatial variability in the quality of Early Jurassic Irish offshore hydrocarbon source-rocks.
(4) To constrain the palaeo-environmental conditions that governed the formation of Early Jurassic Irish offshore hydrocarbon source-rocks.
(5) To provide a database to PIP/ PAD of Early Jurassic hydrocarbon source-rock stratigraphic occurrence and its hydrocarbon potential, which will inform future PIP/PAD strategies in Irish hydrocarbon exploration and production.