Talk Outline Introduction - Geology of Northern Ireland Petroleum Exploration – History of exploration – Conventional and unconventional gas resources – Basins and exploration plays • Northeast ‘concealed’ basins • Southwest Carboniferous basin
– Legislation and regulation
Competition for the subsurface Conclusions
Geology of Northern Ireland
Indigenous oil and gas resources Could • Enhance security of supply by reducing dependence on imported oil, gas and coal • Provide inward investment and create employment • Generate income through corporation tax (30%), ringfenced petroleum tax (32%) and royalties (7.5%) on petroleum production revenue
Potential for oil and gas resources in NI – limited exploration but no production to date
History of exploration • Petroleum legislation enacted in 1964 • First licence, in Fermanagh, in 1965 • Exploration activity modest – cycles driven by prices, discoveries in analogous settings and technological advances • 10 seismic surveys and 15 exploration wells • Some oil and gas shows but no production BUT Significant untested potential for both oil and gas
Petroleum prospectivity in Northern Ireland Southwest
Concealed Basins
Unconventional gas
Reservoir Permo-Triassic sandstones
Reservoir Carboniferous shales
Seal
& sandstones
Permo-Triassic mudstones
Seal Carboniferous shales
Source Carboniferous shales
Source Carboniferous coals & shales
Traps Structural Stratigraphic
Traps Non-essential
Secondary targets Carboniferous sandstones Unconventional gas
Elements of conventional petroleum exploration play Elements Organic-rich source rock Permeable reservoir rock Impermeable caprock Efficient trap Processes Source maturation Trap formation Hydrocarbon migration
Relative timing of processes is crucial!
Conventional and ‘unconventional’ gas resources Characterised by reservoir quality and production methods Conventional Porosity 10 – 30% Permeability 1mD – 1 Darcy Gas is present as free gas, trapped within the pore space between the grains of the reservoir rock Gas will usually flow from the reservoir up to the surface under its own pressure Unconventional Porosity
