With the fairly recent discovery of technology to utilize shale gas source rocks there is increasing demand for research to help understand how the shale systems work. At Durham we have several projects involving a broad spectrum of topics associated with shale and shale gas.
Shale Gas From Source Rocks in the UK
Research into the Carboniferous hydrocarbon source rock basins of the UK and their potential for shale gas extraction.
- The Holywell Shale System. This project is critically assessing the potential of the Holywell shale in NE Wales as a shale gas resource. Outcrop material is being collected and the geological setting and geochemistry of the materials studied and contrasted (Prof Jon Gluyas, Dr Chris Greenwell, Mr Leo Newport).
Shale Gas and Risk
Shale gas extraction is likely to fail to gain public acceptance and political support unless it is conducted in a manner which is seen to be responsible, open and transparent. A critical element of any future strategy is therefore the inclusion of a transparent and fully participatory engagement between a range of diverse publics, national and local politicians and civil servants, industry representatives and NGOs. The perceived risks associated with shale gas extraction are related to the earthquakes triggered by shale fracturing process, contamination of ground water, risks to air quality, the migration of gases and hydraulic fracturing chemicals to the surface, and the potential mishandling of waste.
Research into microfossils and in particular trace fossils left by burrowing organisms. The implications are on small scale pathways creating porosity and permeability within shale, and could contribute to characterising "sweet spots" (organic rich zones good for gas recovery).
- Biogenic controls on temporal and spatial variability in shale gas reservoir intervals: Predicting the location of 'sweet spots' within shale gas reservoirs is the holy grail of prospectivity. Often the most productive horizons in mudstone successions are not the organic-rich layers but the interbedded, organic-lean, bioturbated grey shales. This project aims to understand the environmental controls on biological activity in mud-dominated successions, the temporal and spatial changes in bioturbation within reservoir intervals, and the impact of trace fossils on shale gas productivity (Dr Howard Armstrong, Dr Liam Herringshaw).
Understanding the controls of fracture style and orientation within mudstone-dominated strata of shale gas sequences, in particular how variations in fluid overpressure and organic carbon content affect the development of fracture systems.
- Fractures within the Toarcian black and grey shales (the Whitby Mudstone Formation) of the Cleveland Basin, northern England. The clean coastal exposures make the Whitby Mudstone Formation an excellent natural laboratory in which to study fracturing (Dr Jonny Imber).