1 research outputs found
Geothermal exploration in the Fell Sandstone Formation (Mississippian) beneath the city centre of Newcastle upon Tyne, UK: the Newcastle Science Central Deep Geothermal Borehole
The postulate that geothermal energy might be recoverable from strata laterally equivalent to the Fell Sandstone
Formation (Carboniferous: Mississippian) beneath Newcastle upon Tyne has been examined by the drilling and testing of the
1821 m deep Newcastle Science Central Deep Geothermal Borehole. This proved 376.5 m of Fell Sandstone Formation below
1400 m, much of which resembled braided river deposits found at outcrop, although some lower portions were reddened and
yielded grains of aeolian affinity. Downhole logging after attainment of thermal equilibrium proved a temperature of 73°C at
1740 m, and allowed estimation of heat flow at about 88 mW m−2. This relatively high value probably reflects deep convective
transfer of heat over a distance of >8 km from the North Pennine Batholith, along the Ninety Fathom Fault. The Fell Sandstone
traversed by the borehole proved to be of low hydraulic conductivity (c. 7×10−5 m d−1). The water that entered the well was
highly saline, with a Na–(Ca)–Cl signature similar to other warm waters encountered in the region. It remains for future
directional drilling to establish whether sufficient natural fracture permeability can be encountered, or wells stimulated, to
support commercial heat production