A new report from the British Geological Survey (BGS) shows that central England may contain almost as much shale gas as has been found in the United States so far. (See full 64-page report here.) The area, centered on Sheffield and Manchester, is underlain by a vast basin containing marine shales up to 16,000 feet thick in basin centers. The BGS considers that any shales deeper than 5,000 below the surface are “mature,” that is, there has been enough time, pressure, and heat flow to turn the organic material in the shale to gas.
Estimates are based on seismic imaging of the basins, known geology, and oil and gas wells in the area. BGS provides three resource estimates, a low estimate of 822 trillion cubic feet (tcf), a mid-range, most probable estimate of 1,329 tcf, and high estimate of 2,281 tcf. To put that in perspective, the well-developed U.K. offshore gas resource is 101 tcf and the U.S. resource currently stands at about 2,500 tcf. Britain consumes about 2.7 tcf per year, so this discovery is significant to future fueling of Britain.
It must be emphasized, however, that these estimates of the inferred resource are very preliminary and work on the economically recoverable portion has not begun.
The report mentions other potential gas-yielding basins in the U.K. including one under London.
The map below shows the location of the Bowland-Hodder shale gas play, as they call it, outlined in purple. The red areas are conventional gas wells, and the green areas are conventional oil wells.
The report is well-detailed in explaining how they calculate resources and reserves. It shows several maps and cross-sections of the geology and geophysical interpretations. The shale basin is not a simple bowl; it has been modified by tectonic events over that past 325 million years – just to make things interesting to a geologist.
Fossil fuel resources of the United States (Written before some of the recent shale gas discoveries)