Environmental Engineering Reference
In-Depth Information
Table 1 UK shales of interest to shale gas extraction (summarised from Andrews
1
and from Harvey and Gray).
4
Province
Basin
Source shale
Thickness (m) Comment
Scotland
Midland Valley
Basin
Strathclyde Group,
Carboniferous
Up to 670
Immature
for oil
Central
Britain
Bowland Basin
Bowland-Hodder
Unit, Craven
Group,
Carboniferous
Typically 150
but reaches
890
First shale of
interest -
basins
within ''gas
window''
Edale Basin
Widmerpool
Trough
Gainsborough
Trough
Cleveland Basin
Wessex
Weald
Province
Wessex Basin
Lias, Lower
Jurassic
Thin beds of
oil shale
Wytch Farm
source rock
Weald Basin
Kimmeridge Clay,
Upper Jurassic
Over 600 in
centre
Immature.
Probably
biogenic
Midlands Microcraton
Tremadoc Shales,
Upper Cambrian
Uncertain
-
N E England
Province
Northumber-
land Trough
Yoredale,
Carboniferous
Shale units
tend to be
thin
-
Stainmore
Trough
South Wales-Bristol Basin
Marros Group,
Carboniferous
Uncertain
Interbedded
with thick
sandstones
Table 2 Shale gas resource (gas-in-place) estimate for the Bowland Shales.
1
Total shale gas resource
estimate (tcf)
Total shale gas resource
estimate (tcm)
Low
(P90)
Central
(P50)
High
(P10)
Low
(P90)
Central
(P50)
High
(P10)
Upper unit 164 264 447 4.6 7.5 12.7
Lower unit 658 1065 1834 18.6 30.2 51.9
Total 822 1329 2281 23.3 37.6 64.6
(Units tcf and tcm are trillions of cubic feet and trillions of cubic metres, respectively).
The study applied a statistical approach to assess the resource, which took
into account variations in the input parameters. As a result, the gas resource
estimates are provided as a range with upper (P10), lower (P90) and median
(P50) values (see Table 2).
With the UK shale gas in its infancy and with very little exploration activity
to date, it is currently too early to make any reliable estimate of the Tech-
nically Recoverable Resource (TRR) or Reserve figure (the proportion of the
TRR that is commercially recoverable).
