Environmental Engineering Reference
In-Depth Information
Figure 17 Possible risk scenarios for shallow and deep gas leakage from shale gas
wells and their mitigation.
cases of seismic activity in the USA
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and this is believed to be due to lu-
brication of a fault zone releasing inherent tectonic stresses as minor
earthquakes. This may actually be beneficial in areas of high tectonic stress
build-up by releasing stress as low level events rather than as a large, po-
tentially damaging earthquake. Lubrication of an unrecognised fault zone
during completion of a vertical reservoir section of the Preese Hall #1 well in
Lancashire, UK, in 2011 resulted in two minor earthquakes as a result of
local tectonic stress release.
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These risks can be mitigated by the acqui-
sition of a geo-hazard 3-D seismic survey over a real track of the lateral well
to identify any faults or fracture zones, with more detailed logging of the
