A hypothetical geomechanics model for qualitative assessment of environmental
impact of shale gas fracking – Part II: Potential seismic hazards
Baolin Wang
Natural Resources Canada
Ottawa, Ontario
bwang@nrcan.gc.ca
Submitted to the CGS Conference, Montreal, Sept. 2013
ABSTRACT
Geomechanics research for shale gas development has not been seen as widely published
as for other geomechanics applications, which is perhaps due to the very recent history of
the shale gas industry. Among those limited publications, focus has often been on
relatively small scale studies around fracking zones or wellbores. There have been
considerable concerns regarding groundwater contamination and seismic hazards
associated with shale gas fracking. There is no doubt that fracking or wellbore scale
geomechanics studies contribute to knowledge of regional effect. However, large scale
models are necessary for understanding potential impact of shale gas development on
groundwater and seismic hazards. There exist major barriers for large scale geomechanics
studies at any site. One of the obvious difficulties is getting geomechanics data.
Acquiring data from a large region and great depth is impractical due to geological
complexity and cost reasons. As such, in order to address the groundwater and seismic
hazard concerns, this paper (Part II) along with its companion paper (Part I) proposes a
large scale hypothetical geomechanics model as a starting point. A Finite Element model
is proposed to investigate ground conditions changes associated with shale gas fracking.
Typical ground conditions that may be encountered at shale gas development sites are
assumed. The model is simplified so that key factors can be investigated. This paper (Part
II) is focused on discussions on ground condition changes that may affect ground
structural behaviour at great depth. Particular emphases are given to ground stress and
deformation changes around fault zones at depth. This hypothetical model study has
allowed a qualitative assessment of potential seismic hazards where fracking takes place.