Could you please bring this to the attention of any students you think may
be interested.
Sorry, if you receive this from multiple mailing lists
Thanks,
Sam Toon
The following Ph.D. Studentship is available
3d Fracture Formation and its Implications for Fluid Flow
Supervisors: George Tuckwell, Peter Styles & Ken Been (Golder Associates)
The main objective of this project is to understand the differences between
a three-dimensional fracture system observed at outcrop and deep
underground, for example in an oil reservoir or nuclear waste repository.
The primary tool for this study is a numerical model to examine changes to
the fracture system on unloading, and to evaluate the control this change in
fracture geometry has on fluid flow through the rock. The student will
modify and apply discrete element code on the newly built KAGe
Supercomputer, a state-of-the-art Beowulf cluster which utilizes award
winning network connectivity developed by Prof Hank Dietz.
Networks of fractures occur in all rocks at all scales. They significantly
influence crustal processes such as deformation and fluid flow, and are
important in exploration and production of hydrocarbons, water and minerals
in the sub-surface. Borehole sampling and geophysics provide information on
frequency and orientation of fractures, however they provide little or no
information on the fracture network connectivity and fluid flow at depth,
and frequently the best view of fracture systems is obtained at outcrop.
The question is whether outcrops can ever be a reasonable analogue of
fracture systems at depth, because the surface exposed rocks have undergone
a different stress history and so often different fracture patterns result.
The key is to identify the components of the fracture network that reflect
the common stress history and utilise these as a prediction for the rock
mass at depth. This project will examine several data sets available to
Golder Associates where there exists both outcrop mapping and
borehole/seismic measurements. Data sets also exist within the department
at Keele, and the student will undertake fieldwork in areas where subsurface
data exist, or are being collected as part of other ongoing projects. Data
will be analysed to characterise fracture systems in terms of the position,
orientation and connectivity, both at outcrop and underground. 3D discrete
element modelling code will be used to simulate the formation and changes to
the fracture system as a result of up lift and stress release in each case
and to understand the factors controlling the fracture geometries seen.
This will allow key information on fracture networks to be extracted from
outcrop studies and there by increase the value in this type of data,
allowing more accurate 3D fracture networks to be constructed. Golder
Associates FracMan software can then be used to evaluate how the geometrical
differences impact the flow and permeability of the fracture network.
The ultimate aim of this project is to be able to use the knowledge gained
by detailed analysis of existing high quality data to better understand the
important differences between fracture systems at outcrop and underground,
and the impact these differences might have on fluid flow through the
fractures.
Please see the following webpages
http://www.esci.keele.ac.uk/geophysics/html/phd2001.html
http://www.esci.keele.ac.uk/geophysics/kage
For further details please contact:
Dr. George Tuckwell,
School of Earth Sciences and Geography,
Keele University,
Keele,
Staffordshire,
United Kingdom, ST5 5BG
Telephone: +44 (0)1782 583176
email: [log in to unmask]
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