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KAPPA Consortium on Unconventional Resources – Draft – 7
th
Feb 2011
p7/10
F – Tentative content and thought starters
The content of the consortium will be reviewed on a quarterly basis. The list below is purely
indicative, a tentative version 1 of the consortium to-do-list.
For each item, the work would involve not only writing software but also research,
bibliography, software implementation, tests, data-hunting and validation on real cases.
Analysis tools
Although it is not the main technical interest of the consortium, we have seen that specialized
tools are useful to provide a first estimate of parameters for the analytical and numerical
models. Hence, any specialized plot or new straight line deemed to be relevant will be added to
the analysis toolkit in Saphir NL and Topaze NL.
Individual fracture properties
Analytical and numerical models currently available have a uniform distribution of fracture
positions, sizes, orientations and properties. Additional developments of the calculations and
user interface could allow individual control and definition of the fractures. This would apply to
both analytical and numerical models.
Use of microseismic information
The flexibility on fracture properties would make the problem even more under-defined than it
is today. This could be compensated by the import of micro-seismic data in order to count,
initialize and position the hydraulic fractures. Microseismics may also bring some large-scale
information on the activated natural fracture network. This information may be used to
calibrate new detailed fracture networks for the numerical model.
Multiphase flow
The simulation of the water flow back is one of the main unknowns that require multiphase
modeling. This would only apply to the numerical model, and will imply accurate modeling of
capillary effects, both in fractures and matrix.
Connection with hydraulic fracture simulation software
It is unlikely that the standard initialization of a two-phase simulation will properly address the
problem of the water flow back. So, beyond the modeling of the diffusion itself, we will have to
initialize the problem with a realistic hypothesis on where the water resides. The best possible
start would be where the hydraulic fracture simulation ends. This would involve a mapping of
the fracture simulation model and the reservoir model.
Multilateral fractured horizontal well
In densely populated areas, such as Western Europe, reducing the surface footprint will be one
of the challenges for the acceptance of unconventional gas production. The use of multilaterals
is going to be the most probable solution. The modeling of such wells will be done both
analytically and numerically.
Exotic diffusion models
Many additional diffusion effects could be added in the numerical model. One of the goals of
the consortium will be to implement those which make sense:
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Klinkenberg effect
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Knudsen diffusion
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Stress dependence in both fracture and reservoir (with different parameters)
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Other desorption isotherms
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Multiple porosities