Laboratory evaluation of time and pressure path dependent, subcritical permeability stimulation of tight sandstone reservoirs

conference paper
2020
Heege, J.H. ter

Wassing, B.B.T.0

Candela, T.
Subcritical crack growth can contribute to stimulation of permeability in geothermal reservoirs as it can lead to lower formation breakdown pressure and enlargement of fracture disturbed zone. This study examines tensile and shear failure due to fluid injection and axial compression in tight sandstones. The overall aim is to identify effects of subcritical crack growth on permeability enhancement. Subcritical crack growth theory and some key experimental data for sandstones were reviewed, and axial compression and fluid injection experiments are performed on a very tight sandstone in a triaxial deformation apparatus. Failure stresses for conventional (short term) experiments with monotonic increase in axial stress or pore pressure and long term experiments with more complex pressure history are compared. The comparison shows some variation in failure strengths that may point to an effect of
subcritical crack growth, but can also be due to sample variability. If the effect of subcritical crack growth is confirmed in experiments of permeability stimulation by fluid injection, results may be used to optimize reservoir stimulation for tight sandstone hydrocarbon or geothermal reservoirs with lower injection rates and volumes. It thereby contributes to more efficient reservoir stimulation with lower risks of inducing felt seismicity.
Topics
Geosciences
TNO Identifier
885007
Repository link
https://resolver.tno.nl/uuid:7fe1969b-ebf2-43b2-bc62-c52e124358cf
Article nr.
ARMA 20–1682
Source title
54th US Rock Mechanics/Geomechanics Symposium held in Golden, Colorado, USA, 28 June-1 July 2020
Pages
1-11
Files
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