A poroelastic model for laboratory water injection test in highly permeable rocks

Research output: Contribution to conferencePaperpeer-review


Water injection laboratory experiments in weak, poorly consolidated sandstones show evidence that the peak injection pressure is much larger than the one predicted by the Haimson-Fairhurst criterion. A model based on poroelasticity, fracture mechanics, and lubrication theory is constructed to simulate the laboratory experiments. It aims at computing the propagation of a bi-wing hydraulic fracture from a borehole with increasing injection rate, until the crack reaches the boundary of the sample. The model is applicable to situations for which the pore pressure field reaches steady-state quasi-instantaneously when changing the injection rate, on account of the large permeability of these rocks. Two asymptotic regimes of solution are found: (i) a rock-flow regime where the induced fracture is hydraulically invisible, and (ii) a fracture-flow regime where the fluid penetrates the rock via the crack. In the rock-flow regime, fracture propagation is stable, i.e., the borehole pressure increases with the injection rate, while in the fracture-flow regime, the reverse is true. It is therefore concluded that the peak injection pressure reflects a transition between two flow regimes, rather than breakdown.

Original languageEnglish (US)
StatePublished - 2020
Event54th U.S. Rock Mechanics/Geomechanics Symposium - Virtual, Online
Duration: Jun 28 2020Jul 1 2020


Conference54th U.S. Rock Mechanics/Geomechanics Symposium
CityVirtual, Online

Bibliographical note

Publisher Copyright:
© 2020 ARMA, American Rock Mechanics Association


Dive into the research topics of 'A poroelastic model for laboratory water injection test in highly permeable rocks'. Together they form a unique fingerprint.

Cite this