Premium
On the risk of hydraulic fracturing in CO 2 geological storage
Author(s) -
Papanastasiou Panos,
Papamichos Euripides,
Atkinson Colin
Publication year - 2016
Publication title -
international journal for numerical and analytical methods in geomechanics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.419
H-Index - 91
eISSN - 1096-9853
pISSN - 0363-9061
DOI - 10.1002/nag.2502
Subject(s) - hydraulic fracturing , brittleness , geotechnical engineering , fracture mechanics , fracture toughness , fracture (geology) , geology , materials science , composite material
Summary We present a contribution on the risk of hydraulic fracturing in CO 2 geological storage using an analytical model of hydraulic fracturing in weak formations. The work is based on a Mohr–Coulomb dislocation model that is extended to account for material with fracture toughness. The complete slip process that is distributed around the crack tip is replaced by superdislocations that are placed in the effective centers. The analytical model enables the identification of a dominant parameter, which defines the regimes of brittle to ductile propagation and the limit at which a mode‐1 fracture cannot advance. We examine also how the corrosive effect of CO 2 on rock strength may affect hydraulic fracture propagation. We found that a hydraulically induced vertical fracture from CO 2 injection is more likely to propagate horizontally than vertically, remaining contained in the storage zone. The horizontal fracture propagation will have a positive effect on the injectivity and storage capacity of the formation. The containment in the vertical direction will mitigate the risk of fracturing and migration of CO 2 to upper layers and back to the atmosphere. Although the corrosive effect of CO 2 is expected to decrease the rock toughness and the resistance to fracturing, the overall decrease of rock strength promotes ductile behavior with the energy dissipated in plastic deformation and hence mitigates the mode‐1 fracture propagation. Copyright © 2016 John Wiley & Sons, Ltd.