• Number 426  |
• November 10, 2014

Mechanics of fracture shearing captured with computed tomography

Researchers at DOE's National Energy Technology Laboratory have completed the first known experiment which visualized the internal breakage of a shale fracture during shearing. Shale fractures were mechanically sheared such that the rough fracture faces moved parallel to each other while an external confining pressure was applied. This fracture shearing is commonly believed to be a critical mechanism for fracture evolution in the subsurface during hydraulic fracturing and other high-stress events, but numerical models rely on simplified models to describe this behavior. Using the core flow equipment associated with the computed tomography scanning facilities at NETL-Morgantown, W.Va., along with some novel shearing devices, this evolution has been visualized. Differential pressure across the core was measured during these experiments and analysis is underway to provide physical relationships between fracture flow properties during this shearing evolution.

[Linda Morton, 304.285.4543,
Linda.morton@netl.doe.gov]