Experimental identification of the transition from elasticity to inelasticity from ultrasonic attenuation analyses

Experimental identification of the transition from elasticity to inelasticity from ultrasonic attenuation analyses

Barnhoorn, A. (TU Delft Applied Geophysics and Petrophysics)
Verheij, Jeroen (Student TU Delft)
Frehner, Marcel (ETH Zürich)
Zhubayev, A. (NAM-Shell Projects and Technology)
Houben, Maartje (Universiteit Utrecht)

2018

The transition from recoverable elastic to permanent inelastic deformation is marked by the onset of fracturing in the brittle field. Detection of this transition in materials is crucial to predict imminent failure/fracturing. We have
used an ultrasonic pulse transmission method to record the change in waveform across this transition during fracturing experiments. The transition from elastic to inelastic deformation coincides with a minimum in ultrasonic attenuation
(i.e., maximum wave amplitude). Prior to this attenuation minimum, the existing microfractures close. After this minimum, new microfractures form and attenuation increases until peak stress conditions, at which point, larger fractures form leading to complete sample failure. In our experiments, velocity changes are not sensitive enough to be indicative for the transition from elastic to inelastic deformation. Analysis of attenuation, not velocity, may thus
detect imminent failure in materials. Our results may help detect fracturing in borehole casings or the near-wellbore area, or they may help predict imminent release of energy by seismic rupture.

http://resolver.tudelft.nl/uuid:85487c17-b20d-4802-92dd-4a2e57b3a348

https://doi.org/10.1190/GEO2017-0534.1

0016-8033

Geophysics, 83 (4), MR221–MR229

Institutional Repository

journal article

© 2018 A. Barnhoorn, Jeroen Verheij, Marcel Frehner, A. Zhubayev, Maartje Houben