Extracting acoustic emissions and microseismic activity from a discrete geomechanical model.

Margaux Raguenel and L. Scholt├Ęs and Paul Cupillard. ( 2015 )
in: 35th Gocad Meeting - 2015 RING Meeting, ASGA

Abstract

A method is proposed to extract microseismic information from a geomechanical model that offers the advantage to explicitly capture the damage mechanisms occurring during rock deformation. The rock is represented as a set of discrete particles interacting one with another through cohesive bonds that can break to simulate the progressive development of fracturing induced by an external loading. A series of numerical simulations was performed and several post-processing techniques were elaborated in order to monitor the appearance of every bond breakage and of the associated energy release. In particular, a clustering method and a frequency-magnitude distribution study were developed. The results were systematically fitted by the Gutenberg-Richter law and a thorough parametric study was performed in order to understand how the b-value was influenced by the different parameters involved in the analysis. We proved that the b-value was not dependent on the numerical parameters as long as the numerical simulations were decently controlled and the sampling was done properly. We also confirmed that the b-value decreases when the confining pressure increases and showed that the contribution of the slips was of second order importance compared to the contribution of the microcracks occurring during failure.

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BibTeX Reference

@INPROCEEDINGS{RaguenelGM2015,
    author = { Raguenel, Margaux and Scholt├Ęs, L. and Cupillard, Paul },
     title = { Extracting acoustic emissions and microseismic activity from a discrete geomechanical model. },
 booktitle = { 35th Gocad Meeting - 2015 RING Meeting },
      year = { 2015 },
 publisher = { ASGA },
  abstract = { A method is proposed to extract microseismic information from a geomechanical model that offers the advantage to explicitly capture the damage mechanisms occurring during rock deformation. The rock is represented as a set of discrete particles interacting one with another through cohesive bonds that can break to simulate the progressive development of fracturing induced by an external loading. A series of numerical simulations was performed and several post-processing techniques were elaborated in order to monitor the appearance of every bond breakage and of the associated energy release. In particular, a clustering method and a frequency-magnitude distribution study were developed. The results were systematically fitted by the Gutenberg-Richter law and a thorough parametric study was performed in order to understand how the b-value was influenced by the different parameters involved in the analysis. We proved that the b-value was not dependent on the numerical parameters as long as the numerical simulations were decently controlled and the sampling was done properly. We also confirmed that the b-value decreases when the confining pressure increases and showed that the contribution of the slips was of second order importance compared to the contribution of the microcracks occurring during failure. }
}