Various Numerical Simulation Methods for Acoustic Emission in Rock

Abstract

AE (Acoustic Emission)AE (Acoustic Emission) or MS (Microseismicity) is a very useful method to understand fracture mechanism and to predict serious rock fracture like rockburst. This method can be applied to monitor reservoirs where water and gas are injected, for example, in underground sequestration of carbon dioxide and in EOR (Enhanced Oil Recovery) of petroleum industry. If a numerical simulation helps to interpret AE monitoring results, AE monitoring would become much more powerful tool for the rock engineering. Thus, in this paper, the authors review various methods that can simulate occurrence of AE events incorporating inhomogeneity of rock.A

Acoustic emission monitoring of hydraulic fracturing using carbon dioxide in a small-scale field experiment

“…In the following analysis, we used well-located hypocenters whose accuracy is expected to be within 50 mm by satisfying the following two conditions: 13 (1) The P wave arrival times could be read at six or more sensors set in three or more different AE holes to enclose the hypocenter three-dimensionally; (2) the standard deviation and the maximum of residuals of arrival times were within 10 μs and 20 μs, respectively. Satisfying these conditions, we located the hypocenters of 1249 AE events during the CO2 injection.…”