Automatic Detection of Proximity AE Doublets for Relative Location of Subsurface Fracture Reservoir

作者：Nagano Koji^*; Ehara Daisuke

来源：Electronics and Communications in Japan, 2010, 93(11): 38-45.

DOI：10.1002/ecj.10234

• geothermal energy
• subsurface fracture
• AE doublets/multiplets
• proximity AE doublets

This paper describes the automatic detection of proximity acoustic emission (AE) doublets. Proximity AE doublets are microseismic data in which a second event with a similar waveform arrives before the attenuation of the first event. The number of AE events is much greater than 1000 when a subsurface fracture reservoir is stimulated during hydraulic fracturing. It is routine and daunting work to detect proximity AE doublets in the many AE events. The cepstrum of proximity AE doublets has a peak at a quefrency that shows an interval between P waves. We analyze three-component AE signals, which represent the three-dimensional particle motion of the AE. Three-component AE measurement is often carried out in subsurface AE measurement. The quefrency of the cepstral maximum is compared among the three components. The cepstra of proximity AE doublets have maxima at similar quefrencies in the three components. On the other hand, the cepstra of AE events other than those of proximity AE doublets have their maxima at different quefrencies in the three components. Ninety-four percent of proximity AE doublets are detected automatically and 100% of 80 events that are not proximity AE doublets are not recognized as proximity AE doublets in the automatic detection.

• 出版日期2010-11