A simple technique to calibrate a downhole AE system to locate subsurface cracks is presented. Cross-hole detonation tests were employed for the calibration. In situ P-wave velocity in the formations is estimated from the P-wave arrival time. A simple formula associated with an appropriate filtering is proposed to equalize the difference of the frequency dependent coupling of tri-axial accelerometers set in a downhole AE sonde. Data measured at Higashi Hachimantai Field support the validity of this technique.
|Number of pages||6|
|Publication status||Published - 1987|
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