| 摘要 |
Perforations into an earth formation from a wellbore may be analyzed as to location, shape and radial depth by placing an inspection apparatus in the wellbore including an acoustic signal transmitter for transmitting acoustic signals over a broad bandwidth for a limited time, and receiving reflected or resonant acoustic signals excited in nearby perforations. The amplitude of the resonant frequency will reach a maximum when the perforation is at a midpoint between the transmitter and receiver. The resonant frequencies may be plotted as a function of signal power or intensity to determine perforation radial depth, based on the assumption that the perforation approximates an elongated cylindrical tube. Resonant frequency breadths may be compared to determine relative permeability of the formation and resonant frequency values may be compared to determine the shape of the perforation cavity.
|
