| 摘要 |
A method and apparatus for normalizing an acoustic wellbore tool by correcting measured sector acoustic signals due to changes in pressure and temperature downhole. The method and apparatus comprises an acoustic wellbore tool (105, Fig.1B) having at least one monopole transmitter (140, Fig.1B) and monopole receiver (155, Fig.1B), and one or more sector transmitters and receivers (145, 150, Fig.1B) disposed along the longitudinal axis of the tool. The theoretical attenuation value of received monopole signals are determined 420 and the attenuation values of sector acoustic signals are determined 425. Then a correction ratio using an average sector attenuation value and a theoretical attenuation value is determined 435, and the sector acoustic signals are corrected 445 using the correction ratio. The theoretical attenuation value may represent the attenuation value of the monopole signal received by the monopole receiver having a longitudinal displacement from the monopole transmitter equal to the longitudinal displacement of the sector receivers from the sector transmitters. |
