| 摘要 |
An embodiment of a method of estimating a property of an earth formation includes: disposing an acoustic tool in a borehole in an earth formation, the acoustic tool including an acoustic source and an acoustic receiver, the borehole having an axial direction; transmitting an acoustic signal into the borehole by the acoustic source, the acoustic signal having a selected frequency and transmitted at a propagation angle relative to the axial direction, the propagation angle selected to excite a desired guided flexural wave mode that propagates along a surface of the borehole; detecting an received acoustic signal by the acoustic receiver; calculating, by a processor, an incident angle of the received acoustic signal, the incident angle relative to the axial direction; measuring a shift of the propagation angle based on the incident angle; and estimating a property of the formation based on the shift of the propagation angle. |
