Polarization and particle motion of the flexural waves in an anisotropic borehole model

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:542990

Zhu, Zhenya; Cheng, C H; Toksoez, N

Two nodes of flexural waves can be generated by a dipole source in an anisotropic borehole. Their velocities are related to those of the fast and slow shear waves in the formation. The particle motions and the polarization diagrams of the fast and slow flexural waves are measured in a borehole model made of phenolite material with transverse isotropy or orthorhombic anisotropy. The experimental results show that the particle motion of the fast flexural wave is linear and is in the same direction as that of the fast shear wave in the formation. The polarization direction of the fast flexural wave coincides with that of the fast shear wave and is independent of the direction of the dipole source. The particle motion of the slow flexural wave is nonlinear and elliptic. Its polarization direction and the variation are dependent on the anisotropic material and the source direction. This means that the slow flexural wave is a more complicated wave mode rather than the simple mode where the particle motion generated by a dipole source is in the direction of the slow shear wave. The polarization characteristics of the fast flexural wave can be applied to determine the principle axis of an anisotropic formation by in-line and cross-line logging data.

• DOE Contract Number: FG02-86ER13636
• OSTI ID: 542990
• Report Number(s): CONF-951013--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
58 GEOSCIENCES
GEOPHYSICAL SURVEYS
NATURAL GAS FIELDS
NATURAL GAS WELLS
OIL FIELDS
OIL WELLS
WELL LOGGING