An investigation on azimuthal anisotropy measurements with ultrasonic dipole data

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

OSTI ID:542989

Tao, Guo; Zhu, Zhenya; Cheng, C H

Three methods for analyzing azimuthal anisotropy from dipole logging data are described and applied to ultrasonic dipole data in this paper, based on the phenomena of flexural wave splitting in anisotropic materials and analogous to the techniques used for VSP data processing. The laboratory measured dipole data are employed to simulate the flexural modes propagating in a transversely isotropic (TI) formation with symmetry axis perpendicular to the borehole, and to examine and compare these methods. Amplitude and particle motion analyses of the laboratory data demonstrate that, only the polarisation direction of the fast flexural mode is consistently in accordance with the fast principle direction of the TI material. The slower mode, which is much easier to be excited and is of much larger amplitude than the fast mode, turns out to be subject to interferences and very complicated. It has not been well understood. Among the three methods used in VSP data processing, namely linear-transform technique, the technique of rotating data matrix and the technique of identifying the eigen direction with polar energy spectrum, the last method works best for the data used in this study. This technique can also be carried out in frequency domain to handle the possible interferences due to the dispersion of flexural modes.

• DOE Contract Number: FG02-86ER13636
• OSTI ID: 542989
• 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