DETERMINING SHEAR SLOWNESS FROM DIPOLE SOURCE-BASED MEASUREMENTS AQUIRED BY A LOGGING WHILE DRILLING ACOUSTIC MEASUREMENT TOOL

摘要

A technique includes receiving data representing time domain waveforms acquired by receivers of a drilling string-disposed acoustic measurement tool in response to energy emitted by at least one dipole source of the tool. The technique includes processing the data to determine slowness values associated with a plurality of acoustic modes, including a formation flexural acoustic mode and a tool flexural acoustic mode. The technique includes identifying slowness-frequency pairs from the slowness values and determining a shear slowness based at least in part on the identified slowness-frequency pairs.

主权项

1. A method comprising:
receiving data representing time domain waveforms acquired by receivers of a drilling string-disposed acoustic measurement tool in response to energy emitted by at least one dipole source of the tool; processing the data to determine slowness values associated with a plurality of acoustic modes including a formation flexural acoustic mode and a tool flexural acoustic mode; identifying slowness-frequency pairs from the slowness values; and determining a shear slowness based at least in part on the identified slowness-frequency pairs.