ANTENNA COUPLING COMPONENT MEASUREMENT TOOL HAVING A ROTATING ANTENNA CONFIGURATION

摘要

Disclosed herein are electromagnetic resistivity logging systems and methods that employ an antenna configuration having at most two transmitter or receiver antenna orientations that rotate relative to the borehole. The measurements made by this reduced-complexity antenna configuration enable the determination of at least seven components of a coupling matrix, which may be determined using a linear system of equations that express the azimuthal dependence of the measurements. For increased reliability, measurement averaging may be performed in azimuthally spaced bins. The coupling matrix components can then be used as the basis for determining logs of various formation parameters, including vertical resistivity and anisotropy.

主权项

1. A logging method that comprises:
receiving at least one of a set of amplitude and phase measurements as a function of azimuthal angle and tool position from a set of receivers having no more than two different receiver orientations in response to signals from a set of transmitters having no more than one transmitter orientation; determining from said set of measurements at least seven components of a coupling matrix as a function of tool position; finding at least one of vertical resistivity and anisotropy as a function of tool position from the coupling matrix components; and storing said vertical resistivity or anisotropy in the form of a log.