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. An electromagnetic resistivity logging tool that comprises:
a rotational position sensor; at least one receiver antenna; a first transmitter antenna having a first transmitter antenna orientation; and a second transmitter antenna having a second, different transmitter antenna orientation; and a processor to receive at least one of a phase and amplitude measurement in response to each of the transmitter antennas at each of a plurality of azimuthal angles to calculate at least one component of a coupling matrix using only transmitter antennas having the first and second transmitter antenna orientations.