DIRECTIONAL RESISTIVITY MEASUREMENTS FOR AZIMUTHAL PROXIMITY DETECTION OF BED BOUNDARIES

An azimuthally tunable resistivity measurement tool comprising transmitter coils and receiver coils, wherein at least some of the transmitter coils or receiver coils are skewed and oriented in differing azimuthal directions, is disclosed. The transmitter coils transmit radio-frequency signals that propagate through a formation surrounding a borehole and the receiver coils measure the relative amplitude and phase of signals received from the surrounding formation. A method for detecting the location of a bed boundary relative to a borehole is also disclosed, including the steps of: generating first and second signals representing azimuthally sensitive measurements of phase shift and attenuation of an electromagnetic signal propagating through a formation around a borehole, wherein the azimuthal sensitivity of the first measurement is in a direction different than that of the second measurement, and receiving electromagnetic signals on first and second skewed receiver antennas respectively oriented in first and second azimuthal directions.