Patent ID: 8117018

Claim:
A method of evaluating an anisotropic earth formation, the method comprising: making azimuthally sensitive measurements indicative of a resistivity property of an earth formation using a downhole assembly in a borehole; making additional measurements indicative of the resistivity property of the earth formation using a transmitter antenna on the downhole assembly having an axis substantially parallel to a longitudinal axis of the downhole assembly and a receiver antenna on the downhole assembly having an axis substantially parallel to the longitudinal axis of the downhole assembly; and using a processor for estimating from the azimuthally sensitive measurements and the additional measurements a value of at least one property from the group: (i) a horizontal resistivity of the earth formation, (ii) a vertical resistivity of the earth formation, (iii) a dip angle of a formation anisotropy axis, and (iv) an azimuth angle of the formation anisotropy axis.