摘要 |
An apparatus for making directional resistivity measurements of a subterranean formation includes a resistivity tool with a longitudinal axis and an outer surface, a first antenna deployed below the outer surface and having an axial mode coil for processing an axial electromagnetic wave and a transverse mode coil for processing a transverse electromagnetic wave to form a joint-coil structure, a second antenna deployed below the outer surface and spaced at an axial distance from the first antenna, at least two sets of slots with different orientations formed on the outer surface. A corresponding method for making directional resistivity measurements includes rotating a resistivity tool in a borehole, utilizing a transmitter-receiver antenna group formed in the resistivity tool to process a superimposition of the axial and transverse electromagnetic waves, and computing a resistivity-related measurement from the superimposition of the axial and transverse electromagnetic waves received on the receiver antenna. |