Abstract: Antenna arrays for well logging/measuring tools are disclosed. The antenna arrays include at least four antenna wire elements. Current provided to or sensed by each of the antenna wire elements can be independently controlled or sensed. The antenna arrays can be configured to produce or sense electromagnetic dipole moments in any direction in three dimensional space.

Abstract: An apparatus and methods for inspecting pipes which may comprise a body attached to a tether for movement in a pipe. The body may comprises at least a transmitter coil and a receiver coil. The receiver coil may be disposed between at least two transmitter coils. The apparatus may also include a circuit for energizing the transmitter coil with a pulsed electromagnetic source and a circuit for receiving and processing a signal from the receiver coil. Methods include inserting an inspection device into a pipe and energizing transmitter coils. A magnetic flux is emitted from the transmitter coils. The method also includes inducing an eddy current within a pipe wall and measuring the electromagnetic flux induced in a receiver coil by the eddy current within the pipe wall.

Abstract: A method for estimating at least one formation parameter from a directional resistivity measurement includes computing a plurality of hypothetical directional resistivity values at a corresponding plurality of formation parameter values. The computation makes use of a forward model having at least one analytical expression that relates a directional resistivity measurement to the formation parameter. The analytical expression includes at least one image source term. Comparison of computed directional resistivity values with measured direct resistivity values enables a value of at least one formation parameter to be selected. The method may be implemented on a downhole processor.

Abstract: A method for estimating at least one formation parameter from a directional resistivity measurement includes computing a plurality of hypothetical directional resistivity values at a corresponding plurality of formation parameter values. The computation makes use of a forward model having at least one analytical expression that relates a directional resistivity measurement to the formation parameter. The analytical expression includes at least one image source term. Comparison of computed directional resistivity values with measured direct resistivity values enables a value of at least one formation parameter to be selected. The method may be implemented on a downhole processor.