Patent ID: 8901932

Claim:
A tool for imaging a formation through a substantially non-conductive drilling fluid, the tool comprises: first circuitry for injecting a current into the formation, wherein a complex impedance to the current is measured, wherein the first circuitry comprises: a first electrode for injecting the current in the formation; and a receive electrode for receiving the current; second circuitry for determining a phase angle of an impedance of the non-conductive drilling fluid, wherein the second circuitry comprises: a second electrode for injecting a second current in the formation, the second electrode is located on the tool at a different distance from the formation as compared to the first electrode, wherein a second complex impedance to the second current is determined; and a processor for determining the phase angle from a difference between the complex impedance and the second complex impedance; and third circuitry for determining a component of the complex impedance that is orthogonal to the phase angle of the impedance of the non-conductive drilling fluid, wherein the phase angle Φ m is determined from the difference ΔZ m by: Φ m =tan −1 (Imag(Δ Z m )/Real(Δ Z m )).