Patent ID: 7609066

Claim:
A method for determining anisotropic properties in a formation, comprising: measuring, with respect to a coordinate system comprising an x-axis and a z-axis, a potential difference V xx along the x-axis using a first set of electrodes disposed along the x-axis and a potential difference V xz along the z-axis using a second set of electrodes disposed along the z-axis for excitation directed along the x-axis, and a potential difference V zx along the x-axis using the first set of electrodes and a potential difference V zz along the z-axis using the second set of electrodes for excitation directed along the z-axis; producing a tensor V comprising potential difference components V xx , V xz , V zx and V zz ; and converting the tensor V to apparent resistivity R for the formation, by solving the relationship comprising R = ( Vxx Vzx Vxz Vzz ) ⁢ ( Kx / Ix Kz / Iz ) ; where K x represents a first geometric factor for the excitation directed along the x-axis; K z represents a second geometric factor for the excitation directed along the z-axis; I x represents a first injection current for the excitation directed along the x-axis; and I z represents a second injection current for the excitation directed along the z-axis.