SPE Formation Evaluation, Vol.10, No.2, 86-90, 1995
INDUCTION LOG ANALYSIS OF THINLY LAMINATED SAND SHALE FORMATION
We examine induction log responses to a thinly laminated sand/ shale sequence in a deviated borehole for arbitrary deviation (or dip) angle and sand/shale composition. We found that the induction log responses in a thinly laminated sand/shale sequence are the same as they would be if the tool is placed in a homogeneous but anisotropic formation with the horizontal and vertical conductivities given respectively by the parallel and the series conductivities of the sequence. Conversely, a thinly laminated sand/shale sequence can be identified as an anisotropic formation by induction logs. We discuss three methods to identify an anisotropic formation using induction-type logs alone.