Bed boundary detection and invasion profiling with uncompensated electromagnetic wave resistivity sensors

摘要

A resistivity tool (800) associated method includes measuring the phase shift of an electromagnetic signal at different locations. Preferably, this is accomplished by a resistivity tool (800) having three receivers (R1, R2, R3). The difference of the phase shifts at the different locations indicates with precision the depth in a borehole of a bed boundary. The preferred resistivity tool also yields improved radial resolution.