A nuclear magnetic resonance (NMR) logging system for measuring fluid
properties of formation penetrated by a well borehole. The system uses a
conductive permanent magnet to generate a field H.sub.0. The conductive
permanent magnet is disposed within a logging tool so that the H.sub.0
field is perpendicular to the axis of the borehole. Soft ferrite elements
are disposed on each pole of the permanent conductive magnet and a RF
coil is disposed about both the permanent magnet and the ferrite. The
resulting H.sub.1 field induced by the RF coil is perpendicular to both
the H.sub.0 and the axis of the borehole. The soft ferrite elements focus
the conductive permanent magnetic field and increase the effectiveness of
the RF antenna. A two coil embodiment is disclosed that produces a
combined RF field which is substantially perpendicular to the static
magnetic field external to the conductive permanent magnet, and is
contained within the soft ferrite elements in the vicinity of said
conductive permanent magnet. Fluid properties of interest are determined
from NMR relaxation times measured by the logging system.