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.

 
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> Magnetic resonance fluid analysis apparatus and method

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