An NMR logging tool for conducting NMR measurements in a plurality of sensitive volumes ranging up to a meter from the tool. The tool comprises a magnetic assembly using one or more permanent magnets and at least one pole piece for extending a magnet pole and shaping the magnetic field to simulate a...http://www.google.de/patents/US7733086?utm_source=gb-gplus-sharePatent US7733086 - Systems and methods for deep-looking NMR logging
