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AbstractMagnetic resonance (MR) logging was originally intended for measuring fluid filled porosity, and for differentiating between producible and non producible fluids. Early tools however came with special operational requirements. Wireline logs were slow and sensitive to wash-outs; early logging while drilling (LWD) measurements did not tolerate tool vibrations. Both required a good deal of preplanning to accommodate limited capability hardware. The paper shows how problems of the past could be solved by the innovative technology of Magnetic Resonance Logging While Drilling (MR-LWD).By returning to basics a new LWD magnetic resonance tool tolerant to vibration and easy to apply could be designed. The novel device acquires valuable data which can be used as well for formation evaluation as for geo-steering under normal drilling conditions and with standard operating practices. This was made possible by a short inter-echo spacing, by a special stabilization, and by a low magnetic field gradient. The new sensor operates with a minimum of preplanning and requires little to no interference with the drilling process.We present an application of the new system in a European onshore well. In the case described we show how reliable deliverables such as porosity and pore-size distribution can be determined from MR-LWD. Formation boundaries and fluid contact can easily be determined. The clear logs and the intuitive presentation of data makes MR while drilling ready for everyday petrophysics.