Nuclear Magnetic Resonance (NMR) has proven to be a very useful tool in petroleum industry. Non-destructive testing saves a lot of money for expensive rock samples and can be applied multiple times if more trials need to be run. NMR is normally used in the oil exploration industry to determine the T2 relaxation time distribution of fluids in core plugs. These distributions can be explained to provide information on pore size distributions, porosity, permeability, and so on.

With the micro-tomographic images to provide a precise model of the rock sample, these experiments can now be reproduced digitally. One of the main purposes of scientific computing is to reproduce real laboratory or "in-situ" experiments, using numerical and computational models. Digital NMR experiments have some advantages over the real experiment, due to their efficiency and lower costs; but they can also provide a better understanding of the physical phenomenon associated to an NMR realization.

In this tutorial, the theoretical background of NMR and the implementations in simulation are introduced first. The set-ups in NMR simulations are shown. In the end two rock examples are simulated and compared with real laboratory experiments.