It is difficult for petrophysicists in evaluating reservoir porosity, permeability and irreducible water saturation in low permeability because of the complicated pore structure. NMR logs have the advantage in this aspect. In this paper, with the analysis of a well with low permeability sandstones, we proposed the models to calculate reservoir porosity based on three parameters models from conventional logs, the parameters of classic SDR and Timur-Coates models are calibrated from 36 core samples, from this, the permeability estimation models from NMR logs are obtained. At the same time, the relationship between pore structure index (K/ϕ) and irreducible water saturation are established for bound water saturation calculation. The application of this well shows that these methods and models are usable in low permeability sandstones.

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