RESEARCH NOTE: permeability control on the relationship between nuclear magnetic resonance (NMR) measured porosity and routine core porosity

A new criterium is proposed as a hypothesis that gives a dividing line between conventional and unconventional reservoir rocks from the permeability point of view. For rocks with higher permeability, the laboratory porosity values are higher than the NMR porosities. For rocks of lower permeability, the laboratory porosity values are lower compared to NMR porosities. This tendency of permeability to control the relation between porosities measured by two techniques is noticed in published data collected from different literature sources.