This paper presents the results of a data mining exercise on core measurements and reports of the Triassic Lower Volpriehausen Sandstone Member (RBMVL) in The Netherlands. The availability of a large accurate online dataset via the Dutch Oil and Gas Portal (NLOG) enables the definition of general reservoir property trends on a regional–subregional scale. Accurately defined trends are capable of restricting the uncertainty range of key parameters in exploration studies (e.g. porosity and permeability), and thus of reducing risk. Plotting core porosity v. core permeability resulted in a curved data cloud on a log-normal plot. Although porosity–permeability relationships are often defined by straight lines, the dataset in this study shows that a curved relationship results in a better fit with permeability measurements over the entire porosity range. Two methods were applied to define a porosity–depth relationship for sandstones of the RBMVL. The results of both methods confirm, and enable quantification of, the well-known trend of decreasing porosity with depth. By assigning grain density attributes to the core measurements, the dependency of the porosity–depth relationship on sedimentary facies and diagenesis type/grade could be determined. This case study demonstrates the power of this free online dataset in understanding reservoir quality.