The probe permeameter is a recently developed device providing a small scale measurement of permeability. About 15,000 probe permeameter measurements were acquired for analysis during this study. These data were acquired by Statoil from cores in two North Sea wells. These cores are from the Middle Iurassic Rannoch Formation of the Brent Group. This reservoir unit was selected for this study because of its laminated nature and challenge to conventional description and simulation practice. All aspects of probe permearnetry are investigated in this study; the volume of investigation, the compatibility with measurements at larger scales, the measurement statistics. the optimum sample spacing. the relationship of the measurements to the geological description and the scale-up of data for two-phase numerical reservoir simulation. Careful analysis of probe and traditional plug data shows that the measurements are compatible. Systematic differences could be accounted for by different treatment effects of the material. The probe measurements show that the permeability distribution in the Rannoch Formation is closely related to the primary depositional structure of the sediment at a hierarchy of scales. This observation is used in combination with conventional simulation techniques to build a more geologically-realistic numerical model of the Rannoch Formation. The scale-up of the small scale measurements is achieved by generation of effective properties for geologically representative elements at various scales and is called the "geopseudo" method. The scale of the natural building blocks within the sediment were determined with the aid of an appropriate outcrop analogue. The model results compare favourably with field production data. This work demonstrates. for the first time. a systematic method for the scale-up of small scale petrophysical properties associated with lamination in sedimentary rocks. as measured by the probe permeameter. Laminated reservoirs are widely encountered and this work. therefore. makes a significant contribution to reservoir engineering practice.