Methods for dividing reservoir flow units?

The oil saturation can be calculated using the capillary pressure curve, which makes it possible to make classifications! This is just a very small part of it!

Flow unit modeling and fine-scale predicted permeability validation in Atokan sandstones: Norcan East field, Kansas Saibal Bhattacharya, Alan P. Byrnes, W. Lynn Watney, and John H. Doveton ABSTRACT Characterizing the reservoir interval into flow units is an effective way to subdivide the net-pay zone into layers for reservoir simulation. Commonly used flow unit identification techniques require a reliable estimate of permeability in the net pay on a foot-by-foot basis. Most of the wells do not have cores, and the literature is replete with different kinds of correlations, transforms, and prediction methods for profiling permeability in pay. However, for robust flow unit determination, predicted permeability at noncored wells requires validation and, if necessary, refinement. This study outlines the use of a spreadsheet-based permeability validation technique to characterize flow units in wells from the Norcan East field, Clark County, Kansas, that produce from Atokan-aged fine-to-very fine-grained quartzarenite sandstones interpreted to have been deposited in brackish-water, tidally dominated restricted tidal-flat, tidal-channel, tidal-bar, and estuary bay environments within a small incised-valley-fill system. The methodology outlined enables the identification of fieldwide free-water level and validates and refines predicted permeability at 0.5-ft (0.15-m) intervals by iteratively reconciling differences in water saturation calculated from wire-line log and a capillary-pressure formulation that models fine-to-very fine-grained sandstone with diagenetic clay and silt or shale laminae. It is recommended that you read this article! AAPG Bulletin, v. 92, no. 6 (June 2008), pp. 709 – 732

A flow unit is a combination of lithofacies with identical seepage characteristics, and this method can be used to precisely characterize the heterogeneity of reservoirs. Parameters such as permeability, vertical heterogeneity parameters of in-layer permeability (coefficient of variation, coefficient of step change, range), porosity, and bound water saturation are generally used as criteria for dividing flow units.