Abstract

Hydraulic and textural properties of the Navajo Sandstone of Early Jurassic age in southern Utah are closely related. Porosity, permeability, unit weight, grain size, sorting, and roundness have been measured and are compared here.

Fine grained sandstone (subarkose and quartzarenite), which is well to moderately well sorted and submature to supermature, is dominant in the Navajo Sandstone. The formation is a significant reservoir interval; its porosity, vertical and horizontal hydraulic conductivities (permeabilities) and water content (at 100 percent saturation) increase from the lower-middle part of the formation to the upper part. A small increase in median and mean grain size, and a slight decrease in sorting also occurs from the lower part of the formation to the upper part. Lower values of dry, saturated, and solid unit weights (density), and cement content apparently are representative of the upper rock unit of the Navajo Sandstone.

Relationships between these parameters, as indicated by their regression equations and correlation coefficients, are complex. Both effective porosity and hydraulic conductivity increase with an increase of median and (or) mean grain size, and with a decrease of unit weight.