The DC electrical properties of fully and partially saturated, poorly cemented Permo-Triassic sandstone samples have been measured in the laboratory and the results analysed using three popular models. The results of this work, undertaken on samples from the Wildmoor Formation, indicate that the Permo-Triassic sandstone of the UK is a typical shaly sandstone, which cannot be satisfactorily modelled using the simple conventional relationships proposed by Archie for application in the oil industry to non-shaly formations. Application of the more sophisticated models of Waxman–Smits and Hanai–Bruggeman more faithfully model the electrical response of the sandstone. In addition, the derived parameter estimates are better able to characterize the electrical properties of the rock and correlate better with other independently determined hydraulic properties. Application of these models in groundwater investigations will therefore lead to better and more useful estimates of hydraulic parameters. More importantly, this knowledge will allow more accurate quantitative interpretation of electrical monitoring of the vadose zone.
Figures & Tables
Fluid Flow and Solute Movement in Sandstones: The Onshore UK Permo-Triassic Red Bed Sequence
Sandstone aquifers are common worldwide: they contain a significant proportion of the Earth’s fresh water supplies. However, because of their textural complexity and the frequent occurrence of both matrix and fracture flow, prediction of flow and pollutant migration is still a considerable challenge. This volume contains a collection of papers summarizing current research on an example sandstone aquifer: the UK Permo-Triassic Sandstone sequence. These red bed, organic-poor sandstones are of fluvial and aeolian origin, are often strongly textured, and are cut by discontinuities of a wide range of permeabilities. Matrix flow often dominates, but fracture flow also occurs. The papers in the volume deal with research on saturated and unsaturated flow, and solute and non-aqueous-phase liquid movement. They cover investigations from laboratory to regional scale, and involve a wide range of approaches, from petrophysical through geophysical and hydrochemical to modelling.
The book is intended to be of interest to researchers and practitioners involved in water resources and groundwater pollution, and to hydrogeology, water engineering, and environmental science students.