Electrical induced polarisation properties of saturated bunter sandstones

[摘要] The research described in this thesis primarily investigates the scope of IP (induced polarisation) as a method of determining the permeabilities of Bunter sandstones in situ. Although a limited amount of preliminary fieldwork has been completed, the project has been largely confined to the laboratory, directed toward identification of the petrophysical factors involved, rather than determination of aquifer geometry. In contrast: to all of the previous studies, the conclusions are supported by a large number of measurements. IP has been measured in the time domain exclusively. Compared to the frequency domain method this offers the advantages of a wider scope of information from which a suitable measure of chargeability may be selected, together with the facility to monitor the potential decay for spurious results. The variation of IP with permeability was investigated for a large number of sandstones with suitable pore water control, and because of the diversity of the results a representative selection of the samples was then subjected to further measurements of IP over a range of pore water salinities. All these data have been described by empirical expressions which relate IP, permeability and matrix conductivity, and some geological implications of these results have been considered. Preliminary fieldwork has been done in the Fylde to find out whether an empirical relationship determined in the laboratory can be used to evaluate field permeabilities directly. The problems involved have been considered and further work in this direction is suggested.

[发布机构] University:University of Birmingham;Department:Department of Geological Sciences

[关键词] G Geography. Anthropology. Recreation;GB Physical geography