An Electronic Minipermeameter for Use in the Field and Laboratory

The quantification of permeability and geostatistical scaling from laboratory to well field to regional systems requires large spatial data sets for which field and laboratory minipermeameters have proven to be effective tools. We developed an electronic gas minipermeameter for use in either the field or the laboratory. This design alleviates several problems common to minipermeameters. In particular, errors in measurement of gas flow rate, calibration of flow rate meters, and countering pressure and temperature effects were reduced by using electronic mass-flow transducers. Problems of sealing the injector (probe) tips and of measuring the permeability of weathering rinds and fracture “skins” were remedied with a sample chamber capable of handling thin wafers or rock cores of arbitrary dimensions. Calibrations with samples of known permeability were excellent. It is now possible to measure permeability very accurately on weathering rinds, fracture surfaces, utcrops, and large hand samples.