Measuring distributions of hydraulic conductivity and specific storativity by the double flowmeter test

The flowmeter test, when modified, can be applied long before the well response reaches a quasi‐steady state. In many practical applications the traditional flowmeter test provides only an order of magnitude estimate of the hydraulic conductivity distribution. Conducting the double flowmeter test, i.e., running the flowmeter test on the same borehole twice (at appropriate times), improves the accuracy of the estimated downhole distribution of the hydraulic conductivity and, in addition, provides the downhole distribution of the specific storativity. Formulae for the hydraulic conductivity and specific storativity of each layer are derived for a case of a layered aquifer. The accuracy of the estimated parameter distributions is evaluated via a first‐order sensitivity analysis. A formula is also found for the equivalent specific storativity of a layered aquifer. In addition, it is shown that accounting for well bore storage in the flowmeter test leads to an inconsistent model, and hence the flowmeter test should be conducted only after well bore storage effects disappear. Copyright 1994 by the American Geophysical Union.

Duke Scholars

Author Zbigniew J. Kabala Civil and Environmental Engineering