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 es timate of the hydraulic conductivity distribution. Conducting the doub le flowmeter test, i.e., running the flowmeter test on the same boreho le twice (at appropriate times), improves the accuracy of the estimate d downhole distribution of the hydraulic conductivity and, in addition , provides the downhole distribution of the specific storativity. Form ulae for the hydraulic conductivity and specific storativity of each l ayer are derived for a case of a layered aquifer. The accuracy of the estimated parameter distributions is evaluated via a first-order sensi tivity analysis. A formula is also found for the equivalent specific s torativity of a layered aquifer. In addition, it is shown that account ing for well bore storage in the flowmeter test leads to an inconsiste nt model, and hence the flowmeter test should be conducted only after well bore storage effects disappear.