Analysis of Slug Tests Using the Concept of Instantaneous Flow

Abstract

A method that extends the Hvorslev solution for a 'Slug Test' to the case of a rapidly recovering well in either, a confined, or unconfined, saturated aquifer is described. The procedure utilizes an orifice to regulate the sand face flow and pressure regime, requiring the simultaneous measurement of the standpipe and sand face pressures. The basics of the required equipment are given with details of the analytical procedure. System capacitance is treated as 'Transportation Lag', and the sand face pressure to flow relationship is determined throughout the test using the concept of the 'Instantaneous Flow Derivative'. That the flow regime in a recovering well is not always continuous is demonstrated, and four types of well response are identified. The result of the hydraulic conductivity for a well obtained using the described, equipment, and analytical procedure, is compared with that obtained using other recognized analytical procedures.