AN ASSESSMENT OF THE NGUYEN AND PINDER METHOD FOR SLUG TEST ANALYSIS

The Nguyen and Pinder method is one of four techniques commonly used f or analysis of response data from slug tests. Limited field research h as raised questions about the reliability of the parameter estimates o btained with this method. A theoretical evaluation of this technique r eveals that errors were made in the derivation of the analytical solut ion upon which the technique is based. Simulation and field examples s how that the errors result in parameter estimates that can differ from actual values by orders of magnitude. These findings indicate that th e Nguyen and Pinder method should no longer be a tool in the repetoire of the field hydrogeologist. If data from a slug test performed in a partially penetrating well in a confined aquifer need to be analyzed, recent work has shown that the Hvorslev method is the best alternative among the commonly used techniques.