Evaluation of Deep Pumping Tests

Abstract

A previously described finite element model for analyzing the effects of pumping and recovery in deep aquifers has been implemented on a micro‐computer. The system includes the effects of leaky aquifers, wellbore storage, skin effects at the well, and single or multiple impervious or recharge boundaries. The recovery of pressure following the cessation of flow into the well is plotted against an inverse function of time (θ). The shape of the curve can be related to values of the parameters describing the hydrogeologic properties. By iteratively modifying the parameters of the model, the engineer can develop a representation of a porous soil or rock layer that is consistent with the results of the pumping tests. Examples show how each parameter affects the calculated results. Applying the model to three sets of tests in deep rock formations shows that consistent results are obtained but that the match between the field data and the computed results is sometimes quite approximate. Nevertheless, the model gives rapid and useful insight into the hydrogeological properties of geotechnical media.