An Inversion Methodology to Calibrate the Model of an Heterogeneous Aquifer from Wellbore Flow Measurements – Case Study

This paper implements different flow calibration methods on an Experimental Hydrogeological Site located near Poitiers city in France. Preliminary reservoir characterization studies confirmed the aquifer heterogeneity. A geostatistical model was built using wellbore static and dynamic hard data as constraints. In particular, flowmeter tests made it possible to determine the position of a productive facies, named "Water", in each well. A history matching technique involving the inversion of facies properties was applied to reproduce well-M7 pumping response and its interferences. Following a prior adjustment of the flow model boundary conditions, the petrophysical properties of the conductive “Water” facies were inversed by matching the first 6 hours of the tests. The match was satisfactory, showing that this conductive facies determines the short-term responses of all wells, except the ones that are poorly or not connected with well M7. Nevertheless, the long-term simulation revealed an increasing difference between the matched and measured responses versus time. The inversion of other porous carbonate facies properties then seemed necessary. This way, the long-term match was actually improved but to a limited extent. In a coming step, this inversion methodology will be further improved using a gradual deformation method to inverse facies distribution.