The accurate characterization of the depositional structure and hydraulic properties is essential to understand flow and solute transport in porous heterogeneous rocks. Hydraulic tomography was shown to be an efficient technique to provide information on the spatial distribution of hydraulic properties in heterogeneous rocks. Due to information about the 3D sedimentary structures is often not available, most of existing field applications of hydraulic tomography relays on either horizontal or vertical two-dimensional forward models to invert head and/or flow data.
In this work, we explore the potential of combining tomographic pumping and flowmeter tests for characterizing aquifer heterogeneity in 3D. We propose a framework for inverting drawdown data with a constraining structure constructed from the interpolation of single-well flowmeter profiles to infer aquifer structure and transmissivities. The inverse model is first validated for several synthetically generated hydrogeological models with complex depositional structures and heterogeneous hydraulic properties within each unit. It is shown that with the constraining structures informed by the flowmeter profiles, the inverted model exhibits realistic depositional features while maintaining an acceptable fitting between the simulated and measured head data. We then apply the method to characterize the sedimentary structure and transmissivities of a real experimental site drilled in layered porous rocks with complex dune structures. The inverted aquifer geometry is in a good agreement with field characterization on outcrops and cores while the main flow direction of the simulation model is also congruent to field measurements.
The authors thank TOTAL for funding this R&D project and giving permission to publish this paper.