Modelling doublets and double porosity

A simple model has been developed as a scoping tool for transport between an injection welland an abstraction well pumping at the same rate (i.e. a doublet) in a fractured porous rock. This modelis aimed primarily at the planning and preliminary interpretation of tracer tests and trial heat exchangeusing thermal doublets in the Chalk aquifer. The model is essentially a particular case of transport alongmultiple flow paths and relies on the invariance of double-porosity transport with respect to velocityvariations along a flow path. Hypothetical simulations demonstrate that solute tracer tests need to besupplemented by information on fracture porosity in order to be able to predict thermal breakthrough