Numerical modeling of the hydraulic signatures of horizontal and inclined faults

Pumping tests in discontinuous media are commonly interpreted using radial/non-radial flow analytical models, which do not account for a large range of multistage real signatures that combine both flow types. The term radial is employed in Barker’s sense, referring to the cross-flow area growth with a flow dimension (n) equal to 2, while multistage refers to a flow response of several time periods with successive n values. Synthetic domains are used to numerically investigate the flow behaviour of faulted media, specifically the effect of fault inclination on multistage signatures. Simulations are performed using single faults surrounded by a permeable matrix to characterize drawdown series and to identify hydrodynamic scenarios associated with some diagnostic multistage n sequences. The n sequence 2 – < 2 – 2 results from interactions between the matrix and a horizontal to weakly inclined fault, while 2 – 1.5 – 2 corresponds to a higher fault inclination and is a combination of the generalized horizontally and vertically faulted models. These results improve the interpretation of ambiguous drawdown series from long-term pumping tests. This provides a better hydraulic characterization of faulted environments, allowing assessment of fault and matrix properties such as fault inclination. The approach is successfully tested on real datasets.