Insights from numerical modeling on the hydrodynamics of non-radial flow in faulted media

The objective of this work is to explore the use of flow dimensions as a tool for characterizing hydraulic conditions in faulted media. Transient flow is numerically simulated in synthetic vertically-faulted reservoirs. Analysis of the obtained time series following the Generalized Radial Flow (GRF) model displays combined radial and fractional signals with a flow dimension n=1.5. Investigating the transient geometry of the frontal equipotential surface shows that fractional flow occurrence is due to abnormal fault diffusion as a consequence of water supply from the matrix under specific conditions. An original hydrodynamical explanation for fractional flow in vertically faulted media is suggested, along with a reinterpretation of the bilinear regime. It is shown that the GRF theory remains valid in such discontinuum as the fundamental relationship between n and the cross-flow area is satisfied. These results provide insights in the use of the flow dimension as a hydraulic diagnostic tool in faulted media.