A generalized radial flow model for hydraulic tests in fractured rock

TLDR

Hydraulic test analysis models are generalized by treating flow dimension as a non‑integral empirical parameter, a refinement particularly useful for fractured media where selecting the appropriate dimension is problematic. Analytical solutions for the generalized radial flow model are derived for constant‑rate, constant‑head, and slug tests, and the formulation incorporates wellbore storage, skin effects, and dual‑porosity extensions. The general solutions also include the less common sinusoidal test.

Abstract

Models commonly used for the analysis of hydraulic test data are generalized by regarding the dimension of the flow to be a parameter which is not necessarily integral and which must be determined empirically. Mathematical solutions for this generalized radial flow model are derived for the standard test conditions: constant rate, constant head, and slug tests. Solutions for the less common, sinusoidal test are contained within the general solutions given. Well bore storage and skin are included and the extension to dual‐porosity media outlined. The model is presented as a model of fractured media, for which it is most likely to find application because of the problem of choosing the appropriate flow dimension.