EVALUATION OF MULTIWELL TEST DATA IN A FAULTED AQUIFER USING LINEAR AND RADIAL FLOW MODELS

An extensive drilling and testing program was undertaken at Carleton U niversity, Ottawa, Canada, to characterize the aquifer for the design of an aquifer thermal energy storage (ATES) system. The substantial da ta base provides an excellent record of well yields and hydraulic resp onses to a series of aquifer tests in a faulted carbonate aquifer. Wel l yield variability is reflected in the wide range in specific capacit y (1.4 to 75.8 L/s/m) and is dependent upon the proximity of a well to a major fault. Constant discharge data, available for nine pumping we lls and several observation wells, reflect both the excellent hydrauli c connection along major faults and the limited hydraulic connection b etween fault blocks. Three different flow models, including vertical f racture and vertical dyke (linear), and Theis (radial), are used to in terpret constant discharge test data from nine pumping wells and sever al observation wells. In all tests, the duration of pumping is suffici ent to identify early-time linear now along faults and late-time pseud o-radial flow between fault blocks. This paper demonstrates the influe nce of fault-induced heterogeneity on the hydraulic response of a carb onate aquifer and demonstrates the application and limitation of simpl e radial continuum models to aquifers of this type.