Transient hydraulic tomography approach to characterize main flowpaths and their connectivity in fractured media

摘要: Abstract In sparse fracture systems flow and transport patterns are often dominated by main flowpaths characterized a strong complexity induced the fractures’ surface roughness, hierarchical arrangement in networks, from interaction of fractures with surrounding rocks. The accurate characterization hydraulic properties connectivity major zones is essential to model flow, solute heat fluid pressure propagation fractured media. this study, we present novel deterministic inverse modeling method for imaging spatial variability transmissivity storativity network fractures. based on numerical that simulates simple three-dimensional (3-D) discrete (DFN) fixed structure. forward coupled an algorithm match observed transients obtained sequential cross-hole tests. This has been successfully tested constant rate injection tests carried out at Grimsel Test Site (GTS) Switzerland. Cross-hole were conducted tomographic configuration, responses monitored four observation intervals various depths two different boreholes. A approach parametrization developed estimate log-transformed (T) (S) values hydraulically active between boreholes inverting transients, under hypothesis T S independent variables. We identified several permeable their without attempting represent explicitly true geometrical (length, orientation, dip), focusing instead calibration capturing behavior. inter-borehole structure agrees well information, including additional data cross-borehole step hydrogeophysical data. Hence, proposed tomography appears be promising characterizing sparsely rock.