A methodology for using borehole temperature-depth profiles under ambient, single and cross-borehole pumping conditions to estimate fracture hydraulic properties

摘要: Temperature profiles in the subsurface are known to be sensitive groundwater flow. Here we show that they also strongly related vertical flow boreholes themselves. Based on a numerical model of and heat transfer at borehole scale, propose method invert temperature measurements derive velocities. This is applied an experimental site fractured crystalline rocks. Vertical velocities deduced from inversion compared with direct heat-pulse flowmeter showing good agreement over two orders magnitudes. Applying this methodology under ambient, single cross-borehole pumping conditions allows us estimate fracture hydraulic head local transmissivity, as well inter-borehole connectivity. Thus, these results provide new insights how include inverse problems for estimating properties.