A study of hydraulic properties in A single fracture with IN-plane heterogeneity: AN evaluation using optical measurements of A transparent replica

Abstract

Experimental examinations for evaluating fractures were conducted by using transparent replicas of a single fracture in order to obtain the fracture data to contribute to the methodology on how to improve the definition of representative parameter values used for a parallel plate fracture model. Quantitative aperture distribution and quantitative tracer concentration data at each point in time were obtained by measuring the attenuation of transmitted light through the fracture in high spatial resolution. The representative aperture values evaluated from the multiple different measurement methods, such as arithmetic mean of aperture distribution measured by the optical method, transport aperture evaluated from the tracer test, and average aperture evaluated from the fracture void volume measurement converged to a unique value that indicates the accuracy of this experimental study. The aperture data was employed for verifying the numerical simulation under the assumption of Local Cubic Law and showed that the calculated flow rate through the fracture is 10% - 100% larger than hydraulic test results. The quantitative tracer concentration data is also very valuable for validating existing numerical code for advection dispersion transport in-plane heterogeneous fractures.