Flow channeling and analysis of tracer tests in heterogeneous porous media
- LBNL Library
Flow and solute transport through porous medium with strongly varying hydraulic conductivity are studied by numerical simulations. The heterogeneity of the porous medium is defined by {sigma} and {lambda}{prime}, which are, respectively, the standard deviation of natural log of permeability values and its correlation range {lambda} divided by transport distance L. The development of flow channeling as a function of these two parameters is demonstrated. The results show that for large heterogeneities, the flow is highly channelized and solute is transported through a few fast paths, and the corresponding breakthrough curves show a high peak at very early times, much shorter than the mean residence time. This effect was studied for a converging radial flow, to simulate tracer tests in a fracture zone or contact-thickness aquifer. It is shown that {sigma}{sup 2}{lambda}{prime} is an appropriate parameter to characterize the tracer dispersion and breakthrough curves. These results are used to study tracer breakthrough data from field experiments performed with nonsorbing tracers. A new procedure is proposed to analyze the results. From the moments of the residence-time distribution represented by the breakthrough curves, the heterogeneity of the porous medium, as characterized by {sigma}{sup 2}{lambda}{prime} and the mean residence time t{sub o}, may be determined.
- Research Organization:
- Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
- Sponsoring Organization:
- USDOE. Assistant Secretary for Environmental Management. Office of Science and Technology; Swedish Nuclear Fuel and Waste Management Company, Japanese Nuclear Cycle Institute BG No.93-317 (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 836660
- Report Number(s):
- LBNL--49153
- Journal Information:
- Water Resources Research, Journal Name: Water Resources Research Journal Issue: 5 Vol. 30
- Country of Publication:
- United States
- Language:
- English
Similar Records
Overview of medium heterogeneity and transport processes
Impact of viscous fingering and permeability heterogeneity on fluid mixing in porous media