skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: SCALE-DEPENDENT DARCY FLOW IN COMPOSITE MEDIA

Abstract

No abstract prepared.

Authors:
;
Publication Date:
Research Org.:
Los Alamos National Lab., NM (US)
Sponsoring Org.:
US Department of Energy (US)
OSTI Identifier:
785033
Report Number(s):
LA-UR-99-2819
TRN: US200307%%429
DOE Contract Number:
W-7405-ENG-36
Resource Type:
Conference
Resource Relation:
Conference: Conference title not supplied, Conference location not supplied, Conference dates not supplied; Other Information: PBD: 1 Nov 1999
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COMPOSITE MATERIALS; DARCY LAW; FLUID FLOW

Citation Formats

D. M. TARTAKOVSKY, and C. L. WINTER. SCALE-DEPENDENT DARCY FLOW IN COMPOSITE MEDIA. United States: N. p., 1999. Web.
D. M. TARTAKOVSKY, & C. L. WINTER. SCALE-DEPENDENT DARCY FLOW IN COMPOSITE MEDIA. United States.
D. M. TARTAKOVSKY, and C. L. WINTER. 1999. "SCALE-DEPENDENT DARCY FLOW IN COMPOSITE MEDIA". United States. doi:. https://www.osti.gov/servlets/purl/785033.
@article{osti_785033,
title = {SCALE-DEPENDENT DARCY FLOW IN COMPOSITE MEDIA},
author = {D. M. TARTAKOVSKY and C. L. WINTER},
abstractNote = {No abstract prepared.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1999,
month =
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • Canadian researchers at the Univ. of Alberta and the Univ. of Calgary have developed a computer program to solve the nonlinear partial differential equations describing transient radial gas flow through porous media. Specifically, the program can handle 4 sets of boundary conditions encountered in a finite radial system. The program has been employed to obtain pressure distributions and mass fluxes as functions of time and position for the constant-terminal rate case and the constant-terminal pressure case, in porous media having different values of permeability, inertial-resistance coefficient, slip coefficient, and rock compressibility. Changes of gas properties with pressure were taken intomore » account. Results indicate that each of these rock properties can, under certain conditions, appreciably affect the transient response. For instance, it was observed that slip, rather than being a laboratory curiosity, can affect the transient response in a typical tight reservoir.« less
  • Joints are normally in contact at roughness asperities; consequently the relative roughness, the ratio of the asperity protrusion to the mean flow aperture, is approximately one, which is orders of magnitude greater than that encountered in more usual situations such as pipe and channel flows. In our experiments the joint roughness was idealized with sawtooth corrugations. We found that Darcy's Law became invalid for Reynolds numbers greater than about 100. Hence, for most of our studies the flow was non-Darcian, and so we adopted the usual convention of representing pressure losses in terms of an apparent friction factor. When themore » roughness peaks were aligned, resulting in maximum flow disturbance, the friction factor increased when the relative roughness was increased, simulating the closure of a joint due to normal-direction loading. However, when the roughness peaks were 180/sup 0/ out of phase, so that peaks were opposite valleys, the friction factor initially increased with greater relative roughness, but then decreased. 2 refs., 8 figs., 2 tabs.« less
  • Abstract not provided.
  • Surface tensions of high-salinity solutions are significantly different from those of pure water. Our objective was to develop and test a methodology to determine whether these surface-tension effects predictably alter imbibition into dry and moist porous media. Static and dynamic experiments were performed using four grades of quartz sand to determine the effects of solution salinity on imbibition. Results were quantified as apparent contact angles between the sand and three solutions (pure water, 5 molal NaNO3, n-hexane). Contact angles determined using a static method in initially air-dried sand ranged from 23° to 31°, with the same values found for bothmore » water and the NaNO3 solution. Effective contact angles determined for the air-dried sand using a dynamic method based on a modified version of the Green and Ampt model were about twice those found using the static method, averaging 45° and 62° for water and the NaNO3 solution, respectively. In pre-wetted sands, the dynamic imbibition data yielded apparent contact angles of 2° and 21° for water and the NaNO3 solution, respectively, with the latter value comparing well to a predicted value of 25° for the NaNO3 solution based solely on surface-tension contrast. The results of this study indicate that on the Darcy-scale, saline solutions appear to follow the relationship of non-zero contact angles with other miscible fluids of different surface tensions used to pre-wet the sand grains, in agreement with the macro-scale infiltration results of Weisbrod et al. [2004].« less
  • Transport of water and solutes through fractured porous media is influenced by a wide variety of complex phenomena including preferential flow, fracture-matrix interactions, and entrapment of the air phase. We have developed a new method for constructing glass fracture-matrix micromodels which provide direct visualization and quantification of the aforementioned phenomena in fracture systems. In the fracture-matrix micromodels, sequential etching provides the necessary contrast between matrix pore-sizes and fracture apertures. Direct visualization of pore-scale flow fields and measurements of local velocity profiles were made possible through tracing trajectories of suspended fluorescent microspheres under a microscope. Results obtained thus far include directmore » measurements of parabolic velocity profiles in water-saturated fractures, details of flowlines associated with trapped air-water interfaces in partially-saturated fractures, and evidence for preferential unsaturated wedge flow along lines of contact between blocks. In general, micromodel experiments are useful for testing conceptual models concerning transport, and for detecting previously unobservable pore-scale phenomena.« less