Anisotropic and heterogeneous water flow in a sheared fracture as estimated in large synthetic fractures

Koji Matsuki, Yusuke Chida, Kiyotoshi Sakaguchi

Research output: Contribution to journalConference articlepeer-review

2 Citations (Scopus)

Abstract

With the application of shear displacements of 12.5 mm, 25 mm and 50 mm to large synthetic fractures created on a computer by a new spectral method, the initial aperture (the aperture when the surfaces are in contact at a single point) was determined for a square area with a side length of from 0. l m to 6.4 m. By taking aperture data at constant intervals to establish a flow area, macroscopic water flow both parallel and perpendicular to the shear displacement was simulated for fractures during closure by solving Reynolds equation to determine the hydraulic aperture. When the fracture is closed after shearing, the hydraulic conductivity shows remarkable anisotropy due to the formation of both channels and ridges perpendicular to the shear displacement. This anisotropy becomes more remarkable with both shear displacement and closure. Thus, the hydraulic transmissivity of a sheared fracture between two boreholes is much greater when the two boreholes are aligned perpendicular to the shear displacement than when they are aligned parallel to the shear displacement. Furthermore, water flow is more localized as shear displacement increases, since fewer channels and ridges with a greater area are formed as shear displacement increases. Thus, a sheared fracture is not always hydraulically conductive when the permeability of the fracture is estimated for a small area, as in borehole logging.

Original languageEnglish
Pages (from-to)401-406
Number of pages6
JournalTransactions - Geothermal Resources Council
Volume29
Publication statusPublished - 2005 Dec 1
EventGeothermal Resources Council 2005 Annual Meeting - Reno, NV, United States
Duration: 2005 Sep 252005 Sep 28

Keywords

  • Anisotropic flow
  • Connectivity
  • Heterogeneous flow
  • Shear
  • Synthetic fracture

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Energy Engineering and Power Technology
  • Geophysics

Fingerprint

Dive into the research topics of 'Anisotropic and heterogeneous water flow in a sheared fracture as estimated in large synthetic fractures'. Together they form a unique fingerprint.

Cite this