Estimating properties of unsaturated fractured formations from injection and falloff tests [electronic resource].
- Berkeley, Calif. : Lawrence Berkeley National Laboratory, 1987.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- Pages: 54 : digital, PDF file
- Additional Creators:
- Lawrence Berkeley National Laboratory
United States. Department of Energy. Office of Scientific and Technical Information
- A new technique for calculating hydraulic properties of unsaturated fractured formations is proposed as an alternative to the common approach involving steady-state analysis of multi-rate gas injection tests. This method is based on graphical analysis of unsteady-state pressure-time data from an injection-falloff test sequence. Both gas and water injection testing are considered. Flow in a horizontal fracture of limited lateral extent, bounded above and below by an impermeable matrix, and intersected by a cylindrical borehole is described by two analytical models developed in this study. The first model corresponds to the early-time infinite acting radial flow period, and the second to the late-time linear flow period. Interpretive equations are derived for computing fracture conductivity and volumetric aperture from early-time pressure data, and fracture width from late-time pressure data. Effects of fracture inclination and gravity are studied numerically and found to be practically negligible for gas as well as water injection. Two simulated injection-falloff tests are analyzed using the suggested procedure. Results are found to be in good agreement with simulator input values. 13 refs., 14 figs., 4 tabs.
- Published through SciTech Connect.
Mishra, S.; Bodvarsson, G.S.; Attanayake, M.P.
- Funding Information:
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