@inbook{e8343653ec974f2092734d3722d4ef6d,
title = "Geostatistical, type-curve, and inverse analyses of pneumatic injection tests in unsaturated fractured tuffs at the apache leap research site near superior, Arizona",
abstract = "Over 270 single-hole [Guzman et al., 1996] and 44 cross-hole pneumatic injection tests [Illman et al., 1998; Illman, 1999] have been conducted at the Apache Leap Research Site (ALRS) near Superior, Arizona. In this paper, we describe a geostatistical analysis of the single-hole data and type-curve as well as numerical inverse interpretations of one cross-hole test, PP4. Our geostatistical analysis yields information about the spatial structure of air permeabilities measured on a nominal scale of 1 m, as well as of other variables such as fracture density. Our type-curve and inverse interpretations of cross-hole test PP4 yield information about pneumatic connections, directional air permeabilities, and airfilled porosities on scales ranging from a few meters to a few tens of meters. The numerical model can be applied simultaneously to pressure data from multiple borehole intervals (and multiple cross-hole tests), which amounts to {"}pneumatic tomography{"} of the rock. Our analyses suggest that (a) pneumatic pressure behavior of unsaturated fractured tuffs at the ALRS can be interpreted by treating the rock as a continuum on scales ranging from meters to tens of meters; (b) this continuum is representative primarily of interconnected fractures; (c) its pneumatic properties nevertheless correlate poorly with fracture density; and (d) air permeability exhibits multiscale random variations in space.",
author = "Guoliang Chen and Illman, {Walter A.} and Thompson, {Dick L.} and Vesselinov, {Velimir V.} and Neuman, {Shlomo P.}",
year = "2000",
doi = "10.1029/GM122p0073",
language = "English (US)",
isbn = "9780875909806",
series = "Geophysical Monograph Series",
publisher = "Blackwell Publishing Ltd",
pages = "73--98",
editor = "Witherspoon, {Paul A.} and Boris Faybishenko and Benson, {Sally M.}",
booktitle = "Dynamics of Fluids in Fractured Rock, 2000",
}