Three-dimensional inverse modelling of pneumatic tests in unsaturated fractured rocks

A three-dimensional inverse model was used to analyse air pressure data from single- and cross-hole air injection tests in unsaturated fractured tuffs at the Apache Leap Research Site in Arizona. The model simulates single-phase airflow in a uniform, isotropic continuum. It treats open borehole intervals as high-permeability and high-porosity cylinders of finite length and radius. Single-hole test data yield local-scale permeabilities, porosities and borehole storage coefficients. Cross-hole test data yield larger-scale permeabilities, porosities and their spatial distributions.