STRUCTURAL RELIABILITY-ANALYSIS FOR ONE-DIMENSIONAL 2-PHASE MISCIBLE FLOW

An analytic structural reliability analysis is performed for first con tact miscible, two-phase, flow in a one-dimensional porous medium. The sensitivity of the probability for time-to-breakthrough is examined f or two common models of the joint Probability distribution between the porosity and the permeability of the medium. First-order analysis is essentially exact for the normal normal model. The accuracy of first-o rder analysis for the normal lognormal model is determined using a spe cific example of field data. A cyclical dependence on the breakthrough probability to the statistical nature of the porosity and permeabilit y is found in the normal-normal model. In the normal-lognormal model, this cyclical variation is reduced, if not entirely eliminated, in fav or of dependence on the statistical nature of the permeability.