This study focused on the response analysis of liquid tracer in gas-liquid, two-phase steady flow in porous media. The tracer tests were conducted in a column filled with glass beads and uniformly saturated with water and gas. First, it is shown that the conventional advection-dispersion equation (ADE) can not explain the breakthrough curves of tracer tests under two-phase flow conditions. The experimental breakthrough curves have an earlier peak and a longer tailing compared with the breakthrough curves described by ADE. The water saturation is not always uniform in the particle region. The mathematical model consisted of a high water saturation layer and low one, between which mass transfer was assumed. Mass balance equations were derived on these assumptions of the two-phase flow in a porous medium. The model calculations well agreed with the experimental data. When fundamental equations are solved by the finite-difference method, it is well known that the standard numerical techniques lead to numerical oscillation in the advection term in the equations. The third-order upstream method applied in this study could reduce the oscillation. Also, this study examined parameter estimation technique by use of optimization programs. Unknown parameters in this model were successfully estimated by the SIMPLEX method.
|Number of pages||12|
|Journal||Journal of the Geothermal Research Society of Japan|
|Publication status||Published - 1998 Jan|