Numerical Simulation of an Air Sparging Field Test

The flow behavior of an air sparging pilot test was simulated using a finite difference, multiphase flow simulator (TETRAD). The field test is one of the only examples where the airflow pattern in the saturated zone is well known. This is a result of the relative homogeneity of the aquifer and the use of an advanced geophysical monitoring technique known as electrical resistance tomography (ERT). ERT is sensitive to the changing water content of the saturated zone during the test and provided a clear image of the size and shape of the principal region of airflow. In addition to ERT results, slug tests and core analyses provided other key calibration data. The multiphase flow simulations provided a good match to the observed pattern of airflow and pressure changes, indicating that such simulations may be useful for evaluating air sparging performance under other conditions.