Interwell Simulation Model for the Advection Dispersion Equation (ISADE)

Abstract

Contaminant transport in porous media is often modeled by solving the Advection Dispersion Equation (ADE) which describes the way the contaminant moves within the bulk fluid as well as the movement of the contaminant due to the bulk movement of the fluid phase. The simulation of contaminant transport can however prove to be computationally expensive especially if the porous medium is discretized into high-resolution grid blocks. We propose an interwell simulation model for advection dispersion equations (ISADE) to predict the concentration of contaminant observed at the pumping well. This method comprises of two main steps. Initially, the model divides the aquifer or reservoir into a series of 1D injector-producer pairs and uses the historical contaminant observation data to estimate five major unknowns in each of these control volumes: the interwell connectivity, the pore volume, the volumetric flowrate at the grid face, the dispersion coefficient, and the number of grids in each control volume. Finally, once the history matching process is complete, the estimated variables are used to predict the concentration of contaminant observed at the wells. Five example cases were studied and the results show that the ISADE model was able to predict with reasonable accuracy the concentration of contaminant observed. Furthermore, the model can easily handle changes in input parameters such as the concentration of contaminants released in the aquifer, and the injection and production rates.