Optimization of the In-Situ Thermal Desorption Process to Remediate Contaminated Soils Using Numerical Reservoir Simulation

Sites contaminated with Non Aqueous Phase Liquids (NAPLs) are a hazard to the environment and the people living in the surrounding areas. Several technologies have been developed to remediate these contaminated sites. They may be classified into two broad categories ex-situ technologies and in-situ technologies. In Situ Thermal Desorption(ISTD) has emerged as a robust and effective in-situ technology for remediation of contaminated soils. It involves the heating the soil to temperatures high enough to vaporize VOCs (Volatile organic compounds) and SVOCs (Semi-volatile organic compounds) that are recovered using vacuum wells and further treated in surface facilities. The objective of this research is to simulate the ISTD process using CMG STARS (Steam, Thermal and Advanced Processes Reservoir Simulator) for various contaminants (TCE, PCE and Aroclor 1242). The effect of thermal chemical reactions, heterogeneity, well spacing and other complexities on the ISTD process were simulated and studied. Finally, multiple well patterns NAPL recovery scheme was simulated to represent a field level application of the ISTD process and the various operating parameters corresponding to different contaminants and soil conditions were studied and guidelines are provided to make the recovery process more efficient.