Estimation of Hydrodynamic Coefficients in Oil-Contaminated Aquifers

One of the most important concerns in aquifers adjacent to oil facilities is pollution caused by LNAPL leaks. Because these compounds have less weight than water, they float on the surface of the water as a layer and move along with the water flow. Recovery of LNAPLs is always difficult and expensive. This study aims to manage the recovering costs by determining the hydrodynamic coefficients of LNAPL. The hydrodynamic coefficients include transmissivity and specific yield. In this study, for the first time, instead of the term specific yield, the term oil specific yield has been used according to the type of fluid in the aquifer. The Rockwork model was used to calculate the oil specific yield and LDRM (LNAPL Distribution and Recovery Model) model was used to calculate LNAPL transmissivity coefficient. The inputs of the LDRM model include soil and LNAPL parameters, porosity, hydraulic conductivity of water saturation, van Genuchten parameters, mass densities of water and LNAPL, surface tensions of water-LNAPL, LNAPL-air and water-air, viscosities of water and LNAPL. From the inputs, LNAPL transmissivities and recoverable and total LNAPL specific volumes were extracted as output results. With the help of the obtained results, maps of LNAPL transmissivities, thickness and recoverable volume of LNAPL were prepared and the best recovery locations were introduced.