Quantifying crude oil spill volume in homogeneous and layered porous media from product thickness in monitoring wells
[Thesis]
K. Bashir
King Fahd University of Petroleum and Minerals (Saudi Arabia)
1997
122
M.S.
King Fahd University of Petroleum and Minerals (Saudi Arabia)
1997
An experimental study was conducted to examine the relation between the hydrocarbon spill volume and its thickness in a fully screened monitoring well in homogeneous and layered soils. Estimates of the spill volume for various hydrocarbon thicknesses were obtained from analytical and empirical models available in literature, using the soil hydraulic parameters estimated from the software SOILPROP. Comparison of the experimental results and the model predictions shows that the analytical models based on the Brooks-Corey and van-Genuchten equations underpredict the spill volume in all the soils at the relative permeability (k/k{\rm s}) ratio of 1% and 0.1%. This ratio significantly affects the model estimates, with estimates at k/ks of 1% considerably higher than corresponding estimates at k/ks of 0.1%. The empirical models also consistently underpredicted the spill volume. A modified analytical model approach based on the concept of a hypothetical soil hydrocarbon depth and linearization of the total saturation function (St) was developed and it estimated the spill volume very closely. The study also shows that soil layering can appreciably affect the spill volume-well hydrocarbon thickness relationship, and may result in an increase or decrease in the well hydrocarbon thickness. This effect can be more pronounced in a real life problem. The maximum recovery of the free hydrocarbon in the columns was about 50%, leaving at least 50% of the total spill volume irrecoverable.