PHYSICAL-PROPERTIES AS INDICATORS OF OIL PENETRATION IN SOILS CONTAMINATED WITH OIL LAKES IN THE GREATER BURGAN OIL-FIELDS, KUWAIT

Measurements were made on 60 samples to determine the physical propert ies of the soil profiles contaminated with oil lakes in Al-Ahmadi and Burgan oil fields which include 80% of the Greater Burgan oil wells in southern Kuwait. The two soil profiles have similar saturation percen tages, field capacities, wilting coefficients, low available water cap acities due to statification and very low matric potential, and high b ulk densities due to compaction by vehicle wheels. The fluviatile orig in, relatively poor sorting and unstable structure of the Burgan soil layers have led to lower hydraulic conductivity and permeability, ther eby restricting oil penetration mainly to the upper 25-45 cm layer. In contrast, the eolian origin, excellent sorting and stable structure o f Al-Ahmadi soil layers have resulted in higher hydraulic conductivity and permeability, and hence allowed the spreading of oil over much gr eater depths (down to 150 cm). The very low values of the hydraulic co nductivities and available water capacities of the zone(s) lying below the impervious Gatch (caliche) layer in the two soil profiles suggest that this layer could act as a moisture barrier impeding any further downward oil penetration.