Crude oil is elevated in one or more metallic elements that may be used as a tracer for following the movement of oil as it disperses from a spill site. In particular, vanadium is an element found in substantially elevated concentrations in many crude oil sources relative to levels found in uncontaminated soils, sediment-water systems, and seawater. Nickel is another element found elevated in most crude oils (Andrade, Covelo, Vega, and Marcet, 2004, Journal of Environmental Quality 33:2103-2110; Sasaki, Maki, Ishihara, and Harayama, 1998. Environmental Science and Technology, 32:3618-3621).
In addition, the brine-like produce water also associated in large quantities with crude oil is substantially elevated in many common sea water metals including Ca, Mg, K, and Na that may contribute to tracking the path of crude oil as it disperses from a spill site. Measuring the movement of metals associated with the oil release should aid in tracking the dispersed oil and possibly produce water released. It may be discovered that using metals such as vanadium and nickel offers particular advantages to following a plume treated with chemical dispersants.
The goal is to apply the measurement of selected elements associated with crude oil as a tracer for a supplemental method to determine the movement of oil, chemically dispersed oil, and the dispersion agent(s) from the spill site in the water column of the Gulf of Mexico. While direct measurements of specific hydrocarbon compounds in the crude oil is obviously a valuable tool for tracer purposes, the non-uniform mixing of chemical dispersants with the crude oil over time, depth, and mixing points may complicate tracking oil plume components.
In addition to measurement of petroleum movement measured by others, It is likely that measuring selected elements associated with the crude oil and its associated produce water will enable better tracking of not only the plume in general, but the different phases of the plume such as untreated petroleum hydrocarbons, dispersed hydrocarbons and the dispersion agent(s), and produce water released with the oil.