The United States Environmental Protection Agency (U.S. EPA), in cooperation with the American Petroleum Institute (API) and the National Petrochemical and Refiners Association (NPRA), has initiated a project to determine the mercury content of crude oil processed in the United States. The focus of the project is to determine the mean concentration and range of concentrations of mercury (total) in crude oil in a statistical fashion. Data generated in the course of the project will be used to estimate an upper limit to the contribution of mercury in crude oil to anthropogenic mercury emissions in the United States. Portions of the project are examining analytical issues, determining concentration variance in crude oil streams and building a database on total mercury concentrations in crude oils processed in the United States.

Limited data are reported that compare three analytical methods used to measure total mercury content in crude oils. The data demonstrate expected analytical method variance, detection limits and mercury species sensitivities. Aspects of the work in progress address questions concerning sampling methods, sample stability and mercury concentration variability in crude oils having a generic market identity. The plan for statistical sampling of crude oils processed in the U.S. is described in general terms.

In addition to the environmental issues, mercury in crude oil has an impact on its market quality (price). Measuring mercury concentrations in crude oil is now becoming more important as mercury's impact on production and processing systems becomes better understood. The EPA/API/NPRA project should assist development of sampling and analysis methods for crude oil and also will assist researchers to study the distribution of mercury in produced fluids throughout production and processing systems.

You can access this article if you purchase or spend a download.