Chemical Treating Agents

This international joint research project is designed to gather data to support decision makers in the process of determining whether dispersants should be used in low energy environments. This information will be useful for dispersant decision making in ice cover (an ice field reduces wave motion) or other calm conditions. Questions to be addressed are: Will the dispersant stay with the oil until there is enough energy to disperse the slick?
How much energy is needed to disperse the slick after dispersants are applied?

October 2006 Conduct a series of in situ burn experiments on the scale of 50 m2 with chemical herders and crude oil at the Fire Training Grounds, Prudhoe Bay, AK. The burns would be conducted in a specially prepared pit containing broken sea ice.

Project will determine whether chemically treated low-viscosity OCS crude oils disperse in a non-breaking wave environmental and if so, to determine whether there is a limiting oil viscosity for chemical dispersion for OCS crude oils in non-breaking waves.

Project is to determine the period of time that oil spill dispersants applied to spilled oil in a calm sea will remain effective before the sea state increases and dispersion occurs. Related work is planned in an ExxonMobil sponsored project coordinated under the Petroleum Environmental Research Forum (PERF). Every effort will be made to coordinate the present study with PERF work. To this end, one of the model oils used in the ExxonMobil PERF study will be included in all phases of testing in the present study.

This project will determine the viscosity limit for the effective application of chemical dispersants to realistic emulsions.

Small wave tank experiments will be used to confirm that the oil selected for use in this project will form stable emulsions. The preliminary effectiveness tests will provide information for determining the testing order of the emulsions. Tests where effectiveness is expected to be poor will be conducted first to prevent tank fouling for subsequent tests.

At-sea field tests were completed in the summer of 2003 in the UK and in the fall of 2003 at Ohmsett to determine the dispersibility of IFO 180 and IFO 380 fuel oils acquired from a refinery in the UK. Additional dispersant effectiveness testing on these oils using small and mid-scale test methods has been completed by other agencies including MMS, the Canadian Department of Fisheries and Oceans and CEDRE in France. The U.S.

Experiments were conducted in 2002 and 2003 at Ohmsett The National Oil Spill Response Test Facility to assess the dispersibility of fresh and weathered Alaskan and Canadian crude oils in very cold water. Results from these experiments indicate that the crude oils tested were dispersible at near freezing water temperatures. However, there has been criticism of the findings related to the heating of the viscous oils prior to discharge onto the waters surface and subsequent dispersant application.

A small number of dispersant effectiveness tests will be conducted at Ohmsett The National Oil Spill Response Test Facility that will complete two important sections of the dispersant effectiveness test matrix not completed during the October 2003 experimental test series. Testing will be conducted on IFO-180 fuel oil treated with Corexit 9500 dispersant at a DOR of 1:25. In replicated tests at sea this combination yielded consistently high levels of dispersant performance.

The objective of the proposed work is to develop a methodology and equipment to enable researchers to produce large quantities of realistic water-in-oil emulsions. These emulsions will be used in test programs at Ohmsett and elsewhere.

This project will conduct standardized laboratory dispersant effectiveness testing to determine if either the Baffled Flask Test (BFT) or the Swirling Flask Test (SWT) is able to predict chemical dispersion effectiveness of oil spills similar to what was experienced in the field during the UK at-sea trials and at Ohmsett-The National Oil Spill Response Test Facility.