Research / Research

Assessment of Dispersant Effectiveness using Ultrasound to Measure Oil Droplet Particle Size Distributions

Project Number
Progress Date
Project Initiation Date
Performing Activity
Principal Investigator
Dr. Paul Panetta
Contracting Agency
Bureau of Safety and Environmental Enforcement
Estimated Completion Date

The goal of this proof-of-concept project was to develop novel ultrasonic scattering methods to measure the droplet size of dispersed oil to provide technologies to monitor the efficacy of subsea dispersant application. ARA developed ultrasonic measurements to determine the crude oil droplet size of dispersed oil to monitor/determine the efficacy of dispersants as a function of oil type, dispersant type, dispersant-to-oil ratio, water temperature, oil temperatures, and the presence of sediment on the effectiveness of dispersants.

The project was accomplished in a series of tasks as described below.

Task 1. ARA will measure the scattering response of oil droplets for various crude oils and dispersants. They assessed commercial sonar and marine acoustic instruments for feasibility to characterize the dispersion and compatibility with measurement protocols and algorithms for future technology transfer.

Task 2. Droplet size was determined using the Laser In-Situ Scattering and Transmissometer (LISST) and visual measurements. Backscattering data was analyzed and correlated with known droplet sizes.

Task 3. The relevant ultrasonic scattering literature was reviewed to choose the appropriate theory for comparison with the experimental measurements. The theories were compared with the experiment to provide guidance for measurement protocol optimization and refinement.

Task 4. ARA developed the droplet sizing algorithm to best characterize the efficacy of the dispersants based on the measurements and theories.

Task 5. The ability of the measurement protocol to determine dispersant effectiveness was validated in the Ohmsett wave tank facility.

Latest progress update

Update the Project start date to September 23, 2011.

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Panetta, P..