Dispersant Effectiveness Experiments Conducted on Alaskan Crude Oils in Very Cold Water at the Ohmsett Facility

2008 ◽  
pp. 65-65
Author(s):  
J. V. Mullin
Keyword(s):  
Cold Water ◽  
Crude Oils ◽  
Dispersant Effectiveness

Large-scale cold water dispersant effectiveness experiments with Alaskan crude oils and Corexit 9500 and 9527 dispersants

2009 ◽  
Vol 58 (1) ◽  
pp. 118-128 ◽  
Author(s):  
Randy C. Belore ◽  
Ken Trudel ◽  
Joseph V. Mullin ◽  
Alan Guarino
Keyword(s):  
Large Scale ◽  
Cold Water ◽  
Crude Oils ◽  
Corexit 9500 ◽  
Dispersant Effectiveness

COLD WATER DISPERSANT EFFECTIVENESS EXPERIMENTS CONDUCTED AT OHMSETT WITH ALASKAN CRUDE OILS USING COREXIT 9500 AND 9527 DISPERSANTS

2008 ◽  
Vol 2008 (1) ◽  
pp. 817-822 ◽  
Author(s):  
Joseph Mullin ◽  
Randy Belore ◽  
Ken Trudel
Keyword(s):  
Oil Spill ◽  
Cold Water ◽  
Test Series ◽  
The Arctic ◽  
Crude Oils ◽  
Breaking Wave ◽  
Corexit 9500 ◽  
Oil Spill Response ◽  
Wave Conditions ◽  
Dispersant Effectiveness

ABSTRACT One untested hypothesis in oil spill response is that “chemical dispersants do not work effectively in cold water”. This is due to the general misconception that cold water inhibits dispersant effectiveness (DE) and the lack of experimental data to indicate otherwise. To address this issue, the U.S. Minerals Management Service (MMS) funded and conducted two series of dispersant experiments in very cold water at Ohmsett – The National Oil Spill Response Test facility, located in Leonardo, New Jersey from February-March 2006 and January-March 2007. Four Alaskan crude oils Alaska North Slope (ANS), Endicott, Northstar and Pt. McIntyre and two dispersants Corexit 9500 and Corexit 952 7 were used in the test series. The crude oils were tested fresh, weathered by removal of light ends using air sparging and weathered by placing the oils in the tank in both breaking wave conditions and non-breaking wave conditions. Results from the 2006 and 2007 Ohmsett test series demonstrated that both Corexit 9500 and Corexit 9527 dispersants were more than 90% effective in dispersing the fresh and weathered crude oils tested. This verified the results from laboratory and small-scale experiments. MMS believes that results from these test series will assist government regulators and responders in making science based decisions on the use of dispersants as a response tool for oil spills in the Arctic. The results from the 2006 and 2007 Ohmsett dispersant effectiveness test series dispel the thought that chemical dispersants cannot be effective in cold water.

scholarly journals Large Wave Tank Dispersant Effectiveness Testing in Cold Water

2003 ◽  
Vol 2003 (1) ◽  
pp. 381-385
Author(s):  
Randy Belore
Keyword(s):  
Large Scale ◽  
Cold Water ◽  
Salt Water ◽  
Test Facility ◽  
Crude Oils ◽  
Large Wave ◽  
Water Conditions ◽  
Average Wave ◽  
Dispersant Effectiveness ◽  
Concrete Tank

ABSTRACT Research experiments were completed to determine the viability of using chemical dispersants on two crude oils in very cold water conditions. Tests were completed at Ohmsett (the National Oil Spill Response Test Facility in Leonardo, New Jersey) in late February and early March of 2002. Ohmsett is a large outdoor, above-ground concrete tank (203 m long by 20 m wide by 3.4 m deep) filled with 9.84 million gallons of salt water. The tank has a wave-generating paddle, a wave-dissipating beach, and mobile bridges that transport equipment over its surface. A refrigeration unit was installed to ensure that the water was kept at near freezing temperatures during the entire test program. A total of twelve large-scale tests were completed. Corexit 9500 and Corexit 9527 were applied to fresh and weathered Hibernia and Alaska North Slope crude oils, on cold water (-0.5 to 2.4 °C), at dispersant-to-oil ratios (DORs) ranging from 1:14 to 1:81. The average wave amplitude for the tests ranged between 16.5 and 22.5 cm and the average wave period was between 1.7 and 1.9 seconds. The effectiveness of the dispersant in each test was documented through extensive video records and by measurement of the residual oil remaining within the containment boom at the end of each test. The results clearly show that both dispersants were effective in dispersing the two crude oils tested in cold-water conditions.

DATA ANALYSIS AND MODELING OF DISPERSANT EFFECTIVENESS IN COLD WATER

1987 ◽  
Vol 1987 (1) ◽  
pp. 303-306
Author(s):  
N. M. To ◽  
H. M. Brown ◽  
R. H. Goodman
Keyword(s):  
Data Analysis ◽  
Water Column ◽  
Cold Water ◽  
Material Balance ◽  
Regular Waves ◽  
Measured Concentration ◽  
Wave Basin ◽  
Oil Concentration ◽  
Concentration Measurements ◽  
Dispersant Effectiveness

ABSTRACT Tests on dispersant effectiveness in cold water have been performed, for a number of years, using nonbreaking, regular waves in the Esso wave basin. Oil concentration measurements in the water column have been used to study the kinematics of oil dispersion under regular waves. Data analysis procedures are designed to determine, based on the concentration measurements, the rate of oil dispersion in both horizontal and vertical directions into the water column. Oil dispersion rates are used in a two-dimensional, kinematic, finite difference model to simulate the diffusion and advection of oil in water. The model predicts the amount of oil that dispersed and later resurfaced from the measured concentration history. Based on the model results, a material balance of the oil is obtained. Effectiveness of the dispersant is assessed by the amount of oil remaining after each test. Results of the data analysis provide an insight into the oil dispersion mechanism and a method of improving the accuracy of the numerical model. Effectiveness of different dispersants and different application methods may be compared using this methodology.

BASIC STUDY REVEALS HOW DIFFERENT CRUDE OILS INFLUENCE DISPERSANT PERFORMANCE

1987 ◽  
Vol 1987 (1) ◽  
pp. 293-296 ◽  
Author(s):  
Gerard P. Canevari
Keyword(s):  
Crude Oil ◽  
Crude Oils ◽  
Basic Study ◽  
Oil Emulsion ◽  
Chemical Dispersant ◽  
Surface Active Agents ◽  
Surfactant Phase ◽  
Oil Emulsions ◽  
Dispersant Effectiveness ◽  
Water In Oil Emulsion

ABSTRACT Previous research has shown that crude oils contain various amounts of indigenous surface active agents that stabilize water-in-oil emulsions. It is also known that crude oils stabilize such emulsions to different extents. One aspect of the study was to investigate the relationship between the emulsion forming tendency of the various crude oils and the level of performance of a chemical dispersant on the particular crude oil. The results of the extensive laboratory test program indicated that dispersant effectiveness is a function of both dispersant type and the specific crude oil. However, there is no apparent correlation between the degree of emulsion-forming tendency of the crude oil, which is a function of the indigenous surfactant content, and effectiveness. A “clean” hydrocarbon, tetradecane (C14), was also tested in order to evaluate the absence of any indigenous surfactants on performance. It was found that tetradecane exhibited a higher level of effectiveness compared to the crude oils for each of the dispersants tested. In essence, the indigenous surfactants in the crude oil, in every instance, reduce dispersant effectiveness but to an unpredictable level. This is probably due to the fact that these agents present in crude oil promote a water-in-oil emulsion. Since the chemical dispersant is formulated to produce an oil-in-water dispersion, the interference of these crude oil surfactants is apparent. Hence, tetradecane would be an ideal test oil since the degree of dispersion of tetradecane by a particular dispersant represents the maximum dispersion effectiveness for that product. In order to establish more definitively the role of the indigenous surfactants, this surfactant phase was successfully separated from nine crude oils representative of different emulsion forming tendencies. It was found that the amount of surfactant residue extracted from the crude oil did correlate with the emulsion forming tendency of the crude oil. Finally, the above separated surfactant residue was added to tetradecane at the same concentrations as in the respective crude oil. As expected, in every instance, the surfactant residue decreased dispersant performance compared to “pure” tetradecane.

scholarly journals Dispersant Effectiveness on Heavy Fuel Oil and Crude Oil in New Zealand

2003 ◽  
Vol 2003 (1) ◽  
pp. 509-513 ◽  
Author(s):  
Leigh Stevens ◽  
Julian Roberts
Keyword(s):  
New Zealand ◽  
Field Experiments ◽  
Relative Effectiveness ◽  
Fuel Oil ◽  
Crude Oils ◽  
Heavy Fuel Oil ◽  
Corexit 9500 ◽  
Fuel Oils ◽  
Heavy Fuel Oils ◽  
Dispersant Effectiveness

ABSTRACT The New Zealand (NZ) Maritime Safety Authority (MSA) recently identified seven crude oils and nine IFO-380 heavy fuel oils used or transported in NZ waters that had a high relative risk of being spilt. To determine the relative effectiveness of dispersants stocked by the MSA (Corexit 9527, Slickgone LTSW, Gamlen OSD LT, and Tergo R40) on the oils, effectiveness was tested using the Warren Spring Laboratory (WSL) LR 448 protocol. All testing was on fresh (unweathered) oil at 15°C, at a dispersant to oil ratio (DOR) of 1:25. Effective dispersion was considered to be equivalent to a WSL test result of ≥15%, as proposed in the work of Lunel & Davies (1996). Overall, the seven crude oils tested could be dispersed with MSA stocked dispersants; Corexit 9527 and Slickgone LTSW dispersing the greatest volume of oil, while Gamlen OSD LT and Tergo R40 were effective on the widest range of oils. For the nine IFO-380 heavy fuel oils, dispersant effectiveness was generally lower than for crude oils, and two oils could not be dispersed. Corexit 9527 was the most effective dispersant and worked on the widest range of fuel oils. Slickgone LTSW, Gamlen OSD LT, and Tergo R40 were less effective and worked on a smaller range of fuel oils. To assess whether other dispersants not currently stocked by the MSA offered a significantly improved capacity, two high performance products (Corexit 9500 and Slickgone EW) were tested on the same oils, and across a range of temperatures and DORs. Laboratory results showed that Corexit 9500 and Slickgone EW were significantly more effective on both the crude oils and the IFO-380 heavy fuel oils than existing MSA dispersant stocks. While the results of this study provide a good indication of the relative effectiveness of different dispersants, they do not indicate absolute levels of effectiveness, and field experiments are needed to define how laboratory effectiveness translates to effectiveness in the field.

THE EFFECT OF CRUDE OIL COMPOSITION ON DISPERSANT PERFORMANCE

1985 ◽  
Vol 1985 (1) ◽  
pp. 441-444 ◽  
Author(s):  
Gerard P. Canevari
Keyword(s):  
Crude Oil ◽  
High Viscosity ◽  
Crude Oils ◽  
Chemical Compositions ◽  
Test Results ◽  
Oil Composition ◽  
Oil Viscosity ◽  
Oil Emulsion ◽  
Dispersant Effectiveness ◽  
Water In Oil Emulsion

ABSTRACT Previously, anomalous results from various laboratory dispersant effectiveness tests were believed due to the historic difficulties of replicating field conditions in the laboratory. Some variables were reported to cause differences in dispersant performance, such as the oil viscosity—i.e., both dispersant A and dispersant B exhibited poorer performance as the oil viscosity increased. Other test results showed an opposite trend. For example, dispersant A performed more effectively than dispersant B for Murban crude oil but B was better than A for the more viscous La Rosa crude oil. It is now believed that these inconsistent results are actually due to the chemical compositions of the crude oils. Various factors influence dispersant performance and some initial research directed at determining the mechanism of water-in-oil emulsion (mousse) formation has identified naturally occurring surfactants in the various crude oils. This will provide insight as to how these indigenous agents interacted with the surfactant package in the test dispersant to affect overall performance. Variations in dispersant performance for different crude oils are thus likely to be related to the water-in-oil emulsion formation of the particular crude oil. The results of this work indicate that dispersant treatment should be evaluated during spill situations even if the crude oil physical properties, such as high viscosity, might suggest that dispersant treatment would not be effective.

DISPERSANT EFFECTIVENESS TESTING ON VISCOUS, U.S. OUTER CONTINENTAL SHELF CRUDE OILS AND WATER-IN-OIL EMULSIONS AT OHMSETT

2008 ◽  
Vol 2008 (1) ◽  
pp. 823-828 ◽  
Author(s):  
Randy Belore ◽  
Alun Lewis ◽  
Alan Guarino ◽  
Joe Mullin
Keyword(s):  
Continental Shelf ◽  
Test Facility ◽  
Crude Oils ◽  
Small Scale ◽  
Management Service ◽  
Outer Continental Shelf ◽  
Corexit 9500 ◽  
Viscous Oil ◽  
Oil Emulsions ◽  
Dispersant Effectiveness

ABSTRACT Two separate projects were funded by the US Minerals Management Service to study the dispersibility of viscous crude oils and water-in-oil emulsions. The objective of the first study was to determine the viscosity limit for the effectiveness of chemical dispersants applied to viscous US Outer Continental Shelf crude oils of varied origin. The objective of the second study was to determine the effectiveness of chemical dispersants when applied to water-in-oil emulsions and to determine if similar viscosity limits exist for successful dispersion of emulsions as for non-emulsified crude oils. In both programs, preliminary tests were completed in the small-scale wave tank at SL Ross. Full-scale tests were completed at The National Oil Spill Response Test Facility (Ohmsett) in Leonardo, New Jersey in April 2005 (viscous oils) and December 2005 (emulsions). In the emulsion dispersion program, tests were conducted with both Corexit 9500 and Corexit 9527 dispersants. Only Corexit 9500 was used in the viscous oil dispersion testing. In the viscous oil test program, the effectiveness of the dispersant was influenced by both oil type (viscosity) and to a lesser extent by DOR. In general, the oils with viscosities lower than 6,500 cP were dispersible to a significant degree, whereas the oils with viscosities of 33,000 cP and greater were not. Oils between 6,500 and 33,000 cP were not available for testing to identify dispersant effectiveness between these two viscosities.

Round-Robin Testing of a New EPA Dispersant Effectiveness Protocol

2001 ◽  
Vol 2001 (1) ◽  
pp. 467-470
Author(s):  
Albert D. Venosa ◽  
George A. Sorial ◽  
Dennis W. King
Keyword(s):  
Environmental Protection Agency ◽  
Round Robin ◽  
Crude Oils ◽  
Protection Agency ◽  
Round Robin Test ◽  
Testing Protocol ◽  
Repeatability And Reproducibility ◽  
Dispersant Effectiveness ◽  
Prudhoe Bay ◽  
South Louisiana

ABSTRACT The current U.S. Environmental Protection Agency (EPA) protocol for testing the effectiveness of dispersants, the Swirling Flask Test (SFT), has been found to give widely varying results in the hands of different testing laboratories. A redesign of the testing flask by eliminating the side arm, incorporating baffles in the wall of the flask, and adding a stopcock at the bottom has been adopted to improve reproducibility in the hands of different operators. The new procedure is called the Baffled Flask Test (BFT). Similar to the original SFT, the test is relatively simple, requires minimum equipment, and involves a total time span of about 2.5 hours for testing four replicates on one of the two crude oils. Before EPA can adopt the BFT as the official protocol replacing the SFT, the newly developed test must undergo independent testing in the hands of commercial laboratories. Thus, to demonstrate its repeatability and reproducibility to support its adoption as the new EPA testing protocol, a round-robin test was conducted during the spring 2000 with eight independent laboratories. The participating laboratories were provided with all the supplies needed to conduct the BFT: baffled flasks, South Louisiana and Prudhoe Bay crude oils, six dispersant products, and the artificial seawater formulation used in the protocol. The laboratories were given specific, detailed instructions on how to conduct the tests for the dispersants, including all necessary quality assurance procedures. Results were reported back to EPA and the results were analyzed statistically to quantify repeatability and reproducibility. The paper discusses the data and presents the analysis showing the method's reproducibility.

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