Post on 15-Jan-2016
Advances in Treating Agents for Oil Spill Response with Applicability to the Arctic
Amy Tidwell & Tim Nedwed, ExxonMobil Upstream Research Company
Ian Buist & Randy Belore, SL Ross Environmental Research, Ltd.
Gerald Canevari, Canevari & Associates
2012 United States-Canada Northern Oil and Gas Research ForumAnchorage, Alaska
November 13-15, 2012
Outline
• The OSR Toolbox• Dispersants
− Background
− Development of New Dispersant• In situ Burning
− Background
− Development of Herding Agents• Commercialization Plans • Summary
Spill Response Options: The Toolbox
Mechanical Recovery: Booms & Skimmers
In-Situ Burning
Monitor & Evaluate
Dispersants
The goal is to design a response strategy based on
Net Environmental Benefit Analysis
Background on Dispersants: What are they?
• Dispersants are solutions of surfactants dissolved in a solvent
• Surfactants reduce oil-water interfacial tension – allows slicks to disperse into very small droplets with minimal wave energy
• Dispersed oil rapidly dilutes to concentrations <10 ppm within minutes, <1 ppm within hours, ppb range within a day
Background on Dispersants: What are they?
• Oil-degrading micro-organisms are present everywhere
• Each dispersed oil droplet is a concentrated food source that is rapidly colonized and degraded by marine bacteria
• Rapid dilution allows biodegradation to occur without nutrient or oxygen limitations
• Rapid dilution reduces toxicity issues – dispersed oil plume dilutes to <1 ppm in hours and <1 ppb within 1 – 2 days
Graphic consistent with Venosa & Holder, EPA 2007
Development of New Dispersant Gel
•Consistency of warm honey•Positively buoyant drops•Cohesive & persistent•Oleophilic behavior•85+% active ingredient
Properties of Dispersants Used in Testing
Dispersant
Dispersant Viscosity (15C)Density @ 20C
(g/cc)Viscosity (cP) Shear Rate (s-1)
Corexit 9500 107 100 0.968
New dispersant 1500 10 0.921
Gel Pour Video
9500 Pour Video
Development of New Dispersant: Testing
Dispersant-effectiveness results for light, medium, & heavy crude oils
• Controlled burning of oil “in situ”• Conventional process requires booms to keep oil thick• Fire resistant booms are a challenge to transport• Only operational use offshore during Deepwater Horizon
Background on in situ Burning
Newfoundland Offshore Burn Experiment, 1993
• Herders enable in situ burning without booms• Requires application of small volume of surfactant on water surface on
perimeter of slick• Herding process requires minutes to thicken slick enough to burn• Herder application and burn initiated quickly from a single helicopter
Background on in situ Burning: Herding Agents
Lab-scale application of herders
Development of Herders: Recent Testing
Field testing of herding agents, 2008
• Herder testing since 2004 focused on supporting in situ burning in ice• Recent field tests were done in very limited ice supporting use of
herders in open water
Commercialization Efforts: New Dispersant and Herders
• Dispersant gel
− Plans are for dispersant gel to be available for sale by early 2013
• Herding agents
− Currently listed with US EPA for potential use in US marine waters
− Commercially available through Applied Fabrics, Buffalo, New York
− Helicopter delivery system under final development
Summary and Conclusions
• Two new treating agent technologies – new dispersant and herding agents – have been developed which could enhance oil spill response capabilities
• New dispersant
− Treated light-to-medium oils with 2/3 less dispersant than a currently available product
− Dispersed viscous oils that were previously considered un-dispersible
• Herding Agents
− Potential to enable in situ burning in both ice conditions and open water without the need for fire-resistant booms
− May turn an infrequently used response option into a readily available tool because it can be applied rapidly from helicopters
Questions
Slide 13
Background on Dispersants
Dispersants Enhance Removal of Oil from the Environment Through Biodegradation