ABSTRACT
Controlled in-situ burning (ISB) can rapidly remove large amounts of oil from a marine spill very quickly. Offshore ISB, however, hasn't been widely used for oil spill response. A key reason is that a fire-resistant containment boom is required to achieve a successful burn on water. Fire-resistant booms are logistically challenging to deploy, expensive, and short lived. We present a feasibility study for a new ISB method – the Burning Tongue (BT) concept. We conducted scaled experiments in the Ohmsett wave tank to demonstrate its feasibility and produced a 35-m long “tongue” of burnable oil (average oil thickness 4.2 mm – above thickness for ISB) by towing a conventional boom (with a 12” (0.3 m) deep skirt) partially filled with crude oil and released oil through a 6” (0.15 m) wide opening at the apex. We also found that the boom movement produced a convergence zone just downstream that kept released oil thick and also pulled oil that entrained under the boom skirt into the thick “tongue” of oil.
Computational fluid dynamic modeling was performed to explain the flow hydrodynamics and the formation of the convergence zone, which indicates the phenomenon is universal. Since then, we have built and tested two new prototypes of the burning-tongue gate. Testing was performed (without oil) on a bayou in Louisiana and offshore in the Gulf of Mexico. We believe the positive results from these tests support the full-scale use of the BT concept during a planned offshore demonstration with real oil or during an actual oil spill. By using conventional booms, the Burning Tongue technology allows rapid ISB within the limited time frame in which the oil can be ignited. This in turn will make oil spill cleanup faster and more effective to reduce the environmental impact of oil spills and speed recovery.