Remote Detection of Submerged Orimulsion with a Range-Gated Laser Fluorosensor

Abstract

ABSTRACT Bituminous fuels (in the form of water-based emulsions) are increasingly being used as fuel sources in many countries. When spilled in a marine environment, these emulsified fuels initially disperse and then, under certain circumstances, coalesce to become highly adhesive to beaches and shorelines. These fuels may either float or submerge, depending on the salinity of the water into which the spill occurs. Similar situations are known to occur with some conventional heavy fuels, as was the case with the Erika incident off the coast of France. Technologies to detect these neutrally buoyant and/or submerged fuels are urgently needed. The remote detection of submerged oil is a daunting task. The majority of sensors commonly used for the detection of surface oil slicks are of no use for the detection of submerged oil. Environment Canada and the Canadian Coast Guard have recently undertaken a series of bench-scale studies to develop technologies for the real-time remote detection of neutrally buoyant and/or submerged fuels in the marine environment. The unique capabilities of “active sensors” such as laser fluorosensors are being evaluated for the subsurface detection of heavy petroleum products. The detection of submerged Orimulsion by laser-induced fluorescence has been demonstrated at a distance of 81 m (265 feet) in a small test tank. Further experiments are underway to confirm the real-time detection of submerged Orimulsion, initially on the ground, and then through airborne tests.