Aerial spraying of demulsifiers to enhance the natural dispersion of oil slicks

Large-scale sea trials were conducted to investigate the effectiveness of the aerial application of demulsifiers and the potential of this process in oil spill response. Preliminary tests were first conducted to verify the effectiveness of the Shell demulsifier LA 1834 diluted with Shell Surdyne X113 solvent and to determine the range of swath widths and discharge rates of the aerial spraying system. Four trials were carried out in the southern North Sea using either crude oil or medium fuel oil/gas oil mixes to simulate the oil spill. Infrared, ultraviolet, and video sensing data were obtained during all trials with emphasis on direct comparison between control slicks and slicks treated with aerially sprayed demulsifier. Results show that application of demulsifier solution has enhanced the natural dispersion of both fresh and emulsified oil to a greater degree than the adjacent control slicks. The demulsifier appeared to remain with the treated slicks after aerial application, influencing slick behavior for a considerable time. 5 refs., 6 figs., 2 tabs