Viscosity and drag reduction for temporary storage and transfer of weathered crude oils and emulsions

A study was conducted to assess various concepts for the reduction in viscosity of weathered crude oils and emulsions recovered during oil spill cleanup operations and the reduction in skin friction drag associated with pumping the recovered fluids. The objective was to identify concepts and systems which, alone or in combination with others, could significantly reduce pumping problems associated with the at-sea recovery of Grand Banks crude oils and their emulsions. All potentially useful concepts had to fit into a modular, road-transportable, temporary storage and transfer system for vessels of opportunity. The concepts assessed included chemical additives such as drag reducing agents and pour point depressants; emulsion breaking; use of larger diameter pipes or hoses; free-water injection; pipe coatings; annular water injection; heating the oil; and shearing or mixing. Seven concepts were recommended for further study. Detailed assessment of a conceptual system design involving the use of a Pharos Marine GT-260 skimmer deployed from an oilfield supply vessel is presented. 23 refs., 3 figs., 1 tab