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COBEM 2019
25th International Congress of Mechanical Engineering
EXPERIMENTAL STUDY OF START-UP FLOW OF A THIXOTROPIC FLUID IN PIPELINE
Submission Author:
Roque Martins Duarte Junior , PR
Co-Authors:
Roque Martins Duarte Junior, Tainan Gabardo, Lucas Garcia Pereira, Esther Ihlenfeldt, Eduardo Matos Germer, Cezar Otaviano Ribeiro Negrao
Presenter: Roque Martins Duarte Junior
doi://10.26678/ABCM.COBEM2019.COB2019-1365
Abstract
Oil exploration in ultra-deep waters has increased recently due to recent discoveries of new basins in offshore fields. The rise in offshore production led to an increase in paraffinic oil extraction. During oil transportation from the reservoirs to the seashore, the oil losses heat to the ocean floor. The temperature difference induces the cooling of the oil causing increase of the solubility and precipitation of paraffin crystals, which may lead to oil gelation on the production line during shutdowns. This gelled material exhibits several non-Newtonian fluid characteristics, such as viscoplasticity, elasticity, time dependence, thermal and shear dependence. To restart the flow under these conditions, it is necessary to impose pressures higher than the usual ones. If not controlled, pressure too high may damage the pipeline and cause environmental and financial problems. Therefore, the objective of this paper is to investigate how the time dependence affects the restart pressures. To do so, the flow curve, flow start-up tests with different resting times and start-up visualization were performed. The fluid used will be an aqueous solution of Laponite (2% wt.), which was studied on a laboratory-scale flow loop (long helical pipe) with thermal control. The results of the flow curve showed that the fluid had a shear-thinning behavior. The visualization experiment indicated a higher yield shear stress to start-up the flow. Finally, it was highlighted that the resting time has a considerable influence over the overshoot pressures during the flow start-up.
Keywords
Flow start-up, Laponite, Non-Newtonian fluid, Flow loop
