Crude oils from China, Australasia and many other parts of the world, containing waxy crystals and colloidal asphaltenes, possess distinct non-Newtonian flow properties which depend strongly on the shear and thermal history and result in special difficulties being encountered in all types of viscometers. Experimental techniques are discussed which allow reproducible equilibrium data to be obtained in the concentric cylinder and the cone and plate viscometers. The shear history dependence of the flow properties, which is shown to occur in both Australasian and Chinese crudes, alters the conventional design and scale-up assumptions. Flow in a capillary or pipeline is shown to be a composite effect of the range of shear rates that occurs across the radius of the pipe. An identical composite effect must occur for the scale-up assumption to remain valid. Pipeline flow can be determined from laboratory data by modified design techniques which also allow the quantitative assessment of oil treatment methods. A lower limit to pipeline operation, due to the shear history effect, is shown to exist, which has an effect on the assessment of oil treatment methods and on the operation of declining oil-fields.

You can access this article if you purchase or spend a download.