THE ELASTO-VISCOPLASTIC-TIME-DEPENDENT NATURE OF WAXY CRUDE OILS

Production in reservoirs located in deep and ultra-deep water that contain waxy crude oils faces a huge obstacle imposed by the low temperatures of the environment. When the waxy crude oil is subjected to a temperature below the Gelation Temperature, as in the case investigated in the present work, it exhibits a variety of non-Newtonian features: elasticity, plasticity, viscous effects, and time-dependency, which renders to this material a highly complex behavior. A crucial feature that is frequently ignored when the determination of the yield stress is being carried out is the timedependency nature of these materials. We demonstrate that this character has a significant impact on the measurement of the yield stress and, therefore, values obtained from a protocol that neglects time-dependency can be substantially different from a more careful procedure.

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Bioremediation: Waxy Crude Oils Stranded on Low-Energy Shorelines

International Oil Spill Conference Proceedings ◽

10.7901/2169-3358-1991-1-541 ◽

1991 ◽

Vol 1991 (1) ◽

pp. 541-547 ◽

Cited By ~ 13

Author(s):

Kenneth Lee ◽

Eric M. Levy

Keyword(s):

Salt Marsh ◽

Crude Oil ◽

Nutrient Enrichment ◽

Salt Marshes ◽

Crude Oils ◽

Waxy Crude Oil ◽

Sand Beach ◽

Waxy Crude ◽

Low Concentrations ◽

Waxy Crude Oils

ABSTRACT The degradation of a waxy crude oil (Terra Nova) spilled on sand beach and salt marsh environments in Nova Scotia was monitored over a seven-month period. In the sand beach environment, low concentrations of stranded oil (0.3 percent by volume) were degraded in a matter of days by the indigenous biota, while higher concentrations (3 percent) were much more persistent (components as light as n–C11 remained after six months). In contrast, similar concentrations of oil were found to be extremely resistant to biodegradation in the salt marsh. Our results suggest that cleanup of waxy crude oils at low concentrations in sand beaches should be left to nature, since natural biodegradative processes occur rapidly. At higher oil concentrations, however, nutrient enrichment with agricultural fertilizers was found to be an effective countermeasure. While biodegradation of oil stranded in salt marsh environments is generally limited by oxygen availability, nutrient enrichment may be an effective countermeasure to treat low concentrations of waxy crude oil in salt marshes, provided the oil does not penetrate beneath the aerobic surface layer.

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Thermal Effect on Void Formation of Waxy Crude Oil Using Electrical Capacitance Tomography

Jurnal Teknologi ◽

10.11113/jt.v63.1509 ◽

2013 ◽

Vol 63 (1) ◽

Cited By ~ 1

Author(s):

Areeba Shafquet ◽

Idris Ismail ◽

Azuraien Jaafar

Keyword(s):

Crude Oil ◽

Void Fraction ◽

Crude Oils ◽

Electrical Capacitance Tomography ◽

Electrical Capacitance ◽

Waxy Crude Oil ◽

Sustainable Operations ◽

Waxy Crude ◽

Waxy Crude Oils ◽

Capacitance Tomography

Waxy crude oils are commonly found in many parts of the world and represent a huge amount of the global oil reserves. Precipitation of paraffin waxes during various phases creates many problems in the oil industry. Therefore, waxy crude oils create many flow assurance issues essentially linked to them and understanding of the effect of relevant factors and phenomena are of great practical importance. In process industries, the measurement of void fraction is considerably important for sustainable operations and the erroneous calculation could be the cause of many industrial accidents. The customary approach separates the two-phases first and then measures the mixture as individual components. These methods are not favorable as they may result in the disruption of incessant industrial processes. Due to these limitations, this study is aimed to analyze the gel formation behavior of a waxy crude oil under static and dynamic cooling using non-invasive/non-intrusive experimental technique; i.e. Electrical Capacitance Tomography (ECT). This paper describes a fabrication of dual-plane ECT sensor for testing of waxy crude oil at different temperature conditions. ECT images and raw data measurements have been obtained from the two planes are then normalised and then used for image reconstruction. The findings reported in this paper represent part of an ongoing investigation that may lead to develop a cross-correlation between the two planes. The outcome of the study could be used to fully understand the phenomenon of void fraction in waxy crude based on varying the temperature and also based on the design of ECT sensor.

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