scholarly journals Flow behaviour of water-in-oil emulsions stabilized by wax crystals

2021 ◽  
Author(s):  
Roomana Aafaqi

The large temperature gradients experienced by crude oil emulsions in pipelines found in colder environments can lead to the precipitation, deposition and build-up of wax-like species from the crude oil onto the pipe wall that result in flow assurance problems. The objective of this thesis was to understand the rheological behaviour of model water-in-oil emulsions stabilized by wax crystals. The microstructure, phase transitions and rheology of model emulsions constisting of water, mineral oil, parrafin wax and the emulsifier polyglycerol polyricinoleate (PgPr) were investigated. Changes in emulsion flow begaviour (steady state and dynamic) as a function of composition, termperature and passage through a laboratory-scale flowloop were investigated, with these parameters significantly affecting shear flow, yield stress and viscoelasticity. The gelation temperature of wax-containing ('waxy') oil was slightly lower than that of its equivalent emulsion due to differences in the structure of the gelled emulsion network. Overall, this study successfully showed that there exist significant differences in the microstructure and flow behaviour of model crude oil emulsions when wax and a dispersed aqueous phase are present.

2021 ◽  
Author(s):  
Roomana Aafaqi

The large temperature gradients experienced by crude oil emulsions in pipelines found in colder environments can lead to the precipitation, deposition and build-up of wax-like species from the crude oil onto the pipe wall that result in flow assurance problems. The objective of this thesis was to understand the rheological behaviour of model water-in-oil emulsions stabilized by wax crystals. The microstructure, phase transitions and rheology of model emulsions constisting of water, mineral oil, parrafin wax and the emulsifier polyglycerol polyricinoleate (PgPr) were investigated. Changes in emulsion flow begaviour (steady state and dynamic) as a function of composition, termperature and passage through a laboratory-scale flowloop were investigated, with these parameters significantly affecting shear flow, yield stress and viscoelasticity. The gelation temperature of wax-containing ('waxy') oil was slightly lower than that of its equivalent emulsion due to differences in the structure of the gelled emulsion network. Overall, this study successfully showed that there exist significant differences in the microstructure and flow behaviour of model crude oil emulsions when wax and a dispersed aqueous phase are present.


2021 ◽  
Author(s):  
Samira Haj-Shafiei

The objective of this study was to characterize the flow and rheological behaviour of model wax-stabilized water-in-oil (W/O) emulsions consisting of light mineral oil, paraffin wax and glycerol monooleate as the oil phase and water as the dispersed aqueous phase. An[sic] laboratory-scale benchtop flowloop system was used to explore the flow behaviour of the emulsions' oil phase (oil, paraffin wax and surfactant). The key contribution from this work was that the higher initial temperature gradient (40°C compared to 19°C) experienced by the rapidly-cooled oil led to more initial deposition on the flowloop inner wall. The rheological properties of W/O emulsions with different water cuts (10-50wt%) were also studied. Rotational, oscillatory rheology and creep compliance and recovery were characterized on emulsions aged up to 28 days. Overall, the results demonstrated that emulsion composition, and age could significantly influence an emulsion's flow behaviour and rheological properties.


2021 ◽  
Author(s):  
Samira Haj-Shafiei

The objective of this study was to characterize the flow and rheological behaviour of model wax-stabilized water-in-oil (W/O) emulsions consisting of light mineral oil, paraffin wax and glycerol monooleate as the oil phase and water as the dispersed aqueous phase. An[sic] laboratory-scale benchtop flowloop system was used to explore the flow behaviour of the emulsions' oil phase (oil, paraffin wax and surfactant). The key contribution from this work was that the higher initial temperature gradient (40°C compared to 19°C) experienced by the rapidly-cooled oil led to more initial deposition on the flowloop inner wall. The rheological properties of W/O emulsions with different water cuts (10-50wt%) were also studied. Rotational, oscillatory rheology and creep compliance and recovery were characterized on emulsions aged up to 28 days. Overall, the results demonstrated that emulsion composition, and age could significantly influence an emulsion's flow behaviour and rheological properties.


1987 ◽  
Vol 65 (3) ◽  
pp. 353-360 ◽  
Author(s):  
B. E. Wyslouzil ◽  
M. A. Kessick ◽  
J. H. Masliyah

Author(s):  
Abed Saad ◽  
Nour Abdurahman ◽  
Rosli Mohd Yunus

: In this study, the Sany-glass test was used to evaluate the performance of a new surfactant prepared from corn oil as a demulsifier for crude oil emulsions. Central composite design (CCD), based on the response surface methodology (RSM), was used to investigate the effect of four variables, including demulsifier dosage, water content, temperature, and pH, on the efficiency of water removal from the emulsion. As well, analysis of variance was applied to examine the precision of the CCD mathematical model. The results indicate that demulsifier dose and emulsion pH are two significant parameters determining demulsification. The maximum separation efficiency of 96% was attained at an alkaline pH and with 3500 ppm demulsifier. According to the RSM analysis, the optimal values for the input variables are 40% water content, 3500 ppm demulsifier, 60 °C, and pH 8.


2021 ◽  
Author(s):  
Yuanhao Li ◽  
Jian Zhao ◽  
Hang Dong ◽  
Xiangrui Xi

The microstructure and dynamical behaviors of wax crystals in waxy crude oil are the fundamental reasons for a series of physical phenomena in the process of transportation. In order to...


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