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| Author(s): |
Iara Hernandez Rodriguez
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD) |
| Defense date: | 2014-11-18 |
| Examining board members: |
Paulo Seleghim Júnior;
Luis Fernando Alzuguir Azevedo;
Jorge Luis Baliño;
Roberto Carlos Gonçalves de Oliveira;
Edson Cezar Wendland
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| Advisor: | Oscar Mauricio Hernandez Rodriguez; Paulo Seleghim Júnior |
| Abstract | |
Liquid-liquid flow, especially oil-water flow, has attracted the attention of researchers due to the high demand for petroleum in the current global scenario. The discovery of reserves of heavy and highly viscous oils creates new challenges which are mainly concerned with reducing the significant pressure drop in pipes. Inverse emulsion or oil-in-water dispersions in which the oil is dispersed in water is characterized by its low effective viscosity, making it a desirable type of emulsion in some steps of oil production. These facts make the study of dispersed liquid-liquid flow essential for the design and optimal operation of oil pipelines. However, the studies on such flow pattern are scanty in comparison to those on separate flows, as stratified and annular flow patterns. Drag reduction in oil-water turbulent flow without the addition of any chemical substance has been reported in some studies. This phenomenon has received increasing attention in recent years, because there is not a satisfactory understanding of its dynamics yet. Most studies, almost all using light oils, report drag reduction in dispersion of water-in-oil, with few studies reporting the phenomenon in oil-in-water dispersions. This research comprises an experimental and theoretical study on oil-in-water dispersions in pipes. Pressure gradient, holdup, phase distribution and flow patterns data were obtained to characterize the two-phase flow. A theory was proposed to explain the drag reduction detected in this work, based on the existence of a thin water film flowing in contact with the pipe wall at low Reynolds numbers, avoiding contact between the turbulent core (mixture) and the pipe wall. The liquid film was detected and quantified using visual technique. In addition, a dynamic model based on the hydrodynamic lubrication theory was developed as an attempt to explain the formation of the liquid film. (AU) | |
| FAPESP's process: | 10/08688-3 - Experimental study and modeling of flow of inverse emulsion in pipes |
| Grantee: | Iara Hernandez Rodriguez |
| Support Opportunities: | Scholarships in Brazil - Doctorate |