Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Influence of thermal effects in stability analysis for severe slugging
Submission Author:
Thierry Caique Lima Magalhães , SP
Co-Authors:
Thierry Caique Lima Magalhães, Gabriel Romualdo de Azevedo, Ivanilto Andreolli, Jorge Luis Baliño
Presenter: Thierry Caique Lima Magalhães
doi://10.26678/ABCM.COBEM2021.COB2021-0357
Abstract
In this paper a numerical study on the thermal effects at linear stability analysis for the multiphase flow of oil in a pipeline-riser system is presented. The developed model considers that the flow is one-dimensional and three-phase throughout the system. The liquid and gas phases are considered compressible. Furthermore, it is assumed that oil and water have the same speed and are homogenized. The flow pattern in the pipeline and riser is determined based on the local state variables and inclination angle. The characterization of fluids and the mass transfer between the phases done according to the black oil model while the void fraction depends on the flow pattern. The energy conservation equation is added in a methodology previously developed, in order to take into account the thermal coupling with the mass and momentum conservation equation. The equations were solved numerically using MATLAB software. The results achieved are according with isothermal analysis obtained using the same approach, although some deviations are observed. The eigenvalues largest real part calculated by the model that includes the thermal effects were higher than those obtained by the isothermal model. In both cases, the largest eigenvalue presents a positive real part, therefore the flow is unstable for the standard condition adopted, and consequently, there will be severe slugging. The difference between the largest eigenvalues real part is 87:4%. The deviations occurred due to the effect of temperature on the mass transfer (vaporization), compressibility, expansion, and the thermophysical properties of the phases. The results obtained highlight the potential of this technique, as being a very useful way of evaluate severe slugging in offshore oil production systems.
Keywords
Linear Stability Analysis, Three-phase flow, severe slugging, thermal effects, petroleum production technology
