Aspectos geométricos e hidrodinâmicos de um hidrociclone no processo de separação de sistemas multifásicos: aplicação à indústria do petróleo.

Abstract

The oil industry has traditionally been supported by the use of conventional separators devices based on the gravity effect which are generally bulky and provide high residence time. The hydrocyclone have been commonly used in oil-water separation by the oil industry due to high processing capacity, lower maintenance cost and minor physical space to installation. However has been observed the presence of sand and /or gas during oil production and transportation. For this reason, the need for developing of advanced technologies has strongly arisen, intending to separate sand/oil/water/gas. In this context, the present work aims to study the separation process of sand/water/gas from oil stream, using a hydrocyclone. The research were developed using the commercial package ANSYS CFX 12. The used threedimensional mathematical model considers turbulent and steady state flow and it is based on Eulerian-Eulerian approach for single-phase (water) and multiphase (wateroil, sand-water-oil, sand - water - oil - gas) cases. The influence of turbulence models ( – , RNG – standard and modified, SST and RSM–SSG), and geometric aspects of the physical parameters in predicting of flow behavior in the hydrocyclone were evaluated. Results of axial and tangential velocity profiles, tangential velocity, pressure and volumetric fraction distributions, separation efficiency and pressure drop are presented and analyzed. One can find the three-dimensional flow aspect and reasonable approximation of numerical results with experimental data of the radial distribution of tangential and axial velocity components. The evaluated hydrocyclone was able to separate adequately water, sand and gas from the oil flow with remotion efficiency of 33.07%, 92.52% and 3.81%, respectively, to a four-phase mixture and inlet volumetric flow rate of 8.5 m3/h in the hydrocyclone.