Escoamento trifásico não isotérmico em oleodutos horizontais com vazamento: modelagem e simulação.

Abstract

Networks of pipelines are considered the best option for transport of fluids in the oil industry to long distances which has encouraged the development of leak detection techniques that are fast and accurate to inspect and detect quickly and accurately possible leaks over the pipeline in order to minimize economic and environmental damage. The techniques of leak detection available range from visual observation to mathematical modeling using computational techniques. The present study evaluated the thermo-fluid dynamic of threephase flow (oil-water-gas) with leakage. The equations of conservation of mass, momentum and energy for each phase (oil-continuous phase and gas and water-dispersed phase) were solved using ANSYS CFX®, using a representative structured mesh of the horizontal pipe with a leakage orifice. The Eulerian-Eulerian model and the RNG k-8 turbulence model was used. The physicochemical properties were considered constant. With the volume fraction and temperature fields, and velocity and pressure profile was possible to evaluate the influence of the leakage on the flow and on the development of pressure and pressure drop with time. The results of numerical simulations showed an important role with respect the choice of boundary conditions at the leak orifice (velocity or pressure prescribed). The use of the prescribed pressure condition gave more consistent results compared to those available in the literature.