Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Numerical and experimental study of Flushing process in a horizontal pipe using miscible fluids
Submission Author:
Elcilane Freitas , PR
Co-Authors:
Elcilane Freitas, Murilo Henrique Almeida Santos, Rafaella Casado Silva, Marco Germano Conte, Pedro Leineker Ochoski Machado, Eduardo Nunes dos Santos, Jean Paulo Nakatu Longo, Henrique Stel, Moisés Marcelino Neto, Rigoberto Morales
Presenter: Elcilane Freitas
doi://10.26678/ABCM.COBEM2023.COB2023-0528
Abstract
The displacement of a fluid by another fluid is commonly used to clean oil and gas pipelines that may be subject to problems such as hydrate blockage and corrosion. This type of operation is called Flushing. Typical applications include: pre-commissioning, where saline water is removed to prevent corrosion; commissioning and shutdown operations, where the pipeline fluid is replaced by a safe medium to prevent the formation of hydrates; and decommissioning, where the pipeline fluid is replaced to allow safe disconnection. Optimization of the flushing process, considering the time and volume of fluid spent, requires knowledge about the characteristics of the flow so that the process is enhanced from an economic point of view. In this scenario, this work presents a numerical and experimental study of flushing of fresh water by a viscous fluid. The viscous fluid was a mixture of water and glycerol with viscosities of 3.5cP and 8.5cP. The flow loop consisted of a straight tube of 8.15 m in length and 26 mm in internal diameter, built at Multiphase Flows Research Center - Nuem, at Federal Technological University of Paraná - UTFPR. Time series of the mixture mass concentration were recorded at two different points, 5.135 m and 5.35 m, using resistive sensors. Pressure drop between two points, 2.015 m and 5.335 m, was also recorded. For the experiments with the injection fluid of 3.5cP, the superficial velocities tested were 0.2, 0.3, 0.4, 0.5 and 1 m/s, while for the injected fluid of 8.5 cP, the superficial velocities tested were 0.2, 0.5 and 1 m/s. The instruments were connected to a data acquisition system and were monitored through an interface developed in LabVIEW. The flushing efficiency was analyzed in relation to the viscosity ratios, the behavior of the pseudo-interface between the fluids, as well as the volume of fluid injected necessary to clean the pipe. Numerical simulations were performed using Ansys CFX®. A good agreement with the experimental data was observed.
Keywords
multiphase flow, Flushing, Numerical simulation, Miscible Fluids, liquid-liquid displacement
