Session: 11-07-01 Petroleum Production: Offshore Systems and Subsea Operations

Submission Number: 176552

Water Displacement in Oil Pipelines During Shutdown and Restart: Comparative Assessment Between Experimental Data and a Proposed Mechanistic Model 

In offshore oil and gas production, transient processes occurring in long pipelines often lead to water accumulation, which is typically removed by gas–oil mixtures. This emphasizes the critical role of water removal in preventing flow assurance issues, including corrosion, emulsion formation, and hydrate deposition. The slug flow regime is commonly observed, under these conditions, characterized by the intermittent passage of elongated gas bubbles over a liquid film, which may critically influence water removal and, consequently, promote adverse operational conditions. Therefore, the present work aims to experimentally investigate the time required for water removal by a gas–oil mixture flowing in a 5° upward-inclined pipe (76.2 mm inner diameter, 100 m length). The superficial velocities range between 0.3–0.85 m/s for oil, 0.1–1.5 m/s for air, and 0.073–0.61 m/s for water. In addition, the study seeks to elucidate the liquid–liquid phase distribution and the underlying mechanisms governing water removal in transient three-phase (oil–water–gas) flows. This investigation is particularly relevant because the accumulated water may be removed through distinct mechanisms, such as in the form of a continuous liquid film, as large plugs, or as dispersed droplets within the continuous oil phase Furthermore, the experimental results will be compared with a recently published phenomenological model developed to predict the water removal time based on the liquid-film mechanism. According to the mechanistic model, increasing the superficial velocities of gas and oil improves the ability to displace water, however the combinations of these influences may present better results even with lower oil superficial velocity.

Keywords: Three-phase flow; Transient flow; Slug flow; Liquid-Liquid flow; Water accumulation

Presenting Author: Jaqueline Diniz Da Silva Centro de Estudos de Energia e Petróleo (CEPETRO), Universidade Estadual de Campinas (UNICAMP)

Presenting Author Biography: She is currently a Postdoctoral Researcher at Cepetro, University of Campinas (Unicamp), specializing in multiphase flow, with expertise in instrumentation and flow measurement techniques.

She holds a PhD degree in Mechanical Engineering from the University of São Paulo (EESC-USP), with research focused on two-phase flow heat transfer, involving both experimental and theoretical investigations of local heat transfer coefficients, flow patterns, and pressure drop during condensation in minichannels. Her work employed new low-GWP working fluids considered environmentally friendly alternatives. She completed an international internship at the Laboratory of Sustainable Thermal Energy Technologies, Università degli Studi di Padova.

She also holds a Master’s degree in Thermal Sciences from the same institution, where her research addressed boiling heat transfer and pressure drop in microchannel tubes. She was a visiting researcher at the Colorado School of Mines, where she investigated interfacial phenomena in multiphase flow and gas hydrate formation management.

She is also a co-author of book chapters in Microchannel Phase Change Transport Phenomena and Advances in Heat Transfer.

Authors:

Jaqueline Diniz Da Silva Centro de Estudos de Energia e Petróleo (CEPETRO), Universidade Estadual de Campinas (UNICAMP)
Rodolfo Marcilli Perissinotto Centro de Estudos de Energia e Petróleo (CEPETRO), Universidade Estadual de Campinas (UNICAMP)
Juliana Rangel Cenzi Center for Energy and Petroleum Studies (CEPETRO) - University of Campinas (UNICAMP)
Daniely Amorim Das Neves Center for Energy and Petroleum Studies (CEPETRO) - University of Campinas (UNICAMP)
William Monte Verde Centro de Estudos de Energia e Petróleo (CEPETRO), Universidade Estadual de Campinas (UNICAMP)
Marcelo Souza Castro Centro de Estudos de Energia e Petróleo (CEPETRO), School of Mechanical Engineering (FEM), Universidade Estadual de Campinas (UNICAMP)