Name: KELVIN CRISTIEN DE OLIVEIRA BARBOSA
Publication date: 10/01/2025
Examining board:
Name |
Role |
|---|---|
| ADMILSON TEIXEIRA FRANCO | Examinador Externo |
| EDSON JOSE SOARES | Presidente |
| MÁRCIA CRISTINA KHALIL DE OLIVEIRA | Examinador Externo |
| RENATO DO NASCIMENTO SIQUEIRA | Examinador Interno |
| ROGERIO RAMOS | Examinador Interno |
Summary: In this study, an experimental investigation is conducted on drag reduction (DR) in turbulent single-phase and two-phase (liquid-liquid) flows through the addition of polymers in both the aqueous and oil phases. The literature presents some studies on drag reduction in two-phase flows; however, most of these works focus on gas-liquid flows or liquid-liquid flows with the polymer dissolved in the aqueous phase. Two-phase flow is present in various industrial applications, particularly in the oil and gas industry, where one of the main goals is to increase production flow rates. Therefore, there is growing interest in investigating the effects of drag-reducing polymers in this type of flow. The objective of this work is to evaluate the effect of polymers (soluble in both water and hydrocarbons) on the reduction of the pressure gradient (drag reduction) and analyze polymer degradation in single-phase and two-phase (liquid-liquid) flows. A water-soluble polymer (Diutan Gum – DG) and a hydrocarbon-soluble polymer (Polyisobutylene – PIB) were used, each with three different molecular weights. Initially, for the hydrocarbon-soluble polymer, rheological characterization, preliminary DR tests in single-phase flows, and degradation analysis were performed for the three molecular weights. As expected, drag reduction increased with higher polymer concentrations and molecular weights. In two-phase flow experiments, the flow pattern was dispersed due to the high flow rates. The effects of DG and PIB solutions were studied separately and in combination. The results indicate that drag reducers are effective only in the external phase; in other words, the drag reducer in water is effective for water fractions above 0.5, while the drag reducer in hydrocarbons is effective for water fractions below 0.5. When both phases contain additives, a pressure reduction is observed compared to the case without additives, across the entire range of water fractions. Additionally, it is noteworthy that, at low concentrations (low water fractions), water droplets also act as drag reducers. PIB degradation increases as the total flow rate of the two-phase system rises and is further intensified when the aqueous phase is also treated with additives.
Keywords: Drag reduction, single-phase flow, two-phase flow, polymer degradation, Polyisobutylene (PIB).
