Banca de QUALIFICAÇÃO: ALINE NASCIMENTO VASCONCELOS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ALINE NASCIMENTO VASCONCELOS
DATE: 05/12/2025
TIME: 14:00
LOCAL: LAPET (Laboratório de Pesquisa em Petróleo)
TITLE:

Development of Thermo-Shrinkable Polymer Systems with Low Thermal Conductivity for Pressure Control in Confined Annuli.

KEY WORDS:

Annular Pressure Buildup; Poly(acrylic acid); Inverse suspension polymerization; Thermo-shrinkable; Thermal insulation

PAGES: 68
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Polímeros e Colóides
SUMMARY:

This study aimed to develop thermo-shrinkable polymer systems with low thermal conductivity, based on the inverse suspension polymerization of acrylic acid. The systems were evaluated for their potential applicability in controlling annular pressure buildup (APB), a thermally induced phenomenon that can compromise the integrity of oil and gas wells. For this purpose, acrylic acid was dispersed in olefin, with the aid of a pair of surfactants, and its ability to reduce in volume during heat-induced polymerization was investigated at 5% (FPAA 5%) and 10% (FPAA 10%) acrylic acid. The insulating property was evaluated by means of thermal conductivity measurements. Furthermore, the formulations were analyzed using differential scanning calorimetry (DSC) and rheological measurements. The poly(acrylic acid) samples obtained from the two polymerization reactions were purified and characterized by Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), and thermogravimetric analysis (TGA). FTIR confirmed the successful formation of the polymer, while GPC results showed that increasing the acrylic acid concentration from 5% to 10% led to a higher weight-average molar mass and a lower polydispersity index. The thermal degradation profiles of poly(acrylic acid) exhibited three distinct stages: dehydration, decarboxylation, and thermal degradation of the polymer chain. DSC analysis of the FPAA 5% and FPAA 10% formulations revealed self-acceleration phenomena starting at 78 °C and 72 °C, respectively. Rheological analyses indicated pseudoplastic behavior for both FPAA 5% and FPAA 10% formulations, before and after polymerization. Additionally, a predominance of elastic behavior was observed after polymerization. FPAA5% and FPAA 10% reduced their volumes by 21% and 46%, respectively, as the temperature reached 60 ºC, when compared to a formulation without monomer. Furthermore, FPAA 10% was able to maintain around 50% reduction in volume after a heating-cooling-heating cycle and kept its thermal conductivity constant with increasing temperature (0.18 W/m·K). The inverse suspension polymerization of acrylic acid effectively combined thermally induced volume contraction and thermal insulation in a single formulation. This innovative feature has not yet been reported in the literature and suggests the potential of acrylic acid formulations for APB control.

COMMITTEE MEMBERS:
Presidente - 1149440 - ROSANGELA DE CARVALHO BALABAN
Interna - 3420591 - ANA CAROLINA DE OLIVEIRA NEVES MENEZES
Interno - 1803692 - FABRICIO GAVA MENEZES