Banca de DEFESA: FILIPE JOHNATAN MARTINS DANTAS COSTA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : FILIPE JOHNATAN MARTINS DANTAS COSTA
DATA : 15/10/2019
HORA: 10:00
LOCAL: Auditório do Laboratório de Cimentos
TÍTULO:

THERMAL AND MECHANICAL BEHAVIOR OF CMENTING COMPOSITES CONTAINING CHITOSAN

PALAVRAS-CHAVES:

Chitosan, Portland cement, cementing, oil well, steam injection.

PÁGINAS: 98
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Cerâmicos
RESUMO:

Cementing oil wells requires pastes possessing mechanical properties that are capable of supporting crack growth and propagation to ensure casing integrity. High-temperature environments such as steam injection wells are considered critical and capable of causing changes in the chemical and physical properties of hydrated Portland cement products. Failures in the integrity of the cement sheath increase the risk of negative environmental impacts. Polymers are capable of increasing the interaction between hydrated phases by forming films in cement pastes. Chitosan is a biopolymer and has been studied as an additive for mortars and concretes in the construction industry, acting as a thickener and retarder and capable of reducing pore volume. The aim of this study was to evaluate the thermal and mechanical behavior of chitosan-containing cementitious composites for cementing oil wells subjected to steam injection. Formulations containing up to 5% by weight of chitosan solution were evaluated in fresh and hardened state. The mixtures were cured for 14 days under different conditions. Mechanical compressive and tensile strengths were evaluated by destructive methods. The thermal properties were characterized by heat flow analysis, dilatometry and thermogravimetry. The microstructure was characterized by X-ray diffraction and scanning electron microscopy. Chitosan-containing composites showed improved compressive strength as a result of increasing polymer concentration, being able to absorb up to 50% more energy until fracture compared to a the reference chitosan-free paste. Tensile strength of composites increased after steam injection. Chitosan decreased the dehydration of hydrated calcium silicates, reducing thermal shrinkage and attributing greater thermogravimetric stability to cement pastes. Chitosan showed potential applicability as bio-additive, acting as a dispersed reinforcement in the Portland cement matrix to improve fracture behavior of cement sheaths from steam-injected oil wells.

MEMBROS DA BANCA:
Presidente - 1298936 - ANTONIO EDUARDO MARTINELLI
Externo ao Programa - 1064594 - EVANS PAIVA DA COSTA FERREIRA
Externo ao Programa - 1804366 - JÚLIO CÉZAR DE OLIVEIRA FREITAS
Externo à Instituição - PETRUS D AMORIM SANTA CRUZ OLIVEIRA - UFPE
Externo à Instituição - WENDELL ROSSINE MEDEIROS DE SOUZA - UFERSA