Milled basalt fiber reinforced Portland slurries for oil well applications

• Autor(a) principal: Martinelli, Antonio Eduardo
• Data de Publicação: 2019
• Outros Autores: Paiva, Luanna Carla Matias, Ferreira, Irantécio Mendonça, Freitas, Júlio Cézar de Oliveira, Bezerra, Ulisses Targino
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/31581
• topic: Basalt fiber; Oil well cement; Portland cement; Silica flour

The dispersion of short fibers to oil well Portland slurries may improve the compressive strength and fracture energy of the hardened cementing material. A study was carried out to investigate the effect of the addition of ball-milled basalt fibers (5% BWOC) to Portland slurries. Samples were prepared with and without silica flour (40% BWOC) in the composition and cured for 7 days under different Bottom Hole Static Temperatures (BHST): 80 °C (176 °F) and 300 °C (572 °F). The mechanical properties and the microstructure of the hardened pastes were evaluated by compressive strength tests, X-ray diffraction and scanning electron microscopy. The results showed that milling basalt fibers was a cost efficient method to adjust the length of the basalt wool fibers assuring slurry mixing and, therefore, adequate pumpability. The combined addition of silica flour and basalt fibers improved the fracture energy of samples cured at 80 °C, therefore below the strength retrogression temperature. Curing at 300 °C resulted in significant fiber consumption by pozzolanic reactions that could not be prevented by the addition of silica flour. Therefore, ball-milled basalt fibers can be a cost-efficient and environmental-friendly solution to improve the mechanical properties of oil well cement slurries used below the retrogression temperature