Evolution of elastic modulus and creep of nanoclay modified oil well cement

Nanomaterials like nanosilica, nanoalumina and nanoclay have shown improvement in workability and increased compressive strength when used with cement. However, the potential of using nanoclay to alter the elastic modulus and limit creep of oil-well cement (OWC), specifically when cured under high temperature and pressure, has not been explored. In this investigation, Type-G cement mixed with 1.0 wt.%, 3.0 wt.% and 5.0 wt.% nanoclay and with water/cement ratio of 0.45 was prepared and cured for 7 days under high temperature and pressure of 80 °C (176 °F) and 10 MPa (1500 psi) respectively. Dynamic mechanical analysis was conducted under high temperature to reveal the evolution of the elastic modulus and creep compliance of the different cement-nanoclay mixture with curing time. Thermogravimetric analysis, Scanning Electron Microscope and X-ray Diffraction measurements were performed to support observations of elastic modulus and creep compliance evolution of OWC incorporating nanoclay explaining the microstructural changes that take place in OWC mixture incorporating nanoclay when hydrated under high temperature and pressure.