Mechanical, rheological, and stability performance of simulated in-situ cured oil well cement slurries reinforced with alumina nanofibers

Effects of highly dispersed Alumina Nanofibers (ANF) on the mechanical, rheological, and stability performances in oil well cement were investigated in this study. The cement sheath possesses a vital role in maintaining zonal isolation in the wellbore, supporting the casing, and preventing external casing corrosion. This research focuses on using ANF to improve these functions. Cement class “H” composed of various concentrations of ANF, 0.2% cement friction reducer (CFR), and distilled water were used in this experimental study. The nanofiber dosage consisted of 0.1%–0.4% ANF in increments of 0.1% by weight of cementitious materials. The nanomaterials were dispersed at various times using an ultrasonic batch to ensure uniform dispersion in the cement class “H” matrix. A pre-dispersed version was also provided. The most highly dispersed solution was used in all the cement test analysis. The results indicate the pre-dispersed solution at 0.1% ANF greatly increased the compressive strength by 28% after 8 h of curing and 50% after 24 h of curing at 82.2 °C (180 °F) and 34.47 MPa (5000 psi). Conversely, the tensile strength increased by 9% and 53% after 8 h and 24 h curing, at the same temperature and pressure conditions. Lastly, the differences in rheological, stability performance, and thickening time using cement slurries without ANF compared to slurries with ANF proved insignificant.