Experimental Investigation of Nanosilica Gel Properties for Well Integrity Remediation

Abstract

This study investigates the role of clay mineral, polyacrylamide additive, and nanosilica solution in the creation of a cross-linked gel for well cement repair. Several experimental setups were developed using a rotational viscometer and an Anton rheometer to investigate the impact of nanosilica particles on the rheology and performance prediction of the sealing gel. The results of varying the nanosilica concentration revealed that silica solution with a concentration of 15–25 wt % produced a lower gel strength property over a suitable gelation period, whereas silica solution with a concentration of 30–40 wt % displayed a higher gel strength property but with a short gelation time. The findings also demonstrated that adding 0.15 wt % polyacrylamide (PAM) to 18 wt % nanosilica significantly enhanced the properties of the gel, increasing about 135% in the gel strength, 429% in the yield point, and 122% in the storage modulus without posing any operational issues. The gelation of the nanosilica solution in the downhole environment, on the other hand, was shown to be greatly improved by the clay mineral bentonite, which was present in the formation rock. This research’s findings have improved the oil and gas industry’s understanding of the materials that might be used to improve a sealing gel’s rheological properties for well integrity operations.