Investigation of the Effect of Water Salinity on the Thickening Time of Cement Slurry

Cementing techniques involves the deployment of cement slurry on the oil-well annulus and casing to provide proper zonal separation. The target is to completely hinder fluids in the well from interacting from one part to another, provide anchor for casing, prevent corrosion of the casing, prevent shock loads during drilling, and avoid blowouts, plug off vugular zones and for abandonment. This experiment was done following American Petroleum Institute (API) recommended practice 13B-2, with the aim of investigating the effects of salinity level of water on the thickening time of cement slurry. The significance of the thickening time test is to determine the duration of cementing operation to ensure successful zonal isolation without cementing the drill pipes and damaging the wellbore. The thickening time test was conducted at a constant temperature of 140 °F and downhole pressure of 3000 Psi, the salinity of the water was varied from 200 ppm, 1000 ppm, 10000 ppm, 15000 ppm and 20000 ppm. The results revealed that, the different salinity levels for 100 BC are 131mins, 111mins, 92mins, 65mins and 47mins and the different salinity levels for 70 BC are 122mins, 105mins, 85mins, 61mins and 43mins respectively. The result revealed that salinity level at low temperatures and pressures has accelerating effects on the hydration of cement; that is as the salinity level increases the thickening time decreases and vice-versa. The data produced by the experimental investigations therefore will aid in the optimization of cement design and its use for numerical simulations of well cement performance.