Methods of increasing the thickening times of phosphate-based cementitious compositions in high-temperature wellbores

摘要

A wellbore may be cemented by preparing a cementitious composition comprising water, a metal oxide or hydroxide compound, a phosphate compound, a borate compound, and a sugar, followed by displacing the cementitious composition into the wellbore. The metal oxide or hydroxide compound reacts with the phosphate compound in the wellbore to set into a hard mass. The synergistic effect of the borate compound and the sugar may increase a thickening time of the cementitious composition to in a range of from about 2 hours to about 11 hours at ambient temperatures in the wellbore. As such, the thickening time is sufficient to allow the cementitious composition to be placed in its desired location in the wellbore before setting.