Effect of tartaric acid on the hydration of oil well cement at elevated temperatures between 60 °C and 89 °C

In order to study the abnormal viscosity evolution behavior of oil well cement slurries containing tartaric acid, the influence of tartaric acid on the early-age hydration of oil well cement at high temperatures was investigated by isothermal calorimetry (IC), thermogravimetric analysis (TGA) and quantitative XRD (QXRD) analysis in the temperature range of 60 °C to 89 °C. Results show that, a high dosage of tartaric acid can fundamentally change the typical shape of the cement hydration heat flow curve - two additional exothermic peaks associated with aluminate phase hydration (C 3 A and C 4 AF) appear before the main hydration peak. The unsynchronized hydration of the aluminate phases and the silicate phases was found to be the cause of premature setting. Additionally, long-term curing study (up to 28 d) showed that increasing the dosage of tartaric acid decreased the ultimate hydration extent of C 2 S while it increased the ultimate hydration extent of C 4 AF.