Effects of Thermal Physical Parameters on Circulation Temperature of Cement Slurries

In well cementing operation, to ensure that the cement slurry is safely pumped int the hole, the cement slurry shall have an appropriate thickening time. The circulating temperature of the cement slurry is one of the important factors affecting the thickening time of the cement slurry. The methods for calculating the circulating temperature of a cement slurry in the API Recommended Practice do not satisfy the need for calculating the circulating temperature in different areas and different borehole conditions. Thus, an unsteady state flow heat transfer model is established. By measuring the thermal physical parameters, the coefficients of heat conductivity and specific heat capacities of the drilling fluid, the casing strings, the rocks and the cement slurry are determined, and the temperature field of the cement slurry during injection and displacement is thus simulated. The simulation results show that increasing the coefficients of heat conductivity of the cement slurry and the spacer fluid reduces the circulating temperature of the cement slurry. Decreasing the coefficients of heat conductivity of the casing string and the rocks, the circulating temperature of the cement slurry changes in less than 1 ℃. Data acquired from the Zhejiang Oilfield and the Tarim Oilfield show that the difference between the measured well cementing temperatures and the simulated well cementing temperatures is less than 5 ℃, indicating that the simulated data is accurate and has good consistency with the measured data. Studies on the factors affecting the circulating temperatures of a cement slurry during injection and displacement in well cementing operations provide theoretical supports to the design of the properties of the cement slurry, thereby ensuring the efficient and safe well cementing operations.