The Synthesis and Application of Temperature Sensitivity Resistance Retarder Suitable for Big Temperature Difference Environment

Cement slurry with thickening time of regular pattern is the premise for safe cementing operation. Abnormal thickening time will bring about severe bad effect on well cementing. In temperature range of 100-120℃ changes in the hydrated Portland cement will take place. The thickening time of the cement slurry is of poor regularity, sometimes resulting in reversed thickening or the failure of cement retarder, bringing about hidden dangers to the safety of well cementing operation. A new polymeric cement retarder, CCH120, has been developed and a temperature sensitivity resistant cement slurry (for use in big temperature difference well cementing) treated with the CCH120 has been compared with the presently available cement slurries for their performance. It was found that in 100-120℃, in which cement slurries exhibit temperature sensitivity, the thickening time of the CCH120 treated cement slurry was gradually shortened as the temperature was increased, and no reversed thickening was observed. The mechanisms of this phenomenon are explained in this paper. This cement slurry has temperature sensitivity resistance, thickening time with strong regularity, low fluid loss, high compressive strength, and fast strengthening at the top of the cement slurry.