水泥浆的沉降失重研究

给出了几组无失水条件下的典型失重模拟实验结果,并把失重曲线上失重速率第一次出现增加以前的时间定义为沉降期。分析结果表明:用胶凝和胶凝与水化体积收缩综合作用的观点都不能解释沉降期的失重。为此提出了水泥浆不稳定导致沉降失重的观点,阐述了这种失重的机理、特点和规律,并用这种观点解释了沉降期的实验结果。初步揭示了水泥浆稳定性与失重的关系,指出了提高水泥浆稳定性是控制早期失重和防止气窜的一条基本措施。

STUDY ON WEIGHT LOSS OF CEMENT SLURRY DUE TO PRECIPITATION

The simulation experiment results of a number of typical weight loss under conditions of non-existence of filtration were presented. The time before the first increase of weight loss rate on the weight loss curve was defined as the precipitation period. The data analysis shown that the weight loss in the precipitation period can not be explained by the points of view of gelation alone or of the complex action of gelation and contraction of hydration volume. Therefore a concept of derivation of weight loss due to instability of cement slurry was figured out. The mechanism, the characteristics and the law of weight loss were described and the experimental data in the precipitation period were explained. The correlation between stability of cement slurry and its weight loss was revealed and the enhancing cement slurry stability was taken as a principle measure for control of the preliminary weight loss and prevention of gas channeling.