Laboratory study on grain size of silica in strength recession of heavy oil thermal recovery cement

In order to meet the requirements of heavy oil thermal recovery on cementing cement, this simulation of heavy oil thermal recovery well cement at room temperature solidification, high-temperature thermal recovery of the formation of this special environment, first slurry at atmospheric pressure at 70 ℃ for three days later by a thermal temperature and pressure conservation. In this paper studies at different high temperatures silica sand grain size on the impact of cement strength development as well as the different Ca/Si ratio on impact of the recession of well cement at different high temperature gradient, described the reason that the silica sand grain size and Ca/Si ratio can improve the strength and thermal stability of cement, found the best silica sand grain size and Ca/Si ratio from the mechanism. The studies have an important guiding significance in heavy oil recovery and develop. What is more, it provides a basis for further selection and design of heavy oil slurry system.