4. Conclusion

The high temperature retarder ZOC-H50S was synthesized by designing the molecular structure reasonably. The results of infrared spectrum analyzer showed that the synthesized product was the target product.

In order to evaluate the high temperature retarding property of ZOC-H50S, the thickening properties of different dosages of ZOC-H50S cement slurry were tested at different temperatures, and the differential thermal analysis and thermogravimetric analysis were carried out. The results show that ZOC-H50S has good high temperature retarding performance, suitable for bottom hole circulation temperature of 70 ~ 200 ℃, and can effectively adjust the thickening time of cement slurry by adjusting the dosage of ZOC-H50S according to different cementing requirements; when the temperature is higher than 266 ℃, ZOC-H50S has obvious heat change and mass loss, and its molecular structure is stable and its high temperature resistance is good.

The test results of cement thickening time with different salt content and ZOC-H50S dosage show that ZOC-H50S has good salt resistance and can be used in cementing operation of saline mud system.

The strength development, thickening time, fluidity and API filtration rate of ZOC-H50S cement slurry system under different top and bottom temperature differences are analyzed. The results show that the strength development of ZOC-H50S cement slurry system is good under large temperature difference, which can solve the problem of super retarding setting of top cement slurry in long cementing section; ZOC-H50S has a wide range of operating temperature and is suitable for high and low density cement slurry systems; ZOC-H50S cement slurry system with ZOC-H50S is suitable for high and low density cement slurry systems It is easy to adjust the cementing performance and meet the requirements of long cementing operation.