AMPS, diethanolamine, and calium nitrate as materials of early-strength accelerator were prepared and characterized. Orthogonal experiment was utilized to optimize optimum content of early-strength accelerator. The samples were characterized with powder X-ray diffraction (XRD) and SEM. It is shown that when the weight of 5% early agents were introduced, the 1, 3 and 7 d of cement strength improved by 15.2%、14.3%、16.7%, respectively, which is also a further development in the high temperature.

The AS fluid loss additive was formulated with sodium lignosulfonate and the copolymers obtained by radical polymerization with AMPS and AM as raw material. Orthogonal tests were designed for optimizing the synthetic process of the fluid loss additive AS, and the performance of this fluid loss additive was systematically evaluated. API filtration in saturated salt solution at 150 ℃ is 96 mL; API filtration can be controlled within 50 mL when adding AS between 3% and 8% (weight percentage) at 120 ℃; Meanwhile AS has good compatibility with other additives. Sodium bicarbonate was used to adjust the PH and discharge oxygen of device used in the synthesis process. No nitrogen was needed as protective gas, which simplified the synthesis process. The sodium lignosulfonate derives from the wastewater of paper mill, so it not only reduces the cost but also protects the environment.