Abstract: 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.

Key words: Fluid loss additive ,  Heat resistance ,  Salt resistance ,  Well cementation

摘要：     　采用自由基聚合法，以２－丙烯酰胺基－２－甲基丙磺酸（ＡＭＰＳ）和丙烯酰胺（ＡＭ）为原料合成共聚物，再与木质素磺酸钠复配，合成了降失水剂ＡＳ。通过正交试验优选合成条件，并对降失水剂ＡＳ进行了全面的性能评价。评价结果表明：降失水剂ＡＳ具有较好的耐热性和耐盐性，在１５０℃下，降失水剂ＡＳ在饱和盐水中的ＡＰＩ滤失量（ＡＰＩ滤失量，即按ＡＰＩ标准测量的失水量，简称滤失量）为９６ｍＬ；在１２０℃下，水泥中单独掺入质量分数３％～８％的聚合物可将滤失量控制在５０ｍＬ以内；与其它外加剂的配伍性好。在合成过程中采用ＮａＨＣＯ３调节ｐＨ值和排出装置中氧气，无需通Ｎ２保护，可简化合成工艺。木质素磺酸钠来源于造纸污水，既可降低成本又有利于环保。

关键词: 　降失水剂 , 　耐温 , 　耐盐 , 　固井