高取代度阳离子淀粉的合成及其降滤失性能

Preparation of Cationic Starch with a High Degree of Substitution and Its Performance as Filtrate Reducer for Drilling Fluid

以2,3环-氧丙基三甲基氯化铵为阳离子化试剂,采用半干法合成了季铵型阳离子淀粉。考察了体系的含水量、碱用量、反应温度、反应时间对取代度和反应效率的影响。当淀粉用量为25 g,醚化剂(2,3环-氧丙基三甲基氯化铵(RPTMAC))为13.1 g时,最佳反应条件为NaOH质量分数为1.2%,反应温度80℃,反应时间5 h,反应体系中水的质量分数为25%,此时取代度为0.45,反应效率为80.1%。对其泥浆性能进行初步评价。结果表明,季铵型阳离子淀粉用作泥浆处理剂时具有较好的降滤失能力,抗盐能力强,防塌效果好。

A high substitution cationic starch was prepared by a damp-dry process from starch and 2,3- epoxypropyl-trimethylammonium chloride （EPTMAC）. The effects of the amounts of water and alkaline catalyst as well as reaction temperature, reaction time on the substitution and reaction efficiency were studied. When the amount of starch and that of EPTMAC were 25 g and 13.1 g, respectively,the optimum reaction conditions were that to （NaOH） was 1.2%, reaction temperature 80℃, reaction time 5 h and the amount of water 25.0%. The performance of the cationic starch as a filtrate reducer was evaluated in the laboratory. The experimental results show that the cationic starch has very good capacities of depressing the filter loss, saltresistance and anti-caving.