油井水泥降失水剂HCW-1的合成及性能评价

Synthesis and evaluation of a cement slurry fluid loss control agent HCW-1.

常用的水泥浆降失水剂不同程度地存在着一些缺陷 ,如使水泥浆增稠 ,流动性变差 ;缓凝性较强或高温下水解超缓凝 ;高温下失水性能变差等。研究了 2 丙烯酰胺 2 甲基丙磺酸 (AMPS)、丙烯酸 (AA)和一种功能型单体 (简称为SM )的三元共聚物 (HCW 1)的合成方法及在油井水泥浆中的降失水作用。实验结果表明 ,HCW 1合成条件易于控制 ,工艺简单 ;在 15 0℃以内 ,HCW 1具有较好的抗温降失水功能 ,随加量的增大 ,高温下的失水量也远小于 2 5 0mL ;HCW 1除具有优良的降失水效果外 ,还兼有对水泥浆稠化时间影响小、降低水泥浆自由水含量、对水泥石抗压强度影响小等优点 ;可与其它外加剂复配使用。探讨了其降失水机理 ,认为HCW 1通过吸附基团和水化基团能在水泥颗粒表面形成“水泥颗粒 线性水溶性高分子 水分子吸附层”结构 ,阻塞水泥内部空隙 。

Almost all cement slurry fluid loss control agents currently used expose flaws in different degree,sometimes the slurry is thickened and its rheology become worse, sometimes the delayed coagulation of a agent is too strong to make cement slurry set, or filtration characteristic goes bad at high temperature. Atemporary copolymer from 2-aerylamide-2-methyl propyl sulfonic acid(AMPS), acrylic acid(AA) and a functional monomer(SM in short) was synthesized. The synthesis technology was in troduced and the fil-tration control ability of the product as a fluid loss agent HCW-1 was also evaluated. Results show that the synthesis is simple and the combination condition is controllable; at temper ature below 150 ℃, HCW-1 exhibits excellent filtration characteristic, with the dose increasing, fluid loss far less than 250 mL will be obtained even at higher temperature; it can decrease separating water volume; the product has little effect on both thickening time and the strength of the cement slurry. The fluid loss control mechanism was also studied. It is thought that a structure of cement solid-linear water soluble high molecule-adsorption layer formed on cement particles is responsible for the outstanding filtration property of HCW-1.