无机硅改性羧甲基淀粉钠降滤失剂的研制及其性能

在合成羧甲基淀粉钠(SCMS)的过程中引入水溶性硅酸钠对其进行改性,合成了硅改性的SCMS降滤失剂(Si-SCMS)。XRD和FTIR表征结果显示,产物中有Si—H基团生成,表明无机硅酸钠参与反应生成了有机硅化合物;经TG-DTA分析发现,Si-SCMS降滤失剂的热分解温度为220℃。将Si-SCMS配入钻井液,试样在150℃热滚后的失水量仅为15.2mL,与SCMS降滤失剂相比,抗温性能显著提高;且Si-SCMS降滤失剂的降滤失性能也得到提高。同时探讨了Si-SCMS降滤失剂抗温性能提高的原因,认为无机硅酸钠的引入抑制了SCMS分子的降解,同时改性后Si—H基团的生成使得高聚物分子链的刚性增强,从而导致其抗温性能提高。

Preparation and Properties of a Novel Inorganic Silicon Modified Sodium Carboxylmethyl Starch Filtrate Reducer

A novel inorganic sodium silicate modified filtrate reducer(Si-SCMS)for drilling fluid was prepared through adding water-soluble sodium silicate to cornstarch in synthesis of sodium carboxylmethyl starch(SCMS).The Si—H bonds in the product were discovered by means of XRD and FTIR,which indicated that the inorganic sodium silicate reacted and organosilicon compound formed.Decomposition temperature of Si-SCMS filtrate reducer was discovered up to 220 ℃ by means of TG-DTA.Filter loss of Si-SCMS was only 15.2 mL after heat aging at 150 ℃,while that of SCMS was 20.4 mL under the same conditions.The temperature resistance and filtrate reduction performance of Si-SCMS were heightened significantly compared with SCMS filtrate reducer.The heightening of the temperature resistance is because the inorganic silicon in the molecules inhibits degradation of SCMS,especially rigidity of the molecular chain is enhanced by forming of Si—H bonds.