一种膨润土改性淀粉抗高温降滤失剂的研制及其性能

PREPARATION AND PROPERTIES OF A NOVEL BENTONITE MODIFIED SODIUM CARBOXYL METHYL STARCH FILTRATE REDUCER

以羧甲基淀粉钠盐(CMS-Na)和膨润土为原料,合成了一种膨润土改性羧甲基淀粉抗高温降滤失剂(BCMS),并用XRD和FT-IR对其结构进行了表征。实验结果表明,膨润土层状结构被拆散,同时有C—O—Si键生成;BCMS的热分解温度为290℃。BCMS的钻井液性能结果显示,在150℃加热炉中高温滚动16h后,BCMS的滤失量仅为8.8mL,比CMS-Na的滤失量降低6.2mL;滤失量降低率41%;表观黏度较CMS-Na表观黏度增大1mPa.s,表观黏度上升率为15%。探讨了BCMS的抗高温机理。

To meet the need of starch filtrate reducer in high-temperature drilling, a novel resin of high temperature bentonite carboxyl methyl starch （BCMS） was synthesized through chemical modification by using sodium carboxyl methyl starch （CMS-Na） and bentonite. XRD and FT-IR characterization results show that the layered structure of bentonite is broken and C--O--Si bonds are generated. The thermal stability is studied by the TG analysis, and the thermal decomposition temperature of BCMS is 290 ;C. The properties of BCMS are studied by special instruments of drilling fluid such as Portable roller oven, 6-speed viscometer and API filter press. The results show that the filter loss of BCMS is only 8.8 mL after being heated for 16 h at 150 ℃, which is 6.2 mL less than that of CMS-Na under the same conditions, and the filter loss reduction is 41%, the apparent viscosity increases by 1 mPa ·s, and the apparent viscosity increases by 15 %. The mechanism of the high temperature filtrate reduction of the BCMS was also discussed.