黄原胶接枝共聚物降滤失剂应用性能评价

Evaluating the Performances of Xanthan Gum Graft Copolymer as Fluid Loss Reducer

黄原胶(XG)具有优良的耐盐性和增稠降滤失性能,但耐温性较差。对XG分子结构的分析认为,可利用XG链上的活泼基团接枝丙烯酰胺等乙烯基单体,增强其耐温性能,用作耐温抗盐钻井液处理剂。对比了合成的黄原胶丙烯酰胺等接枝共聚物(XG)降滤失剂与XG在淡水、4％盐水和饱和盐水钻井液中的增粘降滤失性能和抗温性能,并通过岩心膨胀试验对比了XGG、XG和KCl对页岩的抑制性能。试验结果表明,在淡水钻井液中XGG具有极强的增粘效果和降滤失能力,远远超过XG;随着钻井液矿化度的提高,XGG的性能有一定下降,但XGG在各种钻井液中均具有比XG更好的高温增稠和控制失水的能力;XG已具有优良的抑制性,XGG的抑制性得到进一步提高。

Xanthan gum （XG） behaves with both good thickening, fluid loss reducing ability and poor temperature-stable ability. The structure of XG is studied and its antbtempeature ability can be improved by grafting vinyl monmer onto XG. The thickening, fluid loss reducing and anti-temperature ability of synthetic Xanthan gum graft copolymer （XGG） in freshwater fluid, 4% salt fluid and saturated salt fluid are investigated and compared with that of XG. The results indicate XGG shows much better performances in thickening and reducing fluid loss in freshwater fluid than XG. The performances of XGG descends with the increase of salt content, but its ability of controlling fluid loss under high temperature is better than XG in three kinds of drilling fluids. The inhibitive performance of XGG is enhanced when compared with XG.