【摘要】 本文报道一种新的钻井泥浆添加剂,它是由产粘短杆菌(Brevibacterium viscogenes)74-230利用重液体石蜡生产的微生物胞外多糖。向培养基中加入表面活性剂Tweens或Span-80促进胞外多糖的生物合成。测定了它的流变特性,剪切稀释效应、失水量、对盐类和温度的敏感性等,并与甘竺黑腐病黄单胞菌胶(Xanthan gum)、部分水解聚丙烯酰胺和羧甲基纤维素作了对比。结果指出,该多糖作为钻井泥浆添加剂的性能几乎与Xanthan相当,并且比另外两种好得多。更多还原

【Abstract】 In this paper, a new drilling mud additive produced as a microbial exopolysaccharide by Brevibacterium viscogenes 74-230 from a heavy liquid paraffin is reported. Addition of the surfactants of Tweens or Span-80 to the medium can promote polysaccharide biosynthesis, but penicillin G and potassium ion has no advantageous effects on it. Corn steep liquor can be used as a substitute of yeast extraet, but with poorer results. After removal of cells by centrifugation, over 12g/l of polysaecharide can be obtained by ethanol precipitation, at a conversion rate based on liquid paraffin in exce’ss of 40%. Its rheological property, shear thinning effect, water loss, sensitivity to salts as well to as temperature, etc. are determined and compared with xanthan, partially hydrolysis polyacrylamide and carboxylmethylcellulose. The results indicate that the properties of this polysaccharide as a drilling mud additive are almost comparable with those of Xanthan, and far better than those of the other two. It is noteworthy that this polysaccharide is produced from crude oil or its product, while Xanthan is from carbohydrate. Field experiments are still going on.更多还原