摘要
威兰胶是由产碱杆菌以碳水化合物为主要原料,经发酵产生的高分子可溶性胞外杂多糖。研究了微生物多糖威兰胶的结构和流变特性,分别考察了加量、放置时间、剪切速率、剪切时间、温度、矿化度及p H值等因素对微生物多糖威兰胶黏度的影响。结果表明,微生物多糖威兰胶水溶性好,溶液的黏度随着浓度的升高而增加;随着剪切速率增加,威兰胶水溶液的表观黏度逐渐降低,剪切应力逐渐升高,表现为典型的高假塑性流体特性,而且在低剪切速率下具有很高的黏度;瓜尔胶在中性环境中保持稳定,在酸性和碱性溶液中黏度急剧降低,而威兰胶溶液在为2~12的p H值范围内,黏度基本保持稳定,具有良好的酸碱稳定性;耐温性能与瓜胶相比呈现优良的优越性;高价离子的增加,并没有影响到威兰胶在溶液中的缔合网络结构,其可成为一种新型压裂液增稠剂。
Welan gum is a high molecular weight water soluble exopolysaccharide produced through fermentation of carbohydrates by alcaligenes. Studies show that welan gum is soluble readily in water to form solution whose viscosity increases as the concentration of welan gum increases. The apparent viscosity of the welan solutiondecreases shear rate increases, and the shear stress, in the meantime, increases, showing a typical pseudo-plastic behavior. At low shear rate, the welan solution has high apparent viscosity. Guar gum solution retains its viscosity at neutral condition, and loses its viscosity in acidic or basic environment. Contrary to the guar gum, welan gum solution maintains most of its viscosity at p H range of 2-12. Moreover, welan gum has better temperature stability than guar gum. Unlike other polysaccharides, welan gum forms a network structure that is free from the effect of high valence ions. Welan gum will be a new ideal viscosifier for use in well fracturing.
出处
《钻井液与完井液》
CAS
北大核心
2015年第4期84-87,111,共4页
Drilling Fluid & Completion Fluid
关键词
微生物多糖
威兰胶
增稠剂
压裂液
Polysaccharide
Welan gum
Viscosity
Fracturing fluid
作者简介
何静，助理工程师，西安石油大学在职研究生，现在主要从事油田压裂工作液的优化与研究工作。地址：西安科技二路75号陕西延长石油（集团）有限责任公司研究院；邮政编码710075；电话15091331028；E—mail：hejing88950095@163．com。
