摘要
德博拉数（NDc）是表征流体粘弹性的流变参数,可由实验测得的流体第一法向应力差■求出。但聚合物稀溶液的■数值太小,在一般流变仪上测不出。用半经验公式计算NDe的方法虽然简便,但应用范围有限。作者改装了威森堡锥板流变仪并用改装的仪器测定了聚丙烯酰胺稀溶液（1000mg/l）的NDe及表征流体由粘流型转变为粘弹型的临界德博拉数■,将实验结果与用半经验公式计算的结果进行了对此。结果表明,该半经验公式只适用于中等分子量（小于10×106）的浓度不大于1000mg/l的聚合物稀溶液,而对于高分子量（大于10×106）或较高浓度（大于1000mg/l）的聚合物溶液则误差较大,不宜使用。
The Deborah Number,N_(De),is a rheologic characteristic of the viscoelasticity of a fluid and can be determined from experimental data of its first differential normal stress,τ_(11)-τ_(22),which,however,is too little to be measured by an ordinary rheome- ter for dilute polymer solutions.By using the Weissenberg's cone-and-plate rheogonio- meter refitted in this laboratory,accurate values of N_(De) are determined from τ_(11)-τ_(22) values directly,without need to be corrected,for some dilute(1000mg/l)polyacryl- amide solutions.On plots N_(De)-shear rate the critical value of N_(De),which characterizes the transition from viscous to viscoelastic flow,is found.N_(De) can be determined by using a semi-empirical equation suggested in literature[5],which is only true for relatively dilute(C<1000mg/l)solutions of polyacrylamides of mediate molecular weight(M<10 ×10~6),as shown in this study.In cases of higher polymer molecular weight or more concentrated solutions this equation should not be used because of large errors.This work is conducted for the purpose to provide informations on mechanisms of polymer flooding.
出处
《油田化学》
CAS
CSCD
北大核心
1992年第1期50-53,共4页
Oilfield Chemistry
关键词
聚丙烯酰胺
聚合物溶液
多孔介质
Partially Hydrolized Polyacrylamides
Polymer Solutions
Rheological Behavior
Viscoelastisity
Porous Media
