水基钻井液抗高温降黏剂VRA的研究

Studies of a High Temperature Water Base Drilling Fluid Thinner VRA

通过对抗高温聚合物分子结构进行设计,合成出了两性离子型聚合物降黏剂VRA,并对其抗温性、抗盐性和配伍性等性能进行了评价。结果表明,VRA可明显降低淡水钻井液的表观黏度和动切力,获得良好的降黏效果,VRA在盐水和含钙盐水钻井液中也有较好的降黏效果;用VRA处理的不同类型钻井液老化后的表观黏度、动切力均未有明显的增加;而且VRA防止地层坍塌的能力明显优于乙烯基磺酸盐聚合物PAMS-601。由此可以得出,两性离子型聚合物VRA是一种热稳定性和抑制性好、降黏和抗温、抗盐能力强的降黏剂,并有利于油气层的保护。

An amphoteric polymer thinner VRA was developed by molecular design of high temperature polymers,and its temperature stability,salt tolerance and compatibility with other additives were evaluated.It was concluded that VRA reduced the apparent viscosity and yield point of fresh water base drilling fluids to a great extent.VRA also reduced the viscosity of saltwater(including saturated) and calcium contained water base drilling fluids.Aged drilling fluids treated with VRA found no obvious increase in apparent viscosity and yield point.It was also found that VRA was better than PAMS-601,an ethenylated sulfonate polymer,in inhibiting water sensitive sloughing formations.