原油乳状液黏度影响因素及规律性研究
屈晓辉 喻高明
摘 ?????要:研究了不同剪切速率下,二元、三元不同油水比、不同碱含量、不同二元配方条件下形成的乳状液体系黏度的影响因素及其规律。结果表明,高剪切速率下,油水比为7:3形成的三元乳状液最稳定,黏度最大;较高剪切速率下,油水比低于1:1的二元乳状液体系黏度很低,发生相转变;不加碱时,形成的二元乳状液体系黏度较大;加碱时,三元乳状液体系在较低剪切速率下形成的乳状液体系黏度较大,当剪切速率增加到一定值时,三元乳状液发生相转变,黏度降低,且随剪切速率增加变化不明显;低剪切速率下,聚合物+活性剂形成的二元体系乳状液黏度最大,碱+活性剂形成的二元体系乳状液黏度最小;当剪切速率超过一定值时,聚合物+碱形成的二元体系乳状液黏度最大,聚合物+活性剂形成的二元体系乳状液黏度最小。
关 ?键 ?词:黏度;原油乳状液;剪切速率;油水比
中图分类号:TE357 ??????文献标识码:A ???????文章编号: 1671-0460(2019)01-0048-04
Abstract: The influence factors and laws of viscosity of emulsion system formed under different shear rates, different oil-water ratios of binary and ternary systems, different alkali contents and different binary formulations were studied. The results showed that the ternary emulsion with oil-water ratio of 7:3 was the most stable and the viscosity was the greatest at high shear rate. At higher shear rate, the binary emulsion system with oil-water ratio less than 1: 1 had very low viscosity and phase transition happened. When alkali was not added, the viscosity of formed binary emulsion system was larger. When alkali was added, the viscosity of ternary emulsion system formed at lower shear rate was higher. When the shear rate increased to a certain value, the ternary emulsion phase transition happened, and the viscosity decreased, and the change was not obvious with the increase of shear rate. At low shear rate, the viscosity of binary emulsion formed by polymer + active agent was the largest, while that formed by alkali + active agent was the smallest. When the shear rate exceeded a certain value, the viscosity of binary emulsion formed by polymer + alkali was the largest, while that formed by polymer + active agent was the smallest.
Key words: Viscosity; Crude oil emulsion; Shear rate; Oil-water ratio
目前,国内外一些科研工作者对油包水型乳状液的黏度,进行了广泛研究,并推导出许多理论或经验的计算公式。但是,这些公式具体应用于计算不同类型原油的乳状液时,其误差时大时小,而且应用于含水较高的乳状液时,其误差更大。究其原因,乳状液黏度的大小,不但与含水率有关,而且与剪切速度和原油的性质等因素,均有密切的关系[1,2]。
原油乳状液的黏度,不仅与含水率有關,而且与剪切速率和原油的性质等因素有关,因此不进行测定,要精确确定其大小是困难的[3-5]。但是,只要掌握了各因素对乳状液黏度的影响规律后,就可以较准确地计算或估计其大小。大量的研究工作表明,油水乳状液的性质受多种因素的影响,认识和掌握这些影响因素,以便为原油的集输储运工作提供必要的依据[6-9]。本文采用理论分析与实验相结合的方法,研究了乳状液黏度影响因素,通过对实验数据的分析,得出了乳状液黏度随各影响因素的变化规律。
1 ?实验部分
1.1 ?实验仪器及药品
大庆四厂原油;大庆四厂水;聚合物(聚丙烯酰胺),相对分子质量为1 200万;表面活性剂ORS-41,有效浓度 50%;NaOH,分析纯;JJ-1型定时电动搅拌器;控温仪;101A-1型干燥箱;lB801型超级恒温器;Book-Field型黏度计;千分之一精度天平;百分之一精度天平。
1.2 ?实验方法
3 ?结 论
(1)三元乳状液体系黏度随油水比的下降而减小;高剪切速率下,油水比为7:3形成的三元乳状液最稳定,黏度最大。
(2)二元乳状液体系在低剪切速率下形成的乳状液体系黏度较大,且随着油水比的下降,黏度降低;在高剪切速率下,油水比低于1:1的二元乳状液体系黏度很低,发生相转变。
(3)不加碱时,形成的二元乳状液体系黏度较大,且随剪切速率增减而降低;当加入碱时,三元乳狀液体系在较低剪切速率下形成的乳状液体系黏度较大,当剪切速率增加到一定值时,三元乳状液发生相转变,黏度降低,且随剪切速率增加变化不明显。
(4)低剪切速率下,聚合物+活性剂形成的二元体系乳状液黏度最大,碱+活性剂形成的二元体系乳状液黏度最小,且随着剪切速率增加黏度下降;当剪切速率超过一定值时,聚合物+碱形成的二元体系乳状液黏度最大,聚合物+活性剂形成的二元体系乳状液黏度最小。
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