Research on Viscoelastic Properties of Water in Waxy Crude Oil Emulsion Gels with the Effect of Droplet Size and Distribution
Research on Viscoelastic Properties of Water in Waxy Crude Oil Emulsion Gels with the Effect of Droplet Size and Distribution
复制标题
含蜡原油乳液凝胶中水的粘弹性特性对液滴尺寸和分布的影响研究
DOI：
10.1002/cjce.22324
复制
发表时间：
2015
影响因子：
2.1
通讯作者：
Fan Kaifeng
中科院分区：
文献类型：
--
作者：
Li Si;Huang Qiyu;Wang Lei;Fan Kaifeng
凝胶油的粘弹性能反映其结构特征，这对于长停管道的重启运行具有重要意义。由于分散水相的影响，油包水（W/O）乳液的粘弹性性质更加复杂，不可忽视。本文试图从微观角度揭示蜡质粗乳液凝胶的粘弹性特性与温度和含水率的关系。作为流变分析的基础，通过微观观察研究了内相的液滴尺寸和分布。研究发现，分散液滴的总数和索特平均直径都随着水分数的增加而增加。通过一系列小振幅振荡剪切实验，获得了不同水含量乳液凝胶在不同温度下的线性粘弹性区域和粘弹性参数。结果表明，随着水分数的增加，乳液凝胶的结构强度变得更强。这主要归因于吸附蜡晶体的可变形油水界面面积更大以及水滴之间更强的相互作用。根据实验结果，提出了弹性模量、损耗模量和损耗角等粘弹性参数的回归公式，并证明是可靠的。这为油水多相输送管道的重启运行提供了有用的信息。
The viscoelastic properties of gelled oil can reflect its structural characteristics, which are significant for the restart operation of prolonged-shutdownpipelines. The viscoelastic properties of water-in-oil (W/O) emulsions are more complicated on account of the influence from the dispersed waterphase, which cannot be ignored. This paper attempts to reveal the relationship of viscoelastic characteristics to temperature and water fraction forwaxy crude emulsion gels from a micro perspective. As a basis of the rheological analysis, the droplet size and distribution of inner phase are studiedwith microscopic observation. It is found that both the total number and Sauter mean diameter of dispersed droplets increase with growth of thewater fraction. Through a series of small amplitude oscillatory shear experiments, the linear viscoelastic regions and the viscoelastic parameters ofemulsion gels with different water fractions are obtained and compared under varying temperatures. The results provide evidence that as the waterfraction rises, the structural strength of emulsion gels becomes stronger. This can mainly be attributed to the larger deformable oil-water interfacearea with adsorbed wax crystals and the stronger interactions among water droplets. Based on the experimental results, regression formulas forviscoelastic parameters, including elastic modulus, loss modulus, and loss angle, are proposed and proven reliable. This offers useful information forthe restart operation of oil-water multiphase transportation pipelines.