W/O型原油乳状液及其凝胶流变特性研究进展

Progress in rheological studies of W/O emulsion and its gel

W/O型原油乳状液是原油开采和集输过程中常见的油水共存状态,其流变性质是多相混输管道流动安全保障的基础资料。阐述了分散相液滴体积分数及粒径对原油乳状液表观黏度的影响,总结了现有的黏度预测模型;分析了乳状液中无固相存在时及有蜡晶析出时,液滴自身以及液滴与蜡晶共同作用对乳状液黏弹性的影响;从屈服过程的变化及屈服应力、屈服应变的角度,详尽分析了分散相液滴导致原油乳状液凝胶屈服行为发生的改变;从原油乳状液凝胶的结构裂降和结构恢复行为两个方面,分别探讨了含水率对其触变性的影响。

In the process of crude oil exploitation and transportation, water and oil commonly coexist in the form of waterin-crude oil（W/O） emulsion. The rheological properties of this emulsion are the basic information for guaranteeing safe flow in multiphase transportation pipeline. In this paper, the W/O emulsion and its gel rheological properties were studied. Firstly, the effects of the volume fraction and size of dispersed droplets on the apparent viscosity of the emulsion were illustrated, and the existing viscosity prediction models were investigated. Secondly, the influences on the viscoelasticity of the emulsion from the dispersed droplet itself and the joint effect of droplet and wax crystal were analyzed with and without the existence of precipitated solid paraffin particles. Thirdly, the changes of the yield behavior of the emulsion gel caused by dispersed droplets were analyzed in detail from the aspects of yield process, yield stress, and yield strain. And finally, the effects of water content on thixotropic behaviors were discussed in terms of structural breakdown and recovery behaviors of the emulsion gel respectively.