蒸汽吞吐过程油包水型乳状液形成规律研究进展

Research Progress on the Formation Law of Water-in-Oil Emulsions in Steam Huff and Puff Processes

摘要: 针对稠油油田蒸汽吞吐开发中稠油乳化现象严重影响开采效果的问题以及油包水型乳状液形成规律及影响因素不明确的问题，本文运用文献分析的方法，基于油层物理、流体力学及渗流理论，通过分析乳状液中乳化活性组分的界面作用机制，结合文献中温度、含水率、原油组成等关键参数的实验观测数据，开展蒸汽吞吐条件下W/O乳状液形成规律及影响因素的研究。调研中明确了W/O乳状液的形成需油水两相、表面活性物质及乳化能量三个必要条件；揭示了原油黏度、含水率、温度、盐浓度及分散相粒径等因素对乳状液稳定性与物性参数的影响规律；明确了W/O乳状液深褐色至黑色、热力学不稳定但动力学稳定的物理性质，及其黏度、凝点、屈服应力随含水率和温度变化的特征。研究还表明，W/O乳状液的高黏度性与低流动性会阻碍原油渗流，需针对性调控其形成。研究成果深化了对蒸汽吞吐中W/O乳状液形成原因的理解，为提高采收率提供了科学依据，对稠油油田高效开发具有重要的指导意义。

Abstract: Addressing the problem of heavy oil emulsification severely impacting production efficiency during steam huff and puff development in heavy oil fields, and the lack of clarity regarding the formation law and influencing factors of water-in-oil emulsions, this paper employs literature analysis. Based on reservoir physics, fluid mechanics, and seepage theory, it analyzes the interfacial interaction mechanism of emulsifying active components in the emulsion. Combined with experimental observation data on key parameters such as temperature, water cut, and crude oil composition from the literature, this study investigates the formation law and influencing factors of W/O emulsions under steam huff and puff conditions. The study clarified that the formation of water-in-oil emulsions (W/O) requires three essential conditions: oil-water two-phase flow, surfactants, and emulsification energy. It revealed the influence of crude oil viscosity, water cut, temperature, salt concentration, and dispersed phase particle size on the stability and physical properties of the emulsion. The study also clarified the dark brown to black, thermodynamically unstable but kinetically stable physical properties of W/O emulsions, and the characteristics of their viscosity, pour point, and yield stress as a function of water cut and temperature. Furthermore, the study showed that the high viscosity and low fluidity of W/O emulsions hinder crude oil seepage, necessitating targeted control of their formation. These findings deepen the understanding of the formation mechanisms of W/O emulsions in steam huff and puff, providing a scientific basis for improving oil recovery and offering significant guidance for the efficient development of heavy oil fields.