Abstract In this study, a novel visualization methodology to study solvent non-equilibrium exsolution behavior in heavy oil systems is proposed. A Hele-Shaw-like visual cell with adjustable aperture depth, has been designed to overcome the shortcomings of traditional apparatuses such as a hardly-visual PVT cell, or non-visual transfer cylinders. By eliminating the 3D nature of the traditional apparatuses, the true 2D bulk phase visual cell can directly visualize the interface evolution of foamy oil under pressure depletion. Totally, 6 sets of Constant Composition Expansion tests (CCE) were conducted with a CO2-C3H8-heavy live oil system. The effect of pressure depletion rates on solvent non-equilibrium exsolution behavior have been tested. Meanwhile, the initial volume fill-up percentage of live oil in the visual cell was also found to have an effect on foamy oil generation and endurability. This helps to define the appropriate volume of live oil to be saturated in PVT tests that aim to induce non-equilibrium. Through analyzing the deviation of liquid/vapor phase volume fraction from equilibrium state, non-equilibrium regimes of solvent exsolution were effectively found. The experimental design is also able to continuously capture the real-time solvent component exsolution sequence during pressure depletion. Numerical simulation of solvent non-equilibrium exsolution behavior has been conducted by a MATLAB-controlled reservoir simulator with real-time optimization. By dynamically adjusting the K value in the simulator, the total flashed vapor phase volume and the individual solvent component mass was history-matched. The achieved non-equilibrium K values were compared with equilibrium K values, and a delayed solvent exsolution was indicated.

中文翻译：

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溶剂/活性稠油体系泡沫油非平衡相行为研究的一种新型可视化方法

摘要 在这项研究中，提出了一种新的可视化方法来研究稠油系统中溶剂非平衡溶出行为。一种具有可调孔径深度的类 Hele-Shaw 视觉单元旨在克服传统设备的缺点，例如几乎不可见的 PVT 单元或非视觉传输圆柱体。通过消除传统设备的 3D 性质，真正的 2D 体相视觉单元可以直接可视化压力耗尽下泡沫油的界面演变。使用CO2-C3H8-重活油系统总共进行了6组恒定成分膨胀试验（CCE）。已经测试了压力消耗速率对溶剂非平衡溶出行为的影响。同时，还发现视觉细胞中活油的初始体积填充百分比对泡沫油的产生和耐久性有影响。这有助于定义在旨在引起非平衡的 PVT 测试中要饱和的适当体积的活油。通过分析液相/气相体积分数与平衡状态的偏差，有效地发现了溶剂溶出的非平衡状态。实验设计还能够在压力耗尽期间连续捕获实时溶剂组分溶出序列。溶剂非平衡溶出行为的数值模拟已通过具有实时优化的 MATLAB 控制的油藏模拟器进行。通过在模拟器中动态调整K值，总闪蒸气相体积和单个溶剂组分质量是历史匹配的。将获得的非平衡 K 值与平衡 K 值进行比较，并表明溶剂溶出延迟。