The expanding solvent-steam-assisted gravity drainage (ES-SAGD) is a newly proposed thermal recovery technique showing promising efficiency in terms of a smaller steam-to-oil ratio and greater production rate to recover heavy oils and bitumen from oil-bearing formations, where a solvent is coinjected with the steam in the SAGD process. Numerical simulation of the ES-SAGD process requires reliable relative permeability data. The number of reported measurements of relative permeability involving bitumen systems is limited in the literature, mostly because of the experimental difficulties involved in such measurements. The relative permeability data sets for Canadian bitumen, in the presence of solvents, are simply not available in the open literature. The fluid-flow behavior of bitumen/water systems in the presence of solvent is an important matter that must be assessed before the implementation of any ES-SAGD process; therefore, the objective of the current study is to evaluate the impact of a light hydrocarbon solvent (n-hexane) on bitumen/water relative permeability under SAGD conditions. For this purpose, two-phase bitumen/water relative-permeability measurements were conducted in sandpacks over a wide range of temperatures from 70°C to 220°C using Athabasca bitumen, deionized water, and a light hydrocarbon solvent. A well-instrumented experimental setup was developed to perform the relative permeability measurements with the capability of applying confining pressure on the sand and measuring the pore-pressure profile with several intermediate pressure taps. Isothermal oil-displacement tests were carried out with solvent premixed with bitumen. The history-matching approach and Johnson-Bossler-Naumann (JBN) method were used to translate the oil displacement data into the relative-permeability curves. The results obtained with a solvent from this study and without any solvent reported in our previous study are compared to assess the solvent’s impact on relative permeability. In addition, the steady-state relative permeability was measured to assess the reliability of unsteady-state relative permeability. The interfacial tension (IFT) and contact-angle measurements using the same fluids were carried out to determine the fluid/fluid interaction and wettability state of the system under high-pressure/high-temperature (HP/HT) conditions.

The results of the present study confirmed that the two-phase diluted bitumen/water relative permeability is sensitive to temperature, especially in terms of the endpoint relative permeability to bitumen and water. Furthermore, adding normal hexane (below the asphaltene precipitation threshold) not only improves the displacement efficiency of water flooding because of the significant decrease in oil viscosity but also modifies the wettability and IFT of this system. At the same temperature, the two-phase oil/water relative permeability for bitumen/water systems is significantly different when the oil is diluted with the solvent. Also, the impact of solvent is more pronounced at lower temperatures. Furthermore, the consistency between the steady-state and unsteady-state relative permeability data proved that the effect of viscous fingering was small enough.

扩展的溶剂-蒸汽辅助重力排水（ES-SAGD）是一种新提出的热采技术，在较小的汽油比和更高的生产率下，从含油地层中回收重油和沥青，显示出令人鼓舞的效率，在SAGD过程中将溶剂与蒸汽共注入。ES-SAGD过程的数值模拟需要可靠的相对渗透率数据。在文献中涉及沥青系统的相对渗透率的测量报告数量有限，主要是因为此类测量涉及实验困难。在公开文献中根本没有关于在溶剂存在下加拿大沥青的相对渗透率数据集。在存在溶剂的情况下，沥青/水系统的流体流动行为是重要的问题，必须在实施任何ES-SAGD工艺之前对其进行评估；因此，本研究的目的是评估轻烃溶剂（ñ-己烷）在SAGD条件下的沥青/水相对渗透率。为此，使用Athabasca沥青，去离子水和轻烃溶剂在70°C至220°C的宽温度范围内的沙袋中进行了两相沥青/水的相对渗透率测量。开发了一种仪器完善的实验装置，以执行相对渗透率测量，并具有在沙子上施加围压并使用多个中压接头测量孔隙压力分布的能力。用溶剂与沥青预混合进行等温驱油试验。使用历史匹配方法和Johnson-Bossler-Naumann（JBN）方法将油驱替数据转换为相对渗透率曲线。使用本研究中使用溶剂但没有在先前研究中报告的任何溶剂获得的结果进行比较，以评估溶剂对相对渗透率的影响。另外，测量了稳态相对磁导率以评估非稳态相对磁导率的可靠性。进行了使用相同流体的界面张力（IFT）和接触角测量，以确定高压/高温（HP / HT）条件下系统的流体/流体相互作用和润湿性状态。

本研究的结果证实，两相稀释沥青/水的相对渗透率对温度敏感，特别是在端点对沥青和水的相对渗透率方面。此外，添加正己烷（低于沥青质沉淀阈值），由于油粘度显着降低，因此不仅提高了驱油效率，而且还改善了该系统的润湿性和IFT。在相同温度下，当用溶剂稀释油时，沥青/水系统的两相油/水相对渗透率显着不同。同样，在较低温度下溶剂的影响更为明显。此外，