Asphaltene removal from sediments is essential for enhanced oil recovery from heavier crude oil reservoirs and tar sands and bitumen recovery from bottom products in downstream processes. Water injection or water flooding at high pressures exert shear forces that can overcome the adhesive forces between asphaltene and mineral surfaces. The adhesive forces are also affected by ions in the aqueous medium. In the current work we study asphaltene removal from silica surface using shear forces of aqueous media in a parallel plate channel. We demonstrate the effect of varying pH and surfactant conditions in aqueous media on asphaltene removal efficiency. We relate the removal efficiency with fractional asphaltene volume on the surface estimated from atomic force microscopy. The fractional asphaltene volume reduces to 0.12 at pH 10, which is approximately 50% lower than water at neutral pH at the same shear rate. We show that the water-soluble anionic surfactants are inefficient in asphaltene removal, whereas cationic surfactant reduces the asphaltene fraction to 0.30. We conclude that the removal efficiency is affected by the zeta potential of the asphaltene and the surface, where electrostatic repulsion between the asphaltene and the surface and increased wettability in the presence of cationic surfactant improves asphaltene removal.

从沉积物中去除沥青质对于提高重质原油储层和焦油砂的石油采收率以及下游工艺中底部产品的沥青采收率至关重要。高压注水或注水会产生剪切力，可以克服沥青质和矿物表面之间的粘附力。粘附力也受水性介质中的离子影响。在目前的工作中，我们研究了使用平行板通道中水性介质的剪切力从二氧化硅表面去除沥青质。我们证明了水介质中不同的 pH 值和表面活性剂条件对沥青质去除效率的影响。我们将去除效率与从原子力显微镜估计的表面上的分数沥青质体积联系起来。在 pH 值为 10 时，部分沥青质体积减少到 0.12，在相同剪切速率下，它比中性 pH 值的水低约 50%。我们表明水溶性阴离子表面活性剂在去除沥青质方面效率低下，而阳离子表面活性剂将沥青质分数降低到 0.30。我们得出结论，去除效率受沥青质和表面的 zeta 电位的影响，其中沥青质和表面之间的静电排斥以及在阳离子表面活性剂存在下增加的润湿性改善了沥青质的去除。