Adsorption of Petroleum Asphaltenes onto Reservoir Rock Sands Studied by Near-Infrared (NIR) Spectroscopy

Asphaltenes are the most polar petroleum macromolecules. The high polarity causes their rather high superficial activity. A relatively high value of asphaltene adsorption means that this substance is responsible for many phenomena in the petroleum industry, such as well bore plugging and pipeline deposition, stabilization of water/oil emulsions, sedimentation and plugging during crude oil storage, adsorption on refining equipment, and coke formation. The knowledge of kinetic and thermodynamic parameters of adsorption opens a regulation opportunity for the capillary number and wettability. In perspective, it opens a way for physical and chemical engineering of liquid-solid interfaces in the oil industry. In this study, the adsorption parameters of petroleum asphaltenes on quartz, dolomite, and mica sands were investigated using near-infrared (NIR) spectroscopy. Each adsorbent was fractioned in its own particle size range, and the particle size was estimated. The experimental adsorption data were theoretically modeled using Langmuir adsorption. The maximal adsorbed mass density, the adsorption equilibrium constant, and adsorption/desorption rate constants were calculated. The initial stage of the colmatage mechanism for the petroleum collector based on capillary aggregation assumption is offered. Among investigated adsorbents, the highest asphaltene adsorption takes place in the case of mica.