Impact of the Composition and Content of Dissolved-State Paraffins in Model Oil on the Aggregation State of Asphaltenes and the Stability of Water-in-Model Oil Emulsion

Paraffins cause many issues during the production and transportation of crude oils. To date there is abundant research on the rheological properties of crude oils after paraffins crystallize, and the effect of precipitated wax particles on the stability of water-in-crude oil (w/o) emulsions. However, the impact of dissolved-state paraffins on w/o emulsion stability is insufficiently studied. This article focuses on the effect of dissolved-state paraffins with different carbon number distributions (CNDs) on the model oil/water interfacial characteristics and further the stability of water-in-model oil emulsions. It is found that the dissolved-state paraffins can affect the aggregation degree of asphaltenes, thus changing the w/o emulsion stability. The asphaltenes flocculate into larger aggregates when the paraffin content is increased to larger values. The aggregation weakens the diffusibility of the asphaltenes from bulk to interface, so the diffusion rate is reduced significantly with the increasing par...