Oil-Based Binding Resins: Peculiar Water-in-Oil Emulsion Breakers

摘要

Asphaltenes are widely associated with the unwanted stability of water-in-crude oil (w/o) emulsions due to their inhibitory effect on water droplet coalescence. Here, we seek to prove that certain crude oil resins that can bind with asphaltenes, hereafter referred to as binding resins, are capable of solvating these asphaltenes such that the w/o emulsion destabilizes. W/o emulsions were formed using a variety of crude oils as well as model oils with varying amounts of resins and asphaltenes. A modified SARA fractionation technique was adopted to extract the required resins and asphaltenes. Emulsion stability was tracked over time both visually and via the use of pulsed field gradient nuclear magnetic resonance to quantify the emulsions' water droplet size distributions. It was conclusively found that the binding resins significantly improved the demulsification rate of the emulsions formed using both crude oil and model oils. In the case of the model oils, this influence could only be attributed to the removal of the asphaltenes from the droplet surfaces by the binding resins; the effect was shown to be partially independent of the source of the binding resin. The use of this oil fraction subclass for emulsion destabilization shows great promise as a new flow assurance strategy by substituting costly synthetic chemical emulsion destabilizers with naturally occurring resins.