Comparing C5Pe and Asphaltenes under Temperature and Pressure Reservoir Conditions Using an Acoustic Wave Sensor

Abstract

A quartz crystal resonator (QCR) was employed to assess the ability of the C5Pe model asphaltene compound to form nanoaggregates in toluene and bigger flocs that adsorb on the QCR surfaces at a higher concentration of flocculating agent. To allow comparison with real asphaltenes, experiments have been conducted in the same conditions on PetroPhase 2017 asphaltenes. First, the resonance properties of a QCR fully immersed in C5Pe/toluene solution were monitored during an isothermal titration experiment performed with n-heptane at atmospheric pressure. Then, constant mass expansion experiments were carried out to evaluate whether C5Pe precipitates during isothermal depressurization of C5Pe/ toluene + CH4 systems with various CH4 contents. The comparison between C5Pe and PetroPhase 2017 asphaltenes clearly revealed the propensity of C5Pe to self-associate in the presence of a flocculating agent, whereas it shows a lower tendency than asphaltenes to deposit on gold surfaces.