Interfacial Interaction Mechanisms Between Heavy Petroleum And Mineral Surfaces

The liberation process of unconventional oils from different mineral surfaces have been intensively investigated in this study.The effects of mineral chemical heterogeneity,oil composition,heteroatoms and water chemistry on heavy oil liberation,as well as the oil-mineral interaction have been studied on the basis of interfacial dynamic wetting and DLVO colloidal interface theory.The detailed content is shown as follows:(1)The optical image analysis has been applied in investigating the liberation mechanism of heavy oil fractions from the silica and muscovite surfaces.And the oil-mineral surface force measurements have been conducted to verify the liberation model.Besides,the results obtained from molecular dynamics(MD)simulation provide much molecular level information including oil-surface interaction energies,the adsorption and desorption structures,dynamic diffusions.(2)The desorption of saturates,aromatics,resins,asphaltenes(SARA fractions)and bitumen from silica,kaolinite,calcium carbonate have been systematically investigated.Results show that heavier fractions tend to stay attached on the mineral surfaces,lead to the wettability change for the mineral surfaces,and play a dominant role in determining the physicochemical and desorption properties of bitumen(the mixture of SARA fractions).(3)The molecular dynamics(MD)simulation has been adopted to study the adsorption and desorption behaviors of N,O,S heteroatoms containing asphaltenes on the silica surface.Their adsorption and desorption properties are strongly dependent on the type and location of the inside heteroatoms.(4)The effects of type and concentration of ions in solutions on the bitumen-calcium carbonate interaction have been systematically studied.The results show that the presence of ions reduces the adhesion between bitumen and calcium carbonate,and reduces the adsorption amount of calcium carbonate particles on bitumen surface.The previous studies are mainly focused on the macroscopic oil-solid separation process and methods.Different from those,this study provides basic understanding of the interfacial properties of heavy oil liberation from minerals.The in-depth interfacial models and mechanisms have been extracted and summarized.The universal conclusions have been obtained,instead of being confined to specific separation methods.This study can provide theoretical and technical basis for the enhancement of unconventional oil exploitation with low energy consumption,low pollution and high efficiency.