A pre®iously described molecular-thermodynamic framework, based on colloid theory, is used to correlate experimental asphaltene-precipitation data at high-temperature and pressure conditions. In this framework, asphaltenes and resins are represented by pseudopure components, and all other components in a crude oil are presented by a continuous medium that affects ®an der Waals attractions among...

Asphaltenes constitute the heaviest fraction of the aromatic group in crude oil. Aggregation and precipitation of asphaltenes during petroleum processing costs the petroleum industry billions of dollars each year due to downtime and production inefficiencies. Asphaltene aggregation proceeds via a hierarchical self-assembly process that is well-described by the Yen-Mullins model. Nevertheless, t...

When oil is mixed with light alkanes, asphaltenes can precipitate out of oil solutions in a multistep process that involves the formation of nano and colloidal scale particles, the aggregation of asphaltene colloids, and their eventual sedimentation. Amphiphilic dispersants can greatly affect this process. The mechanism of the dispersant action in colloidal asphaltene suspensions in heptane has...

asphaltene precipitation and deposition is a serious problem in many iranian fields. the deposited asphaltene results in partial or total blockage of the wellbore and wellstring reducing or completely seizing oil production. this paper studies the asphaltene problem and mitigation methods in wellstring systematically. it presents new approach based on the combination of thermodynamic modeling o...

Asphaltenes are known as the 'cholesterol' of crude oil. They form nano-aggregates, precipitate, adhere to surfaces, block rock pores and may alter the wetting characteristics of mineral surfaces within the reservoir, hindering oil recovery efficiency. Despite a significant research effort, the structure, aggregation and deposition of asphaltenes under flowing conditions remain poorly understoo...

The SAFT equation of state was used to model asphaltene phase behavior in a model live oil and a recombined oil under reservoir conditions. The equation of state parameters for the asphaltenes were fit to precipitation data from oil titrations with n-alkanes at ambient conditions. The SAFT model was then used to predict the asphaltene stability boundaries in the live oils. A lumping scheme that...

A partial phase diagram for the system athabasca bitumen vacuwn bonoms (ABVB) (24.6 wt. % / 2 mole %) + dodecane (73.8 wt. % / 47 mole %) + hydrogen (1.6 wt % /51 mole %) was constructed in the temperature range 425 K to 725 K and the pressure range 2 MPa to 7 MPa using an X-ray view cell apparatus. This t1uid system is shown to exhibit two phase LIV and three phase LIL2V phase behaviour over p...

The Taguchi design of experiments (DOE) approach is adopted here to evaluate the impact ofeffective factors such as nanoparticles type, nanoparticles to model solution mass ratio, asphaltenestructure, and temperature on asphaltene adsorption equilibrium. Herein, the toluene-asphaltenesolution model is applied. Three commercially nanoparticles (SiO2, Al2O3, and TiO2) are used.<...

The molecular properties of asphaltenes have been the subject of uncertainty in the literature; in particular the molecular architecture is still a matter of debate. Some literature reports provide evidence that the contrast of petroleum asphaltenes versus coal-derived asphaltenes is useful for understanding the governing principles of asphaltene identity. Here, we employ fluorescence correlati...

Asphaltene and smaller aromatic molecules tend to form linear nanoaggregates in bitumen. Over the years bitumen undergoes chemical aging and during this process, the size of the nanoaggregate increases. This increase is associated with an increase in viscosity and brittleness of the bitumen, eventually leading to road deterioration. This paper focuses on understanding the mechanisms behind nano...