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...

the basics of quantum mechanics and statistical thermodynamics were used to predict the potential energy and intermolecular forces of asphaltene molecules. the parameters associated with the chemical structure were also estimated for a specific asphaltene molecule to predict the mie potential function. based on the structural results, a new form of the virial eos with peneloux correction was de...

The basics of quantum mechanics and statistical thermodynamics were used to predict the potential energy and intermolecular forces of asphaltene molecules. The parameters associated with the chemical structure were also estimated for a specific asphaltene molecule to predict the Mie potential function. Based on the structural results, a new form of the Virial EOS with Peneloux correction wa...

Although CO2 injection is one of the most common methods in enhanced oil recovery, it could alter fluid properties of oil and cause some problems such as asphaltene precipitation. The maximum amount of asphaltene precipitation occurs near the fluid pressure and concentration saturation. According to the description of asphaltene deposition onset, the bubble point pressure has a very special imp...

A combination of steady-state fluorescence, fluorescence lifetime measurements and the determination of time-resolved emission spectra were employed to characterize asphaltene toluene solutions. Lifetime measurements were shown to be insensitive to the source of asphaltene or the alkane solvent from which asphaltene was precipitated. This insensitivity suggests that either the composition of At...

The aggregation and solubility of asphaltenes are studied by classical molecular dynamics simulations. Average three-dimensional atomistic models are built on the basis of experimental data for the asphaltenes from a series of crude oil samples. The simulation of two such asphaltene models in four different solvents puts into evidence the formation of oligomeric clusters and gives clues to the ...

The Scott-Magat polymer theory, which assumes that polymers have heterogeneous structure and takes into account the polydispersity in the molecular weight of polymers, is a method to model asphaltene precipitation conditions. The traditional Scott-Magat polymer theory based models assume that the precipitated phase consists of asphaltene only. In the present work, we introduce a model based on ...

We apply a cubic-plus-association equation of state to study the asphaltene precipitation from n-alkane diluted model solutions (asphalteneþtoluene), and heavy oils and bitumens. Heavy oils and bitumens are characterized in terms of saturates, aromatics/resins, and asphaltenes; n-alkanes are treated independently. The asphaltene precipitation is modeled as liquid-liquid phase equilibrium. The s...

The scaling and modeling of the viscosity of suspensions of asphaltene nanoaggregates is carried out successfully taking into consideration the solvation and clustering of nanoaggragates, and the jamming of the suspension at the glass transition volume fraction of asphaltene nanoaggregates. The nanoaggregates of asphaltenes are modeled as solvated disk-shaped “core–shell” particles taking into ...

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...