The asphaltene precipitation of two reservoir oil samples collected from Jinlin oil field has been studied under pressure and with/without CO2-injection conditions. No asphaltene precipitation was detected during the pressure depletion processes without CO2 injection. For the CO2-injected oil systems, the effects of operating pressure, injected CO2 concentration, and multiple-contact on the ons...

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 precipitation of asphaltene, one of the components of oil, in reservoirs, transfer lines, and equipment causes many problems. Accordingly, researchers are prompted to determine the factors affecting asphaltene precipitation and methods of avoiding its formation. Predicting precipitation and examining the simultaneous effect of operational variables on asphaltene precipitation are difficult ...

Asphaltene precipitation is traditionally modeled using polymer solution theories or cubic equations of state. We propose another approach based on artificial neural network technique to model onset of precipitation of dissolved asphaltene in the solution of solvent + precipitant. A mathematical model based on feed-forward artificial neural network technique, which takes advantage of a modified...

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 thermodynam...

Asphaltene precipitation occurs in petroleum fluids under certain unfavorable conditions, but can be controlled by tuning composition. Aromatic solvents in large quantities can prevent precipitation entirely and can dissolve already precipitated asphaltenes. Some polymeric surfactants can dissolve asphaltenes when added at much lower concentrations than required by aromatic solvents. Other disp...

Asphaltene precipitation is a perennial problem in producing and rejming crude oils. To avoid precipitation, it is usefid to know the solubility of asphaltenes in petroleum liquids as a function of temperature, pressure and liquid-phase composition In the novel molecular-thermodynamic flamework presented here, both asphaltenes and resins are represented by pseudo-pure components while all other...

We apply a cubic-plus-association equation of state (CPA-EOS) to study the asphaltene precipitation in live oils from temperature, pressure, and composition effects. The live oils are characterized by considering the pure components, the pseudo-hydrocarbon components, and the hydrocarbon residue. The hydrocarbon residue is further divided into the “heavy” component and asphaltenes. The asphalte...

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...

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...