This paper describes asphaltene precipitation and deposition models implemented in a compositional reservoir simulator. The asphaltene precipitate is modelled as two solids: Solid 1 is thermodynamically reversible and is in equilibrium with the asphaltene component in the oil phase. Solid 2 is created from Solid 1 via a chemical reaction. Solid 2 can be used to represent the flocculation of smaller precipitated asphaltene particles into larger aggregates. This aggregation can be made fully reversible, fully irreversible or partially irreversible. Solid 1 flows as suspended particles in the oil phase, while Solid 2 may flow with the oil or deposit in the rock matrix.

The deposition model incorporates surface deposition, pore-throat plugging and re-entrainment of deposited solid into the flowing liquid phase. Porosity and permeability impairment due to asphaltene deposition are also modelled. Model results are compared to laboratory core floods illustrating core damage due to asphaltene deposition. The model is also applied to studies of primary depletion, and core flood simulations of miscible gas injection for light oils.

Keywords:
remediation of hydrates, precipitation, asphaltene, oil phase, compositional reservoir simulator, upstream oil & gas, simulation, rate coefficient, hydrate remediation, equation
Subjects:
Well & Reservoir Surveillance and Monitoring, Production Chemistry, Metallurgy and Biology, Flow Assurance, Reservoir Characterization, Fluid Characterization, Reservoir Fluid Dynamics, Improved and Enhanced Recovery, Reservoir Simulation, Formation Evaluation & Management, Inhibition and remediation of hydrates, scale, paraffin / wax and asphaltene
Copyright 2004, Society of Petroleum Engineers
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