Computation of Asphaltene Phase Envelope and PVT Properties in MATLAB


  • To calculate the asphaltene phase envelope, effect of gas injections and PVT properties from the modeling approaches, developed at CERE, using the CPA and PC-SAFT (with association term).

Required Experimental Data

  • Reservoir fluid composition up to C6+ fraction.
  • Two upper onset pressure at two different temperatures. However, we recommend at least three data points for better accuracy of results.
  • One bubble pressure.
  • Specific gravity and molecular weight of stock tank oil/C6+ fraction.
  • Asphaltene (wt. %) in the stock tank oil (Optional input) (important when user is interested in absolute value of amount of asphaltene precipitation during the depressurization).


  • Calculation of Asphaltene Phase Envelope (Upper/Lower asphaltene precipitation onset pressure-temperature boundaries).
  • Calculation of effect of gas injection on Asphaltene Phase Envelope.
  • Calculation of asphaltene amount in the oil phase and precipitated asphaltene amount during depressurization of reservoir fluid at constant temperature.
  • Calculation of PVT properties at constant temperature (Differential Vaporization Test: GOR, gas/liquid volume formation factors, gas specific gravity, compressibility factor of gas, compressibility, relative volume, density) (Constant Mass Composition Test: oil phase density, total density (combined density of all phases, relative volume (reference to saturation volume), compressibility)

Required Software

  • MATLAB (32/64 bit)


Alay Arya
Software Manager
DTU Chemical Engineering
+45 45 25 28 64