Volumetric OOIP / OGIP with Monte Carlo
The volumetric equation run tens of thousands of times over triangular distributions, returning P90, P50 and P10 instead of one number that pretends to be certain.
Reservoir
PVT from correlations
Bubble point, solution GOR, Bo, oil and gas viscosity, z-factor and Bg from gravity, temperature and pressure — the module the other reservoir tools call.
Loading the calculation…
This calculation ran in your browser. No value you entered was sent anywhere, and nothing was stored.
How it is calculated
- Bubble point, Rs and Bo from either Standing or Vazquez–Beggs; Vazquez–Beggs additionally corrects gas gravity to 100 psig separator conditions, as the correlation requires.
- Oil viscosity: Beggs–Robinson dead oil and saturated branches, with the Vazquez–Beggs pressure correction above the bubble point.
- Gas: Standing pseudo-criticals, Wichert–Aziz correction for CO₂ and H₂S, Dranchuk–Abou-Kassem z-factor and Lee–Gonzalez–Eakin viscosity.
- Above the bubble point Bo is compressed with the Vazquez–Beggs oil compressibility rather than held flat.
Standards it speaks
Where this stops being true
Standing was fitted to 105 samples of light Californian crude; Vazquez–Beggs to about 6000 measurements across a wider but still conventional range. Outside those ranges — heavy oil, volatile oil, high CO₂, high H₂S — errors of twenty to forty per cent on bubble point are normal, and viscosity errors are routinely worse than that. A single laboratory PVT report on the actual fluid beats every correlation on this page, and where one exists these should be tuned to it, not used as they stand.
Related tools
Gas material balance — P/z
Paste reservoir pressure against cumulative production and read gas in place off the intercept, with z computed at every point rather than assumed constant.
EOR method screening
Ten EOR methods checked against your reservoir and fluid properties, each one told to say exactly which criterion rules it out.
Minimum miscibility pressure
CO₂ and lean-gas MMP from three independent correlations, corrected for injectant impurities, with the spread between them shown rather than averaged away.