Prediction of heptane plus fraction molecular weight variation in hydrocarbon reservoirs

The effects of gravity and temperature gradient on the molecular weight of heptane plus fraction in hydrocarbon reservoirs can be predicted by new methodology. This new methodology, which is based on continuous and irreversible thermodynamics, is able to predict variations of this plus fraction molecular weight in both isothermal and non-isothermal hydrocarbon reservoirs. Model predictions, to date, have agreed well with experimental field data.