Prediction of Oil Production by Gravity Drainage

摘要

Mathematical models to predict oil production accurately bygravity drainage have been few. To this end, an analyticalmodel was developed to determine the ultimate oil recoveryby free-fall gravity drainage. An empirical oil recovery modelwas proposed accordingly to match and predict oil production.The model was tested against experimental, numerical, andfield data of oil production by free-fall gravity drainage. Theresults demonstrated that the oil recovery model could worksatisfactorily in the oil-gas cases studied. Initial oil productionrate, entry capillary pressure, and average residual oilsaturation can be estimated using the oil recovery model. Anapproach was also developed to infer capillary pressure curvesfrom the oil production data by free-fall gravity drainage.