Abstract: Based on beta function of distribution density in probability statistics and derived density function by transformation, a beta cyclical model was developed and a method extracted for the model parameters was presented. By using this model, predictions of production and recoverable reserves in Ninghai oilfield were made. The results showed that the model is suitable for prediction of some other field's productions and recoverable reserves.

Key words: Model, Prediction, Oilfield, Production rate, Recoverable reserves