Abstract: The decline characteristics of Arps model and Weibull model in decline stage are analyzed, and a new general model Q_t=at^q-1/ (1+pbt^q)^1/p for production forecast of oil and gas fields is proposed. It can be simplified into Arps decline model and Weibull growth model respectively when q=1 or p→0. The model can be used to describe the entire process of production and decline rate variations. It is applicable to prediction of production, cumulative production and reserves for various kinds of oil and gas fields.

Key words: oil-gas field, production, recoverable reserve, decline rate, model