Abstract: Natural decline rate is an important index of yield variation of oil field.In view of the predicting circumstance by experience in the past,formula of monthly natural decline rate is deduced in the regular pattern of exponential decline,double curves decline and harmonic decline.On this basis,empirical formula prediction of monthly natural decline rate is proposed on the basis of considerable research and analysis of real field data.According to this method,monthly natural decline rate can be predicted easily and promptly so as to set monthly output performance and workload arrangement of yearly deployment appropriately.It also can be an important reference to early warning for dynamic tendency of development.It can guide the management of the oil field development and production.

Key words: monthly natural decline rate, prediction method, yearly planning, early warning of exploitation