In the tight reservoir like mahu with strong heterogeneity

large differences in the productivity of oil wells and obvious differences in the decline characteristics

the production decline analysis and prediction have important guiding significance to the management of oil well production system and the preparation and optimization of oil field development plan

and are also an important part of reservoir performance analysis. However

the traditional empirical decline models used today

such as the Arps production decline model

power law exponential decline model

Valkó extended exponential decline model

and Duong decline model

have different applicability. When using these methods to fit the production data of the fractured horizontal wells in the Mahu tight reservoir

the accuracy of the fitted results is low. Therefore

a new method of combination that uses different models for fitting in stages based on the model fitting results of Mahu oil wells in different stages is explored

and the examples are applied to verify it in this block. The research results show that this new method has lower error rate and higher degree of agreement than the traditional ones. In addition

by using this method

the prediction results of Estimated Ultimate Recovery（EUR） for the tight oil wells in Mahu reservoir are more accurate

and the method is highly feasible

which can be used as a reference for the research on the production decline law and the productivity prediction of other similar tight oil reservoirs.