For a highly efficient development of overseas deepwater blocks composed of several oilfields

one should make an optimized master plan for producer on-stream sequence and production replacement

and tailor field development strategies for each oilfield according to their unique features.This also ensures the maximum project profits through the effective development optimization.Based on the features and requirements of joint development of multiple deepwater oilfields

we suggested three studies to be carried out to optimize reserve development and production replacement in various scenarios of combined deepwater oilfields development.(1)We established the evaluation standards for reserves ranking through comprehensive mathematical evaluation methods

and clarified the reserve ranks for various oilfields;(2)We established the prediction models for key development indexes for varying reserve levels via the analysis of main controlling factors for production and operation in deepwater oilfields

which can be used as the basis for the calculation of production operation under joint development of different oilfields;(3)We established the mathematical model to satisfy various constraints and to maximize project NPV profits.Process control theories were applied to select the best combination pattern and the optimized drilling sequence for varying ranks of reserves.Application of the methods proposed in this study to the development and deployment of XF deepwater oil region based on the actual oilfield data

we calculated the petroleum reserves for development and the strategy of production replacement to optimize multiple oilfields development under different conditions.The results meet the actual development requirements

so ultimately enhancing the reliability of deepwater oilfield development decisions.