Abstract: In order to solve the development problems of small offshore marginal oilfields with low proved degree and large uncertainty in economical recoverable reserves, in the feasibility study and practice of the developments of a small marginal oilfield in the Bohai Sea, based on the study of the overall development plan of the oilfield, with the goal of "risk quantitative evaluation", the deployment of "pilot evaluation well extended test plan" was optimized to consolidate the basis of oilfield development and avoid the risks of investment decision. Thus, an innovative development model of "integrated" rolling evaluation for offshore independent oil-bearing structures is formed.