Abstract: BZ3-2 Oilfield is located in the middle of Bohai Bay, which is far away from the developed oilfield, and its reserves are small, so its capability to withstand risks is weak.Based on improving the degree of producing reserves, using reservoir engineering and numerical simulation techniques, detailed study on development model, development layers, well pat tern, well type, well location and well spacing had been conducted, appropriate development plan for developing marginal oilfields with high efficiency was made by improving single well's early productivity.In order to avoid development risks and exploit potential of the oilfields, fine study on risks and potential had been carried out and corresponding countermeasures had been made in the plan, which made it more operable.Simplifying the engineering facilities and using simple wellhead plat form and mobile product ion plat form or bee-type platform had improved the effect of oilfield development, which had accumulated a lot of experiences and worked out a new way for developing medsmall marginal oilfields in Bohai Bay in a large scale.