The Chengdao oil field is in a very shallow-water area of Bohai Bay, China. Because of the complicated maritime and geological situation, several techniques were used to study the geology of the reservoir and the engineering requirements to develop the field. Log-constrained seismic inversion was used to estimate the size of the fluvial sand. Reservoir simulation and economic evaluation were used to optimize the development plan including reservoir-pressure maintenance. Enlarged well spacing and irregular well sites were developed to drill to the oil-bearing sands, reduce investment, and improve economic efficiency.