Niudong 1 Well, which recorded a prolific oil flow of 642.9 m3/d and gas flow of 56.3×104 m3/d, discovered a buried hill field in the Baxian Depression, Jizhong sub-basin, Bohai Bay Basin. The exploration of this field has experienced 4 stages: Initial failure, suspension of renewed exploration, regained hope and great breakthrough. The discovery of Niudong 1 Well is of milestone significance in promoting exploration of ultra-deep buried hill fields in the Bohai Bay Basin.