Abstract:Well CSDP-02 is the second well of the eastern sea scientific drilling project of China. The well was completed in 504 days with the five-section structure, at completion diameter of 98mm, and depth of 2843.18m, setting the world depth record in marine scientific full borehole core drilling. This paper introduces the drilling process of the well. The drilling time, drilling efficiency, and footage per run of the well are systematically summarized and analyzed. Based on the analysis, the factors affecting the deep offshore drilling efficiency, such as sea conditions and logistical support, are briefly expounded, which provides reference for improving the deep offshore drilling efficiency.