Development and prospect of the key technologies for the drilling of deep wells in deep water

As the offshore oil and gas exploration and development advances continuously, deep wells in deep water (referred as the dual-deep well) have become the hot spot of exploration and development all over the world. Compared with conventional deepwater wells, dual-deep wells will face more complicated downhole geological setting and marine environment and greater operation risks. In recent years, with the continuous progresses of deepwater drilling operation, a set of key technologies for the drilling of dual-deep wells have been developed preliminarily from 7 aspects, including casing program, managed pressure drilling, drilling fluid system, cementing technology, well control, subsea wellhead and well integrity. These key drilling technologies provide the technological base for speeding up offshore oil and gas exploration and development. The research achievements have been applied in X Block of the South China Sea and the application results are remarkable. It is practically proved that the key technologies for the drilling of dual-deep wells have preliminarily adapted to the drilling operation requirements of deep wells in deep water, and in the future, it is necessary to promote the research and development of the drilling equipment and technologies of automation, scale, information and intelligence, so as to ensure the safe and efficient operation of dual-deep wells.