At present,very large deep water open caisson is main structural form of large hydroelectric engineering,water transport engineering and deep foundation works of bridge.

Under complicated geological conditions,large slenderness ratio ultra-deep well sinks in the ultra-soft soil by prevented sinking method,sinks in hard soil by assisted sinking method,and in the process of sinking to take difficult technical measures of anti-tilt,correcting,and prevent sudden sinking to make large slenderness ratio ultra-deep wells vertically and evenly sink in the position.

Influential factors for the design of ultra-deepwater drilling risers

This paper introduces the oil price promotion to discover the ultra-depth water oil resources and development of the ultra-depth water drilling platform and ultra-depth drilling equipment, also introduces the main characteristics of the 5th and 6th generation drilling platform.