Constrain conditions of variables were defined according to the attainable information of semisubmersibles and design criterion,and a mathematic model of semisubmersible for ultra-deepwater was proposed and optimized by minimizing its heave response in head sea condition on the basis of combinatorial optimization.

This paper studies the damaged stability for upgrade of Nanhai-Ⅱ semisubmersible,obtaining the critical axis.

In this paper,four models are built based on a six generation semisubmersible,and study on hydrodynamic ability,stability,towing resistance and hull steel weight is carried out,which provides a reference for the design.

The paper puts forward six proposals for design of semisubmersible platform of deep water in our country upon the above concept.

Air gap prediction of a semi-submersible platform

Calculating the wave loads of semi-submersible platforms in deep water

Overall strength assessment of semi-submersible platform structures based on direct calculation

Development of deep-sea semi-submersible drilling unit;

In this paper,the general arrangement principal of deep sea semi-submersible drilling unit,the latest generation,is introduced.

Study on motion performance of 3 000 meters deep-water semi-submersible drilling platform;

Prediction and analysis of motion response for a deep sea semi-submersible drilling platform;

Drill floor layout of dual derrick rigs of semi-submersible drilling platforms;