Abstract:  At present, CNOOC's conventional independent four-leg wellhead platform cannot simultaneously meet the requirements of arranging 32 well slots, living quarter, and workover rig module, and using general drilling ship to carry out drilling and completion operations. To achieve all of the above functions, a new type four-leg wellhead platform with two wellhead areas is designed in Bohai oilfield development project. Considering that the space on the four-leg platform is limited, when the drilling ship is on site, there is potential risk of collision between the ship and the workover rig. Through risk identification for the layout plan of the wellhead platform, the layout design result successfully solves the problem, and allows reasonable rest for the platform crane. This platform has produced its first oil.