초록 ▼

A method and apparatus for erecting and removing offshore structures including a jacket and a platform is disclosed. The system of the invention includes a platform-lifting unit, a jacket lifting unit, and a control unit. The platform-lifting unit includes a laterally and vertically movable truss me

A method and apparatus for erecting and removing offshore structures including a jacket and a platform is disclosed. The system of the invention includes a platform-lifting unit, a jacket lifting unit, and a control unit. The platform-lifting unit includes a laterally and vertically movable truss member, which is hingedly connected to a barge with lifting beams, and a means for positioning the truss member at desired height and at lateral displacement above the barge. The jacket-lifting unit contains a ballast tank structure connected to a strong back that has a plurality of grappling members. The control unit contains all supporting and controlling systems for the other units. To remove the platform, the truss member of the platform lifting unit is moved underneath the platform, the truss is raised to exert force on the platform, the platform is severed from the jacket, and the platform is moved on top of the barge. To remove the jacket, the jacket-lifting unit is lowered by controllably flooding the ballast sections at varying rates, the grappling members are securely attached to the jacket structure, the jacket-lifting unit is pulled by the control unit to tilt the jacket, and the ballast sections are deballasted to controllably lift and float the jacket.

대표청구항 ▼

An apparatus for erecting and removing a platform resting above the ocean surface on an offshore structure, said apparatus comprising a barge having a top surface, a strong back mounted on the top surface of the barge in the fore and aft direction, a plurality of spaced apart parallel lifting beams,

An apparatus for erecting and removing a platform resting above the ocean surface on an offshore structure, said apparatus comprising a barge having a top surface, a strong back mounted on the top surface of the barge in the fore and aft direction, a plurality of spaced apart parallel lifting beams, one end of each said lifting beam being pivotly attached to the strong back and the other end of each said lifting beam being pivotly attached to a truss member so that when the lifting beams are moved, the truss member remains in a horizontal orientation above the top surface of the barge, and means for moving and positioning the lifting beams.