Platform crane
AssigneePool Company
InventorJames Eubank Armstrong
Life of this patent
Estimating the term…
Abstract
A mobile crane for use on an offshore oil well platform, comprising parallel base beams adapted to span the capping beams of the platform, and a pedestal and a rotating upper works movably mounted on the base beams. A method is described for erecting a workover rig on the offshore platform by means of the crane, and for expeditiously erecting workover rigs on a plurality of platforms in succession.
Claims7
A method for constructing a rig on an offshore platform having a pair of substantially parallel horizontal capping beams and a deck-mounted crane comprising
- lifting a pair of base beams with said deck-mounted crane and placing them to span said capping beams,
- removably attaching said base beams to said capping beams,
- lifting a pedestal of a second crane with said deck-mounted crane and placing it on said base beams,
- removably attaching said crane pedestal to said base beams,
- lifting a second crane rotating upper works with said deck-mounted crane and placing said works on the pedestal,
- fastening said works to said pedestal, and
- lifting elements of such a rig with said second crane and placing them on said capping beams.
A method of performing workover operations at a plurality of offshore platforms comprising
- erecting a first crane on a first platform,
- erecting a rig on the first platform by means of said first crane.
- erecting a second crane on a second platform while operations are being performed by the rig on the first platform,
- removing the rig from the first platform by means of the first crane,
- removing the first crane from the first platform, and
- erecting the rig on the second platform by means of the second crane.
A method of performing workover operations at a plurality of offshore platforms comprising
- carrying a workover rig and two portable cranes in a vessel,
- erecting the first portable crane on a first platform,
- erecting the rig on the first platform by means of the first portable crane,
- transporting the second portable crane on the vessel to a second platform and erecting the second portable crane on the second platform,
- performing workover operations on the first platform while the second portable crane is being erected,
- removing the workover rig from the first platform by means of the first portable crane and returning it to the vessel,
- removing the first portable crane from the first platform and returning it to the vessel,
- transporting the workover rig on the vessel to the second platform,
- erecting the rig on the second platform by means of the second portable crane,
- transporting the first portable crane to a third platform,
- erecting the first portable crane on the third platform, and
- performing workover operations on the second platform while the first portable crane is being erected on the third platform.
A method for constructing a portable mobile crane on an offshore platform having a fixed crane mounted thereon and a pair of substantially parallel horizontal capping beams comprising,
- lifting a pair of base beams from a transport vessel with said fixed crane,
- placing said base beams on said capping beams whereby the base beams span the capping beams,
- releasably attaching the base beams to the capping beams,
- lifting a crane pedestal from said transport vessel with said fixed crane,
- placing said crane pedestal on the base beams,
- releasably attaching the crane pedestal to the base beams,
- lifting a crane upper works from said transport vessel with said fixed crane,
- placing said crane upper works on said crane pedestal, and attaching the crane upper works to the crane pedestal.
Dependencies are inferred from the claim text.