Patent · US Expired

Lightweight transfer referencing and mooring system

US4802431A · kind A · utility

20Cited by
11References
6Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 27, 1987
Grant dateFeb 7, 1989
Priority date
Expiry dateApr 27, 2007

Classification

  • Technology area (CPC E)Fixed Constructions
  • CPC primaryE21B17/015
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

An offshore fluid transfer system is described for transferring fluid between an underwater pipe and a dynamically positioned vessel at the sea surface, which is relatively lightweight and economical. The system includes a riser having an upper end attached to the vessel and a lower end having a chain table held by chains extending in catenary curves to the sea floor and weighted by a weight hanging by the chain table. The riser supplied substantially the only mooring force most of the time, while thruster equipment on the vessel supplies sufficient additional force a small amount of the time to limit vessel drift in violent storms. The upper several meters of the riser is a rigid pipe, and an instrument that measures tilt of the pipe indicates the amount and direction of drift of the vessel.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.