Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Riser stabilisation

a technology of stabilizing and rising towers, applied in waterborne vessels, drilling accessories, borehole/well accessories, etc., can solve problems such as significant fatigue, and achieve the effect of maximizing the corrective effect of thrust units and maximizing the cancelling

Inactive Publication Date: 2016-07-14
PROPOCEAN
View PDF5 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The patent describes a method and system for stabilizing a riser, which connects a structure on the seabed to the sea surface. The system includes a sensor to detect the riser's movement and a thrust unit to apply a force to the riser. The controller causes the thrust unit to apply an oscillating force to counteract the detected movement of the riser. The technical effect of this invention is to reduce the riser's oscillating movement, which can lead to damage and stability issues.

Problems solved by technology

The inventors have realized that there is a significant problem of fatigue caused by oscillating motion of a riser.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Riser stabilisation
  • Riser stabilisation
  • Riser stabilisation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0062]FIG. 1 shows a simplified diagram of a conventional offshore installation 10. The installation 10 comprises a floating platform 12 (formally a floating production, storage, and offloading system), a production riser 14, and a wellhead 16. The production riser 14 connects the floating platform 12 to the wellhead 16 via a lower riser package 18 (also known as a Christmas tree) and a blow-out protector (BOP) 20. The riser 14 is typically tensioned by a heave compensating system, which is a system that tries to compensate for the relative movement of the floating platform 12 with respect to the seabed, in order to improve the stability of the riser 14.

[0063]Fatigue problems at the upper part of the riser 14 occur at all water depths due to motion of the floating platform 12. It is predominantly roll and pitch motions (i.e. rotation about the horizontal axes) that cause bending moments in the riser 14, but surge and sway motions can also contribute. Tension variations in a heave co...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A method of stabilizing a riser includes applying an oscillating force to the riser, using one or more thrust units on the rise, so as to counteract oscillating movement of the rise, preferably having a first component oscillating at a period between 3 and 20 seconds and a second component oscillating at a period between 1 and 5 minutes, where the thrust units may be positioned at antinodes of the oscillating movement and preferably each comprise three pairs of thrusters respectively configured to provide thrust in three evenly spaced directions.

Description

TECHNICAL FIELD[0001]The present invention relates to stabilizing an offshore riser.BACKGROUND[0002]An offshore riser is a conduit that connects a subsea oil well, or the like, on the seabed to a surface platform. There are a number of types of risers including export and production risers, drilling risers and workover risers. Fatigue of risers is a common challenge for many types of risers. A combination of platform motion, wave forces and vortex induced forces from currents acting on the riser induce fluctuating tension and bending moments in the riser. The fluctuating bending moment induced stresses especially can cause fatigue damage to the riser resulting in a short fatigue life.[0003]When a riser reaches a certain level of fatigue damage, it must be inspected and sometimes replaced (depending on the safety standard, inspection method, detected cracks etc). Inspection and especially replacement of the riser joints is an expensive process, with a riser itself often costing as mu...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(United States)
IPC IPC(8): E21B17/10E21B17/01
CPCE21B17/01E21B17/1078E21B41/04E21B19/004B63B39/08B63B21/502E21B17/015E21B17/085E21B19/002
Inventor HAUGOM, FRODESKAUEN, RONNY
Owner PROPOCEAN
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com