Offshore Pipe Bundle Assembly With Coiled Flowline Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The conventional manufacturing of subsea pipe bundles for riser towers and tie-backs requires large onshore facilities, which are expensive and not always available near installation sites, and offshore assembly faces challenges in aligning and ensuring leak-tightness of long, rigid components.
Innovation Solution
The method involves assembling elongate pipeline bundles offshore by suspending the bundle from a vessel, successively attaching pre-fabricated structural core sections, and incorporating flowline pipes, which can be flexible, composite, or rigid, allowing for a compact storage and efficient assembly process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pipe bundles are manufactured onshore in conventional facilities, then assembly and welding can be performed with stable conditions, but large coastal land areas are required which are expensive and not always available
Solution Approach 1:
The fabrication process is segmented between onshore pre-fabrication of individual pipe sections and offshore final assembly. Individual pipe sections are manufactured onshore with controlled conditions, then transported and assembled offshore, eliminating the need for large continuous onshore facilities while maintaining welding quality.
Solution Approach 2:
The fabrication location is shifted from two-dimensional onshore yard space to three-dimensional offshore space utilization. Pipe sections are assembled in a vertical column structure offshore, utilizing the water column space rather than requiring extensive horizontal coastal land area.
2Area of stationary object
If long rigid pipe sections are assembled offshore, then onshore facility requirements are reduced, but alignment and leak-tightness control becomes more difficult
Solution Approach 1:
Long pipe bundles are divided into shorter, manageable pipe sections that are pre-fabricated onshore and then assembled offshore. This segmentation makes offshore handling and alignment feasible while maintaining the benefit of reduced onshore facility requirements.
Solution Approach 2:
Pipe sections are pre-fabricated, pre-aligned, and pre-tested for leak-tightness onshore before offshore transport and assembly. This preliminary preparation ensures high precision is achieved in controlled onshore conditions, while offshore assembly involves connecting pre-prepared sections.
3Productivity
If flexible and composite pipes are used, then compact storage and efficient assembly are enabled, but additional material complexity is introduced
Solution Approach 1:
The patent utilizes changes in material properties - specifically the flexibility and coilability of modern composite and flexible pipes - to enable compact storage on vessel decks and efficient offshore deployment. These parameter changes allow pipes to be stored in coiled configurations and unrolled during assembly, improving productivity.
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A pipeline bundle for a riser tower or tie-back is manufactured offshore by: suspending the bundle from an installation vessel; adding structural core sections successively to an upper end of the suspended bundle; lowering the bundle after adding each successive core section; and feeding one or more lengths of flowline pipe beside the core sections for incorporation into the bundle. The flowline pipe is coiled on a reel or carousel as a full-length piece before being uncoiled progressively as core sections are added to the lengthening bundle. The flowline pipe is then engaged with guide frames and/or buoyancy blocks supported by the core sections, by movement in a radially-inward direction through a radially-outer opening in a retainer formation. The opening is then closed to hold the flowline pipe in the retainer formation.