Segmented Tendon Elements for Deepwater Pipeline Abandonment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current abandonment and recovery procedures in marine pipelaying face challenges with heavy, expensive, and vulnerable wire systems, as well as limitations in handling high top tensions, particularly in deep water and with heavier pipe systems, leading to issues with storage, damage, and cost.
Innovation Solution
The use of tendon elements to form discontinuous abandonment or recovery strings, which are easier to handle, store, and adjust, and are less prone to damage, allowing for efficient transfer of pipe string weight to a wire or string, enabling effective abandonment and recovery operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous wire systems are used for abandonment and recovery procedures, then the pipeline end can be lowered and raised, but the wire is heavy, expensive, vulnerable to damage, and requires large storage space
Solution Approach 1:
The continuous wire system is divided into discrete tendon elements that can be handled individually. Each tendon element is a separate, manageable component that can be stored compactly on the vessel deck, eliminating the need for large storage space required by continuous wire systems while maintaining the functional capability of abandonment and recovery operations
Solution Approach 2:
The patent employs tendon elements as disposable or limited-life components that replace the expensive, vulnerable continuous wire. These tendon elements are designed to be used for specific abandonment/recovery operations and then discarded or recovered, eliminating the need for expensive, durable continuous wire systems while reducing storage requirements
2Force
If large-diameter wire is used to support heavy pipe string weight, then the wire can bear the load, but the wire becomes extremely long and heavy, taking up great storage space
Solution Approach 1:
The load-bearing function is distributed across multiple discrete tendon elements rather than requiring a single continuous wire. Each tendon element can be optimized for its specific load requirements, and the segmented approach allows for more efficient space utilization on the vessel deck compared to storing a single extremely long wire
3Reliability
If the pipelaying vessel carries spare wire for damaged wire replacement, then wire vulnerability is addressed, but the storage space and cost double
Solution Approach 1:
By segmenting the wire system into discrete tendon elements, the vessel can carry multiple shorter elements that can be stored more efficiently on deck. If one element is damaged, only that specific element needs replacement rather than replacing an entire continuous wire, reducing both storage requirements and costs while maintaining reliability
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A tendon element (36) is cooperable with other tendon elements to form an abandonment or recovery string. The tendon element (36) is elongate to define opposed ends, and comprises: complementary connector formations (62, 64) at respective ends, each connector formation being cooperable, in use when forming a string, with a complementary connector formation of a neighbouring tendon element (36) in the string; a tensile load-bearing member (66) extending between the connector formations; and at least one sleeve (68) removably mounted around the load-bearing member. The sleeve (68) is arranged to be handled by pipe-joint handling apparatus associated with a J-lay tower.