Modular Stress Joint for Subsea Riser Force Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional stress joints for subsea risers are expensive, cumbersome, and require extensive custom design and manufacturing, making them impractical for various subsea well and riser configurations, and they often cannot accommodate the forces and movements effectively due to their large, single-piece construction.
Innovation Solution
Modular stress joints composed of adjustable base members and additional members with varying lengths and wall thicknesses, allowing for customizable length and stiffness, formed from materials like titanium and steel, which can be easily assembled and reused across different configurations, eliminating the need for welding and reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional stress joints are designed as single-piece unitary structures, then structural strength and reliability are improved, but manufacturing cost, complexity, and transport difficulty increase significantly
Solution Approach 1:
The stress joint is divided into multiple modular segments that can be assembled together. Each segment can be manufactured separately using standard processes and then connected through coupling mechanisms, transforming the single-piece construction into a modular assembly that reduces manufacturing complexity while maintaining structural integrity
Solution Approach 2:
Multiple modular segments are combined through coupling mechanisms to form the complete stress joint structure. The coupling elements join the segments together to create a unified structure that functions as a single piece would, but with the advantage of modular manufacturing and assembly
2Adaptability or versatility
If custom-designed stress joints are engineered for each specific subsea well and riser condition, then adaptability to specific forces and movements is improved, but design time, manufacturing cost, and production time increase
Solution Approach 1:
The modular stress joint segments are designed with universal coupling mechanisms and standardized interfaces that allow the same components to be used across different subsea well and riser configurations. This enables a single design platform to serve multiple applications, eliminating the need for custom-designed joints for each specific condition
Solution Approach 2:
The modular assembly allows for dynamic configuration where segments can be added, removed, or repositioned based on the specific forces and movements expected in different subsea environments. The standardized coupling mechanisms enable quick reconfiguration without requiring custom design for each application
3Weight of moving object
If stress joints are made from titanium to reduce weight and increase flexibility, then material performance is improved, but cost and manufacturing complexity increase due to welded flanges and stress concentration points
Solution Approach 1:
The titanium stress joint is segmented into modular sections with standardized coupling mechanisms, eliminating the need for welded flanges and stress concentration points. The segments can be assembled using mechanical connections that distribute forces more evenly throughout the structure, improving manufacturability while maintaining the weight and flexibility benefits of titanium
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 2
AI summary
Modular stress joints usable to compensate for forces applied to a subsea riser or other structure include a base member and one or more additional members. Members having desired lengths can be selected such that the sum of the length of the base member and additional members defines a desired total length. Members having desired wall thicknesses can be selected such that a combination of the wall thicknesses of the base member and each additional member defines an overall wall thickness or stiffness. The total length, overall wall thickness, or both correspond to expected forces applied to the subsea riser or structure, such that the stress joint is adapted to compensate for the forces and prevent damage. The number or length of members used and their thickness or other characteristics can be varied to provide multiple lengths and stiffnesses, such that the stress joint is modular and reconfigurable.