Auxiliary Line Coupling Assembly for Weld-Free Riser Repair
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Solution Overview
Problem
The existing systems for connecting auxiliary lines in oil and gas production risers often require offline repairs due to damaged sections, leading to costly delays and logistical challenges, as the connections are typically welded and require removal of the entire riser for maintenance.
Innovation Solution
A coupling assembly using a split ring and sleeve configuration that allows for secure connection of tubular segments without welding, enabling on-site repairs and maintenance by reducing the need for threaded components that can corrode or seize, and incorporating non-NACE materials for enhanced strength and corrosion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If welded connections are used for auxiliary lines, then pressure integrity is maintained, but repair complexity and downtime increase significantly
Solution Approach 1:
The auxiliary line is divided into modular tubular segments that can be independently connected and disconnected. Each segment can be replaced individually without affecting the entire riser system, enabling quick on-site repairs while maintaining pressure integrity through threaded connections.
Solution Approach 2:
A coupling assembly with split ring and sleeve acts as an intermediary component between tubular segments. This coupling mechanism provides a reliable pressure-containing connection that is much easier to assemble and disassemble than welded joints, allowing rapid replacement of damaged segments.
2Ease of operation
If threaded components are used for connections, then ease of assembly is improved, but corrosion and seizing reduce reliability
Solution Approach 1:
The coupling assembly utilizes non-NACE compliant materials that provide enhanced strength and corrosion resistance compared to traditional threaded components. These materials resist the corrosive marine environment while maintaining the ease of threaded assembly, eliminating the seizing problem associated with conventional materials.
Solution Approach 2:
The coupling assembly is designed as a replaceable component that can be quickly swapped if corroded or damaged. Rather than attempting to protect threaded components indefinitely, the system accepts periodic replacement of these relatively simple components to maintain overall system reliability.
3Reliability
If entire riser removal is required for repairs, then complete system inspection is achieved, but productivity and time efficiency decrease
Solution Approach 1:
The riser system is segmented into modular sections with standardized couplings, allowing individual auxiliary line segments to be inspected and replaced independently. This modular approach enables targeted repairs without removing the entire riser, dramatically reducing downtime while maintaining thorough inspection capabilities.
Solution Approach 2:
Damaged or problematic segments can be extracted and replaced individually from the system. The coupling assembly facilitates easy disconnection of specific segments without disturbing the rest of the riser structure, enabling selective repair rather than complete system removal.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables efficient and cost-effective on-site repair of auxiliary lines, reducing downtime and maintenance costs by allowing for non-welded connections and using stronger materials to maintain pressure integrity and withstand environmental conditions.
Implementation Method 1
threads of the sleeve engage first mating threads on the split ring and second mating threads on the box end to secure the first pipe segment to the second pipe segment
Implementation Method 2
a face of the box end abutting the flange when the pin end is installed within the recess
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A system for coupling a first pipe segment (304, 404) to a second pipe segment (306, 406) includes a pin end (318, 418) including a flange (324, 424). The system includes a box end (340, 440) having a recess (342, 442) configured to receive the pin end (318, 418), a face (350, 450) of the box end (340, 440) abutting the flange (324, 424). The system includes a coupling assembly (302, 402) joining the first pipe segment (304, 404) to the second pipe segment (306, 406) including a split ring (358, 458) arranged proximate the flange (324, 424) and a sleeve (360, 460), wherein threads (362, 462) of the sleeve (360, 460) engage first mating threads (366, 466) on the split ring (358, 458) and second mating threads (364, 464) on the box end (340, 440).