Flexible Riser Inspection Window Cutting for Ultrasonic Access
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Solution Overview
Problem
Flexible risers with insulation cannot be tested for annulus flooding using ultrasonic testing due to the sound waves being blocked by the insulation, leading to potential accelerated corrosion and premature failure from seawater ingress.
Innovation Solution
A tool is used to cut a precise inspection window in the outer layers of the flexible riser, allowing ultrasonic testing by removing the insulation and ensuring the sound waves can penetrate to the armor wires.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulation is added to flexible risers to protect against seawater ingress, then corrosion protection is improved, but ultrasonic testing capability deteriorates because sound waves cannot penetrate the insulation
Solution Approach 1:
The tool segments the inspection process by creating a localized opening (inspection window) through the insulation and outer sheath layers, allowing ultrasonic testing to be performed on a specific section without removing insulation from the entire riser length
Solution Approach 2:
The tool extracts or removes a portion of the insulation and outer sheath to create an inspection window, enabling sound wave penetration for ultrasonic testing while leaving the rest of the insulation intact for continued corrosion protection
2Difficulty of detecting and measuring
If insulation is removed from the flexible riser to enable ultrasonic testing, then testing capability is improved, but corrosion protection deteriorates
Solution Approach 1:
The tool segments the insulation removal to only the necessary inspection area, creating a localized window rather than removing insulation from the entire riser, thus maintaining corrosion protection on the majority of the riser length
Solution Approach 2:
The tool applies local quality by creating a localized inspection window with specific dimensions and characteristics suitable for ultrasonic testing, while the remaining insulation maintains its protective function elsewhere on the riser
3Difficulty of detecting and measuring
If a cutting tool is used to create an inspection window through insulation and outer sheath, then ultrasonic access is improved, but device complexity increases
Solution Approach 1:
The tool is designed with multi-functionality, integrating insulation cutting, outer sheath cutting, and positioning capabilities into a single device that can perform multiple operations to create the inspection window
Solution Approach 2:
The tool merges the cutting function with the positioning and support functions into an integrated system, where the frame structure serves both as support and as part of the cutting mechanism guidance
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
Enables effective ultrasonic testing of flexible risers with insulation, detecting annulus flooding and preventing premature failure by identifying corrosion issues.
Implementation Method 1
testing for flooded or non-flooded condition is accomplished using ultrasonic testing which involves projecting sound waves into the into the riser using a ultrasonic probe and looking for the sound waves to penetrate through the layer of the annulus until it hits the armor wires and bounces back to the probe
Data Source
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AI summary
A tool can be used remove one or more outer layers of a tubular such as a flexible pipeline to enable an inspection on the remaining layers of the flexible pipeline. It allows the precise removal of outer layers of a flexible riser so that inspection can take place tubulars that otherwise could not be inspected with ultrasound.