Underwater Pipeline Cut Verification via Electromagnetic Signal Reflection
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Solution Overview
Problem
The decommissioning of offshore oil and gas platforms is challenging due to the difficulty in confirming the successful cut of pipeline conductors, especially when using abrasive water jet cutting (AWJC) tools, which require top tension and complex equipment, and explosive cutting poses safety concerns.
Innovation Solution
A method using time domain reflectometry (TDR) to transmit an electromagnetic signal through the pipeline and monitor reflected signals to determine the completeness of the cut, allowing for non-invasive testing of the pipeline cut, particularly suitable for underwater or seabed pipelines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If abrasive water jet cutting (AWJC) tools are used to cut the pipeline, then the cutting precision and safety are improved, but the equipment complexity and operational difficulty increase due to the requirement of top tension and shock load-compensated jack
Solution Approach 1:
The patent replaces the complex mechanical top tension system with an electromagnetic testing system. Instead of using a shock load-compensated jack to apply top tension and confirm cut completion mechanically, the invention uses electromagnetic signals transmitted through the pipeline to detect cut status electrically, eliminating the need for heavy mechanical equipment.
Solution Approach 2:
The patent introduces an electromagnetic signal as an intermediary to detect the cut status. The electromagnetic signal acts as a mediator that travels through the pipeline and reflects off the cut interface, providing information about cut completion without requiring direct mechanical interaction or top tension application.
2Reliability
If top tension is applied to confirm the through cut, then the reliability of cut confirmation is improved, but the operational time and equipment requirements increase due to the need for shock load-compensated jack
Solution Approach 1:
The patent performs preliminary electromagnetic testing before and during the cutting process to predict and monitor cut progression. By transmitting electromagnetic signals in advance and monitoring reflections in real-time, the system can determine cut completion without waiting for the lengthy mechanical top tension process.
Solution Approach 2:
The patent substitutes the time-consuming mechanical top tension process with rapid electromagnetic signal transmission and analysis. The electromagnetic method provides immediate feedback on cut status, eliminating the time required to apply and release heavy mechanical loads.
3Productivity
If explosive devices are used to cut the pipeline, then the cutting speed and simplicity are improved, but the safety risks and harmful factors increase
Solution Approach 1:
The patent replaces explosive cutting with electromagnetic testing. Instead of using chemical energy from explosives to sever the pipeline, the invention uses electromagnetic fields to detect cut status, eliminating safety risks associated with explosives while maintaining the ability to confirm cut completion.
Solution Approach 2:
The patent converts the potentially harmful explosive cutting method into a safe electromagnetic detection method. The electromagnetic signals that would otherwise be affected by the cutting process are now used as a beneficial tool to monitor and confirm cut completion without introducing any harmful factors.
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 real-time monitoring of the cutting process and confirmation of a complete cut, reducing equipment intensity, costs, and safety risks, and is compatible with 'rigless' designs, facilitating efficient decommissioning operations.
Implementation Method 1
transmitting an electromagnetic signal through the pipeline; monitoring any reflected signal(s)
Data Source
AI summary
Disclosed is a method to determine whether a pipeline has been cut, the method including (a) transmitting an electromagnetic signal through the pipeline; (b) monitoring any reflected signal(s); and (c) interpreting the reflected signal to determine whether the pipeline has been cut.