Cylinder Release Arrangement for Riser Safety
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Solution Overview
Problem
Conventional weak links in riser systems for offshore hydrocarbon wells fail to provide adequate operational flexibility and safety, as they can break under excessive tension or pressure fluctuations, leading to potential damage and environmental hazards.
Innovation Solution
A cylinder release arrangement with a safety joint that includes a first and second riser part connected by a release unit, featuring a piston and piston rod system that allows controlled release of internal pressure and tension, enabling a telescopic action to maintain riser integrity and safety during excessive tension events.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional weak link is designed to break at a predetermined tensile force, then it provides protection against excessive tension, but it cannot adapt to pressure fluctuations and provides limited operational flexibility
Solution Approach 1:
The weak link is designed with a dynamic response mechanism that adapts to varying well pressures. The system transitions from a static predetermined break force to a dynamic system that responds to real-time pressure conditions, allowing the weak link to maintain protection functionality while adapting to operational changes.
Solution Approach 2:
The invention changes the critical parameter from a fixed tensile force threshold to a variable threshold that responds to well pressure conditions. By making the break force parameter dependent on well pressure, the system achieves both reliable protection and operational adaptability.
2Strength
If a conventional weak link uses studs rated for high tensile force, then it can withstand high well pressures, but it requires very limited external tension before breaking and provides limited operational utilization
Solution Approach 1:
The weak link system is segmented into multiple functional components: a high-strength stud for withstanding well pressure, a separate triggering mechanism for controlled release, and a telescopic system for managing the release process. This segmentation allows each component to be optimized for its specific function.
Solution Approach 2:
An intermediary triggering mechanism is introduced between the high-strength stud and the actual connection. This intermediary allows the system to maintain high strength for pressure withstand while enabling controlled release through a separate activation process, thereby improving operational utilization.
3Force
If a conventional weak link breaks due to excessive tension, then it releases the tension force, but it causes undesired riser behavior and potential projectile damage
Solution Approach 1:
The system prepares cushioning and control mechanisms in advance of the actual release event. Telescopic sections and damping elements are pre-positioned to absorb and control the energy release, preventing the violent projectile behavior that occurs with conventional sudden breakage.
Solution Approach 2:
The release process is accelerated and controlled to occur rapidly through a predetermined safe path. The telescopic mechanism allows the riser sections to separate quickly in a controlled manner, rushing through the release event before harmful forces can build up, while still maintaining safety.
4Reliability
If a conventional weak link is designed to break at a given tension point, then it provides predictable failure, but it does not allow time for controlled disconnection and emergency procedures
Solution Approach 1:
The system performs preliminary actions by detecting approaching critical tension levels and activating warning and preparation sequences before the actual release occurs. This preliminary phase allows time for controlled disconnection procedures and emergency responses while maintaining the predictable failure point as a final safety mechanism.
Solution Approach 2:
The release process is divided into periodic stages: monitoring phase, warning phase, preparation phase, and execution phase. This periodic structure transforms a single sudden event into a multi-stage process, providing time for controlled disconnection while maintaining the ultimate predictable failure point.
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
The solution extends the time for emergency shut-down, maintains tension in the riser, limits recoil, and allows for independent internal pressure management, providing a safer and more controlled disconnection of the riser, thus enhancing operational safety and reducing environmental risks.
Implementation Method 1
a piston (17) movable within said cylinder (30) and causing a leakage of fluid from one side of said piston (17) to the other side of said piston (17), when said piston (17) is in a given position within said cylinder (30)
Implementation Method 2
the at least one cylinder (16, 27, 32) arranged to compensate for internal pressure in the riser in the not activated mode and the partly activated mode
Implementation Method 3
at least one axial extending tension rod (20) connected between the two riser parts (8, 9), which tension rod (20) is configured to deform plastically before breaking
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention relates a cylinder release arrangement, wherein at least one cylinder is arranged with a piston within the cylinder, and a cylinder head closing off one end of the cylinder, forming a chamber between the piston and the cylinder head, wherein the cylinder is provided to arrange a leakage of fluid from one side of a piston to the other side of the piston, when the piston is in a given position within the cylinder, and release means are provided for the subsequently controlled release of the cylinder head from the cylinder. The invention also comprises a cylinder arrangement with a release mechanism.