Modular Motion Compensating Floor for Marine Riser Stability
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Solution Overview
Problem
Conventional motion compensation systems for subsea operations are rigidly integrated, expensive, and limited in their ability to accommodate a wide range of relative motion between vessels, platforms, and subsea risers, hindering efficient and cost-effective operations, especially in harsh marine environments.
Innovation Solution
A portable and reusable motion compensating floor system that uses hydraulic cylinders and a riser tensioner to stabilize the platform and riser, allowing for independent movement compensation of heave, pitch, roll, and yaw motions, and includes a counterweight for balancing equipment weight adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional motion compensation systems are rigidly integrated into the frame, deck, and/or hull of a structure, then stability and motion compensation performance are improved, but portability and reusability deteriorate
Solution Approach 1:
The motion compensation system is divided into separate modular components: a base platform attached to the vessel, a movable floor assembly with motion compensation mechanisms, and a riser tensioner system. This segmentation allows the system to be disassembled, transported, and reconfigured for different operations and vessels, resolving the contradiction between stability performance and portability.
Solution Approach 2:
The floor assembly is designed to be movable relative to the base platform through hydraulic cylinders, allowing dynamic adjustment of the floor position and orientation. This dynamic capability enables the system to adapt to different operational requirements while maintaining motion compensation performance, thereby improving both versatility and stability.
2Device complexity
If conventional motion compensation systems are designed for limited range of relative motion and limited axes, then device complexity is reduced, but adaptability to various operational conditions deteriorates
Solution Approach 1:
The motion compensation system is designed with multi-functional capabilities to accommodate a wide range of motion across multiple axes (heave, pitch, roll, yaw) while maintaining relative simplicity. The hydraulic cylinder arrangement and movable floor assembly provide universal adaptability to different operational conditions without requiring complex specialized mechanisms for each axis.
Solution Approach 2:
Hydraulic cylinders serve as intermediary elements between the base platform and the movable floor assembly, enabling smooth transmission of motion compensation forces across multiple axes. This intermediary mechanism allows the system to handle complex multi-axis motion requirements while maintaining structural simplicity and ease of control.
3Stability of the object's composition
If rig or platform is used to stabilize against heave motions and forces from ocean currents and winds, then riser stability is improved, but operation cost and setup time increase
Solution Approach 1:
The motion compensation functionality is extracted from traditional rigid rigs or platforms and integrated into a separate, portable floor assembly that can be attached to various vessel types. This extraction eliminates the need for expensive, time-consuming rig construction and deconstruction, while maintaining riser stability through the specialized motion compensation mechanisms.
Solution Approach 2:
The system replicates the stabilizing function of traditional rigs through a different approach: using movable floors with hydraulic motion compensation instead of rigid structural stabilization. This copying of the stabilizing effect through an alternative mechanism achieves similar riser stability without the high costs and setup times associated with conventional rigs.
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 system effectively reduces or eliminates relative motion between the vessel, riser, and equipment, enabling rigless subsea operations with reduced setup and deconstruction time, improved stability, and extended operational life of subsea equipment.
Implementation Method 1
a first plurality of hydraulic cylinders connect the upper platform to the lower platform... a second plurality of hydraulic cylinders connecting the upper platform to a riser tensioner
Implementation Method 2
a counterweight for balancing equipment weight adjustments
Data Source
AI summary
A motion compensating system and method for use on a vessel during well intervention operations through a riser. The system can comprise an upper floor having an opening therethrough, a lower base having an opening therethrough positioned below the upper floor, a first plurality of cylinders extending between the upper floor and lower base, and a riser tensioner. Each cylinder of the plurality of cylinders can be pivotally connected to the upper floor and lower base for moving the upper floor with respect to the lower base. The riser tensioner can have an upper portion, lower portion, and central cavity extending longitudinally through the upper and lower portions, wherein the upper portion can be adapted for connection with a riser or an intermediate tubular member that is connectable to the riser. The lower portion can be connected to the lower base within or about the opening of the lower base.