Offshore Module Installation Using Ballasted Barge De-ballasting
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Solution Overview
Problem
The existing methods for installing topside modules on offshore support structures with legs extending above the water level are costly, labor-intensive, and complex, as they require expensive equipment like semi-submersible crane vessels, and are not suitable for heights beyond what a ballasted barge can stably support.
Innovation Solution
A method involving supporting the topside module on a barge adjacent to the support leg, de-ballasting to lift it above the water level, and using spacer means to maintain stability and control the lifting process, allowing for the installation of modules with high centers of gravity without the need for semi-submersible crane vessels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If semi-submersible crane vessels are used to install the topside module, then the installation can be performed on support structures with legs extending above water level, but the installation process becomes costly, labor-intensive, and complex
Solution Approach 1:
The patent uses a ballasted barge as an intermediary device to transfer the topside module from the water to the support structure. The barge is positioned adjacent to the support leg, ballasted to submerge, and then de-ballasted to lift the module onto the structure. This intermediary approach eliminates the need for complex semi-submersible crane vessels while achieving the same installation capability.
Solution Approach 2:
The patent replaces expensive, complex semi-submersible crane vessels with a simpler, more economical ballasted barge. The barge is a less sophisticated device that can be easily deployed and removed after the installation, providing a cost-effective alternative that reduces both equipment cost and operational complexity.
2Ease of manufacture
If a ballasted barge is used to support the topside module, then the installation cost is reduced, but the method is not suitable for support structures with legs extending above the stable support height of the barge
Solution Approach 1:
The patent applies preliminary action by positioning the barge adjacent to the support leg before ballasting. The barge is placed in position while floating, then ballasted to submerge and lift the module. This preliminary positioning ensures that when the barge de-ballasts, the module is already in the correct location to be transferred to the support structure, enabling installation on taller structures.
Solution Approach 2:
The patent changes the operational dimension by moving the barge from a horizontal transport mode to a vertical lifting mode through ballasting and de-ballasting. This dimensional transition allows the barge to overcome height limitations and install modules on support structures with legs extending above the barge's stable support height.
3Weight of moving object
If the topside module is lifted to a height above water level, then the module can be installed on the support structure, but stability is lost without additional support mechanisms
Solution Approach 1:
The support leg acts as an intermediary support mechanism during the lifting process. As the barge de-ballasts and lifts the module, the module is positioned adjacent to the support leg, which provides lateral stability and prevents the module from moving away during the elevation process, ensuring stable installation.
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 method efficiently and simply installs topside modules on support structures with legs exceeding the stable height limit of traditional barges, reducing costs and complexity by stabilizing the module during lifting and allowing for controlled elevation.
Implementation Method 1
de-ballasting the barge to lift the topside module to a height above water level
Data Source
AI summary
Method for installing a topside module on an offshore support structure that in use comprises at least one support leg that extends a height above the water level. The method comprises the steps of supporting said topside module on a barge in a position adjacent to said at least one support leg and de-ballasting the barge to lift the topside module a height above water level.