Spar Platform Ice Avoidance via Riser Disconnect
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Solution Overview
Problem
Current floating systems for deepwater oil and gas production in arctic regions are not adequately equipped to withstand or efficiently respond to ice flow conditions, leading to potential damage from icebergs and significant operational disruptions.
Innovation Solution
A spar-type platform with an elongate buoyant hull, adjustable ballast tanks, and a disconnectable riser system that allows the hull to temporarily detach from a support buoy, enabling movement away from impending icebergs and subsequent reconnection when safe, while minimizing exposure to ice flows through controlled ballasting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a drilling platform is left in position during ice flow conditions, then production continues without interruption, but the platform suffers severe damage from crushing ice forces or iceberg collision
Solution Approach 1:
The platform system is divided into separable components: the hull can be detached from the riser support buoy, allowing the hull to move away from ice hazards while the buoy remains in position to maintain well connections. This segmentation enables the platform to preserve production infrastructure while protecting the main hull structure.
Solution Approach 2:
The platform employs adjustable ballast tanks that can dynamically change the hull's draft and position in the water. By adjusting ballast, the platform can rise to reduce exposure to ice flows or lower to maintain operational depth, providing dynamic adaptation to changing ice conditions rather than a fixed static position.
2Strength
If a drilling platform is removed to safer waters during ice flow conditions, then the platform avoids damage, but significant work hours and production hours are lost
Solution Approach 1:
By separating the hull from the riser support buoy through a disconnect system, the platform enables the buoy to remain in position maintaining well connections and production flow, while only the hull needs to move to safer waters. This reduces the time and operational disruption compared to moving the entire platform assembly.
Solution Approach 2:
The riser support buoy acts as an intermediary element that remains stationary in the ice flow zone, maintaining connections to the seabed wells. The hull can disconnect and move away while the buoy serves as a permanent interface between the mobile hull and the fixed well infrastructure, enabling quick reconnection without full platform relocation.
3Object-affected harmful factors
If the hull area exposed to ice flows is reduced by ballasting up, then the platform withstands ice flow conditions better, but the platform has less stability and maneuverability
Solution Approach 1:
The platform uses adjustable ballast tanks that can dynamically modify the hull's draft and waterplane area in response to changing ice conditions. The system can ballast up to reduce ice exposure when needed, and ballast down to improve stability when ice threats subside, providing dynamic rather than static characteristics.
Solution Approach 2:
The ballast system changes the physical parameters of the hull's position in the water by controlling water intake and discharge in adjustable tanks. By varying the amount of ballast water, the platform can adjust its draft, buoyancy, and waterplane area to optimize both ice flow resistance and operational stability under different conditions.
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 quick and efficient avoidance of icebergs, reducing the risk of damage and operational downtime by allowing the platform to rise and reposition itself during ice flow conditions, while maintaining operational readiness.
Implementation Method 1
a support buoy disposed in the bottom of the centerwell at the keel of the hull
Implementation Method 2
into which seawater can be selectively and adjustably introduced or evacuated with forced air to provide adjustable ballast for the hull
Data Source
AI summary
A spar-type platform includes a hull defining a centerwell extending downward to a keel. The hull includes a reduced diameter neck portion for diverting ice flow. Adjustable ballast tanks allow the hull to be moved between a ballasted down position defining an upper water line, and a ballasted up position defined by a lower water line. A riser a support buoy is disposed in the keel. Risers extend through the centerwell, each having an upper portion extending upward from the support buoy and a lower portion supported in the support buoy. A disconnect system detachably connects the support buoy to the hull and the upper portion of each riser to the lower portion thereof, whereby the hull and the upper portion of each riser are selectively detachable from the buoy and the lower portion of each riser for movement to avoid a collision with a floating object.