Drill Floor Heave Compensation via Segmented Actuation

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Solution Overview

Problem

Offshore drilling platforms face challenges in maintaining stability against heave motion due to increasing waterplane area, which enhances susceptibility to vertical motion, necessitating effective solutions for stabilization.

Innovation Solution

The implementation of an actuation system, including drawworks and a heave compensation system, to control the vertical movement of the drill floor relative to the platform deck, utilizing active heave drawworks and a heave compensation frame to maintain constant tension and stability during maritime conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the waterplane area of the offshore platform is increased to improve stability against lateral movement and surge, then the platform's resistance to sway and surge is improved, but the platform's susceptibility to heave motion increases

Engineering Contradiction:
Improvestability against lateral movement and surgeVSAvoidsusceptibility to heave motion
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The drill floor is segmented from the platform deck through the introduction of a movable connection system. The drill floor is supported by drawworks and compensation frames that allow independent vertical movement, separating the stability requirements of the platform from those of the drilling operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Heave compensation drawworks and compensation frames are introduced as intermediary devices between the platform deck and the drill floor. These intermediaries actively counteract heave motion through mechanical advantage systems and hydraulic actuators, isolating the drill floor from vertical platform movements.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If a fixed drill floor is used to simplify the structure, then the device complexity is reduced, but the ability to compensate for heave motion is lost

Engineering Contradiction:
Improvestructural simplicityVSAvoidheave compensation capability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The drill floor connection system transitions from a fixed static structure to a dynamic movable system. The drill floor is supported by drawworks with payout reels and compensation frames that can dynamically adjust their position and tension to follow platform heave motion while maintaining operational stability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the physical state and parameters of the connection between drill floor and platform. Hydraulic actuators and tensioning mechanisms adjust parameters such as cable tension, frame position, and mechanical advantage ratios to maintain optimal compensation performance under varying sea conditions.

Inventive Principle:
Principle #35Parameter changes

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 solution effectively stabilizes the drill floor against heave motion, ensuring consistent operation and reducing the impact of wave and wind-induced vertical movements, thereby enhancing operational efficiency and safety.

Implementation Method 1

an actuation system, including drawworks and a heave compensation system, to control the vertical movement of the drill floor relative to the platform deck

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Implementation Method 2

a heave compensation frame to maintain constant tension and stability during maritime conditions

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4022161B1Compensated drill floor
Publication Date: 2025.03.26 ENSCO INTERNATIONAL INC
  • EP4022161B1 patent drawingFigure 1
  • EP4022161B1 patent drawingFigure 2
  • EP4022161B1 patent drawingFigure 3

AI summary

A system (92) includes a first structure (106) configured to be coupled to a tubular string extending to a seafloor (14), whereby the first structure (106) comprises a drill floor (26). The system (92) further includes a second structure (96) configured to provide a lateral force to the first structure (106) while allowing for vertical movement between the first structure (106) and the second structure (96) relative to the seafloor (14).