Telescopic Drilling Rig Heave Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional drilling rigs face challenges such as heavy and inaccessible passive compensation systems, high load variations in shallow waters, lack of redundancy in active draw-work configurations, and ice formation issues, particularly in arctic environments, which affect safety, maintenance, and operational efficiency.
Innovation Solution
A retractable drilling rig with a cylindrical tower structure and integrated winch and heave compensation system, featuring multiple compensator cylinders and a dampening device, allowing for flexible operation and easy maintenance, with a modular design that includes a telescopic tower and multiple lifting wires for enhanced safety and adaptability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a passive compensator system is installed in the top of the drilling rig to compensate for weight hanging on the crown block, then heave compensation is achieved, but the system becomes heavy and difficult to access for maintenance
Solution Approach 1:
The patent inverts the traditional arrangement by moving the compensator system from the top of the derrick down to the drill floor level. The compensator cylinders are now located at the lower level, making them easily accessible for maintenance while still providing effective heave compensation through the wire rope system that extends to the crown block at the top.
2Reliability
If a large cylinder area is used to compensate for maximum load at ultra deep water operations, then maximum load compensation is achieved, but load variations become excessive at small loads in shallower waters
Solution Approach 1:
The patent employs a dynamic configuration where the number of compensator cylinders can be adjusted based on operational requirements. For maximum load compensation at ultra deep water, all cylinders are deployed. For shallower waters with smaller loads, fewer cylinders are used, maintaining load stability and preventing excessive load variations.
Solution Approach 2:
The compensator system is divided into multiple separate compensator cylinders that can be selectively deployed. This segmentation allows the system to be configured in different capacities - using all cylinders for maximum load compensation or only a subset for smaller loads, providing flexibility across different operational scenarios.
3Device complexity
If an active draw-work configuration is used without passive compensator systems, then the system is simpler, but there is no backup in case of electrical power loss
Solution Approach 1:
The patent implements a self-service passive compensator system that automatically provides backup capability without requiring external power sources. The compensator cylinders use stored mechanical energy (pre-tensioned springs or gravity-based mechanisms) to automatically compensate for heave motions and maintain wire rope tension, providing reliable backup in case of electrical power loss while maintaining relative system simplicity.
4Strength
If a traditional pyramidal steel framework is used for the drilling rig, then structural strength is achieved, but the structure is complex and prone to falling objects
Solution Approach 1:
The patent segments the derrick structure into modular sections that can be assembled in a more compact configuration. This modular approach maintains the necessary structural strength while reducing overall complexity and the number of potential falling object hazards compared to traditional pyramidal frameworks.
Solution Approach 2:
The patent employs a nested configuration where the compensator system components are integrated within the derrick structure itself rather than being external additions. The compensator cylinders and associated mechanisms are housed within the derrick's structural elements, reducing overall complexity while maintaining strength.
5Stability of the object's composition
If the drilling rig height is fixed after assembly, then structural stability is maintained, but maintenance work on top becomes difficult
Solution Approach 1:
The patent implements a telescopic derrick structure that can dynamically adjust its height. The derrick sections can be extended or retracted based on operational requirements, allowing the top of the derrick to be brought down to accessible heights for maintenance while maintaining full operational height during drilling operations, all while preserving structural stability through controlled mechanical mechanisms.
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 reduces power requirements, lowers the vessel's height for increased stability and access to restricted areas, provides easier maintenance, and mitigates ice formation risks, while improving safety and operational flexibility across varying depths and environments.
Implementation Method 1
The compensator arrangement has a plurality of compensator cylinders adapted to compensate different loads
Implementation Method 2
a dampening device is arranged operatively between the at least one compensator sheave and the winch
Data Source
Figure 1
Figure 2~3
Figure 4a~4c
AI summary
The invention provides a system for operating a drilling rig on a drilling vessel, the system comprising a drilling tower (2) having at least two segments (4, 5), a first segment (4) is fixedly connected to the drilling vessel (1), a second segment (5) is connected to the first segment (4), said second segment (5) is adapted to move longitudinally relative the first segment (4) by raising and lowering means. A tool (8) is suspended from at least one wire (16), said at least one wire (16) is extending over at least one sheave (7a, 7b) on top of the second segment (5), said at least one wire (16) is coupled to with a passive compensator arrangement (20) and a winch (14), said passive compensator (20) is connected to the winch (14).