Hybrid Riser Tensioning with Electrical Control
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Solution Overview
Problem
Conventional hydro-pneumatic riser tensioning systems exhibit slow response times, increased stress and wear on equipment, high maintenance requirements, and environmental risks due to hydraulic fluid leakage, making them inadequate for deepwater drilling operations.
Innovation Solution
An enhanced riser tensioning system integrating electrical tensioners with hydro-pneumatic components, featuring a controller that measures and adjusts tension dynamically to provide quicker response times, reduce fatigue, and simplify operations, including new control modes for riser position and vessel motion stabilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If hydro-pneumatic tensioning system is used, then tension control function is provided, but response time is too slow
Solution Approach 1:
The patent combines electrical tensioners with hydro-pneumatic tensioners in a hybrid system. The electrical tensioners provide fast response for emergency situations and dynamic adjustments, while the hydro-pneumatic tensioners handle steady-state tension control. This merging of two different tensioning technologies resolves the contradiction by leveraging the speed advantage of electrical systems and the reliability of hydro-pneumatic systems.
2Object-affected harmful factors
If increasing longitudinal over-pull tension is applied, then vortex-induced vibration is suppressed, but stress on supporting equipment increases
Solution Approach 1:
The patent implements dynamic tension control using electrical tensioners that can rapidly adjust tension levels based on real-time conditions. Instead of applying constant high over-pull tension, the system dynamically modulates tension to suppress vortex-induced vibrations only when needed, thereby reducing overall stress on supporting equipment while maintaining effectiveness against VIV.
3Reliability
If hydro-pneumatic tensioning system is used, then tension control is achieved, but maintenance requirements increase
Solution Approach 1:
The patent replaces parts of the mechanical hydro-pneumatic system with electrical tensioners that have fewer moving parts and no hydraulic fluid. Electrical tensioners use electric motors and controlled winding mechanisms, eliminating the need for hydraulic seals, accumulators, and fluid management, thereby significantly reducing maintenance requirements while maintaining tension control reliability.
4Reliability
If hydro-pneumatic tensioning system is used, then tension control function is provided, but risk of hydraulic fluid leakage increases
Solution Approach 1:
The patent extracts and removes the hydraulic fluid system from the tensioning mechanism by replacing it with electrical tensioners. This eliminates the source of potential hydraulic fluid leakage entirely while maintaining the essential tension control function through electrical motor-driven wirelay mechanisms.
5Reliability
If hydro-pneumatic system components are exposed to bending, then tension control is maintained, but failure risk increases
Solution Approach 1:
The patent replaces the mechanical hydro-pneumatic cylinder rod and seal assembly with an electrical tensioner system that uses a motor, gearbox, and wirelay mechanism. This substitution eliminates the bending-exposed mechanical components and seals that are prone to failure, while maintaining tension control through the electrical system's controlled winding and unwinding of the wirelay.
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 hybrid system enhances safety and reliability by offering faster control responses, reducing fatigue and stress on equipment, and simplifying operations, while minimizing maintenance and environmental risks.
Implementation Method 1
Each electrical tensioner may include a motor and an energy inverter. The motor may be configured to convert electrical energy to mechanical energy to adjust the length of a wire coupled to the drilling riser.
Implementation Method 2
An energy storage system and a power dissipater, both of which are also coupled to the DC power distribution bus.
Data Source
AI summary
An enhanced riser control system may employ electrical tensioners coupled to a drilling riser by wires. The electrical tensioners may provide quick response to a tension controller to handle positioning of the drilling riser. The electrical tensioners of the enhanced riser control system may be combined with hydro-pneumatic tensioners in a riser hybrid tensioning system. A controller within the enhanced riser control system may be configured to distribute tension to electrical tensioners and to control electrical tensioners to adjust the length of the first and second wires. Energy from an electrical tensioner may be transferred to an energy storage system or to power dissipaters for dissipating the energy generated by the electrical tensioner. The energy transferred from an electrical tensioner may be energy that has been generated by the electrical tensioner.